Question 1

Low levels of iodide in the diet can lead to an enlarged thyroid.

Accepted Answer

Iodide is necessary for the proper functioning of the thyroid gland. When iodide levels are low, the thyroid gland may enlarge in an attempt to produce more thyroid hormone. This enlargement is known as goiter.

Question 2

Which of the following is true about sleep deprivation?
A) It causes people to lose weight due to increased metabolic activity
B) It has no deleterious effects in the long term
C) It has been correlated with reduced insulin efficiency
D) It causes blood glucose levels to drop
E) none of these

Accepted Answer

Sleep deprivation has been linked to reduced insulin efficiency, which can lead to an increased risk of developing type 2 diabetes. A, B, and D are all incorrect statements about the effects of sleep deprivation on the body.

Question 3

Studies of metabolism usually separate the reactions into pathways, such as the Krebs' Cycle or the Pentose Phosphate Pathway. This is really an artificial designation, since these pathways are all intimately linked and overlap.

Accepted Answer

The statement is true. Although metabolism is often discussed in terms of specific pathways, these pathways are interconnected and overlap in numerous ways.

Question 4

Dietary supplements are sometimes indicated for which of the following minerals?
A) calcium
B) chloride
C) potassium
D) sodium

Accepted Answer

Calcium supplements are often recommended to help prevent or treat osteoporosis and other conditions related to calcium deficiency.

Question 5

Proteins eaten in excess can be stored to satisfy future protein requirements.

Accepted Answer

Unlike carbohydrates and fats, the body does not store excess protein. Any excess protein is broken down and excreted, so it cannot be stored for future use.

Question 6

For which of the following is there no RDA (recommended daily allowance)?
A) calcium
B) fluoride
C) iodine
D) iron

Accepted Answer

There is no RDA for fluoride. Instead, there is an Adequate Intake (AI) level established by the National Academies of Sciences, Engineering, and Medicine.

Question 7

Which of the following link photosynthesis and carbon dioxide fixation? A) ATP:ADP and NADP⁺:NADPH B) ATP:ADP and NAD⁺:NADH C) NTP:NDP D) none of these

Accepted Answer

ATP:ADP and NADP^+ :NADPH are involved in the energy transfer and reduction processes, respectively, linking photosynthesis and carbon dioxide fixation.

Question 8

What happens to the nitrogen from excess protein? A) It is stored as carbohydrate. B) It is stored as fat. C) It is eliminated through the urea cycle. D) It is exhaled as N₂ gas. E) It is stored to make future proteins

Accepted Answer

Excess nitrogen from protein is eliminated through the urea cycle. The body cannot store excess nitrogen, so it must be excreted. Urea is produced in the liver from ammonia generated by the breakdown of amino acids, and it is then excreted by the kidneys.

Question 9

Which of the following is not a macronutrient?
A) carbohydrates
B) fats
C) proteins
D) iron

Accepted Answer

Carbohydrates, fats, and proteins are macronutrients as they are needed in large amounts by the body for energy and growth. Iron is a micronutrient as it is only needed in small amounts by the body for proper functioning.

Question 10

Which pathway is central to virtually all living organisms?
A) glycolysis.
B) citric acid cycle
C) electron transport chain
D) photosynthesis
E) fatty acid metabolism

Accepted Answer

The answer of Which pathway is central to virtually all...

Question 11

Overdoses are possible for which of the following vitamins? A) vitamins A, D, and E B) vitamins A, C, and E C) vitamins A, B₁, and C D) vitamins A, B₁, and B₆

Accepted Answer

Vitamins A, D, and E are fat soluble vitamins, which means that they can accumulate in the body and cause toxicity if consumed in excessive amounts. Vitamins B and C are water soluble, meaning any excess is excreted in urine and overdoses are rare.

Question 12

Which of the following is a water-soluble vitamin? A) A B) B₆ C) D D) E

Accepted Answer

B₆ is not a real vitamin. A, D and E are fat-soluble vitamins, which means they are stored in the body's fat tissues and excess accumulation can lead to toxicity. Water-soluble vitamins, such as vitamin B and C, are not stored and excess amounts are excreted in the urine. Therefore, the best choice for a water-soluble vitamin is B.

Question 13

What function do vitamins usually serve?
A) coenzymes or precursors of coenzymes
B) intermediates of the TCA cycle
C) precursors of amino acids
D) hormones or second messengers

Accepted Answer

Vitamins are often coenzymes or precursors of coenzymes, which means they assist enzymes in facilitating metabolic reactions. This is a crucial function for maintaining various biological processes in the body, such as energy production and macronutrient synthesis. Some vitamins can also act as antioxidants, helping to prevent oxidative damage to cells.

