Foundations Of Biomedical Science - Semester 2 2015

Front 1

List the main differences between prokaryotic and eukaryotic cells

Back 1

Prokaryotic - bacteria and archaea

- smaller 0.1 - 10um

- no nuclear membrane

- membrane structures absent

- complex cell wall

- smaller ribosomes

- reproduce by binary fission

Eukaryotic - plants, animals, algae, fungi, protozoa

- larger 10 - 100um

- nuclear membrane

- membrane bound organelles (structures)

- plants, fungi and algae have simple cell walls (animals and protozoa don't)

- larger ribosomes

- reproduce by mitosis/meosis

- some cells can specialise (form tissue)

Front 2

Fungi are prokaryotic - true or false

Back 2

False - they're eukaryotic

Front 3

List the 3 processes of motility for protozoa

Back 3

1. flagella

2. cilia
3. pseudopodia

Front 4

The cell wall of bacteria contain polysaccharide and peptidoglycan - true or false

Back 4

true

Front 5

Approx what percentage of microbes are pathogenic? Harmless? Opportunistic?

Back 5

Pathogenic 3%

Harmless 87%

Opportunistic 10%

Front 6

Name the 2 structures that make up all viruses (and third which may be present)

Back 6

1. Nucleic acid (RNA or DNA)

2. Protein capsule (capsid)

3. Only in some viruses - lipid envelope

Front 7

Which scientist discovered pasteurisation? What was it first used for? What else did he develop?

Back 7

Louis Pasteur. To avoid the spoilage of wine. Culture methods and ways of behaving in a lab.

Front 8

What type of organism causes Malaria and how is it transmitted?

Back 8

A protozoa. By the bite of a mosquito (Anopheles).

Front 9

Which scientist first demonstrated that microorganisms caused disease? Germ theory.

Back 9

Robert Koch

Front 10

What are Koch's postulates?

Back 10

1. The specific CAUSATIVE AGENT must be found in EVERY CASE of the disease.

2. The disease organism must be ISOLATED IN PURE CULTURE.

3. INOCULATION of a sample of the culture into a health, susceptible animal must PRODUCE SAME DISEASE.

4. The disease ORGANISM must be RECOVERED from the INFECTED ANIMAL.

Front 11

What is a pure culture?

Back 11

A culture in which only one strain or clone is present.

Front 12

In scientific nomenclature, which part of the following name is the genus and which is the species?
Staphylococcus aureus.

Back 12

"Staphylococcus" is the genus and "aureus" is the species.

Front 13

Describe the types and functions of (on bacteria):
a) glycocalyx
b) flagella
c) pili

Back 13

a) glycocalyx
- slime (not firmly attached, not highly organised) and capsules (firmly attached, more organised)

- adherence and protection from phagocytosis (by WBCells and bacteriophage - virus which kills bacteria)

- made of polypeptides and peptidoglycans

b) flagella - motility MLAP

- monotrichous (one),

- lophotrichous (many one end),

- amphitrichous (many both ends),

- peritrichous (all over)

c) pili

- bristle-like, longer, singly or pairs

- adherence and conjugation

Front 14

What is the main difference between gram positive and gram negative bacteria?

Back 14

Gram positive

- large amount of peptidoglycan in cell wall

- stains blue-purple (by crystal violet)

- usually exotoxin secreted by living cells

Gram negative

- small amount of peptidoglycan in cell wall

- stains pink (carbol fuchsin)

- endotoxin released in wall fragments of dead cell

Front 15

List and describe the steps of a gram stain

Back 15

F C I D C

1. Fixation - heat slide slightly to soften outer layer of bacteria and attach them to slide

2. Stain crystal violet - 30 secs

3. Iodine treatment (lugols) - 30 secs

4. Decolourisation (alcohol/acetone) - 15 secs*

5. Counterstain (carbol fuchsin) - 30 secs

Front 16

How do bacteria reproduce and what are the steps?

Back 16

Binary fission.

1. Cell elongates and DNA is replicated

2. Cell wall and plasma membrane begin to divide

3. Cross-wall (septum) forms completely around divided DNA

4. Cells separate

Front 17

List and explain the phases of bacterial growth

Back 17

Lag Exp Stat Dec

1. Lag phase - bacteria adapt to conditions and start to divide and grow exponentially

2. Exponential phase - period where cells double, growth increases very rapidly as they double in numbers

3. Stationary phase - results from a situation in which growth rate and death rate are equal, often due to a growth-limiting factor such as the depletion of an essential nutrient, and/or the formation of an inhibitory product

4. Decline (death) phase - bacteria die, maybe due to lack of nutrients, a temperature which is too high or low, or the wrong living conditions.

Front 18

What are: mesophiles, psychrophiles, obligate anaerobes, facultative anaerobes and carboxyphiles?

Back 18

* Mesophiles - bacteria that grow in body temperatures (10-45 degrees C, optimum 37C)
* Psychrophiles - bacteria that grow in cooler temps (0 to <20C, optimum 15C)

* Obligate anaerobes - bacteria that require oxygen to grow (ie. air, which is 21% O2)

* Facultative anaerobes - bacteria which can grow with or without oxygen

* Carboxyphiles - bacteria that need higher levels of CO2 to grow (2.5 - 10% CO2)

Front 19

Describe respiration and fermentation in bacteria

Back 19

Respiration = process of creating energy (ATP) using oxygen and pyruvic acid and glycolysis with high ATP yield (obligate aerobes and facultative anaerobes)

Fermentation = process of creating energy (ATP) without oxygen, using pyruvic acid and glycolysis with low ATP yield (obligate anaerobes and facultative anaerobes)

Front 20

Describe glycolysis.

1) what is the starting carbohydrate,

2) what is the storage molecule produced,

3) what is the end product?

Back 20

It's a metabolic pathway that converts glucose into pyruvate. The free energy released in this process is used to form the high-energy compounds ATP (adenosine triphosphate) and NADH (reduced nicotinamide adenine dinucleotide).

1) glucose

2) ATP

3) Pyruvic acid CHECK THIS ANSWER

Front 21

Describe the terms:

1) catabolism

2) anabolism

3) oxidation

4) reduction

5) enzymes

Back 21

1) catabolism - destruction of cells (think Cata)

2) anabolism - creation of cells (think of Ana)

3) oxidation - loss of electrons (OIL)

4) reduction - gain of electrons (RIG)

5) enzymes - protein catalysts which speed up the rate of reaction without being consumed in the reaction

Front 22

What factors (growth and nutritional conditions) need to be considered when culturing bacteria?

Back 22

L W T F P I G

- Light

- Water

- Temperature

- Food (nutrients = proteins, sugars, starch etc)

- pH (of medium)

- Ionic strength / osmotic pressure

- Gaseous requirement (ie. O2, CO2)

Front 23

What is a "Microbial Biofilm"?

Back 23

- Microbial Biofilm is formed by either single organism or many bacteria, on wet surfaces.

- Everywhere in nature (teeth, dental implants, catheter lines, water supply).

- Single organisms can secrete an extra-cellular slime layer that protects from physical or chemical destruction.

- Organisms in biofilm 1000X more resistant to antimicrobial agents.

- clinical significance

- negative = causes of caries and periodontal disease

- positive = forms part of defense system against exogenous pathogens

Front 24

What is a "virulence factor"? Give 3 examples.

Back 24

Virulence factors are traits that collectively give microbe the ability to cause disease. Examples (TEA):

1) Production of TOXINS during infection (endotoxins and exotoxins)

2) Release of ENZYMES to help invade tissues, kills host, evades immune system.

3) ADHERENCE factors (fibriae, pili, glycocalyx)

Front 25

What are the 3 types of haemolysis seen on a blood agar plate?

Back 25

1) Alpha - partial lysis of RBC, green/gray zone

2) Beta - completely clear zone around colonies

3) Gamma - no change (non-haemolytic)

Front 26

Describe the function of the following parts of light microscope:

1) Condenser

2) Stage

3) Focusing knobs

4) Objective lenses

5) Ocular lenses

Back 26

1) Condenser - focuses light through the specimen (contrast)

2) Stage - holds microscope slide in position

3) Focusing knobs - moves stage up and down to focus the image

4) Objective lenses - primary lenses that magnify the specimen

5) Ocular lenses - remagnifies the image formed by the objective lens

Front 27

How would you increase contrast when looking at an unstained preparation with bright field illumination?

Back 27

Close the condenser

Front 28

What is the difference between a mixed and pure culture and how can you tell the difference on a culture plate?

Back 28

Pure culture is only one types of microbe and mixed has many types.

Mixed culture you will see different colony morphologies.

Front 29

Explain what selective and differential media are.

Back 29

Selective media - allows only certain bacteria to grow while inhibiting others.

Differential media - contains substances that will allow different bacteria to be distinguished.

Front 30

How are fungi different from plants and animals?

Back 30

Fungi have a cell wall (simple) like plants (complex) but no chlorophyll.

Animal cells do not have a cell wall.

Front 31

How do yeasts differ from moulds?

Back 31

Yeast are unicellular and reproduce by budding.

Moulds are multicellular and reproduce asexually or with sexual spores.

Front 32

What is a dimorphic fungus?

Back 32

A fungus which is yeats or mycelial depending on the environment.

Front 33

What media is used for growing fungi?

Back 33

Sabouraud's agar

Front 34

Why are oranges spoilt by mould rather than bacteria?

Back 34

Acidic environment. Mould creates antibiotics which prevent bacterial growth. High sugar concentration inhibits bacterial growth.

Front 35

List the 5 types of asexual spores of fungi.

Back 35

S C C A B

1. Sporangiospores - sponge like

2. Chlamydospores - caped spores

3. Conidiospores - like dust

4. Arthrospores - joint like, break off

5. Blastospores - budding

Front 36

List the 4 stages of fungal sexual spore formation.

Back 36

1. Cells of + and - thallus fuse

2. After several hours/day/years nuclei fuse (diploid state)

3. Meiosis of nucelus (hapolid state)

4. Hapolid nucleus partitioned into + and - spores

Front 37

List the 3 types of fungal sexual spores

Back 37

B A Z

1. Basidomycota

2. Ascomycota

3. Zygomycota

Front 38

Name one dermatophyte that causes tinea

Back 38

Tinea pedis

Front 39

Sporotrichosis is caused by which fungus?

