Wiley Quizzes

Question 1

Polar molecules are _ nonpolar molecules are _

Answer 1

hydrophilic, hydrophobic

Question 2

The function of a buffer is to?

Answer 2

generate slight changes in pH

Question 3

What macromolecules contain only polymers?

Answer 3

proteins, nucleic acids, polysaccharides

Question 4

Distinct regions of a protein that fold independently of one another and often function in a semi independent manner are called:

Answer 4

domains

Question 5

Where are the polar groups on membrane lipids directed?

Answer 5

aqueous environment

Question 6

where are the hydrophobic regions of a membrane directed towards?

Answer 6

one another

Question 7

fusing two cells causes what to happen after a period of time?

Answer 7

uniform distribution of labels

Question 8

saturated fatty acids:

Answer 8

have straight fatty acyl chains

Question 9

membranes contain lipids, including:

Answer 9

cholesterol, phosphoglycerides and sphingolipids

Question 10

What serves as a fence around portions of the membrane to restrict the distance an integral protein can travel?

Answer 10

membranes underlying cytoskeleton

Question 11

How do Na ions enter a neuron when an AP is initiated?

Answer 11

a voltage gated Na channel

Question 12

Observations of mitochondria within living cells have shown:

Answer 12

they can exist as a highly branched, interconnected tubular network

Question 13

In what form does a portion of a product of glycolysis enter the TCA cycle?

Answer 13

Acetyl CoA

Question 14

Types of carriers found in the ETC of the inner mitochondrial membrane include:

Answer 14

flavoproteins
- cytochromes
- iron sulfur proteins
- ubiquinone
- NOT NAD (for some reason)

Question 15

What is the domain of the inner mitochondrial membrane that is present within the interior of the mitochondrion as a series of invaginated sheets called?

Answer 15

cristae

Question 16

Collagen is largely produced by:

Answer 16

fibroblasts

Question 17

Can more than one type of collagen be found in a single fiber?

Answer 17

yes

Question 18

What are four major components of the ECM in eukaryotes?

Answer 18

collagen
fibronectin
proteoglycans
laminin

Question 19

The addition of a peptide containing an RGD sequence would ___ the binding of cultured cells possessing surface receptors for fibronectin to a fibronectin coated dish

Answer 19

INHIBIT

Question 20

What are four roles of integrins?

Answer 20

• anchor cells to substrate
• transmit signals to intracellular compartment
• participate in inside out signalling
• bind to a diverse array of ligands

Question 21

Integrins:

Answer 21

are receptors found on the cell SURFACE

Question 22

___ are members of an integral membrane glycoprotein family that bind to specific sugar arrangements in oligosaccharides that project from the surfaces of other cells

Answer 22

selectins

Question 23

Why do cells flatten when they make contact with a surface?>

Answer 23

they send out projections that make increasingly stable attachments

Question 24

the endocytic pathway:

Answer 24

moves materials from outside the cell to inside the cell

Question 25

major advantage of using GFP rather than autoradiography is that:

Answer 25

it can be used in living cells

Question 26

the smooth Er has 4 functions including -

Answer 26

storing calcium ions - synthesizing steroid hormones - detoxifying drugs - oxidizing hydrophobic compounds into hydrophillic compounds

Question 27

The endocytic pathway:

Answer 27

moves materials from outside the cell to inside the cell

Question 28

An investigator can visualize biochemical processes within a cell by determining the location of radioactivley labelled materials by this process:

Answer 28

Autoradiography

Question 29

The endomembrane system when homogenized is broken up into vesicles, which are heterogenous but similar in size. these vesicles can be purified and after purification often retain biological activity, these are known as:

Answer 29

microsomes

Question 30

misfolded proteins:

Answer 30

are destroyed

Question 31

The unfolded protein response (4)

Answer 31

- occurs when there are too many misfolded proteins in the ER - is inhibited by BiP - involves the synthesis of more chaperones in the ER - inhibits enzymes involved in protein synthesis

Question 32

What type of cytoskeletal element is characterized as a long hollow unbranched tube with walls composed of tubulin?

Answer 32

microtubules

Question 33

Which cytoskeletal element is found in both the cytoplasm and nucleus?

