Deck 12: Metabolism and Bioenergetics

Question 1

Plants are considered _____.

A) chemoautotrophs
B) photoautotrophs
C) chemoheterotrophs
D) photoheterotrophs
E) none of the above

Answer 1

photoautotrophs

Question 2

Digestion of food by mammals converts _____ into _____ which can be absorbed from the intestines.

A) proteins; dipeptides and tripeptides
B) polysaccharides; monosaccharides and disaccharides
C) cholesterol; acetyl CoA
D) nucleic acids; polynucleotides
E) triacylglycerols; fatty acids

Answer 2

triacylglycerols; fatty acids

Question 3

Digestion of food utilizes enzymes that catalyze _____ reactions.

A) hydrolysis
B) reduction
C) condensation
D) oxidative
E) group transfer

Answer 3

hydrolysis

Question 4

Which of the following is used to move lipids around the bloodstream?

A) micelles
B) liposomes
C) liposuctions
D) lipoproteins
E) cholesterol esters

Question 5

The bulk of triacylglycerols in the human body are stored in _____.

A) liver cells
B) adipocytes
C) muscle cells
D) nerve cells
E) lipoproteins

Question 6

The _____ stores glucose as glycogen and converts excess glucose to _____.

A) muscle; amino acids
B) adipose tissue; fatty acids
C) liver; fatty acids
D) brain; energy
E) none of the above

Question 7

Amino acids can be converted to _____.

A) carbohydrates
B) fatty acids
C) nucleotides
D) peptides
E) all of the above

Question 8

Which of the following is mobilized for energy use by a phosphorolysis reaction, not a hydrolysis?

A) glycogen
B) protein
C) triacylglycerols
D) polynucleotides
E) cholesterol esters

Question 9

Degradation of proteins within a cell can occur within the _____ or by use of _____.

A) endoplasmic reticulum; protease enzymes chymotrypsin and trypsin
B) Golgi apparatus; protease enzymes chymotrypsin and trypsin
C) endoplasmic reticulum; a proteasome
D) lysosome; a proteasome
E) mitochondria; ubiquitin

Question 10

The _____-terminus of ubiquitin is linked to a _____ residue of proteins to be degraded.

A) N; Asp
B) N; Glu
C) C; Lys
D) C; Ser
E) C; Tyr

Question 11

Which of the following molecules is involved with the oxidation of glucose, synthesis of fatty acids and oxidation of fatty acids?

A) pyruvate
B) acetyl-CoA
C) alanine
D) oxaloacetate
E) glyceraldehyde-3-phosphate

Question 12

Which of the following is more highly oxidized than acetaldehyde?

A) ethane
B) ethanol
C) ethylene
D) ethylene glycol
E) acetic acid

Question 13

The oxidized form of NADH is _____.

A) NADH⁺
B) NAD⁺
C) NADH
D) NADH₂
E) none of the above

Question 14

Which of the following molecules is in the most reduced state?

A) methane
B) formaldehyde
C) formic acid
D) methanol
E) carbon dioxide

Question 15

The conversion of a carbohydrate into CO₂ is a(n) _____ process; the conversion of CO₂ into a carbohydrate is a(n) _____ process.

A) reductive; oxidative
B) endergonic; exergonic
C) exergonic; endergonic
D) oxidative; exergonic
E) endergonic; reductive

Question 16

Which of the following is a lipid-soluble electron carrier in its reduced state?

A) NADPH
B) NADH
C) NAD⁺
D) ubiquinol
E) ubiquinone

Question 17

Which of the following is correct regarding metabolic pathways?

A) most pathways are isolated from other pathways
B) the activity of most pathways is not regulated
C) all cells within a multi-cellular organism contain the same pathways
D) anabolic pathways never occur at the same time as catabolic pathways
E) none of the above are correct

Question 18

Which of the following is correctly described?

