Deck 16: Nutrition and the Organization of Metabolism

Question 1

Which of the following 2 energy-rich primary products are generated from the transformation of light energy into chemical energy in phototrophs?

A)ATP and NAD⁺
B)NADPH and ATP
C)NADH and NADPH
D)ATP and NADH

Answer 1

B

Question 2

Which of the following regarding metabolic pathways is correct?

A)Catabolic pathways are generally reductive,while anabolic pathways are generally oxidative.
B)Catabolic pathways use a wide variety of substrates to produce a small number of waste products.
C)An amphibolic pathway is extremely wasteful because it simultaneously operates as both an anabolic pathway and a catabolic pathway.
D)NAD⁺ is used as a reducing agent in catabolic pathways,while NADPH is used as an oxidizing agent in anabolic pathways.

Answer 2

B

Question 3

Which of the following concerning obligate anaerobes is correct?

A)These organisms can use oxygen if it is present in their environment.
B)These organisms cannot use oxygen as their final electron acceptor.
C)These organisms carry out fermentation for at least 50% of their ATP production.
D)Most of these organisms are vegetative fungi.

Answer 3

B

Question 4

Which of the following terms classifies species that can adapt to anaerobic conditions by substituting other electron acceptors for oxygen in their energy-producing pathways?

A)aerobes
B)obligate aerobes
C)facultative anaerobes
D)obligate anaerobes

Question 5

Which of the following are the final products of aerobic catabolism?

A)pyruvate and H₂O
B)acetyl-CoA and CO₂
C)CO₂ and H₂O
D)pyruvate and acetyl-CoA

Question 6

Solar energy is converted to the chemical energy of organic molecules by photoautotrophs.Which of the following species recovers this energy by metabolizing the organic substrates?

A)heterotrophs
B)chemoautotrophs
C)homotrophs
D)aerobes

Question 7

Which of the following regarding the relationship between catabolism and anabolism is correct?

A)They occur in many of the same organelles.
B)They occur at different times.
C)Products of one process provide substrates for the other.
D)Anabolism is exergonic while catabolism is endergonic.

Question 8

In which of the following major pathways do most organisms show marked similarity?

A)metabolism
B)sleep patterns
C)gene expression
D)cell division

Question 9

Which of the following do chemoheterotrophs require?

A)organic carbon sources and light
B)carbon dioxide and light
C)organic carbon sources and oxidation-reduction reactions
D)carbon dioxide and oxidation-reduction reactions

Question 10

Which of the following is NOT a characteristic of metabolon?

A)separate units of enzymes
B)discrete multi-enzyme complex
C)soluble enzymes associated into stable multi-enzyme complexes
D)membrane-bound multi-enzyme systems

Question 11

Which of the following terms defines the most ancient of the metabolic pathways in which energy is released from glucose and captured in the form of ATP under anaerobic conditions?

A)photo-oxidation
B)oxidative phosphorylation
C)citric acid cycle
D)glycolysis

Question 12

Which of the following is NOT a characteristic of metabolism?

A)a process that synthesizes either energy or complex cellular substances
B)a process of intermediates
C)the conversion of food energy into energy of motion
D)a free-flow unregulated process

Question 13

Which of the following lifeforms is NOT a chemoheterotroph?

A)Staphylococci aureus
B)fungus
C)alga
D)animal

Question 14

Which of the following is a characteristic of anabolism?

A)formation of new covalent bonds
B)breakdown of complex molecules
C)formation of ATP
D)acceptance of electron by NADPH

Question 15

Which of the following are differences between photoautotrophs and heterotrophic cells?

A)Photoautotrophs use light energy for synthesis of organic molecules,while heterotrophs metabolize organic substances for fuel and building blocks.
B)Photoautotrophs use organic compounds as a source of carbon,while heterotrophs use CO₂ as a source of carbon.
C)Photoautotrophs synthesize CO₂,while heterotrophs synthesize O₂.
D)Heterotrophs convert solar energy into chemical energy,while photoautotrophs break down organic molecules.

Question 16

Which of the following pathways synthesizes glucose from non-carbohydrate precursors,uses 7 of the same enzymes as glycolysis,but must replace 3 enzymes of glycolysis because they are irreversible?

A)Glycogenolysis
B)gluconeogenesis
C)oxidative phosphorylation
D)fatty acid synthesis

Question 17

Which of the following common 2-carbon intermediates do many of the catabolic pathways converge to?

A)glucose
B)acetyl group of acetyl-CoA
C)lactic acid
D)carbon dioxide

Question 18

Which of the following is the major advantage of a multi-enzyme complex?

A)Its large size enables it to span an entire membrane.
B)The product of one enzyme is passed directly to the next enzyme without the possibility of diffusion.
C)Multi-enzyme complexes are much less likely to be inhibited.
D)It confers enzyme instability.