Answer 33

intermediate filaments

Question 34

The substrate for kinesin motors are:

Answer 34

microtubules

Question 35

assembly of tubulin dimers requires that __ must be bound to the tubulin subunit

Answer 35

GTP

Question 36

The core of a cilium is called the___

Answer 36

axoneme

Question 37

What controls the assembly and disassembly of intermediate filaments?

Answer 37

phosphorylation and dephosphorlyation

Question 38

What motor is associated with microfilaments

Answer 38

MYOSIN is the motor, actin is the filament

Question 39

Before incorporation into a filament, an actin monomer binds a molecule of___

Answer 39

ATP

Question 40

The myosin motor is driven by ___

Answer 40

hydrolysis if ATP

Question 41

What effect does the binding of the SRP to the growing polypeptide chain and the ribosome have on protein synthesis?

Answer 41

protein synthesis ceases temporarily

Question 42

The signal sequence is typically found on the _____ of a peptide designated to be inserted into the lumen of the RER

Answer 42

amino terminus

Question 43

Cells are infected with a virus carrying a temp sensitive mutant VSVG gene that encodes a protein that cannot leave the ER of infected cells grown at restricted temperatures (40C). Thus at higher temperatures:

Answer 43

The VSVG protein cannot leave the ER

Question 44

During the process of meiosis is the number of chromosomes doubled or reduced by half?

Answer 44

reduced by half

Question 45

When two genes are located on the same chromosome what can you estimate / assume?

Answer 45

that the frequency of recombination between genes allows one to estimate the distance between them

Question 46

Do telomeres play a role in recombination during meiosis?

Answer 46

no they do not

Question 47

The fact that chromosomes become shorter with each replication is known as the

Answer 47

end replication problem

Question 48

Alleles are:

Answer 48

different forms of a gene for the same trait

Question 49

When examining chromosomes in cells starting meiosis. Sutton observed the chromosomes were organized in pairs that came to be called ___ pairs; the members of each pair formed a complex called a:

Answer 49

homologous, bivalent

Question 50

What are the four parts of DNA structure proposed by Watson and crick? (4)

Answer 50

- DNA is helical -Large #s of H bonds hold DNA in a stable configuration but breaking individual bonds allows the strands to separate - The two strands are complimentary to one another - Pyrimidines bind to purines

Question 51

Fluorescent in situ hybridization FISH is used to:

Answer 51

locate sequences of DNA on a chromosome

Question 52

How is DNA denaturation usually measured?

Answer 52

Absorbance of UV light by DNA increases as DNA denatures

Question 53

Transposable elements are segments of DNA that may be ____

Answer 53

mobile

Question 54

What causes unequal crossing over?

Answer 54

a pair of homologous chromosomes aligns imperfectly during meiosis followed by genetic exchange

Question 55

Constitutive heterochromatin is ____

Answer 55

permanently compacted and not transcribed

Question 56

What makes adult females genetic mosaics?

Answer 56

inactivated X chromosomes can be from either parent in each cell

Question 57

Histones are: (4)

Answer 57

- involved with packaging eukaryotic chromatin - highly conserved - positiviley charged - contain high amounts of arginine and lysine

Question 58

The formation of heterochromatin: (4)

Answer 58

- is related to the state of the histones - is involved in X inactivation - is identified by methylation of certain residues in the histones - results in patterns that may be transmitted to daughter cells

Question 59

Order levels of chromosomal organization from most dispersed to most condensed

Answer 59

- nucleosomes - 30nm filaments - supercoiled loops - mitotic chromosomes

Question 60

Epigenetic inheritance:

Answer 60

Is not encoded by DNA

Question 61

Differences in the epigenomes of identical twins:

Answer 61

are thought to arise due to differences in environmental conditions

Question 62

How many X chromosomes are active in female and male cells?

Answer 62

1 in each

Question 63

What is the advantage of the highly condensed state of the DNA of mitotic chromosomes?

Answer 63

favours delivery of an intact package of DNA to daughter cells

Question 64

In bacterial cells, a single ___ contains a cluster of related genes that can be coordinately regulated by switching transcription of these regulated genes on and off at a site called the ___

Answer 64

operon, operator

Question 65

What kind of molecules must pass between the nucleus and the cytoplasm?