Back 39

Sporothrix schenckii

Front 40

Systematic mycoses are caused by which fungi? (fungal infection affecting internal organs)

Back 40

Dimorphic fungal pathogen (ie. blastomycosis)

They can overcome the physiological and cellular defences of the normal human host by changing their morphological form. They are geographically restricted and the primary site of infection is usually pulmonary, following the inhalation of conidia.

Front 41

Candidosis, crytococcosis and pneumosystis pneumonia are diseasescaused by opportunistic fungi. True or false?

Back 41

True

Front 42

Mycotoxins contaminate approximately 25% of foods world wide,however usually do not cause disease, why?

Back 42

Because only rarely are the levels of these mycotoxins are at dangerous levels.

Front 43

Why can’t viruses by grown on artificial media?

Back 43

They need a host cell to replicate.

Front 44

What is the main feature of viruses that is used to classifythem?

Back 44

Whether they contain RNA or DNA.

Front 45

What two main viral symmetries do viruses causing humandiseases have?

Back 45

1. Helical shape (spiral)

2. Polyhedral (cubic/icosahedral)

3. (rare) Complex - ie. bacteriophages

Front 46

What two ways that viruses can cause disease?

Back 46

1. By replication in host cell - causing cell damage

2. By human immune system response - causing cell damage

*****************

Front 47

List the stages of viral infectivity.

Back 47

A P R P A R

1. Attachment

2. Penetration

3. Replication

4. Production

5. Assembley

6. Release

Front 48

List two methods of viral control.

Back 48

H E V D U D

Any 2 of these...

1. Heat

2. Ether

3. Vaccine

4. Disinfectant

5. UV

6. Drugs (anti-viral)

Front 49

What is the basic structure of viruses?

Back 49

1. Nucleic acid (RNA or DNA)

2. Protein shell (capsid)

Some also have a lipid envelope.

Front 50

List two modes of transmission of viruses.

Back 50

I F P A P A

1. Inoculation (direct)

2. Food-borne

3. Physical contact

4. Arthropod-borne

5. Placental (intra-placental) - mother

6. Air-borne

Front 51

List two methods of detecting viruses for diagnosticpurposes.

Back 51

1. Electron microscope

2. Blood tests

3. Isolation of virus on cell/animal culture

Front 52

What is a “prion”?

Back 52

Proteinaceous Infectious Particle - protein particle agent of infection of variety of neurodegenerative diseases (no RNA or DNA) - not a virus

Front 53

What are the names for round and flat worms?

Back 53

Round = nematode

Flat = platyhelminth

Front 54

Trichinella spiralis is found in what type of food?

Back 54

Pig meat

Front 55

What is the common name for cestodia?

Back 55

Tape worms

Front 56

Why are nematode infections so common?

Back 56

Lack of clean drinking water and proper sanitation in developing countries (eggs infect a host via the fecal/oral route).

Front 57

What are the symptoms of Malaria and why do these symptoms occur?

Back 57

Symptoms include: fever, chills, nausea and headache. Caused by the mass lysis (bursting) of red blood cells, brought about by the protozoan infection.

Front 58

What is the main rout of infection for parasites? What isan exception?

Back 58

Ingestion.

Malaria protozoa which is transmitted via the bite of the mosquito.

Front 59

Ascaris lumbricoides,Trichuris trichiura and Enterobiusvermicularis are what type of helminth?

Back 59

Nematodes (round worms).

Front 60

Who was responsible for introducing handwashing (antisepsis, reduced obstetrics mortality to <1%)?

Back 60

Ignaz Semmelweis

Front 61

Who was the first to describe single celled organisms and further developed the microscope?

Back 61

Antoni van Leewenhoek

Front 62

Why did it take Antoni van Leewenhoek 2 years to discover bacteria after he discovered protozoa in 1674? And why didn't he tell anyone?

Back 62

Because bacteria were so much smaller than protozoa. And he thought people would think he was a witch.

Front 63

What is the total microbial load? How many cells in the body? Where are majority found?

Back 63

Microbial load = 10 to power 14

Body cells = 10 to power 13

Majority found in large intestine

Front 64

Why is microbiology important?

Back 64

1) Studying infectious diseases led to understanding of:

- personal and community HYGIENE

- microbial VIRULENCE and disease severity

- PREVENTION and control of disease transmission

2) Food processing and canning - hygiene

3) Industrial microbiology - brewing

4) Environmental

Front 65

What 5 attitudes inhibit critical thinking and sabotage capacity for critical thought?

Back 65

Intellectual arrogance

Intellectual laziness

Lack of respect for reason

Lack of respect for evidence

Unwillingness to listen

Front 66

Why is critical thinking essential, esp in science?

Back 66

- Irrespective of intention no one likes deception. Humans value truth, honesty, goodness, accuracy, fairness, free from bias.

- The truth used to make informed decisions

Front 67

What is critical thinking?

Back 67

- NOT passively accepting everything you see or hear

- every lecture starting point to evaluate currently held truths

- science not black and white, shades of grey, interpretation varies, results can be complicated by variables

- science is not static, but dynamic

Front 68

What are some key features of algae?

Back 68

- unicellular (ponds, lakes - produce most of world O2, food for water life = phytoplankton)

or multicellular (seaweed, kelp)

- photosynthetic (like plants)

Front 69

Name 3 methods of motility in Protozoa and give an example of each.

Back 69

1. pseudopodia - false foot ie. Amoeba

2. cilia - hair like ie. Paramecium

3. flagella - whip-like structure ie. Euglena

Front 70

How do fungi differ from plants? And from animals?

Back 70

Fungi obtain their food from other organisms and not by photosynthesis.

Fungi have a (simple) cell wall and animals do not.

Front 71

What are the two types of fungi and what differentiates them?

Back 71

1. Yeast - unicellular, oval or round

- reproduce by budding (asexually)

2. Moulds - multicellular

- produce hyphae (filaments) - are furry

- reproduce sexually (ABZ) and asexually (spores, SCCAB)

Front 72

Bacteria are single-celled Prokaryotes.

What are the two dominant shapes?

Give example of each.

What are their cell walls made of?

Back 72

Cocci (round) and bacilla (rod).

Cocci = E.coli

Bacilli = Staphylococcus aureus

Polysaccharides and peptidoglycans

Front 73

What is a bacteriophage? What does it do?

Back 73

It's a virus which parasitises a bacterium by infecting it and reproducing inside it (injects RNA into a bacteria cell)

Front 74

What are the cell walls of Gram-positive Bacteria and Gram-negative Bacteria made of? And cell membrane?

Back 74

Gram-positive Bacteria

thick layer of peptidoglycan

teichoic acid and lipoteichoic acid

Gram-negative Bacteria

thin layer of peptidoglycan

outer membrane (lipopolysaccharide)

Cell membrane = bilayer phospholipids and associated proteins - is selectively permeable

Front 75

What are only 2 types of bacteria which forms spores? Endospores.

Back 75

Bacillus and Clostridium.

Front 76

What are these solutions?

Hypotonic

Hypertonic

Isotonic

Halophile

Back 76

- Hypotonic - lower concn soln outside cell, water flows into cell and bursts (lysis)

- Hypertonic - higher concn soln inside cell, water flows out of cell causing shrinkage (crenation)

- Isotonic - solute concn inside and outside equal

- Halophile - microbes grow in high salt concn

Front 77

How do the following obtain energy and carbon?

Photoautotroph

Photoheterotroph

Chemoautotroph

Chemoheterotroph

Back 77

Photoautotroph

- E = light, C = CO2

Photoheterotroph

- E = light, C = organic compounds

Chemoautotroph

- E = inorganic compounds, C = CO2

Chemoheterotroph

- E = organic compounds, C = org compounds

Front 78

What are the stages of infectious disease?

Back 78

I P I D C

1. Incubation period - no symptoms

2. Prodromal phase - mild symptoms

3. Invasive phase - identifiable disease

4. Decline phase - reduction of microbes

5. Convalescence

Front 79

What are the 5 steps of lab diagnosis of bacterial infection?

Back 79

Co T P I S

1. Specimen COLLECTION

2. Specimen TRANSPORTATION to lab

3. Specimen PROCESSING

4. IDENTIFICATION of pathogens

5. Antimicrobial SUSCEPTIBILTY testing

Front 80

What are the 2 types of electron microscopy?

Back 80

Transmission Electron Microscope (TEM) - ultrastructure of cells (interior)

Scanning Electron Microscope (SEM) - metal coated specimens (gold), surface images

Front 81

What is a clinical infection?

Back 81

An infection with signs and symptoms

Front 82

What is a subclinical infection?

Back 82

An infection with pathogen but no symptoms

Front 83

What is an iatrogenic (nosocomial) infection?

Back 83

An infection from a medical practitioner / intervention. Nosocomial is specifically from a hospital.

Front 84

How are respiratory infections transmitted?

Back 84

Via the respiratory/salivary route through one of these methods:

- droplets (cough/sneeze)

- saliva

- soil/dust

- water aerosols

Front 85

Zoonoses is a term used for what kind of disease?

Back 85

Zoonoses is a disease which can be transmitted to humans from animals

- Direct animal-human

- Animal-vector(mosquito)-human

- Human-vector(mosquito)-human

Front 86

Explain the terms:
Endemic
Epidemic
Pandemic
Sporadic

Back 86

Endemic = disease present in a community (region) all of the time, usually only clinical in a few

Epidemic = wide spread disease within a community (region), affecting many people but only occasionally present

Pandemic = wide spread epidemic, not confined to a single community or region (more than one continent)

Sporadic = widely scattered disease, occurring singly, irregularly, infrequently

Front 87

What is Epidemiology?

Back 87

The branch of medicine which with incidence, distribution, and possible control of diseases and other factors relating to health.

Front 88

Explain the difference between Morbidity and Mortality.

Back 88

Morbidity = the number made ILL by an infective agent,
whereas...
Mortality = the number of DEATHS caused by an infective agent.

Front 89

Explain the difference between Incidence and Prevalence.

