Question 1

The American Heart Association advocates that 30% or less of our calories should come from fats,but the typical US diet actually exceeds 40% fat.

Accepted Answer

The statement is true according to the American Heart Association's recommendation and research on the typical US diet.

Question 2

What happens to the nitrogen from excess protein?

Accepted Answer

Excess nitrogen from protein metabolism is converted into urea by the liver and is then eliminated through the kidneys in the form of urine. The nitrogen is not stored as carbohydrate or fat and is not exhaled as N₂ gas.

Question 3

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

Accepted Answer

There is no RDA for fluoride. Instead, there is an Adequate Intake (AI) level.

Question 4

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, but rather at the tip of the pyramid as part of the "use sparingly" category. The bottom of the pyramid is comprised of foods that should make up the bulk of our diet such as fruits, vegetables, and whole grains.

Question 5

Which of the following is not true concerning leptin?

Accepted Answer

Leptin does not stimulate acetyl-CoA carboxylase, but rather inhibits its activity.

Question 6

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

Accepted Answer

When alcohol is consumed, it is converted to acetate, which is then converted to acetyl-CoA. Acetyl-CoA is a precursor to fatty acid synthesis, which can lead to the accumulation of fat in the body. This process is exacerbated when combined with a high-calorie diet and a sedentary lifestyle, which are commonly associated with heavy drinking. Alcohol can also disrupt the normal mechanisms for fat metabolism, further contributing to weight gain.

Question 7

Which of the following link photosynthesis and carbon dioxide fixation?

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

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 are constantly being broken down and degraded in the body, so it is necessary to consume quality protein in order to maintain and repair the body's structures.

Question 9

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

Accepted Answer

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

Question 10

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

Accepted Answer

Iodine is required for the production of thyroid hormones. If there is a low level of iodine in the diet, the thyroid gland may enlarge in an attempt to produce more hormones, which can lead to a condition called goiter.

Question 11

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

Accepted Answer

Unlike carbohydrates and fats, the human body cannot store excess protein. Instead, it is broken down into waste products or used for energy, and any excess is excreted through urine.

Question 12

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

While it is common to separate metabolic reactions into pathways for the purposes of studying them, in reality these pathways are interconnected and overlap with one another.

Question 13

Which of the following is a water-soluble vitamin?

Accepted Answer

Water-soluble vitamins are vitamins that dissolve in water and are easily excreted from the body, so they need to be replenished in the body on a regular basis. Out of the options given, only B vitamins are water-soluble.

Question 14

The following are not essential in the human diet.

Accepted Answer

Ethanol is not a dietary requirement for humans. Nucleic acids, while important for various biological functions, are not considered essential nutrients because the body can synthesize them. Heme-containing compounds, specifically from dietary sources, are not essential either, as the body can produce heme. Therefore, none of these listed items are required in the human diet, making E the correct choice.

Question 15

Overdoses are possible for which of the following vitamins?

Accepted Answer

Vitamins A, D, and E are fat-soluble vitamins that can accumulate in the body and cause toxicity if taken in excessive amounts. Vitamins B and C are water-soluble vitamins that are excreted in the urine if taken in excess and are less likely to cause toxicity.

Question 16

What function do vitamins usually serve?

Accepted Answer

Vitamins generally serve as coenzymes or precursors of coenzymes, playing a crucial role in metabolic reactions. They help enzymes to function properly, making the reactions more efficient. While some vitamins may serve other functions, such as vitamin D acting as a hormone, their primary role is serving as coenzymes.

Question 17

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

An essential nutrient is a nutrient that must be obtained from the diet because the body either does not produce it or cannot produce enough of it to sustain life.

Question 18

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

Accepted Answer

Both Acetyl-CoA and Oxaloacetate are intermediates in the citric acid cycle, as well as being involved in other pathways. Pyruvate is formed in glycolysis and is also a substrate for gluconeogenesis. Cholesterol, on the other hand, has specific metabolic pathways and does not overlap with other pathways.

Question 19

Which of the following is not a macronutrient?

Accepted Answer

Macronutrients are nutrients that are required in large amounts by the body, and they include carbohydrates, fats, and proteins. Iron is a micronutrient, meaning it is required in smaller amounts by the body.

Question 20

Which pathway is central to virtually all living organisms?

Accepted Answer

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

Quiz 24: Integration of Metabolism: Cellular Signaling