Deck 24: Metabolic Pathways for Lipids and Amino Acids

Question 1

The digestion of fats begins when the fat globules are

A)emulsified by bile salts.
B)hydrolyzed to glycerol and fatty acids.
C)hydrolyzed to glucose and amino acids.
D)attacked by protease enzymes to form smaller fat globules.
E)converted to lipoproteins for greater solubility.

Answer 1

emulsified by bile salts.

Question 2

Most of the glycerol produced by fatty acid breakdown is converted eventually to

A)amino acids.
B)fat.
C)glucose.
D)protein.
E)lactate.

Answer 2

glucose.

Question 3

The 2-carbon segments removed from a fatty acid during metabolism are used to form

A)acetyl CoA.
B)lactate.
C)CoA.
D)glucose.
E)pyruvate.

Answer 3

acetyl CoA.

Question 4

Fat stores in the body are mobilized when

A)adipocyte concentrations are high.
B)blood glucose levels are high.
C)glucagon production is low.
D)glucose and glycogen stores are low.
E)insulin production is high.

Question 5

The source of energy for red blood cells is

A)fatty acids.
B)glycerol.
C)amino acids.
D)lactate.
E)glucose.

Question 6

Fatty acids and glycerol are produced from the metabolism of

A)amino acids.
B)glucose.
C)proteins.
D)carbohydrates.
E)lipids.

Question 7

Which step is found in the breakdown of a fat?

A) direct substrate phosphorylation
B) an oxidation with CoQ
C) an activation that requires 2 ATP
D) an oxidation with a cytochrome
E) production of pyruvate

Question 8

The removal of 2-carbon segments of a fatty acid for further metabolism is called

A) dehydration.
B) decarboxylation.
C) deglyceration.
D)
E) transamination

Question 9

Red blood cells do not metabolize fatty acids because they have

A)a cell wall.
B)no mitochondria.
C)no DNA.
D)a cell membrane.
E)no nucleus.

Question 10

The heart muscle's primary source of fuel is

A)lactate.
B)fatty acids.
C)glycogen.
D)glucose.
E)amino acids.

Question 11

Most of the energy stored in the human body is in the form of

A)triacylglycerols.
B)the amino acid pool.
C)glucose.
D)glycogen.
E)muscle tissue.

Question 12

A chylomicron is a

A)transport lipoprotein.
B)triacylglycerol.
C)storage protein.
D)digestive enzyme.
E)lipase.

Question 13

Most of the glycerol produced by fatty acid breakdown goes to the

A)brain.
B)liver.
C)small intestine.
D)pancreas.
E)gall bladder.

Question 14

The small droplets of fat that are the first step in the digestion of dietary fats are called

A)emulsions.
B)micelles.
C)lipoproteins.
D)bile drops.
E)detergents.

Question 15

The digestion of fats begins in the

A)mouth.
B)pancreas.
C)large intestine.
D)stomach.
E)small intestine.

Question 16

The enzymes that break down triacylglycerols into fatty acids and glycerol are called

A)hydrolases.
B)oxidoreductases.
C)lyases.
D)lipases.
E)aconitases.

Question 17

Fatty acids are not a source of energy for the brain because

A)they are metabolized before they get as far as the brain.
B)the citric acid cycle does not operate in the brain.
C)there is no lipase in the brain.
D)they cannot diffuse across the blood-brain barrier.
E)chylomicrons are too large for absorption by brain cells.

Question 18

The series of reactions that produces energy by hydrolyzing fats to units of acetyl CoA is called

A) hydration.
B)
C) transamination.
D)
E)hydrolysis.

Question 19

The action of pancreatic lipase on triacylglycerols produces

A)emulsions.
B)low-density lipoproteins.
C)monoacylglycerols and free fatty acids.
D)micelles.
E)high-density lipoproteins.

Question 20

Fat cells are known as

A)monoacylglycerols.
B)islet cells.
C)glycerides.
D)adipocytes.
E)lysosomes.

Question 21

The energy released by the oxidation of a cis fatty acid is

A) used immediately to form ATP.
B) slightly less than that obtained from a trans fatty acid.
C) less than that obtained from one glucose molecule.
D) slightly more than that obtained from a trans fatty acid.
E) the same as that obtained from a trans fatty acid.

Question 22

What is the total number of ATP molecules produced from the lauric acid found in coconut oil?

A) 95 ATP
B) 97 ATP
C) 90 ATP
D) 100 ATP
E) 78 ATP

Question 23

In type 2 diabetes mellitus,

A)birth of a baby restores normal pancreatic function.
B)sufficient insulin is produced, but cannot be used.
C)glucose intake is too low.
D)the pancreas produces insufficient insulin.
E)blood glucose levels are too low.

Question 24

In type 1 diabetes mellitus,

A)glucose intake is too low.
B)sufficient insulin is produced, but cannot be used.
C)the pancreas produces insufficient insulin.
D)blood glucose levels are too low.
E)birth of a baby restores normal pancreatic function.

Question 25

The complete oxidation of produces _____ molecules of ATP.

A) 82
B) 78
C) 80
D) 64
E) 76

Question 26

When excess acetyl CoA accumulates in the liver, a pathway called ________ is initiated.

A)gluconeogenesis
B)transamination
C)glycolysis
D)ketogenesis
E)emulsification

Question 27

Ketosis can lower the blood pH below 7.4, producing the condition

A)ketoacidosis.
B)anemia.
C)hypokalemia.
D)ketoalkalosis.
E)hyponatremia.

Question 28

Myristic acid, a fatty acid, undergoes the cycle times.

