24. Nutrition, Metabolism, Energy Balance

Which of the following statements is false?

a. Metabolism is the sum of all the reactions in the body.

b. Anabolic pathways are exergonic and release energy.

c. Catabolic pathways break larger substances into smaller substances.

d. The body 'pays for' anabolic reactions with the energy from catabolic reactions.

Which nutrient is the preferred fuel for essentially every cell in the body?

a. Glucose

b. Fatty acids

c. Glycerol

d. Amino acids

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

a. During an oxidation-reduction reaction, the compound with the greatest electron affinity accepts electrons and is oxidized.

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

b. The electromotive force is generated by the flow of electrons from one substance that is oxidized to another substance that is reduced.c.

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

c. NAD+ and FAD are electron carriers in the cell.

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

d. ATP is the 'money' that the cell uses to 'pay for' the cell's exergonic reactions.

Does ATP possess a 'high-energy bond'? Explain. How does ATP provide energy to drive a reaction or process?

Place the following events of glucose catabolism in the correct order, placing a 1 by the first event, a 2 by the second, and so forth.

________Electrons are passed between electron carriers in the inner mitochondrial membrane, and hydrogen ions are pumped into the intermembrane space.

________ATP is generated in the cytosol by substrate-level phosphorylation; NADH is generated as well. Hydrogen ions pass through the channel of ATP synthase and ATP is released from the enzyme.

________Acetyl-CoA is combined with oxaloacetate to form citrate.

________ATP is consumed to split glucose into two three-carbon compounds.

________Pyruvate loses a carbon, forming acetyl-CoA, carbon dioxide, and NADH.

________Citrate undergoes a series of oxidation-reduction reactions that generate ATP, NADH, and FADH2.

Which of the following statements is false?

a. Oxaloacetate is regenerated at the completion of the citric acid cycle.

b. Glycolysis takes place in the cytosol.

c. The energy yield from oxidative phosphorylation is much greater than the yield from substrate-level phosphorylation.

d. The electromotive force directly generates ATP.

What is the role of oxygen in oxidative phosphorylation?

The amino groups from amino acid catabolism are eliminated as which of the following compounds?

a. Uric acid

b. Ammonium ions

c. Ammonia

d. Urea

Mark the following as true or false. If a statement is false, correct it to make a true statement.

a. The reactions of β-oxidation crop fatty acids into three-carbon pyruvate units.

Which of the following can be used to synthesize fatty acids?

a. Glucose

b. Amino acids

c. Both a and b

d. Neither a nor b

Identify the following characteristics as belonging to the absorptive state or the postabsorptive state.

a. Ketogenesis occurs.________

b. Gluconeogenesis and glucose sparing take place.________

c. Glycogenesis and lipogenesis take place.________

d. Protein synthesis decreases or stops.________

e. Glucose is readily available and is used as the primary fuel for most cells.________

f. Lipolysis releases fatty acids into the blood.________

Why is heat production a good way to measure the body's metabolic rate?

Which of the following best defines the basal metabolic rate?

a. The rate of heat production during exercise

b. The rate at which glucose is catabolized

c. The amount of energy needed for the body's anabolic reactions

d. The energy cost of living

Mark the following as true or false. If a statement is false, correct it to make a true statement.

b. Most amino acids are converted into products that are oxidized by β-oxidation.

Mark the following as true or false. If a statement is false, correct it to make a true statement.

c. he final common pathway for carbohydrate, protein, and lipid catabolism is the same.

Mark the following as true or false. If a statement is false, correct it to make a true statement.

d. at oxidation generates more ATP than protein or carbohydrate catabolism.

Mark the following as true or false. If a statement is false, correct it to make a true statement.

e. Fat and protein catabolism take place primarily in the cytosol.

When fats are catabolized by the liver, some of the acetyl-CoA is converted into:

a. amino acids.

b. ketone bodies.

c. glucose.

d. glycerol.

Fill in the blanks: Glucose is stored by the process of ________ and new glucose is generated by the process of ________ .

Certain dietary supplements for weight loss contain drugs that are claimed to block the absorption of polysaccharides such as starch. If a 'starch blocker' actually worked and fully prevented the absorption of carbohydrates into the bloodstream, what effects would this have on protein and lipid metabolism?

The condition hyperthyroidism is characterized by an increase in the level of thyroid hormone. People with untreated hyperthyroidism often complain of feeling hot. Explain this finding.

Erythrocytes lack organelles, including mitochondria. What sort of carbohydrate catabolism can erythrocytes undergo? Explain.

A patient presents to a clinic with acute ingestion of the poison cyanide, which blocks the functioning of the electron transport chain. He is exhibiting many of the symptoms seen with suffocation (lack of breathing). Explain this finding. Would the level of oxygen in the body be normal, elevated, or decreased in cyanide poisoning? Explain.