Microbiology Lecture Test 1

Front 1

What are capnophiles?

Back 1

Thrive in higher levels of CO2 (5-10%)

Front 2

Give two example of capnophiles.

Back 2

Haemophilus influenzae
Campylobacter jejuni

Front 3

Superoxide dismutase

Back 3

converts oxygen radicals into hydrogen peroxide

Front 4

catalase

Back 4

converts hydrogen peroxide into water and oxygen

Front 5

Requires oxygen

Back 5

obligate aerobe

Front 6

Example of obligate aerobe

Back 6

Pseudomonas aeruginosa

Front 7

Label each thioglycollate tube to indicate the oxygen requirements of the microbes growing in them and give a microorganism example of each.

Back 7

A) Obligate aerobes
Pseudomonas aeruginosa
B) Obligate anaerobes
Clostridium botulinum
C.) Facultative anaerobes
Escherichia Coli
D.) Aerotolerant anaerobes
Propionibacterium acnes

Front 8

Define microaerophile and give an example.

Back 8

Prefers lower than atmospheric oxygen level.
Campylobacter jejuni

Front 9

How does salt and sugar effect osmotic pressure?

Back 9

Salt and sugar draws water out of the interior of the cells.

Front 10

Give an example of a halophile.

Back 10

Staphylococcus aureus

Front 11

What is a pure culture?

Back 11

one organism
colony from one cell

Front 12

What is the streak plate method?

Back 12

The most commonly used for of isolation in which a sterile loop is used to inoculate an agar plate using a serious of streaks.

Front 13

What is the pour plate method?

Back 13

The initial sample is diluted with a serous of transfers and the final dilutions are mixed with warm agar.

Front 14

Define culture media.

Back 14

liquid or gel designed to support the growth of microorganisms.

Front 15

What is defined media?

Back 15

synthetic medium in which the exact chemical composition is known.

Front 16

Define complex media.

Back 16

contains nutrients released by the partial digestion of yeast, beef, soy, or proteins such as casein from milk. The exact composition is unknown because the digestion releases byproducts.

Front 17

Define differential media

Back 17

the media helps to differentiate the organisms on the agar plate

Front 18

Selective media

Back 18

Either favors or inhibits the growth of selected microorganisms

Front 19

Enrichment media

Back 19

enriched in order to grow less dominant species

Front 20

What are the methods of preserving cultures?

Back 20

Refrigeration
deep-freezing (-50 to -95C)
Lyophilization (freeze-drying)

Front 21

What are reference cultures and who makes them?

Back 21

cultures created for lab use. ATCC: American Type Culture Collection

Front 22

define catabolism

Back 22

breakdown or release of energy (exergonic)

Front 23

Define anabolism

Back 23

uses energy to build up molecules. (endergonic)

Front 24

Define Oxidation and Reduction

Back 24

Oxidation is loss of e-
reduction is gain of e-

Front 25

define metabolism

Back 25

sum of all chemical processes carried out by living organisms

Front 26

NAD and FAD

Back 26

Derived from vitamins and serve as e- carriers

Front 27

What are enzymes?

Back 27

end with -ase
remain unchanged
increase rate of run
decrease activation energy

Front 28

factors that effect rxn rate

Back 28

pH
temperature
substrate concentration

Front 29

What is a competitive inhibitor?

Back 29

Occurs when alternate substrate has similar composition to the usual substrate.

Front 30

What is allosteric inhibition?

Back 30

When an enzyme has a secondary active site that binds a substrate thereby altering the configuration and inhibiting the active site.

Front 31

What is feedback inhibition?

Back 31

Regulation of enzymatic pathway in which the product of the pathway acts as an allosteric inhibitor.

Front 32

What are the steps of aerobic respiration?

Back 32

pyruvate oxidation
the Krebs cycle
Oxidative phosphorylation

Forms 36 ATP per glucose molecule

Front 33

What is the starting molecule of glycolysis?

Back 33

Glucose

Front 34

What is the final end molecule of glycolysis?

Back 34

pyruvic acid

Front 35

What is the total direct, total indirect and the net ATP production in glycolysis?

