Deck 14: Metabolism

Question 1

A metabolic pathway in which a series of reactions is used to repeatedly break down or build up a molecule is defined as a ___ pathway.

A) linear
B) circular
C) spiral
D) coupled

Answer 1

spiral

Question 2

The amount of energy obtained from hydrolysis of ATP is

A) -11.8 kcal.
B) - 36 kcal.
C) -4.5 kcal.
D) -7.3 kcal.

Answer 2

-7.3 kcal.

Question 3

___ is defined as the reactions that break down large molecules into small ones and release energy in the form of ATP.

A) Metabolism
B) Catabolism
C) Anabolism
D) Hydrolysis

Answer 3

Catabolism

Question 4

A metabolic pathway in which the final product is also a starting material is defined as a ___ pathway.

A) linear
B) circular
C) spiral
D) coupled

Question 5

Protein synthesis is a form of ___.

A) metabolism
B) catabolism
C) anabolism
D) hydrolysis

Question 6

The biosynthesis of fatty acids is a form of ___.

A) metabolism
B) catabolism
C) anabolism
D) hydrolysis

Question 7

Which is the structure for ATP?

A)
B)
C)
D) All of these choices are correct formulas for ATP.

Question 8

The location in the cell where ATP is produced is the ___.

A) mitochondria
B) lysosome
C) nucleus
D) cell membrane

Question 9

Which choice is a goal of catabolism?

A) the production of heat
B) the attachment of the coenzyme A residue
C) the generation of ATP molecules
D) the production of two-carbon fragments

Question 10

The acetyl-CoA from the fatty acid catabolism enters the ___ whereas the reduced coenzymes NADH and FADH₂ enter ___.

A) citric acid cycle/the electron transport chain
B) electron transport chain/glycolysis
C) citric acid cycle/glycolysis
D) glycolysis/the citric acid cycle

Question 11

During glycolysis and under aerobic conditions, pyruvate is converted into ___.

A) lactate
B) acetyl-CoA
C) ketones
D) ADP

Question 12

___ takes place in the cytoplasm while ___ takes place in the mitochondria.

A) Citric acid cycle/electron transport chain
B) Electron transport chain/glycolysis
C) Citric acid cycle/glycolysis
D) Glycolysis/citric acid cycle

Question 13

The NADH or FADH₂ produced from fatty acid oxidation can enter ___ where these coenzymes are recycled to their oxidized forms.

A) glycolysis
B) gluconeogenesis
C) citric acid cycle
D) electron transport chain

Question 14

Glycolysis is a form of ___.

A) metabolism
B) catabolism
C) anabolism
D) hydrolysis

Question 15

Acetyl-CoA produced as a result of glycolysis enters the ___ metabolic pathway.

A) glycolysis
B) gluconeogenesis
C) citric acid cycle
D) electron transport chain

Question 16

The process by which ADP is converted to ATP takes place in the ___ and one of the processes by which this change occurs is known as ___.

A) mitochondria/oxidative phosphorylation
B) cytoplasm/oxidative phosphorylation
C) mitochondria/citric acid cycle
D) cytoplasm/citric acid cycle

Question 17

Which of the following bonds is broken when ATP is hydrolyzed?

A) hydrogen bond
B) phosphoester bond
C) N-glycosidic bond
D) phosphoanhydride bond

Question 18

___ is exclusively used to for reductive biosynthesis reactions.

A) NADPH
B) ATP
C) ADP
D) NAD⁺

Question 19

Most of triglyceride digestion occurs in the ___.

A) mouth
B) stomach
C) small intestine
D) liver

Question 20

The digestion of proteins begins in the stomach with hydrolysis being catalyzed by ___.

A) chymotrypsin
B) pepsin
C) amylase
D) lipase

Question 21

Amylase

A) is an enzyme that continues functioning in the stomach.
B) is the only enzyme in the saliva that hydrolyzes proteins.
C) is a carbohydrate easily digested in the stomach.
D) catalyzes hydrolysis of some of the bonds in amylose.

Question 22

How do the monosaccharides produced during digestion get into the circulatory system?

A) They are absorbed by the cells in the intestinal lining and are released into the blood.
B) They are absorbed by the cells in the stomach lining and released into the blood.
C) They are able to move between the cells of the stomach lining directly into the blood.
D) They are transported by the action of the cell membranes of the digestive tract.

Question 23

The digestion of ___ begins in the mouth and continues in the small intestine where the large molecules are broken down into ___.

A) proteins/amino acids
B) carbohydrates/monosaccharides
C) lipids/fatty acids and glycerol and monoacylglycerides
D) fiber/starch

Question 24

Digestion of ___ begins in the stomach.

A) starch and proteins
B) starch and triglycerides
C) triglycerides and proteins
D) starch and all other oglio-orpolysaccharides

Question 25

The digestion of lactose to galactose and glucose occurs in the ___.

A) mouth
B) stomach
C) intestine
D) liver

Question 26

The digestion of ___ takes place in the stomach by the actions of enzymes operating at low pH. This digestion continues in the small intestine and the large molecules are broken down into ___.

