Cell Biology -- Ch1

Front 1

how is cell and molecular biology "reductionist"

Back 1

it is based on the view that knowledge of the parts of the whole can explain the character of the whole

Front 2

To whom is the discovery of cells generally credited to?

Back 2

Robert Hooke

Front 3

Who began constructing high quality, simple microscopes; first to view water and saw "animalcules"; & first to describe bacteria?

Back 3

Anton van Leeuwenhoek
Late 1600's

Front 4

Which German botonist, in 1838, concluded that tissues were made of cells and a plant derived from a single cell?

Back 4

Matthias Schleiden

Front 5

Which German zoologist, and colleague of M. Schleiden, proposed 2 of the 3 tenets of the cell theory?

Back 5

Theodor Schwann

Front 6

What two tenets of the cell theory did Theodor Schwann propose?

Back 6

1. all organisms are composed of one or more cells
2. the cell is the structural unit of life

Front 7

Which German pathologist, in 1855, proposed the third tenet of the cell theory?

Back 7

Rudolf Virchow

Front 8

What was the third tenet of the cell theory proposed by Rudolf Virchow?

Back 8

Cells can arise only by division from a preexisting cell -- religious challenge

Front 9

cells

Back 9

life is the most basic property of cells, and cells are the smallest unit to exhibit this property

Front 10

Who was the first to culture human cells?

Back 10

George Gey of Johns Hopkins in 1951

Front 11

What cells did George Gey culture, what did he name them, how long were they cultured?

Back 11

Cultured -- malignant tumor
Named them -- HeLa cells (from donor Henrietta Lacks)
Culture -- continues today

Front 12

Why are cells cultured outside the body and what is this procedure referred to?

Back 12

1. simpler to study than cells in the body
2. in vitro (process or reaction occuring in an artificial environment)

Front 13

Scanning electron microscope

Back 13

examines detailed surfaces of the cells

Front 14

transmission electron microscope

Back 14

reveals detailed internal structures of the cell

Front 15

What are the 9 basic properties of cells?

Back 15

1. highly complex & organized
2. possess genetic program & means to use it
3. capable of producing more of themselves
4. acquire and utilize energy
5. carry out a variety of chemical reactions
6. engage in mechanical stuff
7. able to respond to stimuli
8. capable of self-regulation
9. evolve

Front 16

what do more complex structures require?

Back 16

1. > number of parts in their propper place
2. > regulation/control to maintain system
3. < tolerance for error

Front 17

What is the error rate of DNA duplication?

Back 17

< 1 mistake every 10 million nucleotides -- most of these quickly corrected

Front 18

what consistancy can be found across a type of cell?

Back 18

1. cell apperance -- particular shape and location of organelle
2. organelle -- consistent composition of macromolecules arranged in a predictable pattern

Front 19

what are some basic processes which are similar in all living organisms?

Back 19

1. synthesis of proteins
2. construction of membrane
3. conservation of chemical energy

Front 20

describe gentic material relative to organism construction

Back 20

organisms are built from information encoded in genes which are packaged into a set of chromosomes and found in the cell nucleus

Front 21

what 3 major activities are genes involved in?

Back 21

1. blueprints for constructing cellular structures
2. directions for running cellular activities
3. program for making more of themselves

Front 22

what aspect of genes, at the level of molecular structure, allows for the biological basis of evolution?

Back 22

molecular structure of genes allow for changes in genetic information (mutations)

Front 23

Discuss cells ability to produce more of themselves

Back 23

1. reproduce by division
2. somatic = diploid - diploid x2
3. gamete = diploid - haploid x4
*sperm x4; egg x1 + 3 polar bodies

Front 24

why do cells acquire and utilize energy?

Back 24

necessary to maintain complexity and organization -- prevent natural gravitation toward increased entropy (s)

Front 25

where does virtually all energy for life on earth come from?

Back 25

electromagnetic radiation from the sun

Front 26

how does sunlight become energy?

Back 26

light captured by light-absorbing pigments in photosynthetic cells & converted via photosynthesis into chemical energy stored as sucrose or starch

Front 27

in what form is energy primarily packaged / delivered to humans?

