Ch 25

Question 1

Define Metabolism

Answer 1

the sum of all body chemical reactions

Question 2

Define Catabolism

Answer 2

is breaking down larger molecules into smaller molecules. Catabolic reactions provide more energy than they consume; they are exergonic – they liberate heat

Question 3

Define Anabolism

Answer 3

is building up smaller molecules into larger molecules. Anabolic reactions consume more energy than they produce; they are endergonic – they consume heat

Question 4

Metabolism and Nutrition

Answer 4

• Metabolism is an energy-balancing act
  
  • ATP (adenosine triphosphate), is the energy currency unit that participates most often in living cells which couples energy-releasing catabolic reactions to energy-requiring anabolic reactions.
    
    • The exact reactions that occur depend on which enzymes are active in a particular cell at a particular time

Question 5

Define nutrient

Answer 5

is a “food or liquid that supplies the body’s metabolic needs. Nutrients include: A necessary chemical (such as Na+ and other minerals) A substance that provides energy (such as lipids or carbohydrates like glucose) Something that helps in growth of new body components (such as vitamins) A substance that repairs or maintains body functions (such as proteins, or amino acids to make proteins)

Question 6

ATP

Answer 6

ATP temporarily stores and transfers energy given off in catabolic reactions and transfers it to anabolic reactions that require energy.

Question 7

How Do We Get Energy From ATP?

Answer 7

By breaking the high- energy bonds between the last two phosphates in ATP

Question 8

Define Oxidation-reduction or redox reactions

Answer 8

• Oxidation – removal of electrons
  
  • Decrease in potential energy
  • Dehydrogenation – removal of hydrogens
  • Liberated hydrogen transferred by coenzymes
    
    • Nicotinamide adenine dinucleotide (NAD)
    • Flavin adenine dinucleotide (FAD)
  • Glucose is oxidized
• Reduction – addition of electrons
  
  • Increase in potential energy

Question 9

REDOX Reactions

Answer 9

• Chemical reactions in which a pair of electrons are exchanged as a means of transferring energy
  
  • Oxidation is the removal of electrons
  • Reduction is the addition of electrons

Question 10

Oxidation Reduction Chemisty: Redox Chemistry

Answer 10

• Oxidation and Reduction reactions always take place simultaneously.
• Loss of electrons – oxidation
• Gain of electrons - reduction

Question 11

Carbohydrate Metabolism

Answer 11

• Glucose (C6H12O6) is not just an example we happen to choose – it is indeed the body’s preferred source of fuel.
  
  • During digestion, polysaccharides and disaccharides are hydrolyzed into the monosaccharides glucose (80%), fructose, and galactose
  • These are absorbed into the villi of the small intestine and carried to the liver

Question 12

Summary of Cellular Respiration

Answer 12

• In the total oxidation of 1 molecule of glucose, 36-38 molecules of ATPs are generated, depending on the tissue.
  
  • Only 4 ATP are generated by substrate level phosphorylation (directly transferring a high energy phosphate from one organic molecule to another) in glycolysis and the Krebs cycle
  • Most of the ATP (either 32 or 34) is made by oxidative phosphorylation using the cytochromes of the electron transport chain and O2 as the final electron acceptor

Question 13

Summary of Cellular Respiration

Answer 13

• The location of events of cellular respiration are summarized in this graphic
  
  • Glycolysis is occurring in the cytoplasm
  • The Krebs cycle takes place in the mitochondrial matrix
  • The cytochrome proteins of the electron transport chain are embedded into the inner mitochondrial membrane

Question 14

Cellular Respiration

Answer 14

Question 15

Glucose Anabolism

Answer 15

• GLYCOGENESIS - Glucose synthesized to GLYCOGEN
• GLUCONEOGENESIS is the process of forming “new” glucose or its metabolites from fat or protein breakdown
• GLYCOGENOLYSIS is break down of glycogen

Question 16

Glucose storage - GLYCOGENESIS

Answer 16

• Glucose stored as glycogen: glycogenesis
  
  • Polysaccharide that is the only stored carbohydrate in humans
  • Insulin stimulates hepatocytes and skeletal muscle cells to synthesize glycogen
  • 75% stored in skeletal muscle, 25% in liver
  • Glucose → G6P → G1P → Uridine diphosphate glucose →glycogen
• and release into blood

Question 17

Glucose release - GLYCOGENOLYSIS

Answer 17

• Glucose release: glycogenolysis
  
  • Glycogen stored in hepatocytes broken down into glucose and release into blood
  • HEPATOCYTES: GLYCOGEN → G1P → G6P → GLUCOSE
  • MUSCLE: GLYCOGEN → G1P

