Cell Bio exam

c. they arise from non-living things

Which of the following statements about living things is FALSE?

a. they are highly organized

b. they are composed of cells

c. they arise from non-living things

d. they reproduce themselves

b. archea

In which domain would you expect Thermus aquatics, an extreme thermophile, to belong?

a. bacteria

b. archea

c. heterokonta

d. eukarya

a. transcription, translation

the synthesis of RNA from DNA is called _________,__ while the synthesis of protein from RNA is called ______.

a. replication, transcription

b. translation, transcription

c. transcription, translation

d. transcription, replication

a. frog egg- paramecium- nucleus- protein

which one of the following orders the cellular components from largest to smallest?

a. frog egg- paramecium-nucleus- protein

b. bacterium -frog egg- DNA- mitochondria

c. polysaccharide - protein- plant celll- ER

d. nucleus- mitochondria - protein- plant cell

d. 690

based on your understanding of florescent tags, which one of the following would you predict to be the emission wavelength of a molecule whose excitation wavelength is 590?

a.390

b.490

c.590

d.690

c. 0.2um

The limit of resolution for light microscopy is ____.

a. 2nm

b.0.2nm

c.0.2um

d. 2um

d. scanning electron microscopy

The type of microcopy the reveals details about the cell surface is called _________.

a. light microscopy

b. fluorescence microscopy

c. transmission electron microscopy

d. scanning electron microscopy

a. cytoplasm, cytosol

Whereas everything inside the plasmid membrane and outside the nucleus is the _____,__ the solution inside the plasma membrane and outside the organelles is the ___.

a. cytoplasm, cytosol

b. cytosol, cytolumen

c. cytosol, cytoplasm

d. cytolumen, cytosol

c. lipid synthesis, calcium

The ER is the site of _________ and stores _______.

a. protein synthesis, protons

b. DNA synthesis, calcium

c. lipid synthesis, calcium

d. polysaccharide synthesis, protons

a. Golgi apparatus

Which organelle does NOT contain DNA?

a. Golgi apparatus

b. mitochondrion

c. nucleus

d. chloroplast

a. larger genomes are associated with greater organisms

Which statement is NOT consistent with the C value paradox?

a. larger genomes are associated with greater organisms complexity

b. genome sizes vary greatly among species

c. some protozoan species have the largest genomes

d. archaea tend to have small genomes

a. a nucleus

Although there are many distinct prokaryotic species, most have a small range of shapes, sizes, and growth rates. Which of the following characteristics are NOT observed in prokaryotes?

a. a nucleus

b. DNA replication machinery

c. ribosomes

d. membrane bilayers

a. vacuole, cell wall

In plant cells, the _____ controls the turgor pressure while the ____ resits the outward force of turgor pressure

a. vacuole, cell wall

b. chloroplast, plasma membrane

c. plasma membrane, chloroplast

d. cell wall, vacuole

c. proteins

Monosaccharides are NOT building block for which one of the following

a. carbohydrates

b. starch

c. proteins

d. cellulose

c. condensation, glycosidic

A __ reaction between two monosaccharides forms ____ bond.__

a. condensation, peptide

b. hydrolysis, glycosidic

c. condensation, glycosidic

d. hydrolysis, peptide

b. beta (1,4)

In the disaccharide shown below, the type of linkage is ____.

a. alpha (1,4)

b. beta (1,4)

c. alpha (1,6)

d. beta (1,6)

a. unsaturated

Fatty acids whose hydrocarbon tails have at least one double bond are said to be ____.

a. unsaturated

b. saturated

c. ionic

d. hydrophilic

c. produce lipids with fatty acids tiles that are longer and have fewer double bonds

Nighttime in the desert can be surprisingly cool, even in the summer. Yet the desert plants must endure daytime temperatures in excess 45 degree C. What adjustments might these plants make as the day warms up in order to maintain the same level of membrane fluidity?

a. produce lipids with fatty acid tails that re shorter and have more double bonds

b. produce lipids with fatty acids tails that are long and have more double bonds

c. produce lipids with fatty acids tails that are longer and have fewer double bonds

d. produce lipids with fatty acids tails that are shorter and have fewer double bonds

b. it contains both hydrophilic and hydrophobic regions

A phospholipids is considered an amphipathic molecule because __________.