Back 35

Glycolysis uses 2 ATP
Total direct is 4 ATP
Total Indirect is 6 ATP
Net Total is 2 ATP

Front 36

How many ATP are made from each NAD+?

Back 36

3 ATP indirectly made from NAD+

Front 37

What is the net output from glycolysis. List all molecules not just ATP

Back 37

2 ATP
2 NADH
2 Pyruvate

Front 38

What is the net output from glycolysis. List all molecules not just ATP

Back 38

2 ATP
2 NADH
2 Pyruvate

Front 39

What are the net products of the synthesis of acetyl-CoA from one molecule of glucose from glycolysis.

Back 39

2 acetyl-CoA
2 CO2
2 NADH

Front 40

Where does the Krebs cycle occur in prokaryotes? Eukaryotes?

Back 40

Cytosol of prokaryotes
Mitochondria of eukaryotes

Front 41

What is the net output of the Krebs cycle per each molecule of glucose that enters glycolysis?

Back 41

2 molecules of ATP
2 molecules of FADH2
6 molecules of NADH
4 molecules of CO2

Front 42

What is the difference between aerobic respiration and anaerobic respiration.

Back 42

Aerobic respiration uses oxygen as final electron accepter.
Anaerobic respiration uses molecule other than oxygen as final electron acceptor.

Front 43

How many ATP are formed from the electron transport chain (ETC) from one molecule of glucose entering glycolysis.

Back 43

34 ATP

Front 44

What is the starting product and the end product of the Krebs cycle?

Back 44

Starting product = Acetyl-CoA
End Product = Oxaloacetic acid

Front 45

How many NADH and FADH2 are formed during the Krebs Cycle from one glucose molecule?

Back 45

6 NADH
2 FADH2

Front 46

How many NADH are formed from one molecule of glucose from the production of acetyl-CoA from pyruvate?

Back 46

2 NADH

Front 47

What are two alternative pathways to glycolysis?

Back 47

Pentose phosphate pathway
Entner-Doudoroff pathway

Front 48

What is the purpose of alternative pathways to glycolysis?

Back 48

Produces different metabolites needed in anabolic pathways and reduces coenzymes, however it produces fewer molecules of ATP that glycolysis.

Front 49

The Pentose Phosphate Pathway

Back 49

The Pentose Phosphate Pathway.

Front 50

The Entner-Doudoroff Pathway.

Back 50

The Entner-Doudoroff Pathway.

Front 51

Why does fermentation occur?

Back 51

Sometimes cells cannot completely oxidize glucose by cellular respiration. An organic molecule within the cell acts as final electron acceptor.

Front 52

What determines the fermentation products an organism produces

Back 52

Enzymes and available substrates.

Front 53

Give an example of an organism that uses the Entner-Doudoroff pathway

Back 53

Pseudomonas aeruginosa
(strict aerobe)

Front 54

Give an example of an organism that uses the pentose phosphate pathway.

Back 54

Escherichia coli

Front 55

Give an example of an organism that uses the fermentation pathway.

Back 55

Saccharomyces cerevisiae

Front 56

Destruction of all microorganisms in or on an object

Back 56

sterilization

Front 57

Destruction of most microorganisms on nonliving tissue. Kills everything but acid fast and endospores.

Back 57

disinfection

Front 58

Reduction in the number of microorganisms and viruses, particularly potential pathogens, on living tissue (sanitize to disinfect)

Back 58

antiseptic

Front 59

lowers the number of pathogenic microbes to meet public health standards

Back 59

sanitization

Front 60

Bacteriocidal vs bacteriostatic

Back 60

bacteriocidal kills the microbe
bacteriostatic inhibits growth

Front 61

What are the factors that affect microbial death rate?

Back 61

1.) Number of organisms
2.) Species and life cycle (endospore and acid fast)
3.) agent concentration
4.) exposure time
5.) environmental (pH, temp, media)

Front 62

The relative susceptibility of microbes to antimicrobial agents

Back 62

Fig 9.2

Front 63

what are the conditions for autoclaving?