Question 18

Glycogenesis and glycogenolysis

Answer 18

Question 19

Glucose formation - GLUCONEOGENESIS

Answer 19

• No food, low glycogen stores in liver, EAT! OR
• Triglycerides and Protein catabolism
• Lactic acid, glycerol, amino acids converted to Pyruvic acid → glucose formation or Krebs cycle

Question 20

Making Glucose

Answer 20

• Gluconeogenesis is the process of forming “new” glucose or its metabolites from fat or protein (from non-carbohydrate sources). Gluconeogenesis is always taking place, but it occurs on a large scale during fasting, starving, or eating a low carbohydrate diet
• Lactic acid, amino acids, and the glycerol portion of triglycerides are used to form glucose molecules or pyruvic acid to enter the Krebs cycle

Question 21

Lipids

Answer 21

• Although the word “fat” is commonly used to mean lipids, fats are, in fact, just one subgroup of lipids called triglycerides
  
  • Other lipids include waxes, sterols (steroid hormones), fat-soluble vitamins (such as vitamins A, D, E and K), monoglycerides, diglycerides, phospholipids, and others
    
    • For metabolic purposes, triglycerides are a condensed form of useable energy

Question 22

Lipids

Answer 22

• All triglycerides are composed of a glycerol backbone combined with 3 fatty acids
• Fatty acids are anywhere from 4 to 24 carbons long,and they may have all single carbon-carbon bonds (saturated), or some double or triple bonds (making them unsaturated)

Question 23

Triglycerides

Answer 23

• are nonpolar, and therefore very hydrophobic molecules
  
  • To be transported in watery blood, they must first be made more water-soluble by combining them with carrier molecules called lipoproteins (produced in the liver)
    
    • Lipoproteins vary in their size, density, and the amount of cholesterol and protein in their make-up

Question 24

Lipoproteins

Answer 24

• In general, however, all lipoproteins have:
  
  • An outer shell that is made hydrophilic due to polar proteins (plus amphipathic phospholipid and cholesterol)
  • An inner core that is hydrophobic - a place where the triglycerides are transported

Question 25

Lipoproteins – Docking proteins

Answer 25

• APO C-2 (activates lipoprotein lipase)
• APO E (hepatocyte docking protein)
• APO B100 (docking protein for LDL to enter by receptor-mediated endocytosis)

Question 26

Types of lipoproteins:

Answer 26

1. Chylomicrons – transport of ingested lipids to adipose tissue for storage (APO C-2 & APO E)
2. Very low-density lipoproteins (VLDL) – endogenous lipids, transport trigs made in liver to adipocytes for storage (APO C-2)
3. Low-density lipoproteins (LDL) are used to transport lipids to repair cells throughout. Contain 75% of total cholesterol in blood (APO B100) (BAD)
4. High-density lipoproteins (HDL) are used to transport excess cholesterol to the liver for elimination (GOOD)

Question 27

Types of lipoproteins:

Question 28

Sources of Cholesterol:

Answer 28

Ingestion

• Fatty foods with or without cholesterol
• Saturated fats (products from breaking saturated fats used by hepatocytes to make cholesterol)

              →Synthesis in hepatocytes

Question 29

Lipid Metabolism

Answer 29

• The term lipogenesis means fat synthesis, while lipolysis refers to the oxidation (catabolism) of lipids to yield glucose (which then yields ATP)
• If the body has no immediate needs, lipids are stored in adipose tissue

Question 30

Lipid Metabolism - Lipogenesis

Answer 30

• Glucose and AAs used be liver and adipose cells to perform lipogenesis
• If ATP needs are met, lipogenesis occurs
• Lipogenesis stimulated by insulin
• Excess carbohydrates, proteins, fats converted into triglycerides

Question 31

Lipid Metabolism - Lipolysis

Answer 31

begins with separating the glycerol backbone of triglycerides from the 3 fatty acids

Question 32

If ATP supply is LOW in cells…

Answer 32

If ATP supply is high in cells, Glyceraldehyde 3-P converted to glucose (gluconeogenesis)

Question 33

Beta oxidation

Answer 33

• is the process of cleaving off 2-carbon fragments from long fatty acid chains
• The 2-carbon acetyl groups are joined to coenzyme A to form acetyl CoA for insertion into Krebs cycle

Question 34

Lipid Metabolism

Answer 34

The oxidation of triglycerides (specifically, the 3 carbon glycerol backbone), results in the formation of ketoacids, (ketone bodies) which must be eliminated by the kidneys in order to maintain homeostasis

Question 35

Ketogenesis

Answer 35

• is a normal part of fat breakdown, but an excess will cause a metabolic acidosis
  
  • A mild ketoacidosis can occur even with a short 24 hour fast, and is responsible for the headaches and some of the other symptoms that are part of fasting

Question 36

Protein Metabolism

Answer 36

• Proteins are not a primary source of energy; and unlike lipids and sugars, proteins are not stored
  