a. it bears two hydrophobic fatty act side chains

b. it contains both hydrophilic and hydrophobic regions

c. one of its fatty acid side chain contains a double bond

d. its structure influences membrane fluidity

c. a hydrophobic ring structure

which one of the following is NOT a component of a phospholipid

a. a glycerol molecule

b. a phosphate group

c. a hydrophobic ring structure

d. a polar head group

c. membrane lipids diffuse within the plane of the membrane

which of the following statements is TRUE?

a. phospholipids will spontaneously form bilayers in non polar solvents

b. in eukaryotes, all membrane bound organelles are surrounded by a single lipid bilayer

c. membrane lipids diffuse within the plane of the membrane

d. membrane lipids frequently flip-flop between one monolayer and the other

b. hydrocarbon tail crystallizes the membrane

Cholesterol serves several functions in mammalian membranes. Which of the following is NOT a function of cholesterol?

a. hydrocarbon tail prevents phospholipid tails from interacting

b. hydrocarbon tail crystallizes the membrane

c. steroid rings stiffen the membrane

d. steroid rings decrease permeability of the membrane

a. hydrophobic side chains associate laterally and end-to-end to form a bilayer

the configuration of cellular membranes arises from the interaction of phospholipids of phospholipids in an aqueous environment to form an energy minimum in which ______.

a. hydrophobic side chian’s associate laterally and end-trend to form a bilayer

b.phospholipids associate laterally to form a single leaflet

c. phospholipid head groups associate laterally and end-to-end to forma bilayer

d. hydrophobic side chains interact with water on one side of the membrane

b. amino acids, peptide

the building blocks of proteins are __ which are linked by _____ bonds.

a. amino acids, glycosidic

b. amino acids, peptide

c. monosaccharides, glycosidic

d. monosaccharides

in the common backbone of all amino acids, to which atom

a. primary

A protein’s _________ structure refers to its linear sequence of amino acids.

a. primary structure

b. secondary

c. teritary

d. quaternary

a. the sequence of amino acids in a polypeptide varies between different proteins

which of the following statement is TRUE?

a. the sequence of amino acids in a polypeptide varies between different proteins

b. the polypeptide backbone is free to rotate about each peptide bond

c. hydrophilic amino acids tend to be found in transmembrane regions of proteins

d. the sequence of atoms in a polypeptide backbone varies between different proteins

d. misfolded PrP converts the correctly folded PrP to misfolded form

the improper folding of PrP is responsible for neurodegenerative disorders including scrapie, mad cow disease, and Creutxfeld-jacob disease

a. misfolded PrP degrades the correctly folded PrP

b. the correctly folded PrP forms aggregates

c. the infectious element is a virus

d. misfolded PrP converts the correctly folded PrP to misfolded form

d. amino acids side chains that point inwards

Which of the following is NOT a feature commonly observed in alpha helices?

a. right handedness

b. H bonds between C=O and N-H that are four amino acids apart

c. cylindrical shape

d. amino acids side chains that point inward

a. alanine

which of the following amino acids would you expect to find buried in the center of a folded protein, sequestered away from water?

a. alanine

b. glutamic acid

c. serine

d. histidine

b.the sum of many weak bonds

interactions between enzyme and substrate _____.

a. change the enzyme over the course of the reaction

b. are the sum of many weak bonds

c. usually covalent

d. independent of the enzymes tertiary structure

d. they can lower deltaG

which of the following statements about enzymes is false?

a. they bind non-covalently

b. they can speed reaction rates

c. the lower activation energy

d. the can lower delta G

c. -50

The delta G of the couples reactions is _____ kcal/mol

ATP + Y → Y-P +ADP delta G=-100 kcal/mole

Y-P +A → B delta G=50kcal/mole

a. 100

b. 50

c. -50

d. -150

d. the rate of florescence recovery due to diffusion of labeled proteins 

In FRAP (fluorescence recovery after photobleaching), protein mobility is measured as _____.

a. the rate of florescence recovery due to labeled protein becoming unbleached

b. a loss in florescence

c. the rate of photobleaching

d. the rate of florescence recovery due to diffusion of labeled proteins

c. polypeptide is attached non-covalently to a membrane-spanning protein

Which once of the following is NOT an integral membrane protein?