Back 27

glucose

Front 28

what organ releases glucose into the bloodstream?

Back 28

liver

Front 29

in what form is glucose stored in humans?

Back 29

glycogen

Front 30

what form of energy is utilized to power the energy-requiring functions of the cell?

Back 30

ATP (adenosine triphosphate)

Front 31

why do the same chemical reactions in the body occur more rapidly than they would outside the body?

Back 31

enzymes -- molecules that greatly increase the rate of a chemical reaction, without being used up

Front 32

the sum total of the chemical reactions in a cell represents that cells _______.

Back 32

metabolism

Front 33

give 3 examples of mechanical activities in cells

Back 33

1. transfer of material from place to place
2. assembly / disassembly of structures
3. movement of entire cell

Front 34

give an example of a type of protein employed by cells to carry out mechanical activities

Back 34

motor proteins -- change shape and initiate mechanical action

Front 35

how do cells repond to stimuli?

Back 35

single cell -- whole cell move
multicellular -- receptors

Front 36

what are cell receptors sensitive to?

Back 36

1. hormones
2. growth factors
3. extracellular materials
4. substances on the surface of other cells

Front 37

give three examples of cellular response, via receptor excitation or inhibition

Back 37

1. alter metabolic activities
2. cell moves
3. apoptosis

Front 38

the importance of a cell's regulatory mechanisms becomes most evident when they ____.

Back 38

break down....consider failure to correct DNA error

Front 39

what are the two fundamentally different classes of cells?

Back 39

1. prokaryotic
2. eukaryotic

Front 40

what distinguishes prokaryotic cells from eukaryotic cells?

Back 40

size & type of organelles

Front 41

what does prokaryotic include?

Back 41

bacteria

Front 42

what does eukaryotic include?

Back 42

1. protists
2. fungi
3. plants
4. animals

Front 43

prokaryotic life began?

Back 43

2.7 bya

Front 44

simple eukaryotic life began?

Back 44

1.6 bya

Front 45

complex multicellular animals began?

Back 45

600 mya

Front 46

similarities and differences between prokaryotes and eukaryotes

Back 46

see table 1.1 pp9

Front 47

the distinction between prokaryotic & eukaryotic cells is based on ___ and not ____.

Back 47

structural complexity; phylogenetic relationship

Front 48

what 2 domains are prokaryotes divided into?

Back 48

1. archaea (archaebacteria)
2. bacteria (eubacteria)

Front 49

which prokaryotic domain is more closely related to eukaryotes, than to the other prokaryote domain?

Back 49

archaea

Front 50

species which can live in extreamly inhospitable environments are often referred to as "___," and are part of which major cell type and domain?

Back 50

extremophiles; prokaryotes; archaea

Front 51

methanogens

Back 51

capable of convertine CO2 and H2 gases into methane (CH4) gas

Front 52

halophils

Back 52

live in extreamly salty environment

Front 53

acidophiles

Back 53

acid loving prokaryotes; pH as low as 0

Front 54

thermophils

Back 54

live at very high temps

Front 55

thermophils & autoclave

Back 55

thermophil > hyperthermophils > strain 121. grow in H2o heated 121C (temp used to sterilize via autoclave)

Front 56

prokaryotes > bacteria include ___ cells

Back 56

smallest known cells

Front 57

what is the only known prokaryote to lack a cell wall & conatain a genome w/ fewer 500 genes?

Back 57

prokaryote > bacteria > mycoplasma (0.2um diameter)

Front 58

what are the most complex prokaryotes?

Back 58

cyanobacteria

Front 59

what are 2 characteristics of cyanobacteria?

Back 59

1.photosynthesis by splitting water molecules which release molecular oxygen
2. nitrogen fixation, the conversion of nitrogen gas into reduced forms of nitrogen that can be used by cells in the synthesis of nitrogen containing organic compounds
*can survive on the barest of resources

Front 60

what % prokaryotes have been cultured?

