Mcb: Exam 3

Front 1

Is regulation by degradation of proteins used by bacteria?

Back 1

Not much

Front 2

When is degredation of proteins used by bacteria?

Back 2

In degredation of special sigma factors when not needed

Front 3

How do prokaryotes regulate gene expression?

Back 3

Regulate expression of a gene for a protein; only express needed genes; repress not needed genes

Front 4

How do eukaryotes regulate gene expression?

Back 4

Regulate protein activity

Front 5

There are ___ sigma factors in E Coli:

Back 5

7

Front 6

There are ___ sigma factors in B subtilis:

Back 6

14

Front 7

Heat shock response is regulated by:

Back 7

sigma-32

Front 8

How does sporulation in B subtilis use sigma factors?

Back 8

It uses alternate sigma factors for each stage and compartment

Front 9

Nitrogen utilization uses what type of sigma factors?

Back 9

Alternate sigma factors plus other control

Front 10

Stringent response changes ____ of sigma factor?

Back 10

Specificity

Front 11

The stringent response signals what?

Back 11

The lack of AAs in a cell

Front 12

Stringent response is mediated by what?

Back 12

Special nucleotides synthesized by RelA

Front 13

RelA is associated with ___ ribosome subunit:

Back 13

50S

Front 14

RelA makes ____ and ____ when uncharged tRNA binds to ribosome:

Back 14

ppGpp and pppGpp

Front 15

What do ppGpp/pppGpp do?

Back 15

Down regulate treatment of rrn genes, tRNA operons and upregulate treatment of AA biosynthesis genes

Front 16

Negative regulation of transcription is carried out by what?

Back 16

DNA-binding proteins called repressors

Front 17

How do repressors work?

Back 17

Bind to special DNA sequences called operators and prevent transcription by RNAP; prevent either elongation or initiation of transcription

Front 18

What are co-repressors or inducers?

Back 18

Ligands that bind to repressors to to regulate repressor activity under different conditions

Front 19

Positive regulation of transcription is carried out by:

Back 19

DNA-binding proteins called activators

Front 20

Genes that are positively regulated are only transcribed when what?

Back 20

When acitvatorsbind to DNA and facilitate RNAP activity at promoters

Front 21

Activators act how?

Back 21

By helping RNAP directly or by helping other activators to bind at promoters

Front 22

Activators bind ligands. What do the ligands do?

Back 22

Regulate DNA-binding activity under different conditions

Front 23

How is the lac operon regulated in E coli?

Back 23

LacI gene encodes repressor that binds DNA and blocks binding of RNAP at pLAC

Front 24

Optimal RNAP binding requires what?

Back 24

De-repression by lac and positive action of CAP-cAMP

Front 25

PLAC has poor ____ region:

Back 25

-35

Front 26

Binding of RNAP requires prior binding of:

Back 26

CAP-cAMP to adjacent site to compensate

Front 27

CAP only binds to DNA when:

Back 27

cAMP levels are high

Front 28

CAMP levels are inversely related to:

Back 28

glc levels in cells

Front 29

CAP activation by cAMP mediated by adenylate cyclase only in gram ___ bacteria:

Back 29

negative

Front 30

Glc down regulates:

Back 30

adenylate cyclase activity

Front 31

Modulon:

Back 31

set of operons that share a common element of regulation

Front 32

How does the SOS system work?

Back 32

LexA represses genes necessary for DNA repair after damage

Front 33

LexA synthesis is controled by?

Back 33

LexA

Front 34

LexA inactivated when?

Back 34

DNA damage is sensed by RecA

Front 35

What does RecA do?

Back 35

Cleaves LexA

Front 36

UmuCD:

Back 36

error prone DNAP V

Front 37

Transcriptionally regulated systems:

Back 37

feeder pathways, developmental pathways

Front 38

Repressor control that use co-repressors:

Back 38

ARG

Front 39

Repressor control that use operon and repressor:

Back 39

trp

Front 40

Repressor control that use attenuation:

Back 40

ARG and trp

Front 41

+ trpworks by:

Back 41

ribosome translates through leader, 3+4 form txn termination loop and it stops

Front 42

- trp works by:

Back 42

ribosome stalls upstream of RNAP, 2+3 forms and no txn termination loop, so txn of genes proceeds

Front 43

Riboswitch:

Back 43

mRNAs bind to metabolites and change conformation; found in bacteria, archea and plants

Front 44

How does regulation of enzyme levels by regulating translation work?