Back 89

Incidence = number of NEW cases over a SPECIFIC PERIOD,

whereas...

Prevalence = number of TOTAL cases (infected or diseased) at a POINT IN TIME (old and new cases).

Front 90

In epidemiological terms how would you classify the disease "AIDS"?

Back 90

AIDS is a global pandemic. Wide spread epidemic, not confined to a single community or region (more than one continent).

Front 91

What factors influence the spread of disease in a community?

Back 91

S T V
1. Population susceptibility - immunity

2. Pathogen transmission mode

3. Virulence of the pathogen

Front 92

List four ways of preventing the spread of disease in a community?

Back 92

W = proper treatment of WATER supplies
I = IMMUNISATION

S = proper SEWAGE treatment

E = EDUCATE the public

R = eliminate RESERVOIRS of infection (ie. killing off herds cattle in mad-cow epidemic)

Front 93

Which disease of the following disease type would most likely spread quickly through the Perth community and why?

a) gastroenteritis
b) a sexually transmitted disease
c) a respiratory disease

Back 93

c) a respiratory disease

- 4 methods transmission - droplet contact, direct and indirect physical contact, air-borne

- people more likely to go out in public/work when sick with cold as opposed to gastro (stay home)

- seasonal

- mutates

Gastroenteritis - 3 methods - oral-fecal route, direct and indirect contact (contaminated surfaces/food/water).
Sexually transmitted - 1 method - via genital-genital, genital-oral and genital-anal routes only.

Front 94

List the stages of infectious disease.

Back 94

I P I D C

1. Incubation - no symptoms

2. Prodromal - mild symptoms

3. Invasive - identifiable disease

4. Decline - reduction of microbes

5. Convalescence

Front 95

What are the two branches of the immune system?

Back 95

Innate = non specific defences, born with, do not require previous exposure to foreign agent

- 1st line defence = skin, mucus membranes, normal flora and secretions

- 2nd line =

1. Serum

- chemical mediators

- inflammation

- complement proteins

2. WBCs

- phagocytes = DNM - Dendritic cells, Neutrophils, Macrophages

- Natural Killer Cells, Mast, Eosino/Baso

Adaptive = specific, response based on specific recognition of invader (foreign agent)
- Humoral/Antibody-mediated (B Cells/lymphocytes) - plasma (antibodies) & memory

- Cell-mediated (T Cells/lymphocytes) - T helper, T cytotoxic cells, T regulator cells

Front 96

How does skin protect against bacteria?

Back 96

First line of defense. Protective barrier.

Front 97

What white blood cells (WBC) types are phagocytic?

Back 97

MEN are phagocytic
Monocytes, Eosinophils and Neutrophils

Front 98

What type of white blood cell (WBC) is mainly involved in the adaptive immune system?

Back 98

Lymphocyte

Front 99

What antibody types are involved in the primary and secondary immune response?

Back 99

M G - think fast car

IgM is involved in the first exposure and primary immune response (first to appear in an infection). Primary response has lag of several days while B cells proliferate (time for invader to do harm). Ig = immunoglobulin

IgG is involved in the second exposure and secondary immune response. Response is much quicker and larger with rapid rise in antibodies. Lasts longer. Memory cells require fewer cycles to become plasma cells.

Front 100

What type of lymphocyte is involved in cell mediated immunity?

Back 100

T Cell (Tc, Th and NKC)

Front 101

List the ways antibodies fight infection.

Back 101

P A N A

1. Coating over bacteria to facilitate recognition and trigger PHAGOCYTOSIS by the phagocytes

2. AGGLUTINATION of particulate matter, including bacteria and viruses, stops spread

3. NEUTRALISATION of toxins released by bacteria
4. ACTIVATE complement (20 proteins)

Front 102

List the antibody isotypes.

Back 102

G A M E D

IgG

IgA

IgM

IgE

IgD

Front 103

What are the 4 cardinal signs of inflammation and how do they come about?

Back 103

- redness (from increased blood flow)

- heat (from increased blood flow)

- swelling (from fluids in tissues)

- pain (pressure exerted on tissues from swelling)

Front 104

Describe the difference between humoral and cell mediated immune responses.

Back 104

As part of adaptive immune system:

Humoral/Antibody immunity =

- antibodies mediated

- action against extracellular invaders

- B cells (lymphocytes)

- extracellular antigens

Cell Mediated immunity =

- lymphocytes directly / indirectly kill infected cells

- act against intracellular invaders (also cancer)

- Cytotoxic T cells (Tc) = Killer T Cells

- intracellular infections (ie. viruses, mycobacteria) and cancer cells

- Natural Killer Cells (NK cells).

Front 105

List and describe the types of T cells.

Back 105

1. Cytotoxic T cells (Tc) - Killer T cells

- wide range of surface receptors against antigens = T cell receptors (TCR)

- each Tc is specific for one receptor

- infected cells express antigen of invader on their surface by cell marker MHC class 1

- Tc binds to these cells via TCR and releases toxic molecules to destroy and initiates apoptosis (cell suicide)

2. T Helper Cells (stimulate)

- in adaptive immune response

- help activity of other immune cells by releasing T cell cytokines
- help suppress or regulate immune responses

- B cell antibody class switching

- activation and growth of cytotoxic T cells

3. T regulator cells (inhibit)

Front 106

What is the MHC and what is its purpose?

Back 106

MHC = Major Histocompatibility Complex

Function = signalling system
MHC molecules bind peptide fragments derived from pathogens and display them on the cell surface for recognition by the appropriate T cells.

MHC I = infected cells present bits of infected agent on cell surface via MHC I for Tc to recognise and kill
MHC II = antigen presenting cells (DC, Macrophages) take up antigen (phagocytosis), go to Lymph node and present via MHC II to T Helper cells, stimulate B cells and/or Tc cells

Front 107

Describe the difference between passive and active vaccination.

Back 107

Passive immune mechanisms = administration of antibodies (no immune response of their own), short term ie. anti-venom

Active immune mechanism = administration of antigen, prophylaxis (prevent future infection), immune response producing own antibodies and memory, long term ie. vaccination

Front 108

How do autoimmune diseases occur?

Back 108

Immune system malfunction. When immune system mistakenly attacks self (own tissues). Mostly western society, women, adults and possibly genetic component. ie. diabetes.

Usually, T cells that react to the tissues of the body are destroyed by the thymus, an organ of the immune system located behind the breastbone. The 'self-attacking' T cells that escape destruction may be activated by a trigger. The exact triggers are unknown, but viral infections and hormones are among the suspects. The rogue T cells then instruct B lymphocytes (B cells) to make antibodies against the particular tissue, organ or system. Such antibodies are called 'autoantibodies'.

Front 109

What are the functions of the immune system?

Back 109

H = HOMEOSTATIC mechanism

S = SURVEILLANCE - detect changes
D = DISCRIMINATE between SELF and NON-SELF

D = DESTROY non-self

Front 110

Who was Typhoid Mary?

Back 110

She was a reservoir of infectious agent and example of ignorance. A cook. A healthy carrier of Salmonella typhi (typhoid fever) who didn't wash her hands and linked to 10 outbreaks, 53 cases and 3 deaths.

Front 111

What is "contact by droplet transmission"?

Back 111

It is a mode of disease transmission - sneezing propels mucus droplets from the respiratory mucosa, transmitting flu or cold viruses to a new host.

Front 112

What is inflammation?

Back 112

- Tissue is damaged
- Chemical mediators are released by damaged cells and resident Mast cells (Basophils).
- Mediators increase:
- vaso-dilation (increase blood flow to area)

- capillary permeability (leak fluid).

- Leads to:
- redness (from increased blood flow)

- heat (from increased blood flow)

- swelling (from fluids in tissues)

- pain (pressure exerted on tissues from swelling)

Front 113

What are the two types of second line of defense in the innate (non-specific) immune system?

Back 113

1. Serum
- complement, a series of 20 proteins which adhere, initiate inflammation and kill cells

- other anti-microbial peptides

2. White Blood Cells (leucocytes)

- phagocytic - Neutrophils, Monocytes, Eosinophils (E's also destroy large parasites)

- Natural Killer Cells (NK) - type of cytotoxic lymphocyte

Front 114

What are the three Antigen Presenting Cells (APCs)? What do they do?

Back 114

BDM

1. B cells

2. Dendritic cells

3. Macrophages

Move around detecting foreign antigens and phagocytosing infectious invaders. Digest and present bits of antigen on surface (via MHC II), travel to lymph node, present antigen to T Helper cells, T Helper then stimulates adaptive immune response

Front 115

What is humoral immunity and what are antibodies?

Back 115

Humoral immunity is antibody mediated immunity.

Antibodies are specialised proteins that recognise and attach to an antigen (recognised antigen on a foreign invader).

Front 116

What is the specific region on antigens where Antibodies bind called?

Back 116

Epitopes or Antigenic Determinants

Front 117

What are plasma cells?

Back 117

When required a B lymphocyte will mature into a plasma cell, which is specialized to produce large quantities of antibodies.

Front 118

Which cell regulates the immune response and how?

Back 118

Activation of B and Tc cells is regulated by the T lymphocytes (T cells).

- T Helper cells (Th) stimulate

- T Regulator cells (Treg) inhibit

Front 119

Give two reasons for preventing microbes from getting into food.

Back 119

Food microbiology
1. Prevent food related illness

2. Prevent food spoilage

Front 120

How could microbes contaminate food?

Back 120

S H I P S

Soil

Handling

Improper storage

Preparation procedures

Slaughtering/harvesting

Front 121

How does fermentation preserve food?

Back 121

Inhibits spoilage by other bacteria

Lactic acid bacteria grow, produce lactic acid, lower pH, other bacteria cannot grow

Front 122

List two of each pathogenic bacteria, viruses and parasites that can cause illness through food or water?

Back 122

Pathogenic bacteria = Salmonella and Staphylococcus aureus

Viruses = Norovirus and Rotavirus

Parasites = Helminths and Giardia lambia

Front 123

Why does spoilage of food appear rapid when the microbes are on the food for long periods before the appearance of spoilage?