Back 60

<1/10 of 1%. 5,000/millions

Front 61

what method can we utilize to better understand the biological diversity of prokaryotes that might be difficult to isolate and view?

Back 61

metagenomics
(RNA sequence analysis)

Front 62

RNA sequencing suggests there are how many different species of bacteria living in the subgingival cavities of our mouth?

Back 62

415

Front 63

90% of prokaryotes are thought to live where?

Back 63

subsurface sediments well beneath the oceans and upper soil layers

Front 64

In many regards the most complex eukaryotic cells are?
why?

Back 64

-unicellular protists
-all the machinery required for the complex activities in which the organism engages is housed within the confines of a single cell

Front 65

multicellular cells become specialized by a process called ____?

Back 65

differentiation

Front 66

the pathway of differentiation followed by each embryonic cell depends primarily on ____?

Back 66

signals it receives from the surrounding environment; these signals in turn depend on the position of that cell within the embryo.

Front 67

why do we use model organsims?

Back 67

1. can't really experiment on humans
2. models have unique valuable characteristics
3. same people using same models = increased progress

Front 68

list six model organisms

Back 68

1. Escherichia coli -- digestive tract bacterium
2. Saccharomyces cerevisiae -- baker/brewer yease
3. Arabidopsis thaliana -- mustard plant
4. Caenorhabditis elegans -- microscopic nematode
5. Drosophila melanogaster -- fruit fly
6. Mus musculus -- common house mouse

Front 69

E.coli

Back 69

1. prokaryote
2. rod shaped bacterium
3. lives in digestive tract of humans/other mammals
4. much knowledgy of molecular biology of cell: mechanisms of replication; transcription; and translation was discovered with this model
5. can be grown haploid

Front 70

S. cerevisiae

Back 70

1. lest complex of eukaryotes commonly studies (single cell like E.coli)
2. brewers / bakers yeast
3. a number of proteins homologous to proteins in human cells
4. small genome encoding 6200 proteins
5. can be grown in haploid state
6. can be grown aerobic or anaerobic
7. Ideal for the identification of genes through the use of mutants

Front 71

A. thaliana

Back 71

1. mustard plant
2. small "plant" genome of 120 million base pairs
3. rapid generation time
4. large seed production
5. height of only a few inches
6. plant - where world gets food from
7. plant > complicated than animals
8. entire genome mapped

Front 72

C. elegans

Back 72

1. microscopic nematode
2. a defined number of cells (1000)
3. each cell develops according to a precise pattern of cell division
4. easily cultured
5. transparent body wall
6. short generation time
*micrograph showing larval nervous system, labeled with green fluorescent protein (GFP), resulted in 2002 nobel prize
7. first complicated organism to have complete genome sequenced

Front 73

D. melanogaster

Back 73

1. fruit fly
2. small/complex eukaryote
3. favored for animal genetic study 100 years
4. well suited for: study of molecular biology development; neurolgical basis of simple bahavior
5. certain larval cells have giant chromosomes, whose individual genes can be identified for the study of evolution and gene expression
6. regular segmented body plan

Front 74

M. musculus

Back 74

1. common house mouse
2. easily kept/bred
3. thousands of different genetic strains have been developed
4. many are stored as frozen embryos
5. "knockout mice" (eliminate gene/can't do this in other organisms

Front 75

zebrafish

Back 75

1. newer model organism
2. transparent larva

Front 76

hematopoietic stem cells (HSCs)

Back 76

blood-forming cells in the bone marrow; normally responsible for replacing millions of red and white blood cells that age and die every minute

Front 77

stem cells

Back 77

undifferentiated cells that are capable of 1)self-renewal 2) differentiation into two or more mature types

Front 78

embryonic stem (ES) cells

Back 78

cells isolated from very young mammalian embryos, which can give rise to all various structures of mammalian fetus (pluripotent)

Front 79

teratoma

Back 79

tumors which can result from undifferentiated ES cells -- can include hair/teeth

Front 80

parthenotes

Back 80

chemically activated oocytes (in absence of sperm), not capable of developing to term, but capable of producing pluripotent ES cells

