Deck 4: Body Weight and Health: Enzymes, Metabolism, and Cellular Respiration

Question 1

Which statement describes enzymes?

A) Enzymes are not very specific.
B) Enzymes are not affected by high heat, as proteins are.
C) Enzymes can be recycled and used over and over again.
D) Enzymes are "used up" during chemical reactions.

Answer 1

C

Question 2

In cellular respiration, which molecule is released after the citric acid cycle?

A) oxygen
B) carbon dioxide
C) water
D) glucose

Answer 2

B

Question 3

Which person might have a high basal metabolic rate?

A) a 70-year-old woman who knits for most of the day
B) a 30-year-old man who is a professional athlete
C) a 50-year-old woman who exercises twice a week
D) a 65-year-old man who walks three miles daily

Answer 3

B

Question 4

Which factor would most affect an individual's basal metabolic rate?

A) caloric intake
B) sleep habits
C) balanced diets
D) exercise levels

Question 5

In the human body, which substrate would protease act upon?

A) protein
B) lipids
C) lactose
D) sucrose

Question 6

Lactose is a disaccharide found in milk. What makes some people "lactose intolerant" as adults?

A) Some people don't produce any enzymes, including the one needed to digest lactose.
B) Lactose can only be digested by people who produce enough lipase to digest it.
C) Lactose-intolerant people don't produce adequate amounts of lactase.
D) The active site of the lactose-digesting enzyme can vary from person to person.

Question 7

Which process provides the carbon dioxide you exhale?

A) aerobic respiration
B) anaerobic respiration
C) glycolysis
D) transpiration

Question 8

Which molecule powers the chemical work within cells?

A) NAD⁺
B) NADPH
C) CO₂
D) ATP

Question 9

Activation energy is similar to the "push" needed to start rolling a stalled car down a hill. How do enzymes fit into this analogy?

A) Enzymes increase the effort that's needed to start the car moving.
B) Enzymes decrease the effort that's needed to start the car moving.
C) Enzymes add a roadblock on the hill that the car will roll down.
D) Enzymes decrease the size and shape of the car that needs to be moved.

Question 10

Which process creates the most ATP per glucose molecule metabolized?

A) glycolysis
B) fermentation
C) anaerobic respiration
D) aerobic cellular respiration

Question 11

What are the proteins that catalyze chemical reactions in the body?

A) enzymes
B) coenzymes
C) antioxidants
D) high-density lipoproteins (HDLs)

Question 12

Which substance is most likely an enzyme?

A) proline
B) stearic acid
C) endopeptidase
D) acetylcholine

Question 13

What type of metabolic pathway requires oxygen?

A) aerobic
B) anaerobic
C) photosynthetic
D) fermentative

Question 14

What actually happens when pyruvic acid loses a carbon dioxide molecule after glycolysis?

A) The pyruvic acid is denatured.
B) The pyruvic acid is phosphorylated.
C) The pyruvic acid is decarboxylated.
D) The pyruvic acid is oxidated.

Question 15

What would happen if activation energy barriers didn't exist?

A) Substrates would not bind properly to enzymes.
B) Chemical reactions in the body would never occur.
C) Coenzymes would not work, but enzyme function would not be affected.
D) All chemical reactions in the body would proceed whether they were needed or not.

Question 16

Assume that a newly developed chemical agent blocks the active site of the enzyme shown in the figure. What molecule should the drug imitate in size and shape?

A) glucose
B) fructose
C) sucrase
D) sucrose

Question 17

How does ATP provide energy to a cell?

A) It loses a phosphate group, releasing energy in the process.
B) It releases electrons, which are a source of energy.
C) It releases protons, which are used in the mitochondrion to create energy.
D) It shuttles electrons across the mitochondrial membrane to create potential energy.

Question 18

How many different amino acids are present in the human body to produce the infinite variety of enzymes and other necessary proteins?

A) 10
B) 20
C) millions
D) an infinite variety

Question 19

What is the source of chemical energy used to power a muscle cell in your arm?

A) pyruvic acid
B) adenosine triphosphate (ATP)
C) nicotinamide adenine dinucleotide (NAD⁺)
D) phospholipids

Question 20

What is the resting energy requirement of a person who is awake but not active? (three words)

Question 21

Which molecule is a "metabolic taxicab" that shuttles electrons?

A) OAA
B) NADH
C) ATP
D) ADP

Question 22

River water piped through dams rushes past turbines in hydroelectric plants to create electricity. Which metabolic process relates to this analogy?