Back 123

Spoilage appears to have rapid onset but it is due to exponential growth pattern microbes

Initial population is mixed but microbe with shortest generation time under conditions of storage will dominate (bacteria dominate over moulds and yeasts).

Front 124

List two uses for microbes in industry.

Back 124

Fermentation of foods - ie. cheese, alcohols

Treatment of polluted water (sewage)

Front 125

List two reasons for treating waste water

Back 125

Remove pathogens

Remove toxins

Prevent contamination drinking water

Prevent foul odours

Remove nutrients which cause pollution

Front 126

****** What is B.O.D?

Back 126

Biochemical Oxygen Demand

- determine levels of biological degradable organic material in water

- this test relies on amount of oxygen required by microbes to remove (degrade) these organic compounds

- test measures decreases in O2 concn following oxygen dependent oxidation of organic compounds by bacteria

- high BOD indicates high levels of organic material in water tested (bigger BOD = most polluted)

Front 127

What does BOD indicate?

Back 127

High BOD indicates high levels of organic material in water tested

Bigger BOD = most polluted

ie. pristine river = <1.0 BOD5 (mg/L)

moderate polluted river = 2 - 8

untreated sewage = 600

slurry from dairy farm = 2,000

Front 128

What is the main process in secondary sewage treatment?

Back 128

Microbial digestion of organic material

Hydrolysis (slow, rate limiting step)

Can be sped up by exo-enzymes produced by microbes

Proteins broken down by proteases, CHOs by amylases, fats/oils by lipases

Front 129

Give 3 uses for Bacteriophage.

Back 129

G I T

1. Genetic recombination (DNA technology)

2. Identify pathogenic bacteria (phage typing)

3. Treatment of bacterial infection

Front 130

What are the advantages of using HIV as a vector for gene therapy?

Back 130

- Integrates into host chromosome
(not all viruses can do this)

- Once there it can continue to be expressed

Front 131

Name 3 different areas of study within the field of Haematology.

Back 131

Blood transfusion/cross matching

Coagulation - platelets

Haemopoiesis - production of blood cells

Front 132

Anaemia is a disease studied in a routine Haematology laboratory. What is Anaemia?

Back 132

A condition in which there is a deficiency (decrease) of red cells or of haemoglobin in the blood, resulting in pallor and weariness.

Front 133

Explain what is meant by the term Leukaemia.

Back 133

A cancer that affects the blood and bone marrow where blood cells are made. There are an increase in WBCs.

Front 134

What is Haemopoiesis?

What is Erythropoiesis?

Granulopoiesis?

Lymphopoiesis?

Monocytopoiesis?

Thrombopoiesis?

Back 134

Haemopoiesis = production of formed elements of blood (WBCs RBCs platelets)

Erythropoiesis = production of RBCs

Granulopoiesis - production of granulocytes Lymphopoiesis - production of lymphocytes

Monocytopoiesis - production of monocytes

Thrombopoiesis - production of platelets

Front 135

What is the correct term for a decrease in neutrophils? Decrease in WBCs?

Back 135

Neutropaenia and Leucopaenia

Increase = -cytosis or -philia

Decrease = -aenia

Front 136

Where does Haemopoiesis occur? Explain why you might have more than one answer!

Back 136

In adult in the bone marrow.

In foetus in bone marrow, liver, lymph nodes, spleen, yolk sac.

More than one answer because in foetus may not yet have bones/bone marrow.

Front 137

Describe the shape of a RBC. Why do RBCs have this shape?

Back 137

Biconcave disc

Shape allows:

- rapid diffusion of gases (greater SA to volume)

- flexibility

- change in shape/size

Front 138

Discuss the significance of the RBC membrane.

Back 138

- shape maintenance of RBC depends on membrane structure

- shape allows rapid diffusion of gases, flexibility and change in size/shape

- lipid bilayer (w membrane proteins and CHOs) which functions as a barrier, but readily passes ions (ie. oxygen)

- Deformability and stability (can pass through small gaps in capillaries)

Front 139

List 3 Granulocytes that can be found in peripheral blood (they have cytoplasmic granules).

What are 2 Agranulocytes?

Back 139

Basophils

Eosinophils

Neutrophils

Lymphocytes

Monocytes

Front 140

List each of the 5 WBC types found in peripheral blood and explain the features that help to identify each of them.

Back 140

Neutrophils - most common, multilobed nucleus, small granules in cytoplasm, bacterial/fungal infections

Basophils - least common, 2-4 lobes nucleus, large cytoplasmic granules (dark staining), involved in hypersensitivity and inflammatory

Eosinophils - bi-lobed nucleus, large strongly staining (orange/red) cytoplasm granules, parasitic infections, dampens allergic response

Monocytes - largest WBC, kidney shaped nucleus, exit into tissues become macrophages, removal old RBCs, antigen processing and presents to T cells

Lymphocytes - second most common, large round nucleus/less cytoplasm - T cells (cell-mediated immunity) and B cells (antibody/humoral immunity)

Front 141

What is the term used to describe variation in:

- RBC size?

- RBC shape?

Back 141

Anisocytosis

Poikilocytosis

Front 142

List 2 specific terms for abnormal RBC shapes and describe the RBC shape for each of these specific terms.

Back 142

Elliptocytes - thin elongated cigar shaped cells

Ovalocytes - oval shaped rather than thin or round

Spherocytes - sphere, loss of biconcave shape

Front 143

What is Polychromasia and what may it indicate?

And Hypochromasia?

Back 143

Polychromasia = variable colour (blue/grey, orange/red), abnormally high number of RBCs in bloodstream as a result of being prematurely released from the bone marrow during blood formation (immature)

Hypochromasia = cells stain paler in colour, decreased Haemoglobin content

Front 144

What physiological processes do platelets have a role in?

Back 144

Primary role is prevention of blood loss via clotting

Front 145

What does the term “Thrombocytopaenia” mean?

Back 145

Decreased platelets

Increase = -cytosis or -philia

Decrease = -aenia

Front 146

What is the term for an increased number of Lymphocytes inthe peripheral blood?

Back 146

Lymphocytosis

Increase = -cytosis or -philia

Decrease = -aenia

Front 147

Either of 2 principles can be used in Automated Cell Counting machines. What are these 2 principles?

Back 147

Electrical impedance

Light scatter

Front 148

What blood cells can be manually counted using a Haemocytometer? (Can the chamber also be used to count anything else besides blood cells?)

Count should be accurate and precise

Back 148

RBCs or WBCs (selective, only one at a time)

RCC = red cell count, WCC = white cell count

Bacterial cells in suspension

WBCs in Cerebrospinal Fluid (CSF)

Front 149

Different areas of a counting chamber are used for counting different types of blood cells. What areas are used for a manual WCC?

Back 149

The four corners (1 x 1 mm squared)

Front 150

Explain why WBC types should always be reported as Absolute Number and not Relative numbers following a Diff.

Back 150

A relative value may seem within normal limits (it is a percentage); however, when the total WBC is considered (relative percentage x total WBC), the absolute value could be an abnormally high or low count.

Front 151

What causes food spoilage?

Back 151

Microbial growth (most common) including bacteria, moulds and yeast

Front 152

What are main methods of food preservation?

Back 152

DIP

1. Prevent microbial contamination

2. Inhibit microbial growth and activities (ie. low temps)

3. Destroy/remove microbes from food

(ie. cleaning, blanching, smoking, drying, fermentation, pasteurisation, canning)

Front 153

What are two types of environmental microbiology?

Back 153

1. Soil microbiology

- critical for humans

- biogeochemical cycles - soil microbes in carbon, nitrogen and sulfur cycles

- degradation of chemicals

2. Aquatic Microbiology & Sewage Treatment

- critical for WA as dry state

- microbes in natural waters

- microbial water pollution

- sewage treatment with microorganisms

Front 154

Correct term for increase in RBCs?

Increase in Eosinophils?

Back 154

Erythrocytosis and Eosinophilia

Increase = -cytosis or -philia

Decrease = -aneia

Front 155

Describe Neutrophils

Back 155

Neutrophils - most common, multilobed nucleus, small granules in cytoplasm, bacterial/fungal infections

Front 156

Describe Basophils

Back 156

Basophils - least common, 2-4 lobes nucleus, large cytoplasmic granules (dark staining), involved in hypersensitivity and inflammatory

Front 157

Describe Eosinophils

Back 157

Eosinophils - bi-lobed nucleus, large strongly staining (orange/red) cytoplasm granules, parasitic infections, dampens allergic response

Front 158

Describe Monocytes

Back 158

Monocytes - largest WBC, kidney shaped nucleus, exit into tissues become macrophages, removal old RBCs, antigen processing and presents to T cells

Front 159

Describe Lymphocytes

Back 159

Lymphocytes - second most common, large round nucleus/less cytoplasm - T cells (cell-mediated immunity) and B cells (antibody/humoral immunity)

Front 160

What does abnormal cell morphology refer to?

Back 160

Abnormal appearance of a cell

Front 161

Explain Histopathology in your own words.

Back 161

The microscopic examination of tissue to determine cause of disease.

Front 162

List some of the hazards associated with working in a Histopathology laboratory.

Back 162

Biological = cross infection

Chemical = fixatives, stains, chemicals

Physical = sharps, radiation

Front 163

Explain what a fixative does and list some features of an ideal fixative.

Back 163

Preserves tissue permanently in a life-like state.

Stabilises tissue and prevents bacterial decomposition.

Ideal fixative = SALES

S = not swell/shrink tissue

A = not add artefact material

L = preserve in life-like state

E = economical

S = safe

Front 164

What fixative/s can be used for Cytology smears?

Back 164

Ethanol and methanol (protein coagulants)

Front 165

List physical agents that can be used to assist in the fixation of tissues.

Back 165

HUM

Heat

Ultrasound

Microwaves

Front 166

True or false: Autolysis represents the changes to tissue that occur before fixation due to bacterial contamination.

Back 166

False. Autolysis is changes to tissue caused by self-digestion.

Front 167

What type of fixative is Neutral Buffered Formalin classed as?

Back 167

It is an Aldehyde.

Formaldehyde is an aldehyde.

Formalin is a solution of formaldehyde gas in water.

