Bio Exam 3 Study Cards

Front 1

Nucleoid

Back 1

a dense region of DNA in a prokaryotic cell

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lag phase

Back 2

the low part on graph

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log phase

Back 3

ex. growth stage

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stationary phase

Back 4

the top part of the graph

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interphase

Back 5

the time when the cell is not dividing. when metabolic activity is high, chromosomes and organelles are duplicated and cell size may increase.

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cytokinesis

Back 6

the ivision of the cytoplasm to form two separate daughter cells immediately after mitosis, meiosis I, or meiosis II

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gap 1 phase

Back 7

the first gap or growth phase of the cell where a portionof interphase after DNA synthesis occurs

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G2 phase

Back 8

The second gap phase where the portoin of interphase after DNA synthesis occurs

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S phase

Back 9

the synthesis phse of the cell cycles the porion of interphase during which DNA is replicated.

Front 10

kinetochore

Back 10

a structure of protens attached to the centromere that links each sister chromatid to th metotic spindle

Front 11

Aster

Back 11

a radial array of short mircrotublles that extends from each centrosome towards the plasma membrand in an animal cell undergoing mitosis

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centriole

Back 12

a structure in the centrosome of an animal cll composed of a cylinder of microtubule triplets arranged in a 9+0 pattern. a centrosome has a pair of centrioles

Front 13

centrosome

Back 13

structue present in the cytoplasm of animal cells important durning cell division; functions as a microtubule-organizing center. a centrosome has two centrioles

Front 14

prophase

Back 14

the first stage of mitosis, in which the chromatin condenses, the necleolus disappears, but the nucleus remains intact.

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metaphase

Back 15

the third stage of mitosis in which the spindle is complete and the chromosomes, attactched to microtubles at their kinetochores are all aligned at teh metaphase plate

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telephase

Back 16

the fifth and final stage of mitosis in which datughe nuclei are forming and cytokinesis has typically begun.

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anaphase

Back 17

the fourth stage of mitosis in which the chromatids of each chromosome have separated and teh daughet chromosomes are moving to the poles of the cell

Front 18

G1 checkpoint

Back 18

cell size, nutrients, DNA damage, growth factors

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G2 checkpoint

Back 19

cell size, DNA damage

Front 20

M checkpoint

Back 20

chromosomal attachment to spindle

Front 21

cyclin

Back 21

a cellular protein that occurs in a cyclically fluctuating concentratoin and that plays an important role in regulating hte cell cycle

Front 22

cyclin dependent kinase

Back 22

a proteinkinase that is ctive only when attached to a particular cyclin

Front 23

MPF (Mitosis-promotion-factor)

Back 23

a protein comples required for a cell to progess from late interphase to mitosis. teh active form consists of cyclin and a protein kinase

Front 24

P27

Back 24

inhibits the cell cycle by making the cyclin/kinase complex inactive

Front 25

Benign tumor
Malignant tumor

Back 25

B- good
M- bad

Front 26

Density-dependent inhibition

Back 26

the phenomenon observoma anmal cells that causes tehm to stop dividing whne hey come into contact with another

Front 27

Anchorage independence

Back 27

the requirement that a cell must be attached to a substratum in order to divide

Front 28

Metastasis

Back 28

the spread of cancer cells to locations distant from their original site

Front 29

Ligand

Back 29

a molecule that binds specifically to another molecules usually a larger one

Front 30

Signal transduction

Back 30

the linkage of a mechanical, chemical, or electromagnetic stimulus to a specific cellular response

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Paracrine signal

Back 31

referring to a secreated molecue that acts on a neighboring cell

Front 32

Autocrine signal

Back 32

a secreated molecule that acts on the cell that secreated it

Front 33

Yeast a and alpha cells

Back 33

two different yeast cells so they can mate

Front 34

A and α peptides

Back 34

used as signals in yeast mating

Front 35

Small amines (epinephrine)

Back 35

for flight or fight response
Hydrophilic ligands need a plasma membrane receptor

Front 36

Hypothalamic peptides

Back 36

hormone for puberty
Hydrophilic ligands need a plasma membrane receptor

Front 37

Plant growth regulators (auxin, gibberellic acid)

Back 37

unique hormones
Hydrophilic ligands need a plasma membrane receptor

Front 38

Nitric oxide (NO)

Back 38

Lipid soluble ligands have receptor within the cell.

Front 39

Prostaglandin

Back 39

Lipid soluble ligands have receptor within the cell.

based on a fatty acid backbone

Front 40

G protein-couple receptor

Back 40

have three early steps of signal transduction.
1.After binding the ligand it can now bind a G protein.
2. The G protein is activated by a GDP exchange for a GTP.
3.The G protein-GTP complex then binds to some type of effector enzyme which then in turn is activated.
G protein-coupled receptors are the targets of many bacterial toxins, much misery and death.
e.g.cholera toxin causes an intestinal cell G protein to stay in the activated state (never hydrolyzing GTP) and thereby causing the cell to pump ions into the intestine.
Water follows by osmosis leading to dehydration and death.
Propose a simple treatment for the symptoms

Front 41

Tyrosine kinase receptor

Back 41

Protein tyrosine kinase receptors (e.g. for insulin and polypeptide growth factors) which bind the ligand and then become activated with a kinase function which acts directly on itself to become activated, and on other proteins that have tyrosines.
The activated receptor does not have intermediate molecules (like G proteins).