A) proteins/amino acids
B) carbohydrates/monosaccharides
C) lipids/fatty acids and glycerol and monoacylglycerides
D) fiber/starch

Question 27

The digestion of ___ occurs in the small intestine where the large molecules are emulsified by bile and are broken down into ___ before being absorbed into the blood stream.

A) proteins/amino acids
B) carbohydrates/monosaccharides
C) lipids/fatty acids/glycerol and monoacylglycerides
D) fiber/cellulose

Question 28

The allosteric enzyme phospofructokinase is switched off by ___.

A) glucose
B) isocitrate
C) AMP
D) ATP

Question 29

One step in the catabolism of glucose involves the conversion of glucose 6-phosphate into ___.

A) glucose
B) fructose 6-phosphate
C) glucose 3-phosphate
D) pyruvate

Question 30

Where in a cell do the formation of acetyl-CoA and the citric acid cycle occur?

A) cytoplasm
B) mitochondria
C) nucleus
D) lysosome

Question 31

Glycolysis is controlled in steps:

A) 1, 2, and 3
B) 2, 5 and 7
C) 1, 3 and 10
D) 3, 5 and 8

Question 32

Gluconeogenesis is a process by which glucose is produced

A) in the liver from noncarbohydrate sources.
B) in the mitochondrion if there is an excess of fructose.
C) by the enzymes located on the cristae.
D) by exactly reversing the process of glycolysis.

Question 33

Gluconeogenesis is a form of ___.

A) metabolism
B) catabolism
C) anabolism
D) hydrolysis

Question 34

One way that insulin reduces blood sugar is by

A) increasing the rate of change of blood sugar to fructose.
B) increasing the rate of glycogen metabolism.
C) increasing the rate of glucose uptake by cells.
D) increasing the concentration of glycogen phosphorylase.

Question 35

Which kind of a process is glycogenesis?

A) catabolic
B) anabolic
C) hydrolysis
D) hydrogenation

Question 36

What is a possible response to a drop in blood glucose concentration?

A) Anaerobic metabolism of sugars occurs instead of aerobic pathways.
B) The rate of the production of the enzymes necessary to produce glucose is increased.
C) Glycogenolysis is switched on and glycogenesis is switched off.
D) The production of glucose 6-phosphate is switched off.

Question 37

Which of the choices below present products of the citric acid cycle?

A) ATP, ADP, and CO₂
B) NADH, FADH₂, and GTP
C) FAD, NAD⁺, ADP, and H₂O
D) CO₂, H₂O, ATP, and GTP, and NAD⁺

Question 38

The citric acid cycle has which step as a main control?

A) step 3, isocitrate $\rightarrow$$\alpha$ -ketoglutarate
B) step 1, acetyl-CoA $\rightarrow$ citrate
C) step 7, fumarate $\rightarrow$ malate
D) step 8, malate $\rightarrow$ oxaloacetate

Question 39

The compounds needed to start the citric acid cycle are

A) acetyl-CoA and citrate.
B) isocitrate and NAD⁺.
C) acetyl-CoA and NADH.
D) acetyl-CoA and oxaloacetate.

Question 40

Sometimes the reduction of oxygen to water is incomplete, resulting in

A) a greater production of ATP because there are more hydrogen ions present.
B) toxic products, which are superoxide or hydrogen peroxide.
C) a greater production of FADH₂ from the extra hydrogen ions.
D) hydrogen gas, which can be excreted and does not build up.

Question 41

What is the total yield of ATP obtained when 1 glucose molecule goes through glycolysis and the citric acid cycle?

A) 25 ATP
B) 28 - 29 ATP
C) 30 - 32 ATP
D) 35 ATP

Question 42

The oxidation of which of the following provides rapid generation of heat in newborn infants?

A) White fat cells
B) Brown fat cells
C) ATP synthase
D) glutamate

Question 43

The electron transport chain

A) takes place in the special membranes located in the nucleus of the cell.
B) produces FADH₂ by means of hydrolysis reactions.
C) utilizes the H⁺ released to produce complexes for later reaction.
D) and oxidative phosphorylation together produce ATP.

Question 44

The NADH and FADH₂ used by the electron transport chain are normally produced in the mitochondria; however,

A) NADH is also produced during glycolysis in the cytoplasm.
B) NADH is only produced and used in the mitochondria; FADH₂ can be used elsewhere.
C) FADH₂ is also produced by the citric acid cycle; NADH is not.
D) FADH₂ produced in the mitochondria has more energy than does NADH.

Question 45

Each spiral of the $\beta$ -oxidative spiral of fatty acid catabolism removes ___ carbon atoms from a fatty acid producing acetyl-CoA, NADH and FADH₂.

A) 1
B) 2
C) 3
D) 4

Question 46

The fatty acids produced from the hydrolysis of triglycerides can

A) be used to enter directly into glycolysis, producing extra ATP.
B) be oxidized to produce acetyl-CoA, which enters the citric acid cycle.
C) produce glucose by a pathway separate from gluconeogenesis.
D) be modified to undergo either glycolysis or gluconeogenesis.

