biochem

describe the differences in translation between (+) ssrna viruses like (like the coronavirus) and (-) ssrna viruses (like the influenza virus)

(+) ssrna virus: genome stored as rna that is readily translated to form proteins (-) ssrna virus: transcribe the (+) version of the rna first

for most cells, the extracellular calcium concentration is around 10000 times higher than the intracellular calcium concentration. what is the membrane potential established by this electrochemical gradient?

+123 mv

at ph 7, the charge on a glutamic acid molecule is:

-1

which of the following is LEAST likely to be the resting potential of a cell?

0 mv

consider a reaction catalyzed by enzyme a with a km value of 5*10^-6 m and vmax of 20 mmol/min at a concentration of 5*10^-6 m substrate, the rate of the reaction will be:

10 mmol/min

which fatty acid can be synthesized by humans?

16:0

zwitterions are amphoteric, meaning that they act as both acids and bases. at what ph are amino acids predominantly in their zwitterion form?

2 < ph < 9

a certain protein is 8 amino acids in length. how many different amino acid sequences are possible for their protein?

2.56*10^10

at a concentration of 5*10^-4 m substrate, the rate of reaction will be:

20 mmol/min

a gene encodes a protein with 150 amino acids. there is one intron of 1000 base pairs (bp), a 5' untranslated region of 100 bp, and a 3' untranslated region 200 bp. in the final mrna, about how many bases lie between the the start aug codon and final termination codon?

450

you have just sequenced a piece of dna that reads as follows: 5' tatttgagacatcc 3' what would the base sequence of the mrna transcribed from the dna be?

5' ggaugucccaaaga 3'

how many distinct tripeptides can be formed from one valine molecule, one alanine molecule, and one leucine molecule?

6

in lysine, the pea of the side chain is about 10.5. assuming that the carboxyl and amino groups are 2 and 9, respectively, the pi of lysine is closest to:

9.8

during fatty acid mobilization, which of the following occur(s)? I. hsl is activated II. free fatty acids are released III. gluconeogenesis proceeds in adipocytes

I and II only

steroid hormones are steroids that: I. have specific high affinity receptors II. travel in the bloodstream from endocrine glands to distant sites III. affect gene transcription by binding directly to dna

I and II only

the cyclic forms of monosaccharides are: I. hemiacetals II. hemiketals III. acetals

I and II only

which amino acids contribute most significantly to the pi of a protein? I. lysine II. glycine III. arginine

I and III only

which of the following are examples of non coding rna (ncrna)? why are they called that? I. trna II. mrna III. rrna

I and III only ncrna: not coded into protein

an specified virus uses rna as its genetic material. this viral rna could possibly lead to the synthesis of twice of the following? I. cdna II. mrna III. proteins

I, II, and III

endonuclease are used for which of the following? I. gene therapy II. southern blotting III. dna repair

I, II, and III

how does prokaryotic dna differ from eukaryotic dna? I. prokaryotic dna lacks nucleosomes II. eukaryotic dna has telomeres III. prokaryotic dna is replicated by a different dna polymerase IV. eukaryotic dna is circular when not restricted by centromeres

I, II, and III

resting membrane potential depends on: I. the differential distribution of ions across the membrane II. active transport processes III. selectively permeability of the phospholipid bilayer

I, II, and III

which of the following could result from an absence of apolipoproteins? I. an inability ro secrete lipid transport lipoproteins II. an inability to endocytose lipoproteins III. a decreased ability to removed excess cholesterol from blood vessels

I, II, and III

which of the following is a reason for conjugating proteins? I. to direct their delivery to a particular organelle II. to direct their delivery to the cell membrane III. to add a cofactors needed for their activity

I, II, and III

hormones are found in the body in very low concentrations, but tend to have a strong effect what type of receptors are hormones most likely to act on? I. ligand gated ion channels II. enzyme linked receptors III. g protein coupled receptors

