122 Unit 8 practice quiz

Niacin (vitamin B3) is important for ATP synthesis because it forms NAD. What specific role does NAD play in energy metabolism?

It transfers hydrogens released during glycolysis and Krebs cycle to the electron transport system.

Cells synthesize new organic components for which of the following reasons?

a) structural maintenance b) growth and repair c) production of secretions

The minimum resting energy expenditure of an awake, alert person is called

basal metabolic rate

In a healthy individual who has just finished eating a large nutrient-balanced meal

blood plasma will have an increased concentration of fats, glucose, and amino acids

A chemical reaction by which the -NH2 group is removed from an amino acid is known as

deamination

During cellular respiration, how much of the original energy in the glucose molecule is transferred into ATP and how much is instead converted into (lost as) heat?

40% to ATP and 60% to heat

A disorder caused by the ingestion of excessive quantities of a fat-soluble vitamin is known as

hypervitaminosis

In skeletal muscle, one major disadvantage of relying solely on glycolysis under anaerobic conditions is that:

lactic acid accumulates in the muscle.

During starvation (a long-term situation)

little or no glycogen is stored in the liver

When the body is relying on internal energy reserves to continue meeting its energy demands, it is in the ________ state.

postabsorptive

Glycolysis breaks down glucose into

pyruvic acid

The function of the citric acid cycle is to

remove hydrogen atoms from organic molecules and transfer them to coenzymes.

Resting energy expenditure is most directly determined by monitoring

respiration

Most nutrient absorption takes place in the

small intestine

Low-density lipoproteins function to

transport cholesterol to cells for use in plasma membranes or hormone synthesis

________ is deficient in one or more of the essential amino acids.

An incomplete protein

The molecule that supplies our cells with an immediate source of energy is

ATP

Which of the following is calculated directly by using a person's height and weight?

BMI

The electron transport system a) receives electrons from coenzymes. b) produces more the ATP than Glycolysis c) is located on the inner mitochondrial membrane (the cristae).

All of the above

Acetyl CoA for the citric acid cycle may be formed through metabolism of: fatty acids glucose amino acids

all of the above

Glycolytic breakdown of glucose first results in ________ molecules. a) 2 pyruvate (pyruvic acid) b) 2 NADH c) 2 ATP (net)

all of the above

Which of the following increases the breakdown of triglycerides in adipose tissue? epinephrine thyroid hormone exercise

all of the above

Poisons like cyanide bind to ________ and prevent electron transfer.

cytochromes

During cellular respiration, which set of reactions produces water?

electron transport

The vitamin that is a coenzyme in amino acid and nucleic acid metabolism is

folic acid (folate)

If the cell starts with fat as its fuel source, which of the following reactions will NOT occur?

glycolysis

the correct sequence of events during carbohydrate metabolism?

glycolysis----Krebs cycle----electron transport

Temperature regulation is

influenced by peripheral thermoreceptors in the skin

The conversion of one amino acid to another

is done by transamination

A decrease in body weight occurs when caloric intake

is less than basal metabolism plus external work

Body temperature

is regulated primarily by regulating heat loss

NAD, which acts as a hydrogen carrier in the cell, is derived from

niacin (nicotinic acid)

Coenzyme A is derived from

pantothenic acid (Vitamin B5)

True or False: One of the major results of cellular respiration is heat.

true

Lack of exercise and a caloric intake > basal metabolic rate plus external work for a prolonged period may result in

type II diabetes

Impaired fat absorption in the intestine would interfere with the absorption of

vitamin A

Pellagra, an epithelial and mucosal deterioration, results from a deficiency in

vitamin B3 (niacin)

Which of the following is the first step in ATP production from fat?

beta-oxidation

The process that catabolizes fatty acids to acetyl-CoA is called

beta-oxidation.

There are ________ essential amino acids that the body either cannot synthesize or that cannot be produced in amounts sufficient for growing children.

10

All cells use which of the following directly for energy to fuel their work?