Answer 65

DNA and RNA

Question 66

Identical alleles that display different levels of activity based upon wether they are present on the maternal chromosome or on the paternal chromosome are said to be _____

Answer 66

imprinted

Question 67

What molecule binds at the core promoter sites associated with RNA polymerase?

Answer 67

general transcription factors

Question 68

THe extent to which a given gene is transcribed presumably depends on:

Answer 68

the combination of transcription factors bound to upstream regulatory elements

Question 69

Alternate splicing measns that?

Answer 69

the same gene can encode for multiple protiens

Question 70

The miRNAs that regulated mRNA translation and stability:

Answer 70

typically bind to sites in the 3'UTR of their target mRNAs

Question 71

What are three mechanisms used as translational level control of gene expression?

Answer 71

- localization of mRNA - controlled if mRNA is translated - controlling length of time mRNA is translated

Question 72

_____ can degrade proteins that have been targeted by the attachment of _____

Answer 72

proteasomes, polyubiquitin chain

Question 73

Eukaryotes regulate gene expression at all levels except :

Answer 73

replication

Question 74

In a cell that produces only one type of protein, what is the size relationship between hnRNA and mRNA?

Answer 74

hnRNA is always larger than mRNA

Question 75

Introns are ___ of the final mRNA

Answer 75

cut out

Question 76

are mRNAs in prokaryotes and eukaryotes similar in structure?

Answer 76

no

Question 77

Peptide bond formation is catalyzed by _____ in the ___

Answer 77

ribozymes in the large ribosomal subunit

Question 78

Prokaryotic mRNA may be _____ before ____ is complete

Answer 78

translated, transcription

Question 79

Polysomes (polyribosomes) are a group of ribosomes joined together by ____

Answer 79

a single mRNA

Question 80

The mechanical changed that ribosomes undergo is driven by energy from ____

Answer 80

GTP hydrolysis

Question 81

Chromosome regions containing rDNA are located in the ____

Answer 81

nucleoli!

Question 82

What is the origin of virtually all of the signals that regulate cellular activities?

Answer 82

cell surface

Question 83

Sometimes an enzyme is activated by a receptor and generates a second messenger. This enzyme is called ____

Answer 83

an EFFECTOR

Question 84

The Gprotein coupled receptor family contain seven ______ as a structural motif

Answer 84

transmembrane a helices

Question 85

_______ are enzymes that phosphorylate specific tyrosine residues on protein substrates

Answer 85

Protein-tyrosine kinases

Question 86

Once the kinase domain of receptor protein tyrosine kinase has been activated, what does the activated receptor PTK do?

Answer 86

each receptor subunit phosphorylates its partner on tyrosine residues found in regions adjacent to the kinase domain

Question 87

The activation of RTKs is characterized by:

Answer 87

dimerization and autophosphorylation

Question 88

Okazaki fragments are synthesized using the ____ strand in the ____ direction

Answer 88

lagging, 5-3

Question 89

The function of DNA ligase in replication is to:

Answer 89

link Okazaki fragments

Question 90

Replication is said to be _________

Answer 90

semidiscontinuous

Question 91

a replicating prokaryotic chromosome has _______ replication forks, a eukaryotic chromosome has _____

Answer 91

two, many

Question 92

In eukaryotes, which dna polymerase is thought to be the primary DNA synthesizing enzyme during replication of the LAGGING strand?

Answer 92

DNA pol δ

Question 93

Which DNA polymerase in bacteria is mostly involved in DNA repair and removing RNA primers at the 5' ends of Okazaki fragments?

Answer 93

DNA pol I

Question 94

If a cell in the G2 phase is fused with a cell in the M phase:::

Answer 94

the G2 nucleus will enter the M phase

Question 95

DNA synthesis occurs during which phase of the cell cycle?

Answer 95

S phase

Question 96

When the cyclin concentration ____, CDK is activated, causing ____

Answer 96

rises, enter the M phase

Question 97

What are the two major phases in the cell cycle?

Answer 97

Mphase, interphase

Question 98

What major event occurs during anaphase?

Answer 98

sister chromatids separate and are pulled to opposite poles

Question 99

IN what phase do microtubules attach to kinetochores?

Answer 99

prometaphase