Problem L3.1
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.
Problem L2.1
Exercise is said to 'burn' fat. In what ways is this analogy true?
Problem L2.2
Certain diet plans claim that a person may eat all the protein he or she wants, as protein is not stored by the body. Is this claim completely accurate? Explain.
Problem L3.2
Your friend hears about the latest fad diet that consists entirely of fat. Predict the initial effects such a diet might have on your friend's concentration, memory, and other nervous system functions. Would you recommend this diet to anyone? Why or why not?
Problem L3.3
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?
Problem L3.4
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.
Problem L3.5
When you are exercising, your respiratory rate increases and you exhale more carbon dioxide. Explain this. What will happen to the pH of the blood if the respiratory rate does not increase? Why?
Problem L2.3
Erythrocytes lack organelles, including mitochondria. What sort of carbohydrate catabolism can erythrocytes undergo? Explain.
Problem L2.4a
You are performing a lab experiment to measure your lab partner's metabolic rate. To perform the experiment, your lab partner is hooked up to a machine that measures her oxygen consumption.
a. Why is the amount of oxygen that your lab partner consumes a good way to measure her metabolic rate?
Problem L2.4b
You are performing a lab experiment to measure your lab partner's metabolic rate. To perform the experiment, your lab partner is hooked up to a machine that measures her oxygen consumption.
b. Your lab partner just ran up three flights of stairs to get to lab on time. Will the measured metabolic rate be her basal metabolic rate? Why or why not?
Problem L2.5
People with extremely restricted caloric intake often complain of being cold. What does this signify about their metabolic rate?
Problem 1
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.
Problem 2
Which nutrient is the preferred fuel for essentially every cell in the body?
a. Glucose
b. Fatty acids
c. Glycerol
d. Amino acids
Problem 3
A/an____ reaction releases energy because the products have less energy than the reactants, whereas a/an_____reaction consumes energy because the products have more energy than the reactants.
Problem 4a
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.
Problem 4b
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.
Ch. 23 Metabolism and Nutrition