Cycles & Transport Mechanisms

Question 1

What is the primary role of the TCA cycle in the production of ATP?

Answer 1

Transfer electrons from substrates to coenzymes

Question 2

What is the electron transport system’s role in the generation of ATP?

Answer 2

It creates a steep concentration gradient across the inner mitochondrial membrane

Question 3

How does a decrease in the level of cytoplasmic NAD affect ATP production in mitochondria?

Answer 3

ATP production decreases

Question 4

NADH produced by glycolysis in skeletal muscle fibers leads to production of two ATP molecules in mitochondria, but NADH produced by glycolysis in cardiac muscle cells leads to production of three ATP molecules. Why?

Answer 4

Different intermediaries

Question 5

Why is oxidative phosphorylation the most important mechanism for generating ATP?

Answer 5

It produces more than 90% of ATP used by body cells

Question 6

What contributes to the increased amount of urea in blood during the post absorptive state?

Answer 6

Protein digestion

Question 7

What consequence(s) is (are) the result of a dietary deficiency of one or more essential amino acids?

Answer 7

Protein deficiency disease occurs. Protein synthesis comes to a half.

Question 8

Why are proteins an impractical source of quick energy, a “last ditch” source of energy?

Answer 8

Proteins are more difficult to break apart than are carbohydrates or lipids. NH4, a by-product of protein catabolism, is toxic. Protein catabolism threatens homeostasis.

Question 9

Why do athletes in intensive training try to maintain a positive nitrogen balance?

Answer 9

They actively synthesize N compounds, so must absorb more than they secrete

Question 10

Why does a diet that is deficient in pyridoxine (vitamin B6) affect protein metabolism?

Answer 10

The first step in amino acid catabolism requires a coenzyme derivative of B6-

Question 11

Why are high-density lipoproteins (HDLs) considered beneficial?

Answer 11

They reduce fat and cholesterol in the bloodstream

Question 12

Why is catabolism of dietary carbohydrates and proteins considered “not as productive” as catabolism of lipids?

Answer 12

Lipids release almost twice the energy of proteins or carbohydrates

Question 13

Why are LDL’s considered “bad cholesterol”?

Answer 13

They deliver cholesterol to peripheral tissues. They often end up in arterial plaques.

Question 14

Why does hypervitaminosis more commonly involve fat-soluble vitamins?

Answer 14

Excess fat-soluble vitamins are stored in body lipids

Question 15

What characteristic of lipoproteins allows them to be made water-soluble?

Answer 15

They have a superficial coating of phospholipids and proteins

Question 16

Which of the following vitamins can be synthesized inside the body?

Answer 16

Vitamins D & K

Question 17

How would a decrease in the amount of bile salts in the bile affect the amount of vitamin A in the body?

Answer 17

It would decrease Vitamin A

Question 18

How would the BMR of a pregnant woman compare with her own BMR before she became pregnant?

Answer 18

Higher when pregnant

Question 19

What effect does vasoconstriction of peripheral blood vessels have on an individual’s body temperature on a hot day?

Answer 19

An increase in body temperature

Question 20

In cold condition, how does blood flow change to restrict heat loss?

Answer 20

Heat transfer from warm blood in arteries warms cooler venous blood

Question 21

Which of the following is a true statement?

Answer 21

Glycogenesis will facilitate the storage of glucose in cells

Question 22

What is NOT true with regard to glycolysis?

Answer 22

It is an anaerobic process that occurs in the cytoplasm. The first step of glycolysis phosphorylates glucose and traps it in the cell. The breakdown of glucose can lead to lactic acid accumulation.

Question 23

What process in the liver increases after you have eaten a high-carbohydrate meal?

Answer 23

Glycogenesis

Question 24

In infants, the highly vascularized tissue b/w the shoulder blades is referred to as ___ fat and contains adipocytes that have many___?

Answer 24

Brown, mitochondria

Question 25

In training for competitive sports what might increase athletic performance?

Answer 25

Increased carbohydrates in the diet 3 days prior to an event

Question 26

What happens during the process of transamination?

Answer 26

A keto acid is converted into amino acid that can leave the mitochondria