a. polypeptide spend the lipid bilayer as an alpha helix

b. polypeptide spend the lipid bilayer as a beta barrel

c. polypeptide is attached non-covalently to a membrane-spanning protein

d. polypeptide is attached to the membrane by a posttranslationally added lipid tail

b. potassium ion

In a synthetic lipid bilayer (lacking proteins) which of the following has the lowest rate of diffusion across an artificial membrane?

a. ethanol

b. potassium ion

c. water

d. glucose

d. passive transport

the movement of a solute across a membrane down/with its electrochemical gradient is called ______.

a. active transport

b. free transport

c. passive transport

d. passive transport

### d. the net negative charge on the cytosolic side of the membrane enhances the rate of glucose import into the cells by the uniporter

Which of the following statements is false?

a. during couples transport, one solute moves down/with its electrochemical gradient while another solute moves up/against its electrochemical gradient

b. transporters undergo transitions between different conformations, depending on whether the substrate binding pocket is empty to occupied

c. the electrochemical gradient for K+ across the plasma membrane of animals is small the net negative charge on the cytolytic side of the membrane enhances the rate of glucose import into the cell

d. the net negative charge on the cytosolic side of the membrane enhances the rate of glucose import into the cells by the uniporter

**b. they transport molecules at a higher rate than channels**

### which one of the following statement about transporter (uniports) is FALSE?

### a. they mediate passive transport

### b. they transport molecules at a higher rate than channels

### c. they bind to the molecule they transport with high specificity

### d. they undergo conformational change during transport

b. coupled transport

when one molecules moves through a transport protein again (up) its electrochemical gradient while a second molecules moves through the same transport protein with (down) its electrochemical gradient, this process is called ____.

a. passive transport

b. couples transport

c. uniport

d. multiport

b 2K+ into and 3 Na+ out 

for every one ATP hydrolyzed, the Na+/K+ pump moves ____ the cell

a. 2 Na+ into and 3K+ out of

b. 2K+ into and 3 Na+ out

c. 3Na+ into and 2K+ out of

d. 3K+ into and 2Na+ out of

a. sodium, into

an uncharged moles moves across the plasma membrane of an animal cell using symport transporter. This uncharged molecules is most likely cotransported with ___ __and moves__ __ the cell

a. sodium, into

b. potassium, into

c. sodium, out of

d. potassium, out of

a. the driving force is weak because the concentration gradient and the electrical gradient favor movement in the opposite directions 

if the concentration of chloride ion (Cl-) is high outside the cell, which of the following most accurately describes the driving forces for the movement of Cl-?

a. the driving force is weak because the concentration gradient and the electrical gradient favor movement in the opposite directions

b. the driving force is strong because the concentration gradient and the electrical gradient favor movement into the cell

c. the driving force is negative because the concentration gradient and the electrical gradient favor movement into the cell

d. the driving force is high because the concentration gradient and the electrical gradient favor movement in the opposite directions

a. carboxyl group

Which of the following is not a part of a nucleotide?

a. carboxyl group

b. phosphate group

c. pentose

d. nitrogen-containing base  

d. the two DNA strands run antiparallel

In a DNA double helix _________.

a. the two DNA strands are identical

b. purines with purines

c. thymine pairs with cytosine

d. the two DNA strands run antiparallel

b.2

Which one of the follow double stranded DNA sequences has the highest melting temperature?


1. GATCG

CTAGC
2. GGCCG

CCGGC


3. AATTA

TTAAT


4. AATCA

TTAGT

a. 3

b. 2

c. 1

d. 4

\

b. 5’3’

In linear nucleic acids, nucleotides are bonded through their ___ __and.__ _____carbon atoms

a. 5’2’

b. 5’3’

c.4’2’

d.4’3’

d. the RNA sugar ring bears a 2’ OH

although RNA and DNA are similar in structure, one difference is that _________.

a. RNA uses the base cytosine

b. the DNA sugar ring bears a 3’OH

c. DNA uses the base adenine

d. the RNA sugar ring bears a 2’OH

c. histone proteins, nucleosomes

in eukaryotic cells, DNA is packages by looping the double helix around ____ __to form__ ______.