A) proteome: the complete set of proteins present in a cell at a given time
B) metabolome: the complete set of metabolic enzymes active in a cell at a given time
C) transcriptome: the complete set of proteins being synthesized at a given time
D) genome: the complete set of genes that are expressed at a given time
E) none of the above

Question 19

Which of the following is an essential amino acid?

A) Ala
B) Val
C) Cys
D) Tyr
E) Gly

Question 20

Which of the following vitamins is correctly paired with its biochemical function?

A) folic acid: carboxylation reactions
B) biotin: decarboxylation reactions
C) riboflavin: acyl transfer reactions
D) pyridoxine: amino-group transfer reactions
E) pantothenic acid: redox reactions

Question 21

Which of the following vitamins is correctly paired with the disease that is caused by its deficiency?

A) biotin: scurvy
B) pantothenic acid: beriberi
C) nicotinamide: pellagra
D) thiamine: anemia
E) folic acid: rickets

Question 22

When a reaction is at equilibrium, the $\Delta$ G is equal to _____.

A) 1
B) 0
C) -1
D) $\Delta$ G°
E) none of the above

Question 23

If the $\Delta$ G° is known, how can K_eq be calculated?

A) K_eq = log e^{( $\Delta$ G° 11ee7c68_2bc0_26ba_ae82_e338791695a2_TBW1044_11 /RT)}
B) K_eq = e^{( $\Delta$ G° 11ee7c68_2bc0_26ba_ae82_e338791695a2_TBW1044_11 /T $\Delta$ S)}
C) K_eq = RT ln $\Delta$ G° 11ee7c68_2bc0_26ba_ae82_e338791695a2_TBW1044_11
D) K_eq = e^{-( $\Delta$ G° 11ee7c68_2bc0_26ba_ae82_e338791695a2_TBW1044_11 /RT)}
E) K_eq = ln ( $\Delta$ G° 11ee7c68_2bc0_26ba_ae82_e338791695a2_TBW1044_11 /T $\Delta$ S)

Question 24

For the following reaction, calculate the K_eq at 25°C.
Succinyl-CoA + acetoacetate acetoacetyl-CoA + succinate $\Delta$ G° = -1.25 kJ/mol

A) 0.602
B) 1.00
C) 1.66
D) 3.21
E) 4.22c*c 10²

Question 25

For the following reaction, calculate the $\Delta$ G° at 37°C.
Glucose-6-phosphate fructose-6-phosphate K_eq = 0.517

A) -2.87 kJ/mol
B) -1.70 kJ/mol
C) 0.203 kJ/mol
D) -0.738 kJ/mol
E) 1.70 kJ/mol

Question 26

For the following reaction, calculate the $\Delta$ G at 37°C, given concentrations for glucose-1-phosphate of 25 mM and glucose-6-phosphate of 1 mM.
Glucose-1-phosphate glucose-6-phosphate $\Delta$ G° = -7.1 kJ/mol

A) -15.4 kJ/mol
B) -8.1 kJ/mol
C) -6.1 kJ/mol
D) 1.2 kJ/mol
E) none of the above

Question 27

What is the intracellular glucose concentration if the $\Delta$ G for the following reaction is -20.1 kJ/mol at 37°C and concentrations for glucose-6-phosphate and phosphate are both 1 mM?
Glucose-6-phosphate glucose + P_i $\Delta$ G° = -13.8 kJ/mol

A) 1.9 $\mu$ M
B) 87 $\mu$ M
C) 1.9 mM
D) 27 mM
E) 87 mM

Question 28

Which of the following describes the bonding of the three phosphates to adenosine in ATP? How many phosphoanhydride bonds are found in ATP?