Front 81

size: paramecium; frog egg

Back 81

1.5 mm long; 2.5mm diameter

Front 82

size:
epithelial cell

Back 82

30 um height

Front 83

size:
lymphocyte

Back 83

12 um diameter

Front 84

size:
chloroplast

Back 84

8 um diameter

Front 85

size:
mitochondrion

Back 85

2 um long

Front 86

size:
bacterium

Back 86

1 um long

Front 87

size:
cilium

Back 87

250 nm diameter

Front 88

size:
HIV

Back 88

100 nm diameter

Front 89

size:
Ribosome

Back 89

30 nm diameter

Front 90

size:
actin filament

Back 90

6 nm diameter

Front 91

size:
lipid bilayer

Back 91

5 nm wide

Front 92

size:
myoglobin

Back 92

4.5 nm diameter

Front 93

size:
DNA molecule

Back 93

2 nm wide

Front 94

size:
water molecule

Back 94

4 A diameter

Front 95

size:
hydrogen atom

Back 95

1 A diameter

Front 96

size:
in general macromolecules such as ribosomes, microtubules, microfilaments

Back 96

between 5-25 nm

Front 97

size:
nuclei

Back 97

5-10 um in diameter

Front 98

size:
prokayotic cells range in lenght

Back 98

1-5 um

Front 99

size:
eukaryotic cells range in length

Back 99

10-30 um

Front 100

List 3 reasons why cells are small

Back 100

1. most eukaryotic cells = single nucleus = 2 copy genes = limited templates for production mRNA
2. increase in cell size = decrease in surface area/volume ratio. certain point surface not sufficient to move materials needed
3. cells depend on diffusion. cell too large = too long for substances to diffuse

Front 101

who filterd out smallest known bacterium, discovering filtrate was still infective?

Back 101

Dmitri Ivanovsky

Front 102

infectious material discovered by Dmitri Ivanovsky became knows as ___?

Back 102

viruses

Front 103

Wendell Stanley

Back 103

thought virus responsible for tobacco mosaic disease was a protein -- was a rod shaped particle consisting of single RNA molecule surrounded by helical shell composed of protein subunits

Front 104

list some examples of human disease, which viruses are responsible for

Back 104

1. AIDS
2. polio
3. influenza
4. cold sores
5. measles
6. few types of cancer

Front 105

what is a common property shared by all viruses?

Back 105

obligatory intracellular parasites (cannot reproduce unless present inside a host cell)

Front 106

what is the term for a virus outside a cell?

Back 106

virion

Front 107

what type of genetic material do viruses contain?

Back 107

1. RNA or DNA
2. single stranded or double stranded
3. can contain 3-100's of genes

Front 108

what surrounds the genetic material of a virion?

Back 108

capsid (a protein capsule), constructed from a specific number of subunits

Front 109

Are virions organisms? explain

Back 109

no. macromolecule aggregates of inanimate particles.
--unable to reproduce, metabolize, or carry on any other activities of life

Front 110

many viruses have capsid whose subunits are organized into ____?

Back 110

polyhedron (structure having planar faces)

Front 111

what is common polyhedral shape?

Back 111

20-sided icosahedron (ex:adenoviurs; resp infections)

Front 112

in many animal viruses, including HIV, how is the capsid modified?

Back 112

surrounded by a lipid-containing outer envelope derived from the modified plasma membrane of the host as the virus buds from the host cell surface

Front 113

bacteriophages

Back 113

1. bacterial viruses
2. among most complex viurses

Front 114

T bacteriophages

Back 114

1. used in key experiments that revealed structure and properties of genetic material
2. polyhedral head containing DNA
3. cylindrical stalk through which the DNA in injected into bacterial cell
4. tail fibers
**resembles landing module for moon

Front 115

how do viruses attach to host cells?

Back 115

viral surface proteins are able to bind to a particular surface component of its host cell

Front 116

specificity

Back 116

refers to the types of cells which can be acted upon

Front 117

host range

Back 117

refers to the range of organs or species able to be infected

Front 118

how is it possible to study viruses under a light microscope?