a. nucleosomes, 30nm fibers

b. histone proteins, centrosomes

c. histones proteins, nucleosomes

d. centrosomes, nucleosomes

d. each DNA double helix consists off one strand from the parent DNA molecule and one new strand

DNA replication is considered semiconservative because after one round of replication

a. the original DNA double helix is still intact

b. one DNA double helix consists of two new strands an the other double helix consists of two parental strands

c. within each DNA double helix each strand consists of portions of new DNA and portions of DNA from each parent

d. each DNA double helix consists of one strand from the parent DNA molecules and one new strand

b. it is common around centromeres

Which one of the following statements about heterochromatin is true?

a. it is decondensed

b. it is common around centromeres

c. it is transcribed

d. it encodes proteins b.

a. two bands, conservative

After growing E. coli. in N15 medium, they switched the E. coli to N14 medium for one generation time and then determined the density of the DNA by centrifugation. The results yielded _______,__ which allowed them to rule out _______ model of DNA replication

a. two bands, conservative

b. two bands, semi conservative

c. one intermediate band, conservative

d. one intermediate band, semi-conservative

a. template, 5’ to 3’

during DNA replication, the polymerase synthesis the ___ __strand in the__ _______ direction.

a. template, 5’ to 3’

b. daughter, 5’ to 3’

c. daughter, 3’ to 5’

d. template, 3’ to 5’

b. telomerase, 3’

the enzyme __ contains a short RNA that is used as a template to extend the _______ end go a chromosome during replication of a telomerase.

a. telomerase, 5’

b. telomerase 3’

c. RNAse, 3’

d. RNAse, 5’

b. 2

In both eukaryotes and prokaryotes, every origin of replication has _______ replication forks

a. 1

b. 2

c. 3

d. 4

d. it will be more likely to generate mismatched base pairs

You have discovered an “Exo” mutant form of DNA polymerase win which the 3’ to 5’ exonuclease function has been destroyed but the ability to join nucleotides together is unchanged. Which of the following properties do ou expect the mutant polymerase to have?

a. it will polymerize in both the 5’ to 3’ direction and the 3’ to 5’ direction

b. it will polymerize more slowly then the normal polymerize

c. it will fall off the template more frequently then the normal polymerase

d. it will be more likely to generate mismatched base pairs

a. 10^7, 10^9

after DNA proofreading, 1 mistake is made per ____ nucleotides copies; after mismatch repair 1 mistake is made per ____________ nucleotides copied.

a.10^7, 10^9

b.10^9, 10^7

c. 10^4, 10^6

d. 10^6, 10^4

d. the presence of a nick in the DNA

During mismatch repair, repair proteins are believed to recognize the newly synthesized strand by _____.

a. a distortion

b. its acetylation status

c. its methylation status

d. the presence of a nick in the DNA

d. covalent linkages between bases

DNA damage can be caused by environmental factors, like UV radiation, or can occur spontaneously. Fortunately, the cell has many mechanisms to repair such damage. One type of DNA damage involves the formation of thymine dimers, which results in _________.

a. a guanine

b. a nucleotide missing the A or G base

c. a nucleotide missing the C or T base

d. covalent linkages between bases

b. a double-stranded DNA is interested into the target site

Which feature is shared by retrotransposons and DNA-only transposons?

a. an RNA intermediate

b. a double-stranded DNA is interested into the target site

c. the enzyme reverse transcriptase is encoded by the transposon

d. they are equally prevalent in the human genome

c. both encoded an enzyme

Retrotransposons are similar to retroviruses in that _____.

a. neither are confined to one cell and it descendants

b. neither use the host cell’s translation machinery

c. both encode an enzyme that synthesizes the DNA

d. both encode coat proteins

b. 3’ to 5’

During transcription, the DNA template is read in the ______ direction.

a. 5’ to 3’

b. 3’ to 5’

c. N to C terminus

d. C to N terminus

a. coding, control

Within a gene, a ___ region is a DNA sequence that encodes RNA and a _____ region is a DNA sequence that regulates transcription

a. coding, control

b. control, coding

c. noncoding, control

d. coding, barcoding

a. some of the mismatches are not corrected

During DNA replication which of the following is true about proofreading?

a. some mismatches are not corrected

b. proofreading requires the 2’ OH of the incorrect nucleotide

c. endonuclease activity removes the incorrect nucleotide

d. RNA polymerase catalyzes the proofreading reaction

c. recognizes promoter sites in the DNA

the sigma subunit of bacterial RNA polymerase _____.