II and III only

which of these amino acids has a chiral carbon in the side chain? I. serine II. threonine III. isoleucine

II and III only

which of the following is correct about fat soluble vitamins? I. vitamin e is important for calcium regulation II. vitamin d protects against cancer because it is a biological antioxidant III. vitamin k is necessary for the post translational introduction of calcium binding sites IV. vitamin a is metabolized to retinal, which is important for sight

III and IV only

which of the following is/are true of amphipathic molecules? I. they are all phospholipids II. they all contain a sphingosine backbone III. they can have either phosphodiester or glycosidic linkages to their polar head groups

III only

a biopsy is done on a child with an enlarged liver and shows accumulation of glycogen granules with single glucose residues remaining at the branch points near the periphery of the granule. the most likely genetic defect is in the gene encoding:

a 1,6 glucosidase

which of the following statements about terpenes is FALSE?

a triterpene is made of three isoprene moieties, and therefore has 15 carbons

fatty acids enter the catabolic pathway in the form of:

acetyl coa

which of the following best characterizes the process of fatty acid synthesis?

activation followed by bond formation, reduction, dehydration, and reduction

peptidyl transferase connects the carboxylate group of one amino group of an incoming amino acid. what type of linkage is created in this peptide bond?

amide

which of the following directly provides the energy needed to form atp in the mitochondrion?

an electrochemical proton gradient

which of the following statements about enzyme kinetics is FALSE?

an increase in the substrate concentration (at constant enzyme concentration) leads to proportional increases in the rate of the reaction

which of the following characteristics is NOT attributed to antibodies?

antibodies bind to more than one antigen

double stranded rna cannot be translated by the ribosome and is marked for degradation in the cell. which of the following strands of rna would prevent mature mrna in the cytoplasm from being translated?

antisense mrna to the one produced

some enzymes require the presence of a nonprotein molecule to behave catalytically. an enzyme devoid of this molecule is called a(n):

apoenzyme

which of the following statements is FALSE?

atp stores are turned over more than 10 000 times daily

which of the following enzymes cleaves polysaccharide chains and yields maltose exclusively?

b amylase

researchers have identified a certain prion that causes the human protein abc to misfiled by affecting a helices. when a cell is infected by this particular prion, what most likely happens to protein abc at the molecular level?

b sheet replace normal a helices, binding to other b sheets and causing the proteins to aggregate

in the absence of oxygen, which tissue will experience damage most rapidly?

brain

which of the following is NOT a method by which enzymes decrease the activation energy for biological reactions?

breaking bonds in the enzyme irreversibly to provide energy

which of the following is most likely to be found bound to a protein in the body?

calcium

which of the following biomolecules is LEAST likely to contain an aromatic ring?

carbohydrates

when fatty acid b oxidation predominates in the liver, mitochondrial pyruvate is most likely to be:

carboxylated to oxaloacetate for entry into gluconeogenesis

which of the following correctly pairs a tissue with its preferred energy source in the well fed state?

cardiac muscle - fatty acids

what is the function of lcat?

cat catalyzes the production of cholesterol esters

adding heat to a closed biological system will do all of the following EXCEPT:

cause the system to do work to maintain a fixed internal energy

how is cdna best characterized?

cdna results from the reverse transcription of processed mrna

which of the following is NOT involved in cell migration?

centrioles

which of the following dna sequences would have the highest melting temperature?

cgcaccatccg

which of the following is true about cholesterol?

cholesterol is a steroid hormone precursor

how do chylomicrons and vldl differ?

chylomicrons are synthesized in the intestine, vldl are synthesized in the liver

which of the following INCORRECTLY pairs a metabolic process with its site of occurrence?

citric acid cycle - outer mitochondrial membrane

which of the following proteins is most likely to be found extracellularly?

collagen

which complex does NOT contribute to the proton motive force?

complex II

why might uracil be excluded from dna but not rna?