Front 42

Ion channel receptor

Back 42

e.g. for acetylcholine) which bind the ligand and then increase or decrease a specific ion entry (e.g. sodium entry) which directly acts on the cell by changing electrostatic potential across the membrane.
The membrane potential is changed thereby changing other membrane protein’s function.
Other ion channels (voltage-gated ion channels) respond to electrical signals generated by the first ion channel.

Front 43

Intracellular receptor

Back 43

are within the cytoplasm and become activated transcription factors able to directly affect transcription.

Front 44

G proteins

Back 44

activates Adenylyl cyclase

Front 45

Cyclic AMP

Back 45

AMP:Made from ATP by the enzyme adenylyl cyclase which is activated by an activated G protein
cAMP then acts by activating protein kinase A the first of a series of kinases (a kinase cascade)

Front 46

Adenylyl cyclase

Back 46

activated by G proteins which activates ATP to turn into cAMP

Front 47

IP3 (inositol triphosphate)
DAG (diacylglycerol)

Back 47

second messengers.
These are made from membrane phospholipids by the enzyme phospholipase C.
They then act to open up calcium channels in ER.

Front 48

Scaffolding protein

Back 48

To improve signal transduction efficiencies the components of the pathways may be held together in a multiplex by a scaffolding protein

Front 49

Epidermal growth factor

Back 49

is a protein paracrine ligand which binds to the EGF receptor.

Front 50

Mitogen

Back 50

moves to the nucleus and alters regulatory transcription factors to increase gene transcription for cell division genes.

Front 51

Ras protein

Back 51

an G protein which is activated by EGF

Front 52

Transforming factor

Back 52

is genetic information

Front 53

Streptococcus smooth and rough phenotype

Back 53

smooth=virus
rough=not virus

Front 54

A. Hershey and M. Chase

Back 54

used a bacteriophage (bacterial virus) of only a protein coat surrounding a DNA genome

Front 55

T2 bacteriophage

Back 55

attaches to E. coli and then 20 minutes later the cell lyses releases 200 newly formed T2.

Front 56

Conservative, semi-conservative, dispersive replication

Back 56

separate
like normal
patches

Front 57

Ultracentrifugation density gradient

Back 57

used to separate DNA based on density

Front 58

Initiator

Back 58

binds at origin of replication

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Helicase

Back 59

unwinds parental double helix at replicaition forks

Front 60

Topoisomerase

Back 60

relieves overwinding strain ahead of replicaiton forks by breaking, swiveling and rejoining DNA strands

Front 61

Single-strand binding protein

Back 61

binds to and stabilaizes single stranded DNA until it can e used as a template

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DNA polymerase III and I

Back 62

pol III synthesizes new DNA strand by covalently addingnucleotides to the 3 prime end of a pre-existiing DNA strand or RNA primer

pol I removes RNA nuecleotides of primer from 5 prime end and replaces them with DNA nucleotides

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Sliding clamp protein

Back 63

encircles the newdouble ehliz like a doghnut and moves pol III along teh DNA template strand

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Ligase

Back 64

joins 3 prime end of DNA that replaces primer to rest o leading strand and joings Okazaki fragments of lagging strand

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Okazaki fragments

Back 65

DNA must be made in short sections of DNA plus the primer

Front 66

Telomere

Back 66

end replication.

Front 67

Telomerase

Back 67

a special DNA polymerase

Front 68

Mismatch repair

Back 68

distorts the helix but is recognized by DNA polymerase I which proofreads the helix and breaks the phosphodiester bonds in a 3’to 5’direction to take out the mismatched base.

Front 69

Xeroderma pigmentosa

Back 69

is a genetic disease preventing excision repair.

Front 70

Thymine dimer

Back 70

ultraviolet light causes a covalent bond to form between adjacent thymine bases on the same strand

repared post-replication

Front 71

Nucleotide excision repair

Back 71

involves nucleases to cut out a sequence and DNA polymerase and ligase to repair the nick.

Front 72

mRNA

Back 72

the RNA intermediate between genes and proteins

Front 73

RNA polymerase

Back 73

which pries the DNA strands apart and hooks together the RNA nucleotides

Front 74

promoter

Back 74

The DNA sequence where RNA polymerase attaches

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terminator

Back 75

the sequence signaling the end of transcription

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transcription unit

Back 76

The stretch of DNA that is transcribed

Front 77

initiation

Back 77

the first part of transcription

Front 78

introns

Back 78

noncoding regions are called intervening sequences

Front 79

tRNA

Back 79

cell translates an mRNA message into protein with the help of an adaptor