Question 47

Which of the following products are formed in one pass through the $\beta$ -oxidation spiral when a fatty acyl-CoA is shortened by two carbon atoms?

A) NADH and pyruvate
B) FADH₂ and pyruvate
C) NADH and FADH₂
D) ATP and glycogen

Question 48

If acetyl-CoA concentrations reach too high levels,

A) ketone bodies can be produced leading to a toxic condition.
B) the citric acid cycle increases in reaction rate to use the excess acetyl-CoA.
C) pathways other than the citric acid cycle activate to remove the excess acetyl-CoA.
D) the ketone bodies are stored in special cells and used as a source of energy when required.

Question 49

Lipogenesis

A) produces fatty acids by means of a spiral pathway.
B) produces fatty acids by joining two carbon atoms at a time.
C) does not produce all of the fatty acids required by hum
D) All of these answer choices are correct.

Question 50

In a cell, fatty acid biosynthesis occurs in ___.

A) mitochondria
B) the cytoplasm
C) the nucleus
D) lysosome

Question 51

The condition of ketoacidosis is

A) a potentially fatal buildup of acetoacetate or 3-hydroxybutyrate lowering blood pH.
B) due to a lowered production of ketone bodies than is normal.
C) the increase in pH of the cells due to ketone body production.
D) only found when anaerobic catabolism of fat occurs.

Question 52

Beginning with octanoic acid, how many passes through the $\beta$ -oxidation spiral will take place?

A) 3
B) 4
C) 6
D) 8

Question 53

Protein digestion produces amino acids

A) that are further digested by glycolysis to produce ATP.
B) that can be used to produce new peptides and proteins.
C) that undergo transamination to produce all known amino acids.
D) that can be linked together with glycerol to produce lipids.

Question 54

NH₄⁺ is normally excreted from the human body by means of ___.

A) ammonium ions
B) urea
C) uremic acid
D) uric acid

Question 55

During catabolism, proteins are broken down into amino acids. The amine groups are transferred to an $\beta$ -keto acid by a process known as ___. The amino acids of $\beta$ -keto acids are then converted into ___ before being excreted in urine.

A) oxidative phosphorylation/pyruvate
B) glycolysis/acetyl-CoA
C) ketosis/acetone
D) transamination/urea

Question 56

During oxidative deamination

A) ammonium ions are removed from one amino acid and placed on another amino acid.
B) oxygen reacts with the amino acid releasing nitrogen-oxygen compounds.
C) new compounds are produced by the addition of a carboxyl group.
D) potentially toxic ammonium ions are produced.

Question 57

Which of the following is produced when the amino acid aspartate undergoes transamination reaction shown here?

A)
B)
C)
D)

Question 58

In a coupled reaction of a metabolic pathway, a spontaneous reaction provides the energy needed by a nonspontaneous one.

Question 59

Catabolism reactions are those that produce more complex molecules from the simpler molecules along with a release of energy.

Question 60

Glycogen can be broken down to form glucose 1-phosphate, which is directly involved in glycolysis.

Question 61

The overall net result of glycolysis is the conversion of one glucose to two pyruvates, 3 NADH, 4 ATP and energy.

Question 62

ATP is used up in glycolysis and produced in glucogenesis.

Question 63

Glycolysis occurs in cytoplasm; the next step in carbohydrate metabolism, the citric acid cycle, occurs in mitochondria.

Question 64

The brown fat cells found in newborn babies have a greater number of mitochondria than other fat cells and are capable of much faster metabolism of triglycerides than the fat cells found in adults.

Question 65

The fatty acid synthesis in the body occurs primarily in the cytoplasm.

Question 66

___ are subcellular organelles that have an outer and an inner membrane used for transport of electrons and molecules.

Question 67

Starch digestion is initiated by the enzyme ___.

Question 68

Complete the following table:

Question 69

The process by which glucose is split into pyruvate is ___.

Question 70

In humans, pyruvate is reduced to lactate when the conditions are ___ such as after a vigorous exercise.

Question 71

___ molecule of glucose can produce 30-32 ATP during catabolism.

Question 72

The hydrolysis of triglycerides is performed by the ___ enzymes.

Question 73

Of the 20 amino acids used by humans, ___ can be converted into citric acid cycle intermediates.

Question 74

Is glycolysis catabolism or anabolism?

Question 75

Is gluconeogenesis catabolism or anabolism?

Question 76

Is citric acid cycle catabolism or anabolism?

Question 77

Is $\beta$ -oxidation spiral catabolism or anabolism?

Question 78

Is oxidative deamination catabolism or anabolism?

Question 79

Draw ATP and label the ribose and also the phosphoanhydride bond, that when cleaved, results in the conversion of ATP into ADP.

Question 80

Differentiate between the products of glycolysis under aerobic and anaerobic conditions.