cytosine degradation results in uracil

at 25 degrees c the delta g degree for a certain reaction a <> b + 2c is 0. if the concentration of a, b, and c in the cell at 25 degrees c are all 10 mm, how does the delta g compare to the measurement taken with 1 mm concentrations?

delta g is less than delta g degree, thus the reaction is spontaneous

which of the following is true of diffusion and osmosis?

diffusion and osmosis rely on the concentration gradient of only the compound of interest

a food scientist researches a new way to cook eggs. which of the following methods will effectively denature the primary structure of egg proteins?

digestive enzymes

what is the central dogma of molecular biology?

dna > rna > protein

which of the following is NOT used by eukaryotes to increase transcription of a gene?

dna methylation

topoisomerase are enzymes involved in:

dna replication and transcription

which of the following statements regarding differences between dna and rna is FALSE?

dna strands replicate in a 5' to 3' direction, whereas rna is synthesized in a 3' to 5' direction

what monomers make up dna? rna? protein?

dna: deoxynucleotide rna: ribonucleotide protein: amino acid

which of the following side effects would be anticipated in someone taking leptin to promote weight loss?

drowsiness

the ability to exist in both an oxidized and a reduced state is characteristic of:

electron carriers

which of the following best explains why cytosolic nadh can yield potentially less atp than mitochondrial nadh?

electrons transfer from cytosol to matrix can take more than pathway

anderson disease is caused by a mutation in branching enzyme and is associated with cirrhosis. scientists theorize the cause is likely an immune response against abnormal glycogen. which of the following best describes the ratio of glycogen a 1,4 to a 1,6 linkages in individuals with this disorder?

elevated

which of the following best describes the charge in entropy that occurs during protein folding?

entropy of the water increases; entropy of the protein decreases

which process is expected to begin earliest in prolonged fast?

enzyme phosphorylation and dephosphorylation

a researcher studies the properties of amino acids at different ph levels. if the ph is equal to the pka in beaker 1, which of the following is true regarding the amino acid?

exactly 1/2 of the amino acid has been deprotonated

a student is trying to determine the type of membrane transport occurring in a cell. she finds that the molecule to be transported in very large and polar, and when transported across the membrane, no energy is required. which of the following is the most likely mechanism of transport?

facilitated diffusion

which of the following correctly shows the amounts of atp produced from the given high energy carriers?

fadh2 > 1.5 atp

which of the following is LEAST likely to result from protein degradation and processing by the liver?

fatty acids

vacuum ultraviolet circular dichroism is an experimental technique used to identify b turns in polypeptide chains. which of the following correctly describes the location and content of b turns?

found on the surface of proteins. and consist of amino acids with polar r groups

the metabolism of which of the following sugars would be LEAST affected by the inhibition of the enzyme phosphofructokinase 1?

fructose

a scientist shines plane polarized light through various amino acids. which amino acid will not show optically activity?

g

which of the following is a sphingolipid?

ganglioside

which of the following is an ethical concern of gene sequencing?

gene sequencing impacts relatives, thus privacy concerns may be raised

which of the following is NOT a component of all trimeric g proteins?

gi

a man is given antibiotics to treat a urinary tract infection and develops an episode of red b blood cell lysis. further studies show weakness fo the plasma membrane and heinz bodies (collections of oxidized hemoglobin). which of the following enzymes is most likely defective in this patient?

glucose 6 phosphate dehydrogenase

which of the following transporters is used by cells in the liver to store excess glucose and by beta cells in the pancreas as a glucose sensor?

glut 2

when insulin is released, it acts to increase the absorption of glucose into skeletal muscle predominantly through which of the following transporters?

glut 4

a patient with a consistent blood glucose level greater than 300 mg/dl is determined to be in diabetic ketoacidosis (dka). which of the following amino acids would not be protonated when ph falls below 6.25?

glutamic acid (pi = 3.08)

which of the following is true about glycerophospholipids?

