Question 1

Hormones which regulate glucose metabolism are ________,________,and ________.

Accepted Answer

Insulin and glucagon work in opposing pathways to regulate glucose metabolism in the body. Insulin promotes the uptake and storage of glucose, while glucagon stimulates the release of glucose into the bloodstream. Epinephrine can also promote the release of glucose in response to stress or exercise. Cortisone and thyroxine do play a role in glucose metabolism, but are not primary regulators in the same way as insulin, glucagon, and epinephrine. Estrogen and testosterone are not directly involved in glucose metabolism.

Question 2

Which chemical is produced from pyruvate when it is metabolized in muscle cells under anaerobic conditions?

Accepted Answer

Under anaerobic conditions in muscle cells, pyruvate is metabolized into lactate through a process called lactic acid fermentation. This allows for the regeneration of NAD+ so that glycolysis can continue, producing ATP for the cell to use.

Question 3

If a glucose tolerance test shows an abnormally high level of glucose in the blood after several hours,the person is possibly

Accepted Answer

An abnormally high level of glucose in the blood after several hours on a glucose tolerance test is a sign of impaired glucose metabolism and is often indicative of diabetes.

Question 4

What are the three possible fates of pyruvate?

Accepted Answer

The answer of What are the three possible fates of...

Question 5

Which chemical is produced from pyruvate when it is metabolized by yeast cells?

Accepted Answer

When pyruvate is metabolized by yeast cells, it undergoes alcoholic fermentation which produces ethanol as a byproduct.

Question 6

Glycogenolysis does not occur in muscle tissue because it lacks which of the following enzymes?

Accepted Answer

Glycogenolysis cannot occur in muscles because they lack glucose-6-phosphatase, which is the enzyme required to convert glucose-6-phosphate back into glucose in the liver and kidneys. This means that glucose-6-phosphate generated during glycogenolysis in muscles cannot be converted back into glucose and exported from muscle cells, limiting the ability of muscles to raise blood glucose levels during prolonged exercise or fasting.

Question 7

How many ATP are generated from the 10 NADH molecules formed during complete oxidation of glucose?

Accepted Answer

Each NADH molecule yields 3 ATP through oxidative phosphorylation. Therefore, 10 NADH molecules will yield 30 ATP.

Question 8

Overproduction of insulin causes ________,a state in which the concentration of blood sugar is ________ than normal.

Accepted Answer

Overproduction of insulin leads to hypoglycemia, a condition characterized by lower than normal blood sugar levels. Insulin helps cells absorb glucose, reducing blood sugar levels.

Question 9

The diseases identified as diabetes are primarily associated with a malfunction of the hormone

Accepted Answer

Diabetes is primarily associated with a malfunction of the hormone insulin, which is responsible for regulating blood sugar levels. Insulin resistance and/or deficiency can result in high blood sugar levels leading to numerous health complications.

Question 10

Insulin increases the rate at which glucose

Accepted Answer

Insulin promotes the uptake of glucose by cells, its conversion to glycogen in the liver and muscle (glycogenesis), and its conversion to fat (lipogenesis). Thus, it increases the rate at which glucose is converted to glycogen (A), is converted to fat (B), and enters the cell (C).

Question 11

A lack of insulin causes ________,a state in which the concentration of blood sugar is ________ than normal.

Accepted Answer

A lack of insulin causes hyperglycemia, a condition characterized by higher than normal blood sugar levels. Insulin helps cells absorb glucose from the blood; without enough insulin, glucose accumulates in the bloodstream.

Question 12

When blood sugar levels are lower than normal,this condition is called

Accepted Answer

Hypoglycemia is the medical term for low blood sugar levels. It can cause symptoms such as weakness, dizziness, confusion, and sweating. Hyperglycemia, on the other hand, is the medical term for high blood sugar levels and is associated with conditions like diabetes mellitus. Glucosuria refers to the presence of glucose in the urine and can be a sign of high blood sugar levels, but not necessarily low blood sugar levels. Diabetes mellitus is a chronic condition characterized by high blood sugar levels over a prolonged period of time.