Back 44

SRNAS bind to mRNA and block translation, leading to degredation of the RNA

Front 45

How does covalent modification of glutamine synthetase work?

Back 45

In nitrogen-rich media GS is progressively adenylated by pII and becomes less active

Front 46

PII activity is controlled by:

Back 46

gln and aKG levels

Front 47

How many total AMP-binding sites are there?

Back 47

12

Front 48

How many different biosynthetic pathways use gln as nitrogen donor and regulates GA via feedback inhibition?

Back 48

9

Front 49

Allosteric regulation is used in what type of pathways?

Back 49

Catabolic and anabolic and feedback inhibition

Front 50

Allosteric regulation occurs when?

Back 50

When activity of an enzyme is reversibly regulated by ligand or other modulator

Front 51

Allosteric modulater controls via:

Back 51

conformational changes in regulated protein (+ or -)

Front 52

Can allosteric effectors change Km or Vmax?

Back 52

Yes

Front 53

Is a 3rd party enzyme needed for allosteric regulation?

Back 53

No

Front 54

All biosynthesis of building blocks is ___ controlled at first step:

Back 54

negatively

Front 55

What is often the regulator at the first step in many species:

Back 55

His

Front 56

The first enzyme leading to arg synthesis is:

Back 56

AGS

Front 57

The first enzyme leading to pro synthesis is:

Back 57

GK

Front 58

In the 2-component regulatory system sensors are:

Back 58

integral membrane proteins; often kinases that autophosphorylate when stressor binds

Front 59

In the 2-component regulatory system phosphorylated sensor kinase does what?

Back 59

Transfers Pi to response regulator that controls target genes

Front 60

chemo taxis:

Back 60

directed movement in response to chemicals

Front 61

Aerotaxis:

Back 61

directed movement in response to oxygen

Front 62

PH taxis:

Back 62

directed movement either toward or away from acd/ alkaline conditions

Front 63

Magnetotaxis:

Back 63

directed movement along geomagnetic lines of force

Front 64

Thermotaxis:

Back 64

directed movement toward a range of temperatures

Front 65

Phototaxis:

Back 65

directed movement toward wavelengths of light

Front 66

Chemotaxis in E coli random runs and tumbles in absence of attractent leads to what type of movement?

Back 66

little net movement

Front 67

Attractants lead to longer runs when?

Back 67

When diretion is up the gradient towards the attractent

Front 68

Sensory proteins are found where?

Back 68

In membrane

Front 69

Sensory proteins do what?

Back 69

Bind chemoattractents/ chemorepellents

Front 70

MCPs interact with ___ and ____:

Back 70

CheA and CheW

Front 71

MCPs form:

Back 71

CheA-P when bound to repellants

Front 72

Is the rate of formation of CheA-P increased or decreased when MCP binds attractent?

Back 72

Decreased

Front 73

CheA-P phosphorylates CheY to generate ____ :

Back 73

CheY-P

Front 74

CheY-P interacts with flagellar motor to induce ___ rotation and tumbling:

Back 74

clockwise

Front 75

CheY does not interact with flagellar motor leading to:

Back 75

long runs

Front 76

In adaption, MCPs are methylated by:

Back 76

CheR

Front 77

In adaption CheA-P phosphorylates CheB to form a demethylase that removes ____:

Back 77

methyl groups from MCPs

Front 78

What type of MCPs are most responsive?

Back 78

Unmethylated

Front 79

Quorum sensing:

Back 79

a form of intracellular communication that allows cells to know when population is concentrated enough for group activity

Front 80

What is used to control quorum sensing?

Back 80

AHL

Front 81

What phylum are endospore forming bacteria a part of?

Back 81

Firmicutes

Front 82

How does initiation of sporulation work?

Back 82

Level of SpoOA-P regulates when cell begins sporulation

Front 83

What keeps SpoOA-P levels low?