Question 14

Which of the following vitamins is involved in hydroxylation reactions of collagen
A) Vitamin A
B) Vitamin C
C) Vitamin D
D) Vitamin E
E) none of these

Accepted Answer

Vitamin C is involved in hydroxylation reactions of collagen. Collagen is a protein found in connective tissues such as skin, bones, and tendons, and hydroxylation is a chemical process that adds a hydroxyl group to certain amino acids in collagen to help stabilize its structure. Vitamin C is essential for this process, and a deficiency in vitamin C can lead to weak and brittle collagen fibers, causing symptoms such as scurvy.

Question 15

Sweets and fats are at the top of the food pyramid, because they are so important in our diet.

Accepted Answer

Sweets and fats are not at the top of the food pyramid. They are classified as "discretionary calories" and should be consumed in moderation. The top of the food pyramid is reserved for foods that should be consumed sparingly, such as sugary drinks and processed foods.

Question 16

Which of the following is a lipid soluble vitamin?
A) biotin
B) niacin
C) folic acid
D) vitamin C
E) vitamin E

Accepted Answer

Lipid soluble vitamins dissolve in fat and are absorbed by the body along with dietary fat. Vitamin E is a lipid soluble vitamin. The other options listed are water soluble vitamins.

Question 17

In addition to all the other problems, why can a person get fat from overdrinking alcohol?
A) Alcohol inhibits carnitine palmitoyltransferase I
B) Ethanol is converted to acetate and then to acetyl-CoA which makes lipids
C) Ethanol converts carbohydrates into lipids
D) none of these

Accepted Answer

When alcohol is consumed, it is converted to acetate in the liver. Acetate is then converted to acetyl-CoA, which can be used to synthesize fatty acids and ultimately contribute to the formation of fat cells. This process is referred to as lipogenesis and can lead to weight gain and obesity if excessive amounts of alcohol are consumed. Option A is incorrect as it inhibits fatty acid oxidation leading to accumulation of unused fatty acids. Option C implies that alcohol directly converts carbs to fats which is not true, as alcohol does not undergo gluconeogenesis or generate carbohydrates.

Question 18

An essential nutrient is one which is either not made in the body or is not made in sufficient quantity to allow for survival.

Accepted Answer

Essential nutrients are those that the body cannot make or cannot make in sufficient amounts to meet its needs for growth, maintenance, and repair of tissues. They must be obtained through the diet. Examples of essential nutrients include certain amino acids, fatty acids, vitamins, and minerals.

Question 19

Which of the following compounds does not overlap between several pathways?
A) Acetyl-CoA
B) Oxaloacetate
C) Cholesterol
D) Pyruvate
E) Fumarate

Accepted Answer

Cholesterol is primarily synthesized in the liver and is not involved in energy metabolism pathways such as the citric acid cycle or oxidative phosphorylation. In contrast, acetyl-CoA, oxaloacetate, pyruvate, and fumarate are all involved in multiple energy metabolism pathways.

Question 20

Proteins are always being degraded, so there is a constant need for quality protein in order to maintain the body's structures.

Accepted Answer

Proteins undergo constant turnover and are regularly broken down and replaced. Therefore, the body needs a continuous supply of high-quality protein to maintain muscles, organs, and other structures.

Quiz 24: Integration of Metabolism: Cellular Signaling

Low levels of iodide in the diet can lead to an enlarged thyroid.

Which of the following is true about sleep deprivation?

Studies of metabolism usually separate the reactions into pathways, such as the Krebs' Cycle or the Pentose Phosphate Pathway. This is really an artificial designation, since these pathways are all intimately linked and overlap.

Dietary supplements are sometimes indicated for which of the following minerals?

Proteins eaten in excess can be stored to satisfy future protein requirements.

For which of the following is there no RDA (recommended daily allowance) ?

Which of the following link photosynthesis and carbon dioxide fixation?

What happens to the nitrogen from excess protein?

Which of the following is not a macronutrient?

Which pathway is central to virtually all living organisms?

Overdoses are possible for which of the following vitamins?

Which of the following is a water-soluble vitamin?

What function do vitamins usually serve?

Which of the following vitamins is involved in hydroxylation reactions of collagen

Sweets and fats are at the top of the food pyramid, because they are so important in our diet.

Which of the following is a lipid soluble vitamin?

In addition to all the other problems, why can a person get fat from overdrinking alcohol?

An essential nutrient is one which is either not made in the body or is not made in sufficient quantity to allow for survival.

Which of the following compounds does not overlap between several pathways?

Proteins are always being degraded, so there is a constant need for quality protein in order to maintain the body's structures.