A) the splitting of glucose during glycolysis
B) the release of carbon dioxide during the citric acid cycle
C) the transport of electrons by NADH
D) the passage of hydrogen ions through ATP synthase to make ADP into ATP

Question 23

What is the function of the protein channel where H⁺ ions escape into the matrix of the mitochondrion?

A) to add a phosphate to ADP
B) to remove a phosphate from ATP
C) to break the bonds of ATP
D) to create ADP from ATP

Question 24

When a muscle cell contracts, what type of work is being powered by ATP?

A) chemical
B) transport
C) mechanical
D) potential

Question 25

What happens to an ATP molecule after it has released a phosphate?

A) It becomes AMP and is recycled into proteins.
B) It is phosphorylated and becomes ADP.
C) It is converted into lactic acid and transported to the liver for disposal.
D) It is secreted in urine as a waste product of cellular respiration.

Question 26

Creatine phosphate (marketed as "creatine") is a popular supplement taken by weightlifters and other athletes. What might the phosphates in this supplement be expected to do?

A) They readily allow for the regeneration of ATP.
B) They break down glucose during the citric acid cycle.
C) They accept electrons at the end of the electron transport chain.
D) They ensure ATP is never broken down into ADP.

Question 27

What molecule releases energy to power the transport work across cell membranes?

A) ADP
B) ATP
C) NADP
D) NADPH

Question 28

What is the first reactant in the citric acid cycle?

A) pyruvic acid (C₃H₃O₃)
B) glucose (C₆H₁₂O₆)
C) carbon dioxide (CO₂)
D) oxalaoacetate (OAA)

Question 29

If loading and shooting a dart gun is analogous to how ATP functions, which component of ATP is similar to the dart?

A) the nitrogenous base
B) the sugar
C) a phosphate
D) a photon

Question 30

What is the name of the protein channel where H⁺ ions escape into the matrix of the mitochondrion?

A) ATP synthase
B) OAA
C) grana
D) pyruvic acid

Question 31

What are the two molecules produced by cellular respiration?

Question 32

Which process occurs inside the mitochondria?

A) glycolysis
B) fermentation
C) citric acid cycle and electron transport
D) glycolysis and electron transport

Question 33

If necessary, our muscles can rely upon an anaerobic (fermentative) pathway to metabolize glucose, but this can only last a short period of time. Why can't our cells survive very long under such anaerobic conditions?

A) Fermentation doesn't extract enough ATP from glucose to sustain our energy-craving cells.
B) Anaerobic conditions create a "carbon dioxide debt" that must be repaid before cells die.
C) The ethyl alcohol that builds up in muscles as a result of fermentation is a toxin.
D) Lactic acid causes the cell to die when it's exposed to even lower concentrations.

Question 34

During cellular respiration, where does the energy released from glucose go as it is metabolized into the low-energy compounds carbon dioxide and water?

A) The energy goes into ATP.
B) The energy goes into lactic acid.
C) The energy goes out of the cell as heat.
D) The energy goes into electrons that directly power the cell.

Question 35

During the process of cellular respiration, what is the final acceptor for electrons at the end of the electron transport chain?

A) oxygen
B) carbon
C) carbon dioxide
D) hydrogen

Question 36

During glycolysis, what molecule is formed when NAD⁺ picks up a hydrogen atom along with its electron?

A) NADP
B) NADPH
C) NADH
D) H₂O

Question 37

What 3-carbon molecules are produced when a 6-carbon glucose is broken down during glycolysis? (two words)

Question 38

What is the main biochemical function of the electron transport chain?

A) to break glucose into pyruvic acid
B) to add phosphate groups to ATP
C) to regenerate OAA
D) to force hydrogen ions through ATP synthase

Question 39

Which molecules are required by the body but do not produce ATP?

A) carbohydrates
B) proteins
C) fats
D) vitamins

Question 40

What proteins, working in series, catalyze the reactions of the citric acid cycle?

Question 41

Why is oxygen needed in cellular respiration?

A) Oxygen combines with ADP to create ATP.
B) Oxygen is the final electron acceptor in the electron transport chain.
C) Oxygen carries electrons from the citric acid cycle to the electron transport chain.
D) Fermentation in muscle cells relies upon oxygen as an electron acceptor.

Question 42

Which disease may be associated with low levels of body fat and low levels of estrogen?

A) diabetes
B) stroke
C) heart attack
D) osteoporosis

Question 43

Why is a very low level of body fat unhealthy in young women?