Neutral Buffered Formalin = 10% vv Formalin

Front 168

Why is Formalin Buffered to a neutral pH?

Back 168

pH of fixative should remain as close to pH of tissues

to prevent changes in tissue and preserve in a life-like state

Front 169

Give an example of a Chemical Fixative that belongs to each of the following groups (one example for each group).

Aldehydes,

OxidisingAgents,

Protein Coagulants,

Uncertain Mechanism.

Back 169

Aldehydes = formaldehyde

Oxidising Agents = potassium dichromate

Protein Coagulants = ethanol

Uncertain Mechanism = picric acid

Front 170

What is the function of xylene in tissue processing?

Back 170

It's a clearing agent (transition solvent)

Front 171

Why is the histological section cut to approximately 5µm thick?

Back 171

Needs to be thin enough for light microscopy (makes easier to microscopically evaluate tissue morphology)

Front 172

List method/s used for the collection of Cytology samples.

Back 172

Abrasive - epithelial cells collected manually

(ie. body fluids)

Exfoliative - passively shed epithelial cells

(ie. scraping, brushing)

Fine Needle Aspiration - sub epithelial and internal organ collection

(ie. superficial = thyroid, deep = lung)

Front 173

Compare the advantages and disadvantages of Histopathology with Cytopathology.

Back 173

Cytopathology

Advantages = outpatient procedure

rapid collection

relatively non invasive

accurate

inexpensive, low complication rate

Disadvantages = less info than biopsy

adequate sampling can be problematic

Histopathology

Advantages = more info than cytopathology

adequate sampling

accurate
Disadvantages = inpatient procedure

slower collection

invasive

expensive
higher complication rate

Front 174

What factors are involved in fixation?

Back 174

Factors Fixation = POST CD

pH/penetration

Osmolarity

Size of specimen

Temperature

Concentration

Duration

Front 175

What structures require stabilisation in fixation?

Back 175

Cytoskeleton fibrous proteins

Fibrous glycoproteins

Lipoproteins of cell membrane

Mucosubstances

Nucelic acids

Proteins of cytoplasm

Front 176

What are the stages of tissue processing?

Back 176

1. Fixation

2. Processing (dehydration, clearing, embedding, sectioning)

3. Staining

Front 177

What are the two types of staining mechanisms?

Back 177

Anionic (-ve) eosin ions stain +ve charged tissue ions (protein amino groups)

Acid dyes

Eosin - pink

Stains cytoplasm, collagen, RBCs, muscle

Cationic (+ve) methylene blue stain -ve charged tissue (carboxylic, sulfuric, phosphoric acid)

Basic dyes

Haematoxylin - blue/purple

Stains nucleus (nucleic acid and acid mucins)

Front 178

What is diagnostic cytology?

Back 178

Study of cell morphology

Front 179

What are the “building blocks” for protein macromolecules?

Back 179

Amino acids

Front 180

What are the “building blocks” for polysaccharides?

Back 180

monosaccharides (sugars)

Front 181

What are the “building blocks” for nucleic acids?

Back 181

Nucleotides =

phosphate

sugar +

organic base (adenine, thymine, cytosine, guanine)

Front 182

What are the “building blocks” for lipid aggregates?

Back 182

Fatty acids

Surfactant molecules (phospholipids) with hydrophilic heads (phosphate) and hydrophobic tails (Fatty acids)

Front 183

What macromolecule/s can be made up of branched chains?

Back 183

Monosaccharides (as polysaccharides)

Front 184

How many standard amino acids are there?

Back 184

20

Front 185

What is the general structure of an amino acid (diagram is ok).

Back 185

COO-

|

H3N---C---H

|

R

Carboxylic acid group
Amine group

R group which varies

Front 186

How do the standard amino acids differ from one another?

Back 186

R group side chain

Front 187

Amino acids can be classified according to their R group. Why might it be useful to use this classification? (Hint, might some amino acids with similar R groups have similar properties?)

Back 187

Amino acids with similar R groups have similar properties.

For example, nonpolar aliphatic R groups are hydrophobic (dislike water).

Aromatic R groups - ring structure will fluoresce under UV light

Polar uncharged R groups are hydrophilic (like water)

Front 188

What is a peptide bond?

Back 188

Chemical bond between two amino acids.

Formed when the amino N terminus of one AA reacts with the carboxy C terminus of another AA, releasing a molecule of water.

Front 189

Explain why amino acids are important.

Back 189

B E E P

Basic building blocks of proteins

Source of energy

Many inborn errors of metabolism due to absence of enzymes in metabolism of AAs
Precursors to other important biomolecules (ie. histamine, serotonin)

Front 190

BRIEFLY explain what is meant by each of the terms: Protein Primary Structure, Protein Secondary Structure, Protein Tertiary Structure, Protein Quaternary Structure.

Back 190

Protein Primary Structure - linear sequence of AAs

Protein Secondary Structure - backbone of polypeptide chain folds into regular geometric structures (ie. alpha-helix, beta-sheet)

Protein Tertiary Structure - final folded form of the protein, 'native' form of protein

Protein Quaternary Structure - association of 2 or more polypeptide tertiary structures (same or diff)

Front 191

List two examples of terms that describe different secondary structures that can be found in proteins.

Back 191

Alpha-Helix

Beta-Sheet

(Turns)

Front 192

List four of the major roles of Protein.

Back 192

Protein roles = S T E M

Structural support - myosin in muscle

Transport - haemoglobin carries oxygen

Enzymes

Movement - myosin in muscle

Storage - ferritin stores, source AAs

Front 193

Lipids may not be considered true macromolecules because of their structure. Briefly explain.

Back 193

Because individual monomers (fatty acids) are not covalently bonded to each other in a macromolecular structure - not all have fatty acids either

Front 194

Name three (3) major functions of lipids.

Back 194

Lipids functions = S S S

Storage - fuels, insulation, protection, heat production

Structure - biological membranes

Specific biological action - biological messengers, cofactors for enzymes, electron carriers, effectors

Front 195

List some examples of lipid aggregates.

Back 195

Lipid aggregates = L M L M

Liposomes - sphere with aqueous cavity

Micelles - sphere

Lipoproteins - transport lipids around body (ie. LDL HDL)

Membranes - lipid bilayer

We are mostly water (lipids hydrophobic) so need to form aggregates to transport them around body

Front 196

Give one example of an important Monosaccharides.

Back 196

Glucose - simple monomer

Front 197

Give one example of an important Disaccharides.

Back 197

Sucrose

Front 198

List four (4) of the major functions of carbohydrates in a cell.

Back 198

Carbohydrate functions = S A N E

Structure

Antibiotics

Nucleic acids

Energy source

Front 199

Can two sugar molecules have different configurations despite having the same molecular formula? BRIEFLY explain.

Back 199

Yes.

They can form different stereoisomer configurations, and

Monosaccharides with 5+ carbons can mutarotate from a linear chain to a ring structure.

Front 200

Explain the term Diabetes mellitus

Back 200

State of chronic hyperglycaemia which may result from genetic or environmental factors often acting jointly.

Type 1 diabetes = absolute deficiency of insulin (often by birth)

Type 2 diabetes = insulin resistance (often developed later in life)

Front 201

Discuss the statement “The diagnosis and management of Diabetes mellitus is only of concern to a very small portion of the health care industry”. (Hint, you should first decide if this statement is true or false, then BRIEFLY explain why it is true or false.)

Back 201

False.

8% of men and 7% of men have diabetes.

Prevalence increasing and similar trend worldwide.

Increase linked to lifestyle.

Significant issue for certain groups incl Indigenous Australians.

Front 202

How is Diabetes mellitus diagnosed?

Back 202

Plasma glucose (ie. >7.0 mmol/L fasting)

Front 203

Spectrophotometers can be used to measure the absorbance of light of a particular wavelength by a certain material. BRIEFLY explain what is meant by the term absorbance.

Back 203

Absorbance = difference between intensity of incident light beam I0 and intensity of light transmitted by solution It

Front 204

What is Beer’s Law?

Back 204

States that there is a directly proportional relationship between absorbance and concentration (linear).

Front 205

What is Lambert’s Law?

Back 205

As pathlength increases, transmittance decreases and absorbance increases.

Front 206

What is the combined Lambert-Beer Law?

Back 206

Absorbance is related to both concentration and pathlength

A = Ecl

A = absorbance

E = molar absorptivity constant

c = concentation

l = pathlength (1cm)

Front 207

Is it more convenient to use Absorbance or Transmittance to determine the concentration of a substance?

Back 207

Absorbance

Because the relship is linear (not curved like transmittance)

Front 208

Why is the selection of optimal analytical wavelength important for spectrophotometric measurement? (Hint, material to be discussed in Week 12 practical may assist you to answer this).

Back 208

Need to choose wavelength that will provide maximum absorbance, where standard calibration will be linear and give good results.

Front 209

Why is the selection and use of an appropriate Blank important for spectrophotometric measurement? (Hint, material to be discussed in the Week 12 practical may assist you to answer this)

Back 209

The blank is a solution identical to sample solution except does not contain the solute that absorbs light.

This measurement is necessary, because the cell itself scatters some of the light.

Front 210

What is biochemistry?

Back 210

Study of chemical processes in living things

Front 211

What does the abbreviation DNA stand for?

Back 211

Deoxyribose Nucleic Acid

Front 212

What is a gene?

Back 212

A sequence of DNA passed on to offspring.

A unit of heredity which is transferred from a parent to offspring and is held to determine some characteristic of the offspring.

Front 213

What is a genome?

Back 213

Contains all of genetic information of organism.

Front 214

DNA can contain 4 different kinds of bases. What are these 4 bases?

Back 214

AT CG

Adenine

Thymine

Cytosine

Guanine

Front 215

Explain basic DNA structure in terms of Sugars, Phosphates and Bases.

Back 215

Nucleotide = organic base + sugar + phosphate

Nucleotides joined by phosphodiester bonds = ssDNA with sugar (deoxyribose) phosphate backbone

Complementary bases may hydrogen bond
ssDNA + ssDNA = dsDNA

Strands have orientation (dsDNA double helix) and are antiparallel (5' to 3')

Front 216

Explain the “Central Dogma” of Molecular Biology.