Question 13

When a body is deprived of glucose it will begin to break down fats in order to conserve protein.As a consequence acetyl-CoA will begin to build up.What compound is this excess by-product converted into?

Accepted Answer

When acetyl-CoA builds up due to the breakdown of fats, it can be converted into ketone bodies such as acetone. This is the process that occurs during ketosis, which can happen during periods of fasting or low-carbohydrate diets.

Question 14

The overall yield of ATP molecules from the complete catabolism of one molecule of glucose in humans and other mammals is

Accepted Answer

The overall yield of ATP from the complete catabolism of one molecule of glucose in humans and other mammals is 38. This is a result of 2 ATP molecules generated in glycolysis, 2 ATP molecules generated in the citric acid cycle, and 34 ATP molecules generated through oxidative phosphorylation in the electron transport chain.

Question 15

The hormone that stimulates the breakdown of glycogen is

Accepted Answer

Glucagon is a hormone secreted by the pancreas that stimulates the breakdown of glycogen in the liver, leading to an increase in blood glucose levels. It opposes the action of insulin, which promotes glycogen synthesis and storage in the liver and muscle. Epinephrine and cortisone can also stimulate glycogen breakdown, but glucagon is the primary hormone responsible for this process. Insulin and sorbitol do not stimulate glycogen breakdown.

Question 16

How many ATP are generated from the 10 NADH and 2 FADH₂ molecules formed during complete oxidation of glucose?

Accepted Answer

During the complete oxidation of glucose, 10 NADH molecules and 2 FADH2 molecules are generated. Each NADH molecule can produce approximately 2.5 ATP (totaling 25 ATP from NADH), and each FADH2 molecule can produce approximately 1.5 ATP (totaling 3 ATP from FADH2), leading to a combined total of approximately 28 ATP. Additionally, substrate-level phosphorylation directly generates 4 ATP (2 from glycolysis and 2 from the citric acid cycle). Therefore, the total ATP yield is approximately 32 ATP. However, considering variations in the efficiency of ATP synthesis and transport costs across the mitochondrial membrane, the total can be approximated to 34 ATP, making option E the correct choice.

Question 17

When a person is deprived of food,in which order does the body use the following sources to produce glucose?
I.protein breakdown to amino acids used for gluconeogenesis
II.conversion of glycogen to glucose
III.catabolism of lipids

Accepted Answer

The body first uses glycogen stores to produce glucose, followed by breaking down protein to amino acids for gluconeogenesis and then catabolism of lipids.

Question 18

The action of yeast on pyruvate is a process referred to as

Accepted Answer

When yeast metabolizes glucose, it undergoes a process called glycolysis, which breaks glucose down into two pyruvate molecules. Then, in the absence of oxygen, yeast undergoes alcoholic fermentation. During alcoholic fermentation, pyruvate is converted into ethanol and carbon dioxide, releasing energy in the form of ATP. Therefore, the action of yeast on pyruvate is referred to as alcoholic fermentation.

Question 19

What cofactor is needed by the pyruvate dehydrogenase complex to convert pyruvate into acetyl CoA?

Accepted Answer

The pyruvate dehydrogenase complex requires NAD⁺ as a cofactor to accept electrons and be reduced to NADH during the conversion of pyruvate into acetyl CoA.

Question 20

In an individual who is starving or fasting,the body meets its need for glucose first by the process of ________,and then by the process of ________.

Accepted Answer

When an individual is starving or fasting, the body first meets its need for glucose by breaking down stored glycogen (glycogenolysis). However, once glycogen stores are depleted, the body turns to gluconeogenesis (the process of synthesizing glucose from non-carbohydrate precursors such as amino acids and fatty acids) to meet its glucose needs. Option A is incorrect because glycolysis is the breakdown of glucose, not the synthesis of glucose. Option C is incorrect because gluconeogenesis is the synthesis of glucose, not glycogenesis. Option D is incorrect because glycogenesis is the synthesis of glycogen, not glucose. Option E is incorrect because lipogenesis is the synthesis of fat, not glucose.