A) Women need a certain amount of fat to maintain their fertility.
B) Reduced levels of body fat make a woman unable to expend any energy.
C) Women with very low body fat have an increased risk of developing diabetes.
D) Women with very low body fat have an increased risk of heavy menstrual bleeding.

Question 44

What process will follow glycolysis, if oxygen is not available?

A) fermentation
B) cellular respiration
C) phosphorylation
D) the conversion of CO₂ into O₂

Question 45

What happens to the lactic acid created during fermentation in human muscle cells?

A) It is directly converted into ATP.
B) It donates a phosphate to ADP to recharge ATP.
C) It goes to the liver, where it's converted into pyruvic acid.
D) It joins with electrons and hydrogen ions to form H₂O.

Question 46

Shannon has considered herself an extremely healthy person for most of her life. She is a marathon runner and watches her diet very carefully. She has 8% body fat, weighs 105 pounds, and is 5 foot 10 inches tall. Why might Shannon's health still be of concern?

A) She is overweight for her height.
B) She likely has metabolic problems associated with high blood pressure.
C) She doesn't have enough body fat for menstruation or pregnancy.
D) She doesn't consume enough nutrients for normal bodily functions.

Question 47

Which component of fat can be metabolized for the production of ATP?

A) amino acids
B) monosaccharides
C) nucleic acids
D) glycerol

Question 48

Why are eating disorders that severely restrict food intake very dangerous?

A) Menstruation can cease, which may cause sterility.
B) The risk of stroke can increase.
C) They can cause Type 1 diabetes.
D) They can lead to high blood pressure.

Question 49

Which molecules are made during glycolysis?

A) NADH and ATP
B) ADP and NADPH
C) water and NAD⁺
D) oxygen and water

Question 50

The figure shows the different pathways taken by the subunits of macronutrients during cellular respiration. Which macronutrient subunit is never converted into pyruvic acid before entering the citric acid cycle?

A) an amino acid
B) a fatty acid
C) glycerol
D) glucose

Question 51

Why isn't the Body Mass Index (BMI) a perfectly reliable way to estimate your health?

A) It considers your height but not your weight.
B) It considers your weight but not your height.
C) It doesn't account for differences in muscle mass between individuals.
D) Body fat estimates are not correlated with the risk of illness and death.

Question 52

During which process would ethanol and carbon dioxide be released from the cell?

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

Question 53

Why does sour cream have a sharp, tart flavor

A) from the ADP produced by microbes during glycolysis
B) from the lactic acid, produced anaerobically by microbes
C) from the ethyl alcohol formed as the cream is broken down by microbes
D) from the citric acid released by microbes during the citric acid cycle

Question 54

Which condition is associated with obesity?

A) amenorrhea
B) Type 2 diabetes
C) osteoporosis
D) altered heart rhythms

Question 55

How much ATP is produced from one glucose molecule if no oxygen is available during muscle cell contraction?

A) none
B) 1 molecule
C) 2 molecules
D) 26 molecules

Question 56

What type of eating disorder involves consuming large amounts of food, followed by self-induced vomiting?

A) anorexia
B) bulimia
C) osteoporosis
D) diabetes

Question 57

Which molecule results from the process of fermentation?

A) ADP
B) NADPH
C) NADH
D) NAD⁺

Question 58

What does recent research suggest about the relationships between weight and health risks?

A) People of normal weights have the lowest health risks.
B) People who are moderately obese have the highest health risks.
C) People who are slightly overweight have the lowest health risks.
D) People who are underweight have the highest health risks.

Question 59

According to the diagram, how many molecules of oxygen (O₂) combine with electrons and hydrogen ions to form one molecule of water (H₂O) at the end of the electron transport chain?

A) 1/2
B) 1
C) 2
D) none

Question 60

What weight classification would include a person with a BMI of 23?

Question 61

If you ate a piece of toast covered with butter, which macromolecule components would result after your body breaks down the food?

A) amino acids and glycerol
B) glycerol, fatty acids, and monosaccharides
C) monosaccharides and amino acids
D) fatty acids, amino acids, and polysaccharides

Question 62

Which BMI range has the lowest relative risk of death?

A) 18-24.99 (normal weight)
B) 25-29.99 (overweight)
C) 30-34.99 (moderate obesity)
D) 35 and above (severe obesity)

Question 63

What is meant by metabolism?

A) the body's ability to lose weight
B) the body's ability to maintain a constant temperature
C) all of the chemical reactions occurring in the body
D) the chemical reactions that create molecules in the body