Back 83

Abundent nutrients

Front 84

Low levels of ApoOQ-P activate what?

Back 84

Survival responses including formation of abx, toxins etc

Front 85

For normal vegetative growth sigma factor ___ is used:

Back 85

A

Front 86

SpoOA-P leads to expression of 4 sporulation-specific sigma factors that do what?

Back 86

Regulate genes involved in all stages of sporulation

Front 87

Describe life cycle of caulobacter crescentus:

Back 87

loss of flagella, stalk formation and then division

Front 88

What is required for division in Caulobacter crecentus:

Back 88

stalk formation

Front 89

Myxobacteriapartake in “___” behavior which means what?

Back 89

Wolf behavior: vegetative cells secrete slime in trails that other cells follow

Front 90

When prey become scarce what do myxobacteria do?

Back 90

Pile up in aggregates and form fruiting bodies that release myxospores

Front 91

What do multiple cell walls and cartenoids in germinated cells do?

Back 91

Confer protection from harsh environments

Front 92

Akinetes:

Back 92

reproductive cells of cyan bacteria

Front 93

EB:

Back 93

infective form of chlamydia, are dormant and can survive outside cell

Front 94

RB:

Back 94

inhibit formation of phagolysosome, grow and divide, then revert to EBS

Front 95

Fungi are comprised of:

Back 95

yeasts, molds and mushrooms

Front 96

All ______ are non-photosynthetic and non-phagocytotic:

Back 96

fungi

Front 97

Cell walls of fungi are made of:

Back 97

chitin

Front 98

Thallas:

Back 98

non-reproductive body of fungus

Front 99

How does sexual reproduction in fungi work?

Back 99

Haploid spores of 2 mating types grow as filaments, cells from hyphea of 2 different mating types can fuse to make dikaryons

Front 100

Yeast are ____ and can make some ____ _____:

Back 100

transformable, recombinant proteins

Front 101

Yeast have cell walls made of:

Back 101

chitin

Front 102

Most protozoa live:

Back 102

in ponds, streams, lakes, ocean, damp soil

Front 103

All free-living protozoa exist as __________:

Back 103

motile feeding trophozoite

Front 104

Many free-living protozoa have a ____:

Back 104

cyst

Front 105

Flagellates:

Back 105

pathogens including t brucei (sleeping sickness)

Front 106

Ciliates:

Back 106

balantdium causes dysentery

Front 107

Paramecium have a macronucleus which is:

Back 107

not a tru nucleus

Front 108

Macronucleus contains 40-1000 what?

Back 108

Copies of genes needed for rapid growth

Front 109

Algea classification is based on:

Back 109

pigments

Front 110

Examples of algea are:

Back 110

diatoms and coccolithophores

Front 111

What causes red tide?

Back 111

Red algea

Front 112

Red algea cell walls contain:

Back 112

chitin

Front 113

Diatoms:

Back 113

single cells with protective coats made of SiO2

Front 114

Viruses:

Back 114

very abundent, contain: NA (RNA, DNA, DS and SS) and elevelope components and are classified based on these differences

Front 115

Viroids:

Back 115

RNA only and infect plant cells

Front 116

Virusoids:

Back 116

RNA only and infect animal cells via other virions

Front 117

Prions have ___ only:

Back 117

protein

Front 118

Some viral forms are:

Back 118

polyhedral, helical, complex and envelope added

Front 119

General features of viral life cycle are:

Back 119

attachment to host cell, entry into cell, viral-directed synthesis of new viral component, viral assembly and release of fully assembled virions

Front 120

How do viruses get out of cell?

Back 120

Lyse it of bud out

Front 121

Viroid infection agent is:

Back 121

RNA that forms double-stranded regions

Front 122

Plant pathogens include:

Back 122

coconut cadang cadang viroid and chrysanthemum stunt viroid

Front 123

Do virusoids have capsids?

Back 123

No

Front 124

The infectious agent of prions are:

Back 124

protein enriched in beta-pleated sheets

Front 125

PrPsc convert:

Back 125

cellular protein to altered form

Front 126

PrPsc is resistent to:

Back 126

proteases, disinfectants

Front 127

Prion diseases include:

Back 127

scrapie, CJD,and BSE