glycerophospholipids are merely a subset of phospholipids

collagen consists of three helices with carbon backbones that are tightly wrapped around one another in a "triple helix". which of these amino acids is most likely to be found in the highest concentration in collage?

glycine

given that a protein is composed of non polar amino acids and displays typical patterns of protonation/and deprotonation for neutral amino acids, which of the following amino acids is the protein most likely composed of?

glycine, isoleucine, proline

which of the following hormones does NOT directly regulate the activity of hormone sensitive lipase in adipose tissue?

glycogen

which two polysaccharides share all of their glycosidic linkage types in common?

glycogen and amylopectin

andersen's disease (glycogen storage disease type iv) is a condition characterized by a glycogen branching enzyme. absence of this enzyme would be likely to cause all of the following effects EXCEPT:

glycogen devoid of a 1,4 linkages

after an overnight fast, which of the following processes would be expected to occur at an elevated rate compared with the well fed state?

glycogenolysis

after an overnight fast, which of the following enzymes would be expected to have little if any, physiological activity?

glycokinase

the strecker synthesis is often conducted produce racemic mixtures of methionine. which of the following is not a starting component of the strecker synthesis?

grignard reagent

aldonic acids are compounds that:

have been oxidized and have acted as reducing agents

what benefits does the linear polymer structure of dna, rna, and protein provide during transcription and translation?

helps transfer and preserve information encoding

which of the following is NOT a difference between heterochromatin and euchromatin?

heterochromatin is found in the nucleus, whereas euchromatin is in the cytoplasm

each of the following catalyzes a rate limiting step of a carbohydrate metabolism pathway EXCEPT:

hexokinase

which of these amino acids has a side chain that can become ionized in cells?

histidine

how do hormonal controls of glycogen metabolism differ from allosteric controls?

hormonal control is systemic and covalent

which of the following statements regarding polymerase chain reaction is FALSE?

human dna polymerase

an a helix is most likely to held together by:

hydrogen bonds

statin drugs inhibit hmg coa reductase. as such, they are likely prescribed for:

hypercholesterolemia (high cholesterol)

a patient has been exposed to a toxic compound that increases the permeability of mitochondrial membranes to protons. which of the following metabolic changes would be expected in the patient?

increased oxygen utilization

after a brief period of intense exercise, the activity of muscle pyruvate dehydrogenase is greatly increased. this increased activity is most likely due to:

increased pyruvate concentration

human dna polymerase is removed from the freezer and placed in a 60 degrees c water bath. which of the following best describes the change in enzyme activity as the polymerase sample comes to thermal equilibrium with the water bath?

increases then decreases

in which part of the cell is cytochrome c located?

inner mitochondrial membrane

when glucose is in a straight chain formation, it:

is one of a group of 16 stereoisomers

how does the gel for isoelectric focusing differ from the gel for traditional electrophoresis?

isoelectric focusing uses a gel with a ph gradient that encourages a variable charge

which of the following amino acids will provide the most energy when degraded?

isoleucine

what role does peptide transferase play in protein syntheses?

it catalyzes the formation of a peptide bond

in high doses, aspirin functions as a mitochondrial uncoupler. how would this affect glycogen stores?

it causes depletion of glycogen stores

the amino acid histidine is often found in the active site of several enzymes. which of the following best explains why this is true?

its side chain has a pka similar to physiological ph, allowing it to protonate and deprotonate easily

which of the following is true regarding ketolysis?

ketolysis generates acetyl coa

which of the following best describes how the body creates or processes ketone bodies?

ketone bodies are produced in the mitochondria of liver cells after prolonged fasting

ketose sugars may have the ability to act as reducing sugars. which process explains this?

ketose sugars undergo tautomerization

a respiratory quotient approaching 0.6 indicates metabolism primarily of which macromolecule?

lipids

which of the following organs does NOT require a constant supply of glucose from the blood for energy during a fast?