Back 63

15 min at 121C and 15 psi

Front 64

What qualities does the ideal disinfectant possess?

Back 64

1.) Fast acting
2.) Effective on all microbes w/o destroying tissue
3.) penetrates material w/o damaging or discoloring
4.) easy to prepare and stable
5.) cheap and easy to obtain
6.) no odor

Front 65

Study table 9.5

Front 66

Study table 9.5

Front 67

Study table 9.5

Front 68

Study table 9.5

Back 68

Study table 9.5

Front 69

Describe replication.

Back 69

Replication is the process of duplicating the cell's genome. It begins at the origin and terminates at the origin or the end of a linear DNA molecule

Front 70

Describe Transcription.

Back 70

Transcription is the process of RNA synthesis. It begins at the promotor and terminates at the terminator.

Front 71

Describe translation.

Back 71

Translation is the process of polypeptide synthesis. It begins at the AUG start codon and terminates at the UAA, UAG, or UGA stop codons.

Front 72

The Structure of Nucleic Acids

Front 73

The Structure of Nucleic Acids

Back 73

A:T and G:C in DNA
A:U and G:C in RNA
A:T, A:U has 2 H bonds
G:C has 3 H Bons

Front 74

Describe the process of DNA replication.

Back 74

a.) initial process-DNA unzips and forms replication fork
b.) Synthesis of leading strand- continuous synthesis occurs from 5' to 3'
c.) Synthesis of Lagging strand- discontinuous synthesis of the lagging strand which moves away from replication fork

Front 75

How does DNA replication differ in prokaryotes?

Back 75

DNA replication is bidirectional meaning that replication starts at the origin and proceeds in both directions.

Front 76

How can a single prokaryotic mRNA cod for several polypeptides?

Back 76

This figure shows how a single mRNA molecule has transcripts of three genes encoding three polypeptides.

Front 77

What are the coding and non coding regions of RNA called?

Back 77

The coding regions are called Exons and the non-coding regions which are removed are called Introns.

Front 78

What does transcription occur in prokaryotes and eukaryotes?

Back 78

Prokaryotes - cytoplasm
Eukaryotes - nucleus

Front 79

What are the types of RNA?

Back 79

1.) messenger (mRNA)
2.) ribosomal (rRNA) binding site for tRNA
3.) transfer (tRNA) transfers AA from cytoplasm to ribosomes for protein synthesis. Anticodon to mRNA codons.

Front 80

What is the composition of eukaryotic and prokaryotic ribosomes?

Back 80

Eukaryotes have have an 80s ribosome composed of 60S and 40S subunits
Prokaryotes have an 70S ribosome composed of 50S and 30S subunits

Front 81

What does the S stand for in 80S ribosome?

Back 81

Svedburg unit- sedimentation coefficients

Front 82

What is the end of the tRNA complimentary to the mRNA called?

Back 82

Anticodon

Front 83

How does initiation of translation occur?

Back 83

1.) the small ribosomal subunit attaches to mRNA a t ribosome binding site near a start codon (AUG)
2.) the anticodon of tRNA (fMET) aligns with the start codon on the mRNA
3.) The large ribosomal subunit attaches to for an initiation complex.

Front 84

Which direction does the ribosome travel during translation.

Back 84

The ribosome moves from 5' end to 3' end using energy from GTP to move one codon at a time at about 15 AA/sec.

Front 85

What is the most common type of mutation?

Back 85

Point mutation- one base pair is affected
example: insertions, deletion, and substitutions

Front 86

What is a silent mutation?

Back 86

a point mutation that changes one base pair but does not change the amino acid sequence.

Front 87

What are silent, missense and nonsense mutations?

Back 87

1.) Silent- point mutation that does note effect AA sequence
2.) Missense - point mutation that changes AA sequence.
3.) Nonsense - point mutation that creates a stop codon and ends polypeptide synthesis

Front 88

What is a frameshift insertion and frameshift deletion?

Back 88

Frameshift insertion - insertion of an extra nucleotide thereby shifting the nucleotide triplets by one.
Frameshift deletion - nucleotide omission resulting in shift in opposite direction by one nucleotide.