19 20 21 문제

79問 • 2年前

김소영

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問題一覧

Which of these dehydrogenase enzymes is NOT found in the mitochondrial matrix?

lactate dehydrogenase

Which enzyme would NOT be expected to contribute electron carriers to oxidative phospation?

glucose 6-phosphate dehydrogenase

Which ion, atom, or molecule constitutes one reducing equivalent?

hydrogen atom (H+ + e-)

Which statement is false about the cytochrome electron carriers?

The heme of cytochrome c is tightly, but not covalently, bound to its associated protein.

Which compound is NOT electron carrier involved in the respiratory chain?

coenzyme A

Which electron-carrier complex in the respiratory chain oxidizes ubiquinone?

Complex III

How many electrons would enter Complex I from complete oxidation of myristic acid, 14:0?

Which statement is false about Complex I?

Its activity makes the matrix more positively charged

9. Which electron carrier or prosthetic group would NOT function after site-directed mutagenesis substituted Pro for Cys in succinate dehydrogenase?

iron-sulfur center

Which complex does NOT transport H+ from the mitochondrial matrix to the intermembrane space?

Complex II

Which compound is NOT a direct source of electrons for the respiratory chain?

cytosolic NADH

The electron-transfer chain generates ATP by:

creating a proton-motive force.

Which statement regarding the proton-motive force is false?

It results from an [H+] gradient across the outer mitochondrial membrane.

Why are reactive oxygen species (ROS) generated?

Stray electrons bind to oxygen, creating a free radical oxygen species.

How is production of reactive oxygen species (ROS) controlled?

all the answers are correct

The addition of oligomycin, an inhibitor of ATP synthase, to mitochondria suspended in a buffered medium blocks both ATP synthesis and respiration. What would happen if 2,4-dinitrophenol (DNP) were also added to this suspension?

Respiration would resume without ATP synthesis.

What is the major energy barrier for ATP synthase?

release of ATP from the enzyme

The β subunits of ATP synthase:

have three distinct conformations.

With each rotation of 120°, the γ subunit of FoF1 comes into contact with a different β subunit, forcing that β subunit:

into the β-empty conformation.

Which statement regarding ATP synthase is false?

The γ subunit is stationary as the αβ dimers rotate around it.

Succinate dehydrogenase is dysfunctional in a species of garden slug. While its metabolism is compromised on a number of levels, it can still undergo oxidative phosphorylation. What is the maximal P/O ratio for these organisms if NADH is used as an electron source?

2.5

Why is the malate-aspartate shuttle necessary for oxidative phosphorylation in the liver?

to bring the reducing equivalents of NADH into the mitochondrial matrix

Which molecule is part of an important mass-action ratio in most cells and is a modulator of the three major ATP-producing pathways?

ADP

In hypoxic cells:

a subunit of Complex IV is replaced with another subunit optimized for activity under hypoxic conditions.

How is oxidative phosphorylation inhibited during anaerobic conditions?

All of the answers are correct.

Which statement regarding uncoupling protein 1 (UCP1) is false?

It allows for ATP generation in addition to heat formation

27. Which statement does NOT describe a function associated with mitochondria?

They make xenobiotic compounds more soluble for excretion.

Which factor is NOT associated with acetyl-CoA carboxylase?

production of oxaloacetate

Identify the four-step sequence that facilitates fatty acid synthesis.

condensation, reduction, dehydration, reduction

What is the reducing equivalent necessary for fatty acid synthesis?

NADPH

Fatty acid synthase I of mammals:

uses malonyl-CoA to add two-carbon units to a growing fatty acyl chain.

What is the final product of FAS I systems?

16:0

The second cycle of the fatty acid synthesis cycle begins with the condensation of:

malonyl-CoA with a butyryl group bound to ACP.

Which factor is NOT associated with biosynthesis of palmitate?

production of 8 H2O

The equation for palmitate synthesis by fatty acid synthase is: Acetyl-CoA + 7 malonyl-CoA + 14NADPH + 14H+ → palmitate + 7CO2 + 8CoA + 14NADP+ + 6H2O Why are only six waters produced by palmitate synthesis, not seven?

One water is used to liberate palmitate from the synthase.

What enzymatic step is considered to be the rate-limiting step of fatty acid biosynthesis?

acetyl-CoA carboxylase

Which statement regarding regulation of acetyl-CoA carboxylase is false?

Phosphorylation activates acetyl-CoA carboxylase.