a. contain the catalytic activity of the polymerase

b. remains part of the polymerase throughout transcription

c. recognizes promoter sites in the DNA

d. recognizes transcription termination sites in the DNA

d. a single transcript encoding multiple proteins

prokaryotic genes are often organizes into operons, which make _______.

a. multiple transcripts encoding multiple proteins

b. multiple proteins encoding single protein

c. a single transcript encoding a single protein

d. a single transcript encoding multiple proteins

a. when tryptophan is high, activating the repressor

expression of the top operon does not occur ________.

a. when tryptophan is high, activating the repressor

b. when tryptophan is low, activating the repressor

c. when tryptophan is high, inactivating the repressor

d. when tryptophan is low, inactivating the repressor

c. presence of lactose, absence of glucose

under which condition does expression of the lac operon occur?

a. presence of lactose, presence of glucose

b. absence of lactose, presence of glucose

c. presence of lactose, absence of glucose

d. absence of lactose, absence of glucose

a. inactivates the repressor to allow transcription of the operon

during the regulation of the lac operon the presence of lactose,

a. inactivates the repressor to allow transcription of the operon

b. activates the repressor to repress transcription of the operon

c. activates the CAP to induce transcription of the operon

d. inactivates the CAP to prevent transcription of the operon

a. RNA Pol I

which eukaryotic polymerase synthesizes ribosomes RNA (rRNA)?

a. RNA pol I

b. RNA Pol II

c. RNA Pol III

d. DNA Pol

c. TATAAA, 25

for eukaryotic gene encoding protein, ______ is the consensus sequence of the promoter and the transcription begins _________ nucleotides downstream.

a. TATAAA, 10

b. AAAAAA, 10

c. TATAAA, 25

d. AAAAAA,25

a introns

Eukaryotic genes encoding proteins, protein coding sequence is interspersed with ________.

a. introns

b. exons

c. operons

d. enhancers

d. TFIID, TATA Box

During initiation of transcription in eukaryotes, ____ binds the __ within the promoter.

a. TFIIH, TATA Box

b. sigma subunit, -35 and -10 sequence

c. TFIIB, -35 and -10 sequence

d. TFIID, TATA Box

b. 2’OH

During splicing, the lariat formation is dependent on the ______.

a. 7-me-G cap

b. 2’ OH

c. 3’OH

d. poly-A-tail

5’-CUUGGAUC-3’

What is the sequence of the RNA encoded by the DNA template 5’-GATCCAAG-3’

b. the template strand is read by the polymerase from 3’ to 5’

prokaryotic and eukaryotic transcription are similar in that _____.

a. introns must be spliced

b. the template strand is read by the polymerase from 3’ to 5’

c. different polymerases transcribe different classes of RNA

d. the DNA must be unpackaged from nucleosomes

d. anticodon

The 3’ base on a tRNA that binds its compliment on an mRNA is called the ______.

a. reading frame

b. charge

c. codon

d. anticodon

a. 5’-GUA-3’

The codons for tyrosine are 5’-UAU-3’ and 5’-UAC-3’. Which one of the following could be the anticodon?

a. 5’-GUA-3’

b.5’-AUC-3’

c.5’-UAC-3’

d.5’-CAU-3’

c. the first two amino acids would remain the same, but the others would change 

what would happen if the 7th nucleotide were deleted?

5’ GCU-UGU-UUA-CGA-AUU-3’

Ala-Cly-Leu-Arg-Ile

a. entire peptide sequence would change

b. first amino acid would remain the same, but the other would change

c. the first two amino acids would remain the same, but the others would change

d. none of the amino acids would change

d. initiation site

which of the following is not one go the tRNA binding site in a ribosomes?

a. exit site

b. peptide site

c. aminoacyl site

d. initiation site

b. rRNA in the large subunit

During translation, formation of the peptide bond is catalyzed by _____.

a. protein in the large subunit

b. rRNA in the large subunit

c. rRNA in the small subunit

d. protein in the small subunit

d. 4

during translation how many high energy bonds are consumed per amino acid added to a growing peptide?