liver

tumor suppressor genes are most likely to result in cancer through:

loss of function mutations

the conversion of atp to cyclic amp and inorganic phosphate is most likely catalyzed by which class of enzyme?

lyase

during which phase of the cell cycle are dna repair mechanisms least active?

m

what is the function of reverse transcriptase?

making dna from rna

which of the following is digestible by humans and is made of only one type of monosaccharide?

maltose

soap bubbles form because fatty acid salts organize into:

micelles

which of the following statements about saturation is FALSE?

more saturated fatty acids make for a more fluid solution

which of the following is least likely to cause denaturation of proteins?

moving it to a more hypotonic environment

the formation of a glucopyranose from b d glucopyranose is called:

mutarotation

a researcher investigates one mechanism of folding and salvation layer formation. the protein studied is rich in phenylalanine and leucine amino acids. when the protein is submerged in an aqueous solution, the water molecules in the salvation layer cannot form hydrogen bonds with the protein's side chain. what will most likely result from the occurrence of this phenomenon?

nearby water molecules will rearrange themselves in order to maximize hydrogen bonding

in the equation below, substrate c is an allosteric inhibitor to enzyme 1. which of the following is another mechanism necessarily caused by substrate c? a > (enzyme 1) b > (enzyme 2) > c

negative feedback

in the genetic code of human nuclear dna, one of the codons specifying the amino acid tyrosine is uac. if one nucleotide is changed and the codon is mutated to lag, what type of mutation will occur?

nonsense mutation

which enzyme converts gdp to gtp?

nucleosidediphosphate kinase

the reduction half reaction in the last step of the electron transport chain is:

o2 + 4 e- + 4 h+ > 2 h2o

due to their greater stability, antiparallel beta sheets tend to withstand greater physical and solvent induced distortions than their parallel counterparts. this can be attributed to the fact that the polymers in an antiparallel beta pleated sheet run in ___ directions and polymers in a parallel beta pleated sheet run in ___ directions

opposite, same

in glucose degradation under aerobic conditions:

oxygen is the final electron acceptor

a researcher is able to denature a solution with low ph. which of the following bonds is not broken in this solution?

peptide

a particular a helix is known to cross the cell membrane. which of these amino acids is most likely to be found in the transmembrane portion of the helix?

phenylalanine

in a single strand of a nucleic acid, nucleotides are linked by:

phosphodiester bonds

which of the following enzymes is NOT used to trap sugar in the cell?

phosphofructokinase

an investigator is measuring the activity of various enzymes involved in reactions of intermediary metabolism. one of the enzymes has greatly decreased activity compared to reference values. the buffer of the assay contains citrate. which of the following enzymes will most likely be directly affected by the use of citrate?

phosphofructokinase 1

during a myocardial infarction, the oxygen supply to an area of the heart is dramatically reduced, forcing the cardiac myocytes to switch to anaerobic metabolism. under these conditions, which of the following enzymes would be activated by increased levels of intracellular amp?

phosphofructokinase 1

the unique enzymes of gluconeogenesis are used to circumvent specific irreversible steps of glycolysis. which of the following correctly pairs an enzyme from glycolysis with its corresponding enzyme(s) used in gluconeogenesis?

phosphofructokinase I/fructose 1,6 bisphosphate

the dynamic properties of molecules in the cell membrane are most rapid in:

phospholipids moving within the plane of the membrane

the bulk movement of liquid into a cell through vesicular infoldings is known as:

pinocytosis

which of the following is NOT a cell cell junction in animals?

plasmodesmata

compare polymers and monomers

polymer: multiple monomers connected

2,4 dienoyl coa reductase is used in the oxidation of:

polyunsaturated fatty acids

what energy state was described in the introduction to this chapter?

postabsorptive

scientists discover a edna sequence of an uncharacterized protein. in their initial studies, they use a computer program designed to predict protein structure. which of the following levels of protein structure can be most accurately predicted?

