Question 1

Each complex in the electron transport chain collectively acts as a _____ pump that removes H+ from the mitochondrial matrix and pumps it into the space between the inner and outer mitochondrial membranes.

Accepted Answer

The electron transport chain consists of a series of protein complexes embedded in the inner mitochondrial membrane. As electrons flow through the chain, protons are pumped from the mitochondrial matrix into the intermembrane space, creating a proton gradient that is used to generate ATP. Therefore, each complex in the electron transport chain acts as a proton pump, removing H+ from the mitochondrial matrix and pumping it into the intermembrane space.

Question 2

The yield of ATP in aerobic respiration is usually lower than the theoretical 36 molecules due to all of the following,except

Accepted Answer

Production of lactic acid is not a factor that reduces the yield of ATP in aerobic respiration, as it is only produced in anaerobic respiration. The other three factors listed (cost to shuttle NADH into mitochondrion, getting ATP out of the mitochondrion, and different yields per NADH molecule) all contribute to a lower yield of ATP than the theoretical maximum of 36 molecules.

Question 3

Which of the following does NOT contribute to basal metabolism?

Accepted Answer

Exercise programs do not contribute to basal metabolism, as basal metabolism is the energy required for essential physiological processes when the body is at rest. Exercise programs increase metabolic rate above the basal level. Muscle tone, heart contractions, thermoregulation, and cell membrane transport are all essential physiological processes that contribute to basal metabolism.

Question 4

In the first step of the citric acid cycle,______ acid combines with acetyl-CoA to produce citric acid.

Accepted Answer

The first step of the citric acid cycle involves the combination of oxaloacetic acid with acetyl-CoA to produce citric acid.

Question 5

With uncontrolled diabetes mellitus,the increased lipid metabolism will cause an increase in ______ formation.

Accepted Answer

Uncontrolled diabetes leads to increased lipid metabolism, and excessive lipolysis can result in an overproduction of ketone bodies. This occurs because the body is unable to use glucose as fuel due to insulin deficiency, and so it turns to stored fat for energy. The excess ketone bodies, such as acetone, acetoacetate, and beta-hydroxybutyrate, can build up in the blood and cause ketoacidosis, a potentially life-threatening complication. Therefore, option A is the correct choice.

Question 6

The transformation of acetyl-CoA to free fatty acids is a process called _______.

Accepted Answer

Lipogenesis is the process of converting acetyl-CoA to fatty acids. Ketogenesis is the process of converting acetyl-CoA to ketone bodies. Cellular respiration is the process of using oxygen to produce ATP. Glucogenesis is the process of producing glucose from non-carbohydrate sources. Fermentation is the process of producing ATP without oxygen.

Question 7

The body synthesizes nonessential amino acids in a process called oxidative deamination.

Accepted Answer

The body synthesizes nonessential amino acids through a process called transamination, not oxidative deamination.

Question 8

If air temperature is higher than skin temperature,_______ becomes a means of heat loss through evaporation.

Accepted Answer

When the air temperature is higher than the skin temperature, sweating becomes a means of heat loss through evaporation. As sweat evaporates from the skin surface, heat is dissipated in the form of latent heat of vaporization, cooling the skin and the body. Shivering (B), fever (C), chills (D), and vasoconstriction (E) are all mechanisms of heat conservation rather than heat loss.

Quiz 25: Nutrition,metabolism,and Temperature Regulation