Back 118

each virus particle can first be tagged with a single fluorescent molecule, and followed like brightly lit vehicles

Front 119

what are the two basic types of viral infections?

Back 119

1. lytic infection -- virus arrests host's normal synthetic activities, and redirects cell to use its available material to manufacture viral nucleic acids & proteins which assemble into new virons. cell ruptures and new generation of viral cells infect neighboring cells
2. integrated provirus -- does not lead to host cell death. inserts its DNA into host DNA (provirus).

Front 120

provirus can have different effect upon host depending on type of virus & host. Give 3 examples

Back 120

1. Bacterial cells containing provirus behave normally until exposed to stimulus -- then activation dormant viral DNA, cell lyse, viral progeny
2. some animal cells with proviurs -- viral progeny buds leaving the host cell alive for a period (ex: HIV)
3. some animal cells containing provirus loose control over own growth and division and become malignant

Front 121

what are 3 benefits of viruses?

Back 121

1. b/c they mimic activities of host genes, used to study DNA replication & gene expression in their more complex host
2. used as means to introduce foreign genes into human cells (future gene therapy)
3. insect & bacteria-killing viruses might play role against pests and bacterial pathogens (consider antibiotic resistance)

Front 122

T.O. Diener

Back 122

reported in 1971, potato spindle-tuber disease, caused by infectious agent consisting of small circular RNA, totally lacking protein coat

Front 123

viroids (x6)

Back 123

-smaller than viruses
1. RNA 240-600 nucleotides
2. 1/10 size of smaller viruses
3. no evidence codes for proteins
4. utilizes hosts RNA polymerase 2
5. cause disease by interfering with cells normal path of gene expression
6. serious effect on crops

Front 124

what term describes the theory of the origin of eukaryotic cells

Back 124

endosymbiont theory

Front 125

explain endosymbiont theory

Back 125

1. anaerobic, heterotrophic, prokaryote ingested aerobic prokayote
2. ingested prokaryote become mitochondria -- ingesting prokaryote became aerobic
3. plasma membrane invagination of larger prokayote
4. invagination formed membranes that became nuclear envelope / organelles
5. animal cells formed (OR) ingested photosynthetic cyanobacterium and became agal & plant cells

Front 126

what are the 3 basic cell lines and which 2 are closer together

Back 126

1. bacteria, archaea, & eucarya
2. archaea are closer to eukarya than they are to bacteria, despite the fact that they lack a nucleus (based on nucleotide sequence similarities)

Front 127

anaerobic

Back 127

able to derive energy from food without molecular oxygen 02

Front 128

heterotrophic

Back 128

must obtain preformed organic material from their environment

Front 129

what are three methods used to determine the evolutionary relationship between organisms?

Back 129

1. a comparison of nucleotide sequences
2. comparison of biochemical pathways
3. comparison of structural features

Front 130

T or F:
viruses have been successfully grown in pure cultures in test tubes

Back 130

False

Front 131

If you were to study the sequences of nucleic acids in a variety of viruses and viral hosts, you would probably find more similarities:

Back 131

between viruses and their hosts than among different viruses

Front 132

Bone marrow transplants are to blood transfusions as organ engineering is to ? .

Back 132

organ transplant.

Front 133

The most powerful tool for determining evolutionary relationships among cell types is

Back 133

the study of nucleic acid sequences in genomes

Front 134

what are some advantages of using cultured cells to explore the answer to a question of cell structure or function?

Back 134

1.ability to study a single cell type
2.ease of obtaining large numbers of cells
3.ability to minimize number of unknown variables by using carefully controlled in vitro conditions

Front 135

what would be the advantage of using an organism to study cell structure or function?