a. 1

b.2

c.3

d.4

d. degradation in proteasome

the fate of misfolded proteins staged with ubiquitin is ____.

a. refolding by HSP60 family proteins

b. sequestration in the lysosome

c. sequestration in large cytosolic complexes

d. degradation in proteasome

d. translation

which of the following does not occur in the nucleus?

a. transcription

b. splicing

c. poly-adenylation

d. translation

c. shine-dalgarno sequence 

in prokaryotes what is the name of the mRNA sequence that lies upstream (5;) of the start codon and mediates the biding of the small ribosomal subunit?

a. leader sequence

b. initiation sequence

c. shine-dalgarno sequence

d. protein in the small subunit

a. endoplasmic reticulum

Protein import into which organelle is co-translational?

a. endoplasmic reticulum

b. nucleus

c. mitochondria

d. goli

a. nucleus

import into which organelle is post-translational and of fully folded proteins?

a. nucleus

b. er

c. chromoplast

d. mitochondria

a. cytosol

in the sense of any amino acid signal sequence, the default localization of a protein genome is in the _____.

a. cytosol.

b. nucleus

c. er

d. mitochondria

c. mitochondria

you have engineered a double protein two two and only two localization signals, a signal for import Tinto the mitochondria, and single for retention in the ER. Where will the protein ultimately reside?

a. er

b. nucleus

c. mitochondria

d. extracellular space

b. importin

name the nuclear transport receptor, the protein that transport cargo into the nucleus

a. ran

b. exportin

c. importin

d. ran-GEF

b. Ran

what protein hydrolyzes GTP during nuclear import?

a. importin

b. Ran

c. Rab

d. SNARE

d. Ran-GEF, stimulates exchange of GDP for GTP

the protein that activated Ran, allowing it to bind cargo-receptor complexes during nuclear import _____ is

a. Ran-GAP, stimulates hydrolysis activity

b. Ran-GEF, stimulates hydrolysis activity

c. Ran-GAP, stimulates exchange of GDP for GTP

d. Ran-GEF, stimulates exchange of GDP for GTP

b. stimulate hydrolysis activity in the cytosol

during nuclear import, the function of Ran-Gap is to ___.

a. stimulate guanine nucleotide exchange in the cytosol

b. stimulate hydrolysis activity in the cytosol

c. stimulate guanine nucleotide exchange in the nucleus

d. stimulate hydrolysis activity in the nucleus

c. the signal sequence is cleaved from the protein matrix 

which of the following statements about mitochondrial import is TRUE?

a. signal sequence on mitochondrial proteins are usually c terminal

b. most mitochondrial proteins are not imported from the cytosol but are synthesized inside the mitochondria

c. the signal sequence is cleaved from the protein matrix

d. mitochondrial proteins cross the membrane in their native folded state

c. importin

Which of the following proteins is NOT involved in import into the mitochondria?

a. TOM

b. TIM

c. importin

d. signal peptide

c.TOM, TIM

During mitochondrial import, the transport protein_____ __is__ responsible for moving the protein through the outer membrane and the transport protein _________ is responsible for moving the protein through the inner membrane.

a. mitochondrial HSP70, TIM

b. cytosolic HSP70, TOM

c. TOM, TIM

d.TIM, TOM

a. amphipathetic alpha helix

the signal sequence for import of a protein into the mitochondrial is _____.

a. amphipathetic alpha helix

b. hydrophobic alpha helix

c. KDEL

d. hydrophobic alpha helix

a. secreted proteins are first targeted to the ER

which one of the following statements about ER is true ?

a. secreted proteins are first targeted to the ER

b. the ER membrane is continuous with the plasma membrane.

c. proteins to be delivered to the ER lumen are synthesized on the smooth ER

d. the er lumen store sodium ions

b. begin to cross the membrane while still being synthesized 

most proteins destined to enter the endoplasmic reticulum ____.

a. are synthesized on a special population of ER ribosomes

b. begin to cross the membrane while still being synthesized

c. remain within the endoplasmic reticulum

d. are transported across the membrane after their synthesis is complete

c. an N-terminal hydrophobic alpha helix

which one of the following signal sequences for ER import?

a. an N terminal amphipathetic alpha helix

b. a C-terminal KDEL sequence

c. an N-terminal hydrophobic alpha helix

d. a short run of positively charged amino acids