Question 19

Which of the following statements defines an amphibolic pathway?

A)a pathway found in animals living in both land and water
B)a pathway that is carried out in both water and organic solvents
C)a pathway found on both sides of the mitochondrial membrane
D)a pathway that is both anabolic and catabolic in nature

Question 20

Which of the following enzymes serve as the points of regulation in the case of shared anabolic and catabolic pathways?

A)largest enzymes
B)ATP-producing enzymes
C)NADH utilizing enzymes
D)rate-limiting enzymes

Question 21

Which of the following is a possible function of NADPH?

A)to provide reducing equivalents to synthesize glucose from CO₂
B)to carry electrons from anabolic reactions
C)to provide a source of hydrogens for oxidative biosynthesis
D)to be reduced by hydride ions to form NAD⁺

Question 22

Which of the following conditions does NOT have an increased risk associated with it when correlated with excess dietary fat levels?

A)sickle cell anemia
B)heart disease
C)colon cancer
D)breast cancer

Question 23

What of the following arenutritional benefit(s)provided by foods high in fibre?

A)increased speed of digestion
B)stimulation of regular functions of the colon and slowing the rate of absorption of certain foods
C)growth of microorganisms that utilize fibre
D)increased vitamin release from complexes with fibre

Question 24

In which of the following cellular compartments are the enzymes of glycolysis and those of the citric acid cycle found in muscle cells?

A)both in the lumen of the endoplasmic reticulum
B)glycolysis in cytoplasm and citric acid cycle in mitochondria
C)both in mitochondria
D)glycolysis in cytoplasm and citric acid cycle in lumen of the endoplasmic reticulum

Question 25

Which of the following is a result of a high-fat,high-protein,low-carbohydrate diet?

A)The bloodstream has a healthy level of ketone bodies.
B)Glycogen stores are close to maximum capacity.
C)The brain operates most efficiently on this type of diet.
D)Ketone body production generally exceeds rate of elimination.

Question 26

Which of the following does light oxidize in photosynthesis as NADPH is generated?

A)water
B)CO₂
C)NADH
D)ATP

Question 27

Which is of the following is a characteristic of aerobic catabolic pathways?

A)Carbohydrates are hydrolyzed to monosaccharides and then reduced.
B)ATP is hydrolyzed toADP in such pathways.
C)Water is oxidized to O₂.
D)Carbon fuels are oxidized to CO₂.

Question 28

Which of the following is NOT an example of energy transduction?

A)dehydrogenase catalyzed reactions
B)isomerase reactions
C)oxidative phosphorylation
D)NAD⁺-NADH shuttle

Question 29

Which of the following is the major advantage of nuclear magnetic resonance (NMR)spectroscopy for the investigation of metabolism?

A)It utilizes radioisotopes.
B)It utilizes specific metabolic inhibitors.
C)It utilizes autoradiography.
D)It utilizes non-invasive techniques.

Question 30

Which of the following components is excess dietary protein converted into when an individual has a positive nitrogen balance?

A)ribosomes for storage
B)triacylglycerols for storage
C)cholesterol for storage
D)nucleic acids for storage

Question 31

Which of the following vitamins is NOT a coenzyme or a precursor of a coenzyme?

A)thiamine
B)riboflavin
C)retinol
D)niacin

Question 32

By which of the following mechanisms is energy generally extracted from phototrophs and chemotrophs?

A)hydrolysis reactions
B)condensation-cleavage reactions
C)oxidative-reduction reactions
D)acid-base reactions

Question 33

Which of the following is NOT a characteristic of coenzymes?

A)carry functional groups
B)maintain original structure
C)provide a broader range of catalytic properties
D)can be derived from water-soluble vitamins

Question 34

Which of the following is NOT correct regarding nutrition?

A)Dietary protein is a source of essential amino acids.
B)Organisms can produce all of the essential energy-yielding nutrients and micronutrients needed.
C)Complex carbohydrates can provide simple sugars for the glycolytic pathway.
D)Essential fatty acids are components of biological membranes.

Question 35

Which of the following components is excess carbohydrate converted to when dietary carbohydrate consumption exceeds the energy needs of the individual?

A)amino acids and glucose
B)fructose and triacylglycerols
C)triacylglycerols and glycogen
D)glycogen and protein

Question 36

Which of the following are dehydrogenases?

A)Enzymes that move hydrogens within the molecule.
B)Enzymes that add hydrogens across double bonds.
C)Enzymes that transfer hydrogens between substrates.
D)Enzymes that transfer hydride ions to NAD⁺ (or NADP+)and release a proton.

Question 37

Which of the following organic molecules is the most oxidized?

A)aldehyde
B)hydrocarbon
C)CO₂
D)alcohol

Question 38

Which of the following is formed from acetate units to provide metabolic fuel for the brain and other tissue when carbohydrate intake is low?