Back 216

It is an explanation of the flow of genetic information within a biological system.

DNA replicates itself to make more DNA

Some DNA is transcribed into mRNA

Some mRNA is translated into protein

Front 217

BRIEFLY explain the statement “the information for making a new strand of DNA comes from an old strand of DNA”.

Back 217

Old strand DNA contains template (recipe) for new strand.

DNA replicates itself using DNA Polymerase.

Replication produces two identical replicas from one original DNA molecule. Requires primer.

Front 218

BRIEFLY explain the term Transcription.

Back 218

Transcription is first step of gene expression = RNA synthesis.

DNA is copied into RNA (mRNA) by the enzyme RNA polymerase. Does not require primer.

Occurs in nucleus.

Front 219

BRIEFLY explain the term Translation.

Back 219

Translation is second step of gene expression = protein synthesis.

Assembles AAs into protein (polypeptides) from info on mRNA

Occurs at ribosome with rRNA and tRNA (with attached AAs) from cytoplasm.

Front 220

In one short sentence explain what an Intron is.

Back 220

Non coding region on DNA or RNA

Quite high proportion of human DNA is intron - don't know how it's expressed yet

Front 221

In one short sentence explain what an Exon is.

Back 221

Coding region on a DNA or RNA

Front 222

What is a codon?

Back 222

A sequence of three DNA or RNA nucleotides that corresponds with a specific amino acid or stop signal during protein synthesis.

Front 223

What is meant by the term “Genetic Code”?

Back 223

- The set of rules by which information encoded within genetic material (DNA or mRNA sequences) is translated into proteins by living cells.

- Defines how sequences of nucleotide triplets, called codons, specify which amino acid will be added next during protein synthesis.

Universal 3 base codes

61 codons - 20 AAs

3 stop codons

usually start with AUG codon (Methionine)

Front 224

What are two differences between RNA Polymerases and DNA Polymerases?

Back 224

DNA polymerase = synthesizes DNA

RNA polymerase = synthesizes RNA

DNA polymerase needs primer

RNA polymerases = capable of initiating a new strand

RNA polymerases = produces smaller sections

Front 225

BRIEFLY explain what a Restriction Enzyme is.

Back 225

Molecular scissors - enzymes that cut DNA at specific sites, some form sticky ends, some blunt ends

Restriction enzyme (restriction endonucleaseis) an enzyme that cuts DNA at or near specific recognition nucleotide sequences known as restriction sites.

Front 226

BRIEFLY explain what a Ligase Enzyme is.

Back 226

Molecular glue

Ligase enzyme facilitates the joining of DNA strands together by catalyzing the formation of a phosphodiester bond.

Front 227

Explain how PCR could be used in sex determination.

Back 227

Polymerase Chain Reaction (PCR)

Isolate DNA

Amplify specific segments X and Y chromosomes

Estimate the sizes of the PCR products using agarose gel electrophoresis

Based on the pattern of PCR products, can distinguish between male and female samples and determine the gender of an unknown DNA donor.

Front 228

State 3 additional applications PCR could be used for.

Back 228

cloning,

mutation detection,

forensics,

paternity testing.

Front 229

What are the steps of a PCR reaction?

Back 229

PCR = D A E

Denaturation = heat breaks H bonds, separates dsDNS into ssDNA

Annealing = primers anneal (bond) to ssDNA at 3' end

Extension = using DNA polymerase adds dNTPs (complementary nucleotides) one at a time until complete

Front 230

Are there any infectious, disease causing agents that can not be detected using a PCR type reaction? If so name one such agent or disease. (Hint: the answer is yes! You may find this a challenging question. If you know PCR can detect nucleic acid then you will have to find an infectious agent that does not contain nucleic acid. Such agents exist but are unusual.)

Back 230

Yes - a prion - has no DNA

Prion = proteins that are unique in their ability to reproduce on their own and become infectious

Front 231

Describe an application of electrophoresis.

Back 231

Agarose gel electrophoresis

- to separate a mixed population of DNA, RNA or proteins in a matrix of agarose.

- specific DNA sequences can be analyzed, isolated and cloned

- proteins may be separated by charge and/or size and DNA/RNA fragments by length

ie. can be used for analysis of PCR products in paternity testing

Front 232

When electrophoresed over a given period oftime, will a small DNA molecule usually migratea shorter distance or a further/longer distancethrough an agraose gel, compared to a largeDNA molecule?

Back 232

Small DNA molecule will pass through the agarose gel more easily than a larger molecule so will usually migrate a longer distance.

Front 233

True or False? “electrophoresis can separate molecules based on both size and charge”

Back 233

True

Front 234

What types of molecules can be separated using Electrophoresis?

Back 234

DNA

RNA

Proteins

Front 235

A certain type of PAGE can be used to separate denatured proteins. What are denatured proteins?

Back 235

Primary structured proteins where H bonds have been broken

A sequence of AAs remains

Front 236

What makes an ideal vector?

Back 236

T U T E

Target delivery

Unable to replicate
Minimal toxicity / immune response
Control of expression

Front 237

What is meant by the term “metabolism”?

Back 237

- Sequence enzyme catalysed chemical reactions in the cell to maintain life

- Anabolic and catabolic

- Regulated

- Chemical reactions occur as pathways

Front 238

Anabolic and catabolic pathways are different. Briefly explain two of the differences between an anabolic pathway and a catabolic pathway.

Back 238

Anabolic pathway builds molecules

Requires energy

Pathway usually divergent (large number of molecules can make using small no. building blocks)

Catabolic pathway breaks down molecules

Creates energy

Pathway usually convergent (small number of molecules can make using larger no. building blocks)

They proceed at same time

in dynamic steady state

Front 239

What is an enzyme?

Back 239

Catalysts

Important in regulating chemistry of cells and organisms

Speed up rate of reaction

Not consumed in the reaction

Wouldn't exist without them

Front 240

What is an enzyme “active site”?

Back 240

region of an enzyme where substrate molecules bind and undergo a chemical reaction.

3D arrangement of residues that determines catalytic rate

Front 241

When referring to an enzymatic reaction, what is meant by the term “substrate”?

Back 241

molecule upon which an enzyme acts.

Enzymes catalyze chemical reactions involving the substrate(s).

the substrate bonds with the enzyme active site, and an enzyme-substrate complex is formed.

Front 242

When referring to an enzymatic reaction, what is meant by the term “product”?

Back 242

product of the reaction with an enzyme and substrate

enzyme+substrate --> enzyme-substrate --> enzyme+product

Front 243

List and briefly explain four (4) variables that can effect enzyme activity.

Back 243

STEP

Substrate concentration

Temperature

Enzyme concentration

pH

Front 244

A laboratory assay uses an enzymatic reaction as part of the assay procedure. Explain why the incorrect incubation time for the laboratory assay may effect the results of the assay.

Back 244

Because enzyme catalysed reaction is reversible. As reaction proceeds more products are produced. At a point in reaction, products will start to react in reverse direction and amount of products will decrease. Need to incubate for long enough to form maximum products without (velocity max).

Front 245

List 4 different types of biological specimens that may be used in a Biomedical Science or Pathology laboratory.

Back 245

Blood

Urine

Feces

Tissue

Front 246

Name the cellular components of blood.

Back 246

RBCs

WBCs

Platelets

Front 247

Name 3 components of blood required for clotting.

Back 247

Platelets

Calcium

Clotting proteins

Front 248

Is there a difference between serum and plasma? Explain your answer.

Back 248

Yes

Serum is plasma minus clotting proteins

Plasma is liquid portion of blood (WA ICE)

water,

albumin,

immunoglobulins,

coagulation proteins,

electrolytes

Front 249

What is an anticoagulant?

Back 249

Prevent clotting in specimen

Front 250

List one anticoagulant and explain its mode of action.

Back 250

Heparin - inhibits clotting proteins (ie. thrombin)

- used for some Clinical Biochemistry

Sodium citrate - chelates calcium (reversible)

- used for coagulation testing samples

Front 251

Why are different anticoagulants used when collecting blood?

Back 251

???? Need to use correct anticoagulant depending on the reason the blood is being tested - don't want to interfere with the results

Front 252

Why is correct identification of a patient sample important?

Back 252

Because we need to make sure we're testing the correct patient and run the appropriate tests. To prevent incorrect diagnosis, treatment and potential adverse events leading to morbidity or mortality.

Front 253

List 2 reasons that a patient sample may be unsuitable for a laboratory assay, necessitating the recollection of a sample.

Back 253

Incorrect anticoagulant was used

Blood sample was not preserved correctly

Front 254

Haemophilia is a disease studied in a Coagulation laboratory. What is Haemophilia?

Back 254

Medical condition - ability of the blood to clot is severely reduced, causing the sufferer to bleed severely from even a slight injury.

The condition is typically caused by a hereditary lack of a coagulation factor, most often factor VIII.

Front 255

What factors may affect the reliability of a laboratory test result?

Back 255

Limitations of instruments

Human error

Front 256

Explain the term Accuracy when referring to laboratory results. Use a hypothetical example in your explanation.

Back 256

Accuracy =

Closeness of measured value to true value.

Reflects "true value"

Internal validity / reliability

Can use controls to check for accuracy

Can be estimated with one measurement.

Example: Object weighs 100g and we weigh it and get 100g

Front 257

Explain the term Precision when referring to laboratory results. Use a hypothetical example in your explanation.

Back 257

Precision =

How close together a set of measurements are to each other

Nothing to do with "true value"

External validity /reproducibility / generalisability

Can be estimated w multiple measurements

More important - if we're consi

stent

Example: object weighs 100g and we weigh it 4 times and get 88.5, 88.6, 88.6, 88.5

Front 258

Explain briefly how ion exchange works.

Back 258

Separation of solution

Column with matrix resin beads - negatively charged

Solution added at top with positive and negatively charged ions in it

Solution passes through and positive ions will attach to beads, negative will pass through into beaker

Front 259

What is the difference between sterilisation and sanitisation?

Back 259

Sanitisation destroys SOME microorganisms, reducingliving numbers (ie. kills some but not all) t meet product quality and publichealth standards. Often not effective in the presence of organic residues and detergents. Often achieved with moist heat or chemicals.