primary structure

a mutation in which of the following components of the lac operon would lead to a significant reduction in the expression of lactase (one of the structural genes)?

promote

which of the following statements regarding prostaglandins is FALSE?

prostaglandins are endocrine hormones, like steroid hormones

which of the following is NOT a function of the cell membrane?

protein synthesis

which protein properties allow uv spectroscopy to be used as a method of determining concentration?

proteins contain aromatic groups in certain amino acids

all of the following methods are used to produce acetyl coa in cells EXCEPT for one. what is the exception?

reduction of fatty acids

dna copies itself through a process known as:

replication

which of the following tissues is most dependent on insulin?

resting skeletal muscle

rna is used as a template in the formation of edna through the process of:

reverse transcription

keratins are structural proteins integral to the vertebrate epidermis, the secondary structure or keratin is largely composed of a helices. a majority of these a helices are:

right handed in order to decrease steric hindrance between r groups

which of the following enzymes is NOT involved in DNA replication?

rna polymer I

enhancers are transcriptional regulatory sequences that function by enhancing the activity of:

rna polymerase at a single promoter site

a eukaryotic cell has been found to exhibit a truncation mutation that creates an inactive rna polymerase I enzyme. which type of rna will be affected by this inactivation?

rrna

what is the function of sodium dodecyl sulfate (sds) in sds page?

sds solubilizes proteins to give them negative charges, so the separation is based purely on size

what property of protein digesting enzymes allows for a sequence to be determined without fully degrading the protein?

selectivity

a new protein has been discovered in the bottom of the ocean. researchers want to predict the folding patterns of the protein. which of the following will the researchers most likely analyze for these predictions?

sequence of amino acids in polypeptide

which of the following rna molecules or proteins is NOT found in the spliceosome during intron excision?

shrna

gabriel synthesis is often used in the preparation of primary aromatic amines, which can be used as a starting material in the manufacture of dyes. what types of reaction occurs in gabriel synthesis?

sn2

which of the following is NOT a type of glycolipid?

sphingolipid

the majority of triacylglycerols stored in adipocytes originate from:

synthesis in the liver

following translation and folding, many receptor tyrosine kinases exist as monomers in their inactive state on the cell membrane. upon the binding of a ligand, these proteins dimerize and initiate a signaling cascade. during this process, their highest element of protein structure changes from:

tertiary to quaternary

a protein collected through affinity chromatography displays no activity even though it is found to have a high concentration using the bradford protein assay. what best explains these findings?

the active site is occupied by free ligand

a certain enzyme that displays positive cooperativity has four subunits, two of which are bound to substrate. which of the following statements must be true?

the affinity of the enzyme for the substrate is greater than with one substrate bound

why is the a anomer of d glucose less likely to form than the b anode?

the b anomer undergoes less electron repulsion

why are triacylglycerols used in the human body for energy storage?

the carbon atoms of the fatty acid chains are highly reduced and therefore yield more energy upon oxidation

which of the following statements conflicts with the fluid mosaic model?

the cell membrane is static in structural

a researcher works with a protein composed of non polar amino acids that is found in human blood. the researcher studies the behavior of amino acids within the protein after exposure to different conditions condition 1: ph = 2 condition 2: ph = 10 condition 3: ph = 6.8 which of the following is true?

the cooh group is negative while the amino group is positive under condition 3

consider a biochemical reaction a > b, which is catalyzed by a > b dehydrogenase. which of the following statements is true?

the free energy change (delta g) of the catalyzed reaction is the same as for the uncatalyzed reaction

which of the following statements is true about the hydrolysis of atp?

the free energy of hydrolysis of atp is nearly the same for adp

how does the ideal temperature for a reaction change with and without an enzyme catalyst?

the ideal temperature is generally lower with a catalyst than without

how does the inner mitochondrial membrane differ from the outer mitochondrial membrane?