ATP

The vitamin that is required for proper bone growth and for calcium absorption and retention is vitamin

D

The vitamin that prevents breakdown of vitamin A and fatty acids is vitamin

E

Which of the following statements is true about carbohydrates? They contain carbon, hydrogen, and oxygen and the simplest form is a disaccharide. Their main use is to provide energy. They are stored in adipose tissue as fatty acids.

Their main use is to provide energy.

Which of the following terms describes the process by which glucose is metabolized to produce CO2, H2O, and energy?

catabolism

The largest lipoproteins, ________, are produced by intestinal epithelial cells from the fats in food.

chylomicrons

Decreasing blood glucose is a stimulus for the secretion of

glucagon

The conversion of glycerol and amino acids into glucose is called

gluconeogenesis

The process of synthesizing glucose from noncarbohydrates is called

gluconeogenesis

The area of the brain that regulates body temperature is the

hypothalamus

During lipolysis

triglycerides are broken down into glycerol and fatty acids.

A deficiency in vitamin D would result in which of the following disorders?

rickets

What is the net energy yield of the citric acid (Krebs) cycle?

2

Obesity is defined as a body weight more than ________ percent above the ideal body weight for an individual

20

The vitamin that plays a role in maintaining epithelia and is required for the synthesis of visual pigments is vitamin

A

Which part of glucose metabolism yields the greater amount of ATP?

ETC

An adult weighing 130 lb. requires the same amount of energy to walk up a flight of stairs as does an adult weighing 280 lb.

False. It requires more energy for the larger adult because he/she has a higher BMI.

The "good" type of lipoprotein that carries cholesterol from tissues to liver is

HDL (high-density lipoproteins)

Which of the following carry excess cholesterol from peripheral tissues to the liver?

High-density lipoproteins (HDLs)

A balanced diet should

a) include adequate substrates for the production of energy. b) provide essential amino acids and fatty acids. c) contain adequate amounts of vitamins and minerals.

ATP can be used for

a) muscle contraction. b) ion transport. c) protein synthesis. d) glycogen synthesis.

Amino acids and fatty acids may enter the citric acid cycle by way of

acetyl-CoA

The carbon dioxide of respiration is formed during

citric acid cycle

Although other nutrients can feed into the citric acid cycle, ________ yields energy the quickest.

glucose

During the absorptive phase of metabolism

glucose is the primary energy source for most cells

All of the following are reasons why glucose is the primary energy source for cells except a) glucose is a small, soluble molecule. b) glycogen breakdown occurs very slowly. c) glucose can be stored efficiently. d) glycogen breakdown involves only a single enzymatic step. e) glycolysis does not require oxygen to generate ATP.

glycogen breakdown occurs very slowly.

Which of the following is most likely to occur if blood glucose levels are elevated?

glycogenesis

It's been 5 hours since you had breakfast and now you're thinking about trying the new Mexican lunch place that just opened up across the street. The more you think about it, the hungrier you get. That's the result of the ________ that your empty stomach is releasing into your bloodstream.

grehlin

All of the following take place during the absorptive state except

ketone bodies begin to form

All of the following occur during the postabsorptive state except that

levels of blood glucose are elevated

All of the following are true of beta-oxidation except that a) it occurs in the mitochondria. b) fatty acids break down into acetyl-CoA that enter the citric acid cycle. c) lipids are converted into glycogen molecules. d) it requires coenzyme A, NAD, and FAD. e) it ultimately yields large amounts of ATP.

lipids are converted into glycogen molecules.

Urea is formed in the

liver

During electron transport, the transfer of electrons through the cytochromes to oxygen:

makes more ATP than can be made directly from glycolysis.

When a cell needs energy, glycogen may be hydrolyzed to:

many glucose molecules

The sum of all of the biochemical processes going on within the human body at any given time is called

metabolism

Regulation of body temperature is controlled by

shivering vasodilation of cutaneous vessels is regulated by a center in the hypothalamus

Reactions within ________ provide most of the energy needed by a typical cell.

the mitochondria