What is the cellular location for fatty acid elongation and desaturation in both plant and animal cells?

endoplasmic reticulum

Linoleate is an essential fatty acid in humans because humans cannot:

desaturate a fatty acid beyond Δ9.

Which of these is NOT a stage in the synthesis of triacylglycerols?

phosphorylation of a monoacylglycerol to form lysophosphatidic acid

Glyceroneogenesis produces:

glycerol 3-phosphate from pyruvate.

In adipose tissue:

some triacylglycerol synthesis occurs, even during starvation.

How many acetyl-CoA molecules does it take to synthesize one molecule of mevalonate?

three

Why is the formation of mevalonate considered the committed step, and rate-limiting step, in cholesterol synthesis?

Mevalonate’s formation requires 2 NADPH, and the next 1three steps each require ATP.

In cholesterol biosynthesis:

all of the carbons originate in acetyl-CoA.

Which of these is NOT one the three primary forms in which cholesterol is exported from the liver?

oxysterols

Which lipoprotein is the largest and least dense?

chylomicron

In the exogenous lipid transport pathway:

chylomicrons transport lipids from intestine to tissues.

HDL particles are the densest lipoprotein because they contain the highest fraction of:

proteins.

Which statement about liver X receptor (LXR) is true?

All of the statements are true.

Regulation of cholesterol biosynthesis:

occurs in the short term primarily by regulating HMG-CoA reductase.

Cholesterol is NOT converted to:

vitamin A.

Which statement about isopentenyl pyrophosphate is false?

It is the activated precursor of sphingomyelin.

Bacteria deep in a corn field fix nitrogen early in the spring. Once the farmer begins plowing the soil, which process would continue while the others slow or stop?

nitrification

During amino acid synthesis, the delivery of the amino group of the amino acid is usually the last step. From where is it donated?

glutamate

The carefully controlled regulation of glutamine synthetase is due, in part, to at least eight allosteric inhibitors. What term BEST describes the kinetics of inhibition?

synergistic

Both adenylylation and uridylylation play uncharacteristic roles in the formation of Gln from Glu. What are those roles?

regulation of glutamine synthetase activity

Which factor is NOT associated with regulation of glutamine synthetase?

covalent activation by adenylylation

Which factor is NOT considered to be a metabolic precursor for amino acid biosynthesis?

succinate

Which molecule is required as an intermediate, not a cofactor of prosthetic group, by some of the pathways for amino acid and nucleotide synthesis?

phosphoribosyl pyrophosphate

From which amino acid is proline derived?

glutamate

Which cofactor does the synthesis of serine from 3-phosphoglycerate require?

NAD+

The generation of which amino acid requires the formation of 3′-phosphoadenosine 5′-phosphosulfate (PAPS)?

cysteine

Which amino acid is required to convert chorismate to anthranilate in the anthranilate synthase reaction?

glutamine

Histidine biosynthesis in bacteria and plants:

requires incorporation of two atoms donated by the adenine base of ATP.

The common general mechanism for regulation of amino acid biosynthesis:

involves feedback inhibition by the end product of the pathway

What is the primary allosteric inhibitor of amino acid synthesis pathways?

the end product amino acid

Which compound is NOT a neurotransmitter derived from tyrosine?

GABA

Which compound is derived from amino acids?

All of the answers are correct

Synthesis of purine nucleotides does NOT directly involve:

serine.

Which pair of molecules do both purine nucleotide and histidine synthesis use early in the pathways?

phosphoribosyl pyrophosphate and ATP

Which enzyme in the de novo purine nucleotide biosynthesis pathway produces the first intermediate with a complete purine ring?

IMP synthase

The conversion of inosinate to adenylate requires Asp, a nucleoside triphosphate, and it produces fumarate. What other pathway has this same strategy?

the urea cycle

Which enzyme in the de novo pyrimidine biosynthesis pathway in bacteria is subject to feedback inhibition by CTP?

aspartate transcarbamoylase

Which enzymes are required to form GTP from ATP?

a nucleoside monophosphate kinase and nucleoside diphosphate kinase

Which B vitamin is required to synthesize thymidylate (dTMP) from uridylate (dUMP)?

folic acid (vitamin B9)

Xanthine oxidase converts:

hypoxanthine to uric acid.

Nucleotide degradation:

results in production of a citric acid cycle intermediate for thymine.