the inner mitochondrial membrane is less permeable and lacks cholesterol

cysteine has a thiol group as part of its side chain. why does cysteine preferentially disulfide bonds in the extracellular environment?

the interior space is a reducing environment; the exterior space is an oxidizing environment

for a compound to be aromatic, all of the following must be true EXCEPT:

the molecule contains alternating single and double bonds

what is most likely to occur if a patient with hiv is administered a medicinal drug that deactivates the enzyme reverse transcriptase?

the patient's chances at survival will increase

which of the following factors determine an enzyme's specificity?

the three dimensional shape of the active site

which of the following statements is most likely to be true of non polar r groups in aqueous solution?

they are hydrophobic and found buried within proteins

which of the following is true of amphipathic molecules?

they are important to the formation of the phospholipid bilayer and soap bubbles

all of the following are true of epimers EXCEPT:

they have equal but opposite optical activities

glucocorticoids have been implicated in stress related weight gain because:

they increase glucose levels, which causes insulin secretion

why is it preferable to cleave thirster links rather than typical ester links in aerobic metabolism?

thioester hydrolysis has a higher energy yield

which of the following best describes the structure of steroids?

three cyclohexane rings, one cyclopentane ring

which lipid type is LEAST likely to contribute to membrane fluidity?

trans glycerophospholipids

dna is used as a template to generate rrna in a process known as:

transcription

how can one easily differentiate transcription and translation using base words "script" and "translate"?

transcription: using a script of dna to make rna translation: using rna to translate into protein

protein is generated using rna as instructions in a process known as:

translation

a membrane receptor is most likely to be a(n):

transmembrane protein with catalytic activity

what is the fate of long chain fatty acids that are contained with micelles?

transport into chylomicrons released into the lymphatic system

a researcher treats a solution containing animal cells with ouabain, a poisonous substance that interferes with the sodium potassium atpase embedded in the cell membrane, and the cell lyses as a result. which of the following statements best describes ouabain's effects?

treatment with ouabain increases intracellular concentrations of sodium

which of the following is LEAST likely to be required for a series of metabolic reactions?

triacylglycerol acting as a coenzyme

during saponification:

triacylglycerols undergo ester hydrolysis

which of the following processes has the following net reaction? 2 acetyl coa + 6 nad+ + 2 fad + 2 gap + 2 pi + 6 h2o > 4 co2 + 6 nadh + 2 fadh2 + 2 gtp + 6 h+ + 2 coa sh

tricarboxylic acid cycle

what is the primary function of transfer rna (trna) vs ribosomal rna (rrna)?

trna: carries amino acids to the ribosome rrna: structure and function of the ribosome

when trypsin converts chymotrypsinogen to chymotrypsin, some molecules of chymotrypsin bind to a repressor, which in turn binds to an operator region and prevents further transcription of trypsin. this is most similar to which of the following operons?

trp operon during abundance of tryptophan

dna, rna, and protein are all linear polymers

true

the genetic material of (+) ssrna viruses (such as coronavirus) is translated immediately by host cell machinery as compared with dna viruses and retroviruses

true

a researcher wishes to introduce a mutation to an enzyme the utilizes threonine to bind reactants in its active site. which of the following amino acids would replace threonine in such a way to inhibit the activity of the enzyme?

tryptophan

val trna val is the trna that carries valine to the ribosome during translation. which of the following sequences gives an appropriate anticodon for this trna? (note: refer to figure 7.5 for a genetic code table)

uac

which ion channels are responsible for maintaining the resting membrane potential?

ungated channels

high levels of cyclin dependent kinase activity have been impacted in tumorigenesis. which of the following amino acid's r groups would likely remain unchanged in the presence of kinase?

w

which of the statements regarding waxes is FALSE?

waxes are produced only in plants and insects and therefore must be consumed by humans

ser108 and gln114 are residues in the same a helix of an antibody. a hydrogen bond:

will not form between these two residues

in a neutral solution, most amino acids exist as:

zwitterions