Back 135

more meaningful in understanding the role of the process in the overall activity of the organism. (ex: study glucose transport across the plasma membrane of cultured liver cells in response to insulin)

Front 136

what is the advantage of the microvilli on intestinal epithelial cells

Back 136

They greatly increase the surface area/volume ratio of the cell, allowing much greater exchange between the cell and the lumen of the intestine (folding = surface area)

Front 137

was there an advantage to culturing "malignant" cells

Back 137

1. Cancer cells grow in a much less controlled manner than normal cells, which is why they continue to proliferate in the body
2. fewer requirements for growth

Front 138

though viruses are not "living," what features would you consider if making a case that they were

Back 138

1.contain genetic material
2.capable of producing more (though inside host)
3.contain complex biological macromolecules
4.they evolve

Front 139

why the name "cell biology?"

Back 139

1. study of life at the cellular level
2. study of single cell organism
3. study of cells at molecular level

Front 140

what is the focus of cell biology at the cellular level

Back 140

plasma membrane; cell communication

Front 141

what is the focus of cell biology at the molecular level

Back 141

molecules -- DNA, RNA, proteins, amino acids, nucleotides

Front 142

what is the challenge of the "reductionist" concept

Back 142

overlooks synergystic / emergent properties -- might not be able to explain how something works collectively by examining individual parts

Front 143

what new name has been proposed for HeLa cells

Back 143

Helacyton gartleri

Front 144

List 2 characteristic of the HeLa cells

Back 144

1. non-native # chromosomes
2. ecological niche

Front 145

higher order complexity referred to as "layers within layers," and is seen mostly in __

Back 145

metazoans (multicellular organisms)

Front 146

list 5 marks of higher complexity as seen in metazoans

Back 146

1. specialization
2. division of labor
3. communication (facilitates #4)
4. co-ordination
5. similarity of structures between tissues

Front 147

who demonstrated cells are capable of self-regulation

Back 147

Hans Driesch, 1891. split sea urchin embryo & developmental pattern re-organized itself and two embryos arose

Front 148

list 3 reasons why cell processes might involve so many steps

Back 148

1. usual longer pathway provides multiple points of regulation & control
2. early evolution didn't have enzymes necessary to jump from step 1 to step "last"
3. intermediates might serve valuable regulatory functions in their own right

Front 149

how did the first cells arise

Back 149

we dont know

Front 150

list 2 theories of cell evolution and their associated personalities

Back 150

1. small gradual transitions; darwin
2. sudden giant transitions (punctuated equilibria); eldridge & gould

Front 151

prokaryote vs eukaryote...how was this defined

Back 151

1. differences; not on similarities as things are usually defined
2. lack of a nucleus (prokaryote)

Front 152

what was wrong with the early definition of prokaryote vs eukaryote

Back 152

1. says nothing about how the bacteria are related
2. it implies non-eukaryotes are monophyletic (need similarities, not just differences, to determine this)

Front 153

are there more differences or similarities between prokaryotes and eukaryotes

Back 153

more differences

Front 154

cyanobacteria

Back 154

1. most complex of the prokaryotes
2. capable of photosynthesis
3. probably caused the most catastrophic climate change on planet earth ever..generated 02
4. food gathering advantage over competitors
5. 02 killed of competitors

Front 155

what is the approximate time and cost required to sequence the genome of a microbe

Back 155

4.5 hours; $10,000

Front 156

what is the approximate time and cost to sequence the genome of higher vertibrates

Back 156

2-3 days; $50,000

Front 157

which type of stem cells are the most promising

Back 157

ES cells; most plasticity

Front 158

where is the greatest supply of adult stem cells

Back 158

bone marrow of large bones in the legs

Front 159

how do mitochondria contribute to the theory of endosymbiosis

Back 159

1. mitochondria have their own DNA
2. have double membrane (developed second membrane when engulfed)

Front 160

Carl Woese

Back 160

1. 1960's compared rRNA between organisms to determine relationship
2. third lineage, archaea, arose in addition to previous eukaryotic & prokaryotic

Front 161

what are the advantages of using rRNA sequence analysis to compare organisms

Back 161

1. all organisms have rRNA for protein synthesis
2. rRNA is very "conserved"

Front 162

who did Carl Woese argue with & what about

Back 162

1. C. Woese used reductionist approach to sort out archaea (molecules)(phylogenetics)
2. Ernst Mayr (Harvard) was opposed to this & classified according to morphology
3. Woese won !!!