What enzyme catalyzes the conversion of adenine to AMP in the salvage pathway?

adenosine phosphoribosyltransferase

생화학 16,17,18장

생화학 16,17,18장

생화학 14, 15장

생화학 14, 15장

해생2 퀴즈1

해생2 퀴즈1

해생 퀴즈3

해생 퀴즈3

해생 퀴즈4

해생 퀴즈4

해생퀴즈5

해생퀴즈5

생화학 19,21,22장 퀘뱅

생화학 19,21,22장 퀘뱅

생화학 주관식 문제

생화학 주관식 문제

7주차

7주차

독성학

독성학

한약 생약 암기

한약 생약 암기

한약 응용 암기 1

한약 응용 암기 1

Head and neck

Head and neck

問題一覧

Which of these dehydrogenase enzymes is NOT found in the mitochondrial matrix?

lactate dehydrogenase

Which enzyme would NOT be expected to contribute electron carriers to oxidative phospation?

glucose 6-phosphate dehydrogenase

Which ion, atom, or molecule constitutes one reducing equivalent?

hydrogen atom (H+ + e-)

Which statement is false about the cytochrome electron carriers?

The heme of cytochrome c is tightly, but not covalently, bound to its associated protein.

Which compound is NOT electron carrier involved in the respiratory chain?

coenzyme A

Which electron-carrier complex in the respiratory chain oxidizes ubiquinone?

Complex III

How many electrons would enter Complex I from complete oxidation of myristic acid, 14:0?

Which statement is false about Complex I?

Its activity makes the matrix more positively charged

9. Which electron carrier or prosthetic group would NOT function after site-directed mutagenesis substituted Pro for Cys in succinate dehydrogenase?

iron-sulfur center

Which complex does NOT transport H+ from the mitochondrial matrix to the intermembrane space?

Complex II

Which compound is NOT a direct source of electrons for the respiratory chain?

cytosolic NADH

The electron-transfer chain generates ATP by:

creating a proton-motive force.

Which statement regarding the proton-motive force is false?

It results from an [H+] gradient across the outer mitochondrial membrane.

Why are reactive oxygen species (ROS) generated?

Stray electrons bind to oxygen, creating a free radical oxygen species.

How is production of reactive oxygen species (ROS) controlled?

all the answers are correct

Respiration would resume without ATP synthesis.

What is the major energy barrier for ATP synthase?

release of ATP from the enzyme

The β subunits of ATP synthase:

have three distinct conformations.

With each rotation of 120°, the γ subunit of FoF1 comes into contact with a different β subunit, forcing that β subunit:

into the β-empty conformation.

Which statement regarding ATP synthase is false?

The γ subunit is stationary as the αβ dimers rotate around it.

2.5

Why is the malate-aspartate shuttle necessary for oxidative phosphorylation in the liver?

to bring the reducing equivalents of NADH into the mitochondrial matrix

Which molecule is part of an important mass-action ratio in most cells and is a modulator of the three major ATP-producing pathways?

ADP

In hypoxic cells:

a subunit of Complex IV is replaced with another subunit optimized for activity under hypoxic conditions.

How is oxidative phosphorylation inhibited during anaerobic conditions?

All of the answers are correct.

Which statement regarding uncoupling protein 1 (UCP1) is false?

It allows for ATP generation in addition to heat formation

27. Which statement does NOT describe a function associated with mitochondria?

They make xenobiotic compounds more soluble for excretion.

Which factor is NOT associated with acetyl-CoA carboxylase?

production of oxaloacetate

Identify the four-step sequence that facilitates fatty acid synthesis.

condensation, reduction, dehydration, reduction

What is the reducing equivalent necessary for fatty acid synthesis?

NADPH

Fatty acid synthase I of mammals:

uses malonyl-CoA to add two-carbon units to a growing fatty acyl chain.

What is the final product of FAS I systems?

16:0

The second cycle of the fatty acid synthesis cycle begins with the condensation of:

malonyl-CoA with a butyryl group bound to ACP.

Which factor is NOT associated with biosynthesis of palmitate?

production of 8 H2O

One water is used to liberate palmitate from the synthase.

What enzymatic step is considered to be the rate-limiting step of fatty acid biosynthesis?

acetyl-CoA carboxylase

Which statement regarding regulation of acetyl-CoA carboxylase is false?

Phosphorylation activates acetyl-CoA carboxylase.