A)fatty acids
B)ketone bodies
C)amino acids
D)sterols

Question 39

Which of the following cellular components carries out both phospholipid synthesis and oxidative phosphorylation in prokaryotic cells?

A)plasma membrane
B)cytosol
C)mitochondrion
D)endoplasmic reticulum

Question 40

Which of the following is NOT a dietary fibre?

A)maltose
B)pectin
C)cellulose
D)lignin

Question 41

Which of the following components is the mobile carboxyl-group carrier that binds to the enzyme at an ε-amino group of lysine in a variety of enzymatic carboxylations?

A)TPP
B)lipoate
C)propionate
D)biotin

Question 42

Which of the following is a characteristic difference between FAD and NAD⁺?

A)NAD⁺ is a stronger oxidizing agent than FAD.
B)NAD⁺ is reoxidized easily by molecular oxygen,while FAD is not.
C)NAD⁺ binds tightly to its enzyme,while FAD only binds loosely.
D)NAD⁺ transfers 2 electrons,while FAD can transfer 1 or 2.

Question 43

Unsaturated fatty acids in membranes are particularly susceptible to oxidation.Which of the following vitamins may provide protection against this because it is a potent antioxidant?

A)E
B)D₂
C)C
D)B₁₂

Question 44

Which of the following digestion and absorption pathways do retinol and the carotenoids follow?

A)complex carbohydrate
B)protein
C)lipid
D)nucleic acid

Question 45

Which of the following is NOT correct regarding the diseases caused by vitamin deficiencies?

A)Niacin deficiency leads to gout.
B)Vitamin A deficiency leads to night blindness,which can be reversed by adding ?-carotene to the diet.
C)Vitamin B?? prevents pernicious anemia.
D)Vitamin D deficiency leads to demineralization of bones and rickets.

Question 46

Pantothenic acid is the vitamin portion of coenzyme A.Which of the following types of linkages does it form with acyl groups?

A)phosphoanhydride
B)thiosulfur
C)phosphoester
D)thioester

Question 47

Which of the following products are generated when pyruvate,CoA,and NAD⁺ react?

A)succinyl-CoA;CO₂;NAD⁺
B)malonyl-CoA;CO₂;NADH + H⁺
C)methylmalonyl-CoA;CO₂;biotin
D)acetyl-CoA;CO₂;NADH + H⁺

Question 48

Most biotin-dependent carboxylations use a bicarbonate as the carboxylating agent.To which of the following substrates do they transfer the carboxyl group?

A)hydroxyl
B)carboxyl
C)carbonium ion
D)carbanion

Question 49

Which of the following vitamins is needed for coagulation of blood,and what must happen for it to be functional?

A)vitamin D;a co-translational modification of serine
B)vitamin K;a posttranslational carboxylation of glutamate
C)vitamin D;a posttranslational glycosylation of serine
D)vitamin E;a posttranslational glycosylation of tyrosine

Question 50

Which of the following compounds functions to couple acyl-group transfer and electron transfer during oxidation and decarboxylations of α-keto acids?

A)biotin
B)propionate
C)lipoate
D)TPP

Question 51

Which of the following reactions is NOT involved with pyridoxal-5-phosphate (PLP)?

A)phosphorylations
B)racemizations
C)?- and ?-decarboxylations
D)?- and ?-eliminations

Question 52

Which of the following coenzymes does NOT participate in electron transfer?

A)FAD
B)biotin
C)NAD⁺
D)vitamin C

Question 53

Which of the following is higher in thioesters than in oxygen esters?

A)electronegativity
B)resonance
C)group transfer potential
D)positive ΔG

Question 54

The dehydrogenase enzymes facilitate the direct transfer of hydride anion.Which of the following coenzymes is required for this transfer?

A)biotin
B)folic acid
C)NAD⁺
D)lipoic acid

Question 55

Which of the following properties causes pyridoxal-5-phosphate (PLP)to be so versatile?

A)its very quick reaction with simple sugars
B)its ability to be a 1- or 2-electron carrier
C)its ability to form a Schiff base and act as an electron sink
D)its ability to transfer methyl groups

Question 56

Cholecalciferol is hydroxylated twice to form 1,25-dihydroxycholecalciferol,which acts like a hormone.Which of the following does it regulate?

A)calcium and chloride metabolism
B)sodium and calcium metabolism
C)calcium and phosphate metabolism
D)sodium and phosphate metabolism

Question 57

Which of the following vitamins is essential to vision?

A)vitamin A
B)vitamin C
C)vitamin D₂
D)vitamin B₁₂

Question 58

Which of the following is NOT a coenzyme with an adenine nucleotide portion?

A)ATP
B)NADH
C)FMNH₂
D)FADH₂

Question 59

Which of the following are the principal minerals in the human body?

A)iron and chloride
B)sodium and potassium
C)sulfur and phosphorus
D)calcium and phosphorus