A) 6
B) 14
C) 2
D) 7
E) 4

Question 29

Fats are higher in caloric value than carbohydrates because

A) 1 gram of glucose weighs more than 1 gram of fat.
B) fats make use of oxidation.
C) 1 gram of fat produces significantly more ATP than 1 gram of glucose.
D) 1 gram of glucose contains more moles than 1 gram of fat.
E) fats can make use of the citric acid cycle.

Question 30

The function of fatty acyl CoA is to

A)activate a fatty acid for metabolism.
B)produce a 2-carbon segment for metabolism.
C)isomerize cis fatty acids.
D)produce a lipoprotein.
E)cross the blood-brain barrier.

Question 31

During complete oxidation of the fatty acid molecules of acetyl CoA are produced, and the fatty acid goes through the

A) nine; eight
B) nine; nine
C) ten; nine
D) nine; ten
E) ten; ten

Question 32

Myristic acid, a C14 fatty acid, produces ________ acetyl CoA when completely metabolized.

A)14
B)12
C)5
D)7
E)2

Question 33

Fatty acyl CoA cannot cross into the mitochondrial matrix until

A) the citric acid cycle has begun.
B) it binds with a charged carrier molecule called carnitine.
C) the mitochondrial membrane undergoes a modification.
D) oxidation has taken place.
E) it is cut into 2-carbon segments

Question 34

The 2-carbon units obtained by degradation of a fatty acid are further metabolized in

A)
B) the citric acid cycle.
C) glycolysis.
D) transamination.
E) gluconeogenesis.

Question 35

Each acetyl CoA produces ________ ATP in the citric acid cycle.

A)6
B)12
C)10
D)2
E)24

Question 36

Beta-oxidation takes place in the

A)cytoplasm.
B)Golgi body.
C)nucleus.
D)cytosol.
E)mitochondrial matrix.

Question 37

Malonyl CoA contains a 3-carbon compound used in

A)the citric acid cycle.
B)acetyl CoA formation.
C)lipogenesis.
D)gluconeogenesis.
E)glycogenolysis.

Question 38

Ketosis is a condition that can occur if

A)low fat intake occurs.
B)the brain is starved of glucose.
C)too many ketones are ingested.
D)too much protein is available in the diet.
E)ketone bodies instead of glucose are used for energy.

Question 39

Stearic acid, a saturated fatty acid, produces acetyl CoA when completely metabolized.

A) 9
B) 7
C) 8
D) 5
E) 2

Question 40

In the activation of a fatty acid, energy from the hydrolysis of ATP is used to

A) cause a unit of acetyl CoA to separate from the fatty acid chain.
B) add a molecule of water across a double bond to give a hydroxyl group on the \beta carbon.
C) form a double bond in an oxidation reaction.
D) oxidize the hydroxyl group on the
E) join the fatty acid to CoA.

Question 41

All of the nonessential amino acids can be synthesized in the body by transamination, using an amino group from

A)
B) lactic acid.
C) glutamate.
D) pyruvate.
E) oxaloacetate.

Question 42

To synthesize a fatty acid, acetyl groups and cycles of fatty acid synthesis are needed.

A) seven, seven
B) seven, eight
C) eight, seven
D) eight, eight
E) one, one

Question 43

The letters ACP stand for

A)aconitate protein complex.
B)acyl carrier protein.
C)acetyl condensing protein.
D)acetyl CoA-palmitate.
E)acetyl Coenzyme P.

Question 44

The digestion of protein begins in the

A)large intestine.
B)small intestine.
C)mouth.
D)stomach.
E)pancreas.

Question 45

Which of the following does NOT require

A) glycolysis
B) transamination
C) oxidative deamination
D) citric acid cycle
E)

Question 46

In mammals, the ammonium ion produced in oxidative deamination is

A)converted to uric acid, which is excreted by the liver.
B)excreted in the feces.
C)converted to uric acid, which is excreted in the urine.
D)converted to urea, which is excreted in the urine.
E)stored in the liver.

Question 47

The initial digestion of protein is catalyzed by an enzyme called

A)chymotrypsin.
B)amylase.
C)trypsin.
D)peptidase.
E)pepsin.

Question 48

In the urea cycle, argininosuccinate lyase catalyzes the reaction of argininosuccinate to

A)arginine.
B)orthinine.
C)carbamoyl phosphate.
D)arginase.
E)citrulline.

Question 49

The coenzyme(s)used in fatty acid synthesis is (are)

A)FADH₂ and NADH.
B)FADH₂.
C)NADH.
D)NADH and NADPH.
E)NADPH.

Question 50

Which metabolic substrate can be produced from the carbon atoms in the amino acid valine?

A)pyruvate
B)succinyl CoA
C)acetoacetyl CoA
D)fumarate

Question 51

Fatty acid synthesis takes place primarily in

A)liver cells.
B)muscle cells.
C)brain cells.
D)the cytosol.
E)intestinal cells.

Question 52

The nitrogen for nucleotide synthesis comes from

A)DNA.
B)carbohydrates.
C)proteins.
D)RNA.
E)fats.

Question 53

In a(n) ______ reaction, is produced when glutamate is converted to

A)dehydrogenation
B)hydration
C)transamination
D)reduction
E)oxidative deamination

Question 54

Which metabolic substrate can be produced from the carbon atoms in the amino acid phenylalanine?

A)pyruvate
B)succinyl CoA
C)acetoacetyl CoA
D)fumarate

Question 55

Which metabolic substrate can be produced from the carbon atoms in the amino acid lysine?

A)pyruvate
B)succinyl CoA
C)acetoacetyl CoA
D)fumarate

Question 56

The production of new fatty acids is called

A) gluconeogenesis.
B) transesterification.
C) lipogenesis.
D) oxidation.
E)