Sterilisation destroys ALL microorganisms, includingendospores. Used with medical instruments, medical waste, culturemedia/glassware and often achieved via moist heat under pressure (ie. 15 minsat 121 degrees C at 15 psi).

Front 260

What is the difference between a disinfectant and an antiseptic?

Back 260

They are used for different things.

Disinfectant is asubstance that removes or causes the destruction of harmful microbes (notusually spores) from inanimate objects.

Antiseptic is a disinfectant for animate areas (ie.body sites) – not toxic to life.

Front 261

What is pasteurisation?

Back 261

Physical method of disinfection for inanimate objects using heat,typically in range 60-80 deg C for a few mins to kill pathogens and destroymost other bacteria which cause food spoilage (ie. preservation, increase shelflife).

Front 262

What are the temperatures and times for LTLT and HTST relating to pasteurisation?

Back 262

Low Temp Long Time (LTLT) = 63 degC / 30 mins

High Temp Short Time (HTST) = 72 degC / 15 sec

Front 263

List the 3 modes of action for disinfectants?

Back 263

1. Physical – Heat (Pasteurisation)

2. Physical – Radiation

3. Physical – Heat (Boiling)

4. Chemical

Front 264

What is the optimal percentage of alcohol for disinfection?

Back 264

70% - because need some water to create a difference inosmotic pressure so the bacteria lyses (bursts).

Front 265

Betadine is a combination of iodophor and detergent which is used as a skin disinfectant in presurgical operations. List the advantages and disadvantages of Betadine for this use.

Back 265

Advantages: good residual effect, effective on a wide range of microbes, great for some wounds and infections

Disadvantages: skin discolouration, hypersensitivity, Pseudomonas able to grow still, not effective for larger infections-family

Front 266

What is the mechanism of action for Quaternary Ammonium Compounds (QUATs) against bacteria?

Back 266

It is a surfactant. Low level disinfectant. Inactivated by soaps. Quaternary ammonium compounds (QACs) irreversibly bind to the phospholipids and proteins of the membrane, thereby impairing permeability.

Front 267

Why are QUATS no longer used in some hospital settings?

Back 267

Recycling of mop bucket water with Pseudomoasspreads bacteria

Front 268

How could the presence of organic matter interfere with the action of disinfectants?

Back 268

- Presence of organic matter forms precipitate whichremoves disinfectant from contact with bacteria,

- Or reacts with disinfectant toproduce a non-bacterial agent,

- Or coats the bacteria and protects them.

Front 269

UV radiation damages proteins and nucleic acids of bacteria. What is the main disadvantage of UV radiation as a disinfectant?

Back 269

low penetrating power

takes a moderate amount of time for it to be effective (20-30 minutes).

Front 270

What is the “decimal reduction time (D)”?

Back 270

It is the time in minutes for the survivors to be destroyed by one log cycle which represents 90% of the initial population.͈

Front 271

What is Sterilisation?

Back 271

A process by which ALL microbes including endospores aredestroyed.

Front 272

Why are endospores difficult to kill?

Back 272

Bacterial spores are the most heat resistant and difficult to kill microbial structure. The thick spore coat protects it from radiation and chemicals.

Front 273

Why is moist heat better than dry heat?

Back 273

Moist heat is a better conductor of heat and allows better heat penetration. The conditions for moist heat sterilisation are based on killing bacteria spores.

Front 274

In what circumstance would you probably use a dry heat oven instead of autoclaving?

Back 274

Good for glassware, oils and powders, and doesn’t blunt sharps

Front 275

What methods are used to ensure an autoclave is working?

Back 275

1. Autoclave printouts/monitoring

2. Biological – spore strips

3. Autoclave tape (Bowie-Dick) test

Front 276

Name two chemicals used for “cold sterilisation”.

Back 276

Formaldehyde (gas) and Ethylene oxide (gas).

Front 277

How does ionizing radiation affect microbes to kill them?

Back 277

When ionizing radiation strikes bacteria and other microbes, its highenergy breaks chemical bonds in molecules that are vital for cell growth andintegrity. As a result, the microbes die, or can no longer multiply and causeillness or spoilage. Breaking chemical bonds with radiation is known asradiolysis.

Front 278

State the filtration poresize needed to filter out a) bacteria, b) viruses.

Back 278

a) Bacteria = 0.45um

b) Viruses = 0.01um

Front 279

What is the difference between Bacteriostatic and Bactericidal agents?

Back 279

Bacteriostatic agents inhibit growth of microbes whichcan swing the balance of fighting infection towards the immune system.

Bactericidal agents kill the microbes.

Front 280

List the 6 modes of action for anti-bacterial agents.

Back 280

MR DR MC

M. Metabolicinhibitors

R. Inhibitors of RNA synthesis

D. Inhibitors of DNA replication

R. Inhibitors of Ribosome function –protein

M. Membrane-active antimicrobialagents

C. Inhibitors of Cell wall synthesis

Front 281

Describe the action of the β-lactam antibiotics.

Back 281

Inhibit last stage of the cell wall production

Only damage cell wall - humans don't have.

Not effective against resting bacteria - need to be growing and dividing to work.

Front 282

How are bacteria resistant or become resistant to antibiotics?

Back 282

Over prescription leads to over exposure and selective pressure.

Not completing a course of antibiotics that work leads to selecting resistantmutants.

Use in intensive animal farming has led to resistant strains passed toconsumers in foods.

Front 283

Why are antibiotics of no use against the common cold?

Back 283

It’s a virus and not affected by antibiotics

Front 284

Define “antibiotic”.

Back 284

A natural compound produced by microorganisms that killor inhibit other microorganisms. T

Can also be synthetic (artificially made)or semi-synthetic (natural antibiotic compounds that have been artificiallymodified).

Front 285

Why are the β-lactamagents good for treating bacterial infections in humans?

Back 285

Because they only damage the cell wall, which humans(eukaryotes) do not have.

Front 286

Why are manytreatments for fungal infections often toxic to humans?

Back 286

Because fungus is a eukaryote like humans are so often treatments toxic to fungi are toxic to humans as well.
Treatment is usually long term.

Front 287

List two modes ofaction for anti-viral drugs.

Back 287

Drugs that bind free virus preventing entry (ie.Disoxaril for Rhinovirus – treatment for ‘colds’).

Prevention of uncoating of virus (Amantadine forInfluenza)

Front 288

How does cleaning control microbes?

Back 288

Microbes are removed but not killed

often with water and detergent

Front 289

Differences between

Cleaning

Sanitisation

Disinfection

Sterilisation

Back 289

Cleaning = removes but doesn't kill, water/soap

Sanitisation = kills many but not all, not effective with organic residues

Disinfection = chemicals, kills all (antiseptic animate objects, disinfectant for inanimate)

Sterilisation = moist heat, sterlises, killing all including spores

Front 290

What mode of action do alcohols, aldehydes, halogens (iodine), heavy metals and phenols use to disinfect?

Back 290

Protein coagulation / denaturation

Front 291

Which chemical disinfectants disrupt the cell membrane?

Back 291

Surface active agents

halogens (chlorine)

chlorhexadine

phenols

Front 292

What mode of action do metals use to disinfect?

Back 292

chemical antagonism (inactivation of enzymes)

Front 293

What is asepsis in clinical practice?

Back 293

Asepsis = C A S H

personal cleanliness

aseptic techniques

disinfection/sterilisation surfaces/equipment

hand washing

Front 294

What are the details for autoclaving? Sterilisation by moist heat.

Back 294

Temp raised to 121 deg C for 15 minutes at 15 psi (pounds per square inch) is most common

Front 295

What is a HEPA and what does it do?

Back 295

It's a High Efficiency Particulate Air (HEPA) filter in commercial air filtration system

removes particles down to 0.3um

99.97% efficient

Front 296

How do you get human gene to replicate in a bug?

Back 296

Often clone human gene into bug via plasmid cloning vector.

Cloning vector = small piece of DNA, taken from virus, plasmid, or cell of higher organism, can be stably maintained in an organism, and into which a foreign DNA fragment can be inserted for cloning purposes.

Front 297

What is electrophoresis?

Back 297

- tool - analyses and purify DNA, RNA, proteins

- uses small amount of material

- can separate according to size and charge

- matrix of interlocking fibres - things pass through at diff rates - like a SIEVE

- electrophoresis tank, electrical source, gel, dyes

- +vely charge migrate to -ve electrode and vice versa (DNA is -ve)

- agarose gel for larger molecules, PAGE for smaller

- smaller molecules pass through quicker and travel further

Front 298

Why might a protein need to be separated from a mixture of other proteins?

Back 298

I S I D E
- Industry or food (whey protein isolate)

- Study physical/chemical characteristics or particular protein in mixture

- Isolate a particular protein/enzyme

- Determine amino acid sequence in particular protein

- Enhance activity of particular enzyme by purification

Front 299

What types of molecules can be separated from a mixture using Chromatography?

Back 299

Proteins, RNA, DNA and other organic molecules

Front 300

List 3 Chromatography principles that can be used to separate a molecule of interest from a mixture. What property of molecule is being utilised?

Back 300

I S A

All columns with solution being passed through.

Ion Exchange - charge

Size Exclusion - size and shape (large molecules pass through first)

Affinity - chemical bonds, protein is binding to a specific ligand in column

Front 301

What is a catalyst and how does it work?

Back 301

A substance which increases the rate of reaction without being consumed.

Provides alternative raction pathway which has lower activation energy.

Forms a transient intermediate in reaction called transition state.

Front 302

What are two advantages of disinfection by Pasteurisation?

Back 302

Reduces spoilage by bacteria

Extends shelf life

Front 303

What is a reservoir of infection?

Back 303

Any person, animal, plant, soil or substance in which an infectious agent normally lives and multiplies.

Reservoir harbors infectious agent without injury to itself and serves as a source from which other individuals can be infected.

Front 304

What are the primary lymphoid organs?

And secondary lymphoid organs and tissues?