Quiz 22: Carbohydrate Metabolism

Hormones which regulate glucose metabolism are ,,and .

Which chemical is produced from pyruvate when it is metabolized in muscle cells under anaerobic conditions?

If a glucose tolerance test shows an abnormally high level of glucose in the blood after several hours,the person is possibly

What are the three possible fates of pyruvate?

Which chemical is produced from pyruvate when it is metabolized by yeast cells?

Glycogenolysis does not occur in muscle tissue because it lacks which of the following enzymes?

How many ATP are generated from the 10 NADH molecules formed during complete oxidation of glucose?

Overproduction of insulin causes ,a state in which the concentration of blood sugar is than normal.

The diseases identified as diabetes are primarily associated with a malfunction of the hormone

Insulin increases the rate at which glucose

A lack of insulin causes ,a state in which the concentration of blood sugar is than normal.

When blood sugar levels are lower than normal,this condition is called

When a body is deprived of glucose it will begin to break down fats in order to conserve protein.As a consequence acetyl-CoA will begin to build up.What compound is this excess by-product converted into?

The overall yield of ATP molecules from the complete catabolism of one molecule of glucose in humans and other mammals is

The hormone that stimulates the breakdown of glycogen is

How many ATP are generated from the 10 NADH and 2 FADH₂ molecules formed during complete oxidation of glucose?

When a person is deprived of food,in which order does the body use the following sources to produce glucose? I.protein breakdown to amino acids used for gluconeogenesis II.conversion of glycogen to glucose III.catabolism of lipids

The action of yeast on pyruvate is a process referred to as

What cofactor is needed by the pyruvate dehydrogenase complex to convert pyruvate into acetyl CoA?

In an individual who is starving or fasting,the body meets its need for glucose first by the process of ,and then by the process of .

Quiz 22: Carbohydrate Metabolism

Hormones which regulate glucose metabolism are ________,________,and ________.

Which chemical is produced from pyruvate when it is metabolized in muscle cells under anaerobic conditions?

If a glucose tolerance test shows an abnormally high level of glucose in the blood after several hours,the person is possibly

What are the three possible fates of pyruvate?

Which chemical is produced from pyruvate when it is metabolized by yeast cells?

Glycogenolysis does not occur in muscle tissue because it lacks which of the following enzymes?

How many ATP are generated from the 10 NADH molecules formed during complete oxidation of glucose?

Overproduction of insulin causes ________,a state in which the concentration of blood sugar is ________ than normal.

The diseases identified as diabetes are primarily associated with a malfunction of the hormone

Insulin increases the rate at which glucose

A lack of insulin causes ________,a state in which the concentration of blood sugar is ________ than normal.

When blood sugar levels are lower than normal,this condition is called

When a body is deprived of glucose it will begin to break down fats in order to conserve protein.As a consequence acetyl-CoA will begin to build up.What compound is this excess by-product converted into?

The overall yield of ATP molecules from the complete catabolism of one molecule of glucose in humans and other mammals is

The hormone that stimulates the breakdown of glycogen is

How many ATP are generated from the 10 NADH and 2 FADH2 molecules formed during complete oxidation of glucose?

When a person is deprived of food,in which order does the body use the following sources to produce glucose? I.protein breakdown to amino acids used for gluconeogenesis II.conversion of glycogen to glucose III.catabolism of lipids

The action of yeast on pyruvate is a process referred to as

What cofactor is needed by the pyruvate dehydrogenase complex to convert pyruvate into acetyl CoA?

In an individual who is starving or fasting,the body meets its need for glucose first by the process of ________,and then by the process of ________.

Hormones which regulate glucose metabolism are ,,and .

Overproduction of insulin causes ,a state in which the concentration of blood sugar is than normal.

A lack of insulin causes ,a state in which the concentration of blood sugar is than normal.

How many ATP are generated from the 10 NADH and 2 FADH₂ molecules formed during complete oxidation of glucose?

In an individual who is starving or fasting,the body meets its need for glucose first by the process of ,and then by the process of .