What is the cellular location for fatty acid elongation and desaturation in both plant and animal cells?

endoplasmic reticulum

Linoleate is an essential fatty acid in humans because humans cannot:

desaturate a fatty acid beyond Δ9.

Which of these is NOT a stage in the synthesis of triacylglycerols?

phosphorylation of a monoacylglycerol to form lysophosphatidic acid

Glyceroneogenesis produces:

glycerol 3-phosphate from pyruvate.

In adipose tissue:

some triacylglycerol synthesis occurs, even during starvation.

How many acetyl-CoA molecules does it take to synthesize one molecule of mevalonate?

three

Why is the formation of mevalonate considered the committed step, and rate-limiting step, in cholesterol synthesis?

Mevalonate’s formation requires 2 NADPH, and the next 1three steps each require ATP.

In cholesterol biosynthesis:

all of the carbons originate in acetyl-CoA.

Which of these is NOT one the three primary forms in which cholesterol is exported from the liver?

oxysterols

Which lipoprotein is the largest and least dense?

chylomicron

In the exogenous lipid transport pathway:

chylomicrons transport lipids from intestine to tissues.

HDL particles are the densest lipoprotein because they contain the highest fraction of:

proteins.

Which statement about liver X receptor (LXR) is true?

All of the statements are true.

Regulation of cholesterol biosynthesis:

occurs in the short term primarily by regulating HMG-CoA reductase.

Cholesterol is NOT converted to:

vitamin A.

Which statement about isopentenyl pyrophosphate is false?

It is the activated precursor of sphingomyelin.

Bacteria deep in a corn field fix nitrogen early in the spring. Once the farmer begins plowing the soil, which process would continue while the others slow or stop?

nitrification

During amino acid synthesis, the delivery of the amino group of the amino acid is usually the last step. From where is it donated?

glutamate

The carefully controlled regulation of glutamine synthetase is due, in part, to at least eight allosteric inhibitors. What term BEST describes the kinetics of inhibition?

synergistic

Both adenylylation and uridylylation play uncharacteristic roles in the formation of Gln from Glu. What are those roles?

regulation of glutamine synthetase activity

Which factor is NOT associated with regulation of glutamine synthetase?

covalent activation by adenylylation

Which factor is NOT considered to be a metabolic precursor for amino acid biosynthesis?

succinate

Which molecule is required as an intermediate, not a cofactor of prosthetic group, by some of the pathways for amino acid and nucleotide synthesis?

phosphoribosyl pyrophosphate

From which amino acid is proline derived?

glutamate

Which cofactor does the synthesis of serine from 3-phosphoglycerate require?

NAD+

The generation of which amino acid requires the formation of 3′-phosphoadenosine 5′-phosphosulfate (PAPS)?

cysteine

Which amino acid is required to convert chorismate to anthranilate in the anthranilate synthase reaction?

glutamine

Histidine biosynthesis in bacteria and plants:

requires incorporation of two atoms donated by the adenine base of ATP.

The common general mechanism for regulation of amino acid biosynthesis:

involves feedback inhibition by the end product of the pathway

What is the primary allosteric inhibitor of amino acid synthesis pathways?

the end product amino acid

Which compound is NOT a neurotransmitter derived from tyrosine?

GABA

Which compound is derived from amino acids?

All of the answers are correct

Synthesis of purine nucleotides does NOT directly involve:

serine.

Which pair of molecules do both purine nucleotide and histidine synthesis use early in the pathways?

phosphoribosyl pyrophosphate and ATP

Which enzyme in the de novo purine nucleotide biosynthesis pathway produces the first intermediate with a complete purine ring?

IMP synthase

The conversion of inosinate to adenylate requires Asp, a nucleoside triphosphate, and it produces fumarate. What other pathway has this same strategy?

the urea cycle

Which enzyme in the de novo pyrimidine biosynthesis pathway in bacteria is subject to feedback inhibition by CTP?

aspartate transcarbamoylase

Which enzymes are required to form GTP from ATP?

a nucleoside monophosphate kinase and nucleoside diphosphate kinase

Which B vitamin is required to synthesize thymidylate (dTMP) from uridylate (dUMP)?

folic acid (vitamin B9)

Xanthine oxidase converts:

hypoxanthine to uric acid.

Nucleotide degradation:

results in production of a citric acid cycle intermediate for thymine.

What enzyme catalyzes the conversion of adenine to AMP in the salvage pathway?

adenosine phosphoribosyltransferase