Back 304

1. Red bone marrow - B cells, immature T cells

Thymus - mature T cells

2. Organs (capsule) - spleen, lymph nodes

Tissues (no capsule) - lymph nodules, tonsils, appendix, Peyer's patches

Front 305

What is Immunology?

Back 305

The study of the cell, tissues and proteins of the immune system.

How body protects us from external (bacteria, viruses, fungi) and internal (mutations - cancer) attack

Front 306

How does inflammation start? What happens?

Back 306

With tissue damage - damaged cells and Mast cells release chemical mediators.

Chemical mediators:

- increase vaso-dilation (increase blood flow to area - heat and redness)

- capillary permeability (leak fluid = pain and swelling)

- attract WBCs to area (Neutrophils first, monocytes, lymphocytes)

- stimulate production and release WBCs in bone marrow

Front 307

What are Mast Cells? What do they contain?

Back 307

Mast cells are WBCs of immune system, similar to Basophils, release chemical mediators when cells/tissues are damaged. First cells to respond.

Contain granules of heparin (anticoagulant) and histamine (causes increased blood flow, leaky capillaries, swelling, heat etc of inflammation).

Front 308

What cells do T Helper cells stimulate?

Back 308

Macrophages, Cytotoxic T cells and B cells.

Front 309

What do Natural Killer Cells do?

Back 309

- A lymphocyte

- kill cells with reduced MHC I (cancer cells and virus-infected cells)

- also kills cells with ADCC antibody on cell

- Kills by insertion of granules containing perforin
- Part of innate and adaptive immunity

Front 310

What do cytotoxic T cells do?

Back 310

Killer T cell (Tc)

- Have T-cell Receptors (TCRs) which recognise a specific antigen

- Kill cells displaying MHC class I (cell is infected with pathogen and presents fragments of foreign antigen on cell surface as MHC I) = release of toxic molecules, causes lysis and cell suicide

- Kill antigen-presenting cells (APCs) displaying MHC II after Helper T cells have stimulated Tc

Front 311

What are two examples of original vaccinations being used?

Back 311

15th century Middle East, powder of lesions from small pox crusts inserted into skin to preserve the beauty of their daughters

Edward Jenner extracted fluid from milk maid's hands (infected with cowpox) and inoculated into 8 year old James Phipps (resistant to cowpox and smallpox)

Front 312

What cells do HIV destroy? What happens?

Back 312

CD4 (T Helper cells)

Without T Helper, no Tc action and no antibody production

Person dies from being unable to fight infection (adaptive immune system damaged).

Front 313

With respect to microbial spoilage, what is decay? What is putrefaction?

Back 313

Decay = aerobic microbial spoilage

Putrefaction = anaerobic microbial spoliage

Front 314

What are 3 methods of acquiring diseases from food?

Back 314

1. Direct effects of microbes (ie. infections)

2. Toxins (ie. intoxication)

3. Microbial action on food (ie. decay/putrefaction)

Front 315

What diseases can be transmitted in food? Give on example of a bacteria which causes intoxication and one which causes infection?

Back 315

PAST

Prion disease

Anthrax

Staphylococcus Aureus

Tuberculosis (TB)

Intoxication = Staphylococcus Aureus

Infection = Salmonella spp.

Front 316

What microorganisms can we eat? What are advantages?

Back 316

Yeasts, fungi (mushrooms), algae (Euglena) and bacteria (Spirulina and probiotics)

Grow fast, good protein content, save environment

Front 317

What was Dejecti (Effusive Acte)?

Back 317

Law making damages payable if throwers of waste into the street hit and injured a person (only during the day).

Front 318

What is eutrophication?

Back 318

Nutrient pollution in watercourses, causing the enhanced growth of some organisms (phytoplankton and cyanobacteria) causing depletion of O2 and death of aquatic life.

Front 319

What is involved in the primary treatment of sewage?

Back 319

Physical processes

Reduce oils, fats and grit

Remove larger solid and insoluble objects

Front 320

What is involved in tertiary treatment of sewage?

Back 320

Due to high costs not done in many countries

Physical and chemical methods used

To make potable (drinking) water

Only done in London and Sinagpore

Front 321

What are two limitations or ethical problems relating to using viral vectors?

Back 321

Viral vectors may infect healthy cells as well as cancer cells

Viral vector could cause inflammation or immune reaction

Transgene may insert in wrong location and cause cancer or harmful mutations

Front 322

What is the main function of blood?

Back 322

To support the function of body tissues

Front 323

How do stem cells differentiate into mature cells?

Back 323

Under influence of growth factors

Front 324

What is the origin cell of Basophils, Neutrophils, Eosinophils and Monocytes?

Back 324

Myeloblast
(and before that, common myeloid progenitor)

Front 325

What is the origin cell of Natural Killer Cells and Lymphocytes?

Back 325

Common lymphoid progenitor

Front 326

What is the origin cell of thrombocytes (platelets)?

Back 326

Megakaryocyte

(and before that, common myeloid progenitor)

Front 327

What are two examples of Anisocytosis?

Back 327

Anisocytosis is changes in size of RBCs

Microcytosis = decreased size

Macrocytosis = increased size

Front 328

What are 3 examples of WBC (Neutrophil) abnormalities?

Back 328

Toxic granulation - increased size of granules

Left shift - immature, large single nucleus

Right shift - older, many, many lobed nucleus

Front 329

How many litres of blood does the average healthy human have?

Back 329

5L

Front 330

What are two purposes of blood cell counts?

Back 330

Determine if disease is present

Monitor course of disease (treatment)

Front 331

What are some sources of error in manual blood cell counting?

Back 331

Technical error = counting, dilution, sampling

Statistical error = only small proportion cells being counted from total number of cells

Front 332

What dilutions are used in automated cell counting for RBCs and WBCs?

Back 332

RBCs = 1 in 50,000 dilution

WBCs = 1 in 500 dilution (RBCs are lysed)

Front 333

How do we use a blood cell count?

Back 333

Compare the count to the reference range

If result is in range = normal

If above = high

If below = low

If WBC high, for example, then = Leukocytosis

Front 334

In diagnostic cytology, the nucleus reflects the function of the cell and the cytoplasm reflects the activity of the cell. True or false.

Back 334

False

The nucleus reflects the activity of the cell

The cytoplasm reflects the function of the cell.

Front 335

What is a Zwitterion? What is an example of one?

Back 335

A Zwitterion is a dipolar ion.
Both and acid and a base - can accept or donate a proton (H+). in neutral pH 7.

Amphoteric.

Amino acids are ionized in solution and form ions depending on pH of solution. Can act as either acid (contains NH3+) or base (contains COO- ion).

Front 336

What bonds are responsible for primary, secondary, tertiary and quarternary protein structures? What does this mean?

Back 336

Primary = covalent bonds

= very strong bonds

Secondary, tertiary and quarternary

= non-covalent bonds

ie. hydrogen, hydrophobic and van der Waals forces

= weak bonds, can be broken when protein denatured

Front 337

What is a protein domain? What are proteins with more than one domain called?

Back 337

It's a conserved part of a given protein sequence and (tertiary) structure that can evolve, function, and exist independently of the rest of the protein chain.

Mosaic proteins

Front 338

What are some protein general facts?

Back 338

They can be:

Classified into families

Interact with each other

Dynamic (not static) structures

Made of domains

Globular (most) or fibrous

Act as buffers

Front 339

What is diabetes insipidus?

Back 339

A rare form of diabetes.

Caused by deficiency of pituitary hormone vasopressin which regulates kidney function.

Front 340

What equipment do we use measure blood glucose in solution? How does it work?

Back 340

Using a spectrophotometer - using radiant light (ie. UV) and measuring its interaction with the matter to determine concentration (or structure).

Electromagnetic radiation interacts with matter (reflected, absorbed or transmitted) and alters internal energy states of the molecules.

Intensity of light hitting solution (I0) will be different to intensity of light being transmitted (It) - leaving the solution on other side.

Front 341

How many base pairs of DNA do humans have?

Back 341

Approximately 3 billion base pairs of DNA (needs to be compacted to fit into cell)

Front 342

What are VNTRs? What is an application of a VNTR in a PCR?

Back 342

Variable Number of Tandem Repeats - section of genome where short nucleotide sequence is organised as a tandem repeat.

Paternity testing. Do a PCR with DNA from parents and baby - baby should have one line of VNTR in electrophoresis gel match up to one of mother's and one of father's.

Front 343

What is genetic engineering? What "tools" are used?

Back 343

Cutting and pasting DNA. Recombinant DNA = DNA from more than one organism.

Tools =
restriction enzymes (molecular scissors)

& DNA ligase (molecular glue)

Front 344

What is a plasmid?

Back 344

- A small autonomously replicating circular DNA molecule.

- Often found in bacteria as small, circular, double-stranded DNA molecules.

- Sometimes present in archaea and eukaryotic organisms.

Front 345

Why do Molecular Biologists use mRNA instead of genomic DNA when cloning human genes into bacteria via a plasmid?

Back 345

Because if DNA is used, it will contain introns which the bacteria cannot remove. Will result in incorrect translation.

If we use mRNA then the introns have already been removed.

Front 346

Give 2 examples of transgenic plants.

Back 346

Herbicide resistant corn

Flavr Savr tomato

Front 347

What are some advantages and disadvantages of using viral vectors?

Back 347

A: high transfection efficiency

long-term gene expression

D: potential toxicity and cancer-causing

immunogenic

restricted target cell specificity

expensive

Front 348

What is the Free Energy of Activation?

Back 348

It is the activation energy (energy threshold) that has to be reached before a reaction can occur.

Reactants need to form a transition state and pass through to make the products.

Free Energy of Activation (delta G++ or DG) determines the rate of the reaction.

Higher activation energy = slower reaction rate

Lower activation energy = faster reaction rate

Front 349

Why would you want a laboratory test to show sensitivity and specificity?

Back 349

Sensitivity = can detect smaller amounts of analyte

Specificity = measures only the substance to be measured

Ideally want both but can be costly so can't.

Front 350

Test reliability is a combination of which 2 factors? Which one is more important when it comes to patient's results?

Back 350

Accuracy and precision

Precision - more important to be consistent. High level precision improves ability to detect small changes in patient's results over time.