A) one phosphoanhydride bond, two low energy phosphate esters
B) two phosphoanhydride bonds, one low energy phosphate ester
C) three phosphoanhydride bonds, one low energy phosphate ester
D) three phosphoanhydride bonds
E) none of the above

Question 29

If the following reactions were coupled, what would be the overall $\Delta$ G° $\rightarrow$
Glucose + P_i glucose-6-phosphate $\Delta$ G° 11ee7c69_05ae_405c_ae82_f7bc848d8fc6_TBW1044_11 = 13.8 kJ/mol
ATP + H₂O ADP + P_i $\Delta$ G° 11ee7c69_05ae_405c_ae82_f7bc848d8fc6_TBW1044_11 = -30.5 kJ/mol

A) 44.3 kJ/mol
B) 16.7 kJ/mol
C) 0 kJ/mol
D) -16.7 kJ/mol
E) -44.3 kJ/mol

Question 30

Which of the following factors contributes to the highly exergonic nature of ATP hydrolysis?

A) removal of phosphate from the cytoplasm
B) addition of water to the hydrophilic ATP molecule
C) decrease in negative-ion repulsion in ATP
D) low energy of activation for the hydrolysis
E) none of the above

Question 31

Which of the following has the most spontaneous hydrolysis?

A) 1,3-bisphosphoglycerate
B) phosphocreatine
C) glucose-1-phosphate
D) pyrophosphate
E) phosphoenolpyruvate

Question 32

In highly active muscle, _____ is used to regenerate ATP.

A) phosphocreatine
B) 1,3-bisphosphoglycerate
C) pyrophosphate
D) phosphoenolpyruvate
E) acetyl-CoA

Question 33

The $\Delta$ G° for the hydrolysis of acetyl CoA is most similar to the $\Delta$ G° 11ee7c69_05ae_405c_ae82_f7bc848d8fc6_TBW1044_11 for the hydrolysis of _____.

A) 1,3-bisphosphoglycerate
B) ATP
C) glucose-1-phosphate
D) glucose-6-phosphate
E) phosphoenolpyruvate

Question 34

Metabolomics is the study of the metabolic activity of a cell or tissue by identifying and quantifying all of its metabolites.

Question 35

The amino acid ___ is considered essential in humans while ___ is considered non-essential.

Question 36

The reaction below is an example of _________________.

A) dehydration
B) hydration
C) oxidation
D) reduction
E) none of the above

Question 37

Eukaryotes evolved and developed extensive intracellular membraines enclosed in compartments called _______.

A) lysosomes
B) organelles
C) peroxisomes
D) vacuoles

Question 38

Consider the reaction A + B « C + D. After reaching equilibrium at 25°C, the following concentrations of reactants and products were measured: [A] = 10 µM, [B] = 15 µM, [C] = 10 µM, [D] = 10 µM. Calculate $\Delta$ G° for this reaction.

A) 1,000 J/mol
B) 10 kJ/mol
C) 1 J/mol
D) insufficient data to determine answer
E) none of the above

Question 39

Phosphoglucomutase catalyzes the reaction in which a phosphate group is transferred from the C-1 of glucose to the C-6 of glucose (G1P $\rightleftarrows$ G6P). A student incubates a 0.2 M solution of glucose-1-phosphate overnight with a small amount of the enzyme. At equilibrium the concentration of glucose-1-phosphate is 9.0 × 10^-3 M and the concentration of glucose-6-phosphate is 19.1 × 10^-2 M.
Calculate the equilibrium constant (K_eq) and the standard state free energy ( $\Delta$ G°') for this reaction at 25°C.

Question 40

Acetylcholinesterase catalyzes the reaction in which acetylcholine is hydrolyzed into acetate and choline. This is a reversible reaction. A student incubates a 1 M solution of acetylcholine for two hours with 100uL of acetylcholinesterase. At equilibrium the concentration of acetylcholine is 3.0 × 10 mM and the concentration of acetate and choline are 5.2 × 10^-3 M and 7.4 x 10^-2 M, respectively.
Calculate the equilibrium constant (K_eq) and the standard state free energy ( $\Delta$ G°') for this reaction at 17°C.