  • Yet a certain amount of protein catabolism occurs in the body each day as proteins from worn-out cells are broken down into amino acids
    
    • Some amino acids are converted into other amino acids, peptide bonds are re-formed, and new proteins are synthesized as part of the recycling process

Question 37

Protein Metabolism

Answer 37

• In protein synthesis, transamination refers to the transfer of an amino group (NH2) to pyruvic acid or another acid in the Krebs cycle to form an amino acid
• In protein catabolism, deamination refers to the removal of an amino group leaving the carbons of a carboxylic acid to be used to make ATP
  
  • Essential amino acids are the 10 amino acids that can’t be synthesized by the body
  • Non-essential amino acids are the others that can be synthesized by the body

Question 38

Metabolic Crossroads

Answer 38

Three pivotal molecules stand at the crossroads of many of the chemical reactions in carbohydrate, lipid, and protein metabolism: acetyl-CoA, glucose-6-phosphate, and pyruvic acid occupy these key entry points into, and out of the Krebs cycle

Question 39

Metabolic Adaptation:

During the Absorptive State

Answer 39

ingested nutrients enter the blood stream and glucose is readily available

Question 40

Metabolic Adaptation:

During the Postabsorptive state

Answer 40

• absorption of nutrients from GI tract is complete and energy needs must be met by fuels in the body
  
  • Maintaining a steady blood glucose is critical because the nervous system and red blood cells depend solely on glucose as an energy source
    
    • The effects of insulin dominate

Question 41

The Absorptive State

Answer 41

• Soon after a meal glucose, amino acids, and lipid nutrients enter the blood. Triglycerides enter the blood carried in large lipoproteins called chylomicrons. There are 2 metabolic hallmarks of this state:
  
  • Glucose is oxidized to produce ATP in all body cells
  • Any excess fuel molecules are stored in hepatocytes, adipocytes, and skeletal muscle cells
• Pancreatic beta cells begin to release insulin to promote entry of glucose and amino acids into cells

Question 42

The Absorptive State

Answer 42

During the absorptive state, most body cells are concerned with producing ATP by oxidizing glucose

Question 43

The Postabsorptive State

Answer 43

• About 4 hours after the last meal absorption in the small intestine is nearly complete and blood glucose levels start to fall. The main metabolic challenge at this point is to maintain normal blood glucose levels
  
  • As blood glucose levels decline, insulin secretion falls and glucagon secretion increases
    
    • Blood glucose levels are sustained by the breakdown of liver glycogen, lipolysis, and gluconeogenesis using lactic acid and/or amino acids

Question 44

The Postabsorptive State

Answer 44

The process is supported by sympathetic nerve endings that release norepinephrine, and by the adrenal medulla that releases epinephrine and norepinephrine directly into the blood

Question 45

Basal Metabolic Rate

Answer 45

• The metabolic rate is the overall rate at which metabolic reactions use energy. Basal metabolic rate (BMR) is measured with the body in a quiet, fasting condition
  
  • Whatever the metabolic rate (other than death!), heat is a constant by-product of metabolic reactions, and can be expressed in calories
  • The BMR is 1200–1800 Cal/day in adults, or about 24 Cal/kg of body mass in adult males and 22 Cal/kg in adult females

Question 46

Body Temperature

Answer 46

• Despite wide fluctuations in environmental temperatures, homeostatic mechanisms maintain a normal range for internal (core) body temperature at 37°C (98.6°F)
  
  • Peripheral tissues can be much cooler (“shell temperature 1-6°C lower)
    
    • Body temperature is maintained by hormonal regulation of the BMR, exercise, and sympathetic nervous system stimulation

Question 47

Heat and Energy Balance

Answer 47

• Heat loss occurs through:
  
  • Conduction to solid materials in contact with the body, e.g. walking barefoot on the floor
  • Convection is the transfer of heat when a gas or liquid flows over an object, e.g. using a fan on a hot day
  • Thermal radiation is the transfer of heat in the form of electromagnetic energy (infrared, and encompassing visible light) between two bodies not in contact
  • Evaporation occurs when converting a liquid to a gas

Question 48

The Hypothalamic Thermostat

Answer 48

• The control center that functions as the body’s thermostat is a group of neurons in the anterior part (preoptic area) of the hypothalamus that receives impulses from thermoreceptors scattered throughout the body
  
  • Neurons of the preoptic area generate nerve impulses at a higher frequency when blood temperature increases, and at a lower frequency when blood temperature decreases

Question 49

Thermoregulation

Answer 49

• If the core temperature declines, skin blood vessels constrict and thyroid hormones and catecholamines (epinephrine and norepinephrine) are released. Cellular metabolism increases and shivering my ensue
• If core body temperature rises, blood vessels of the skin dilate, sweat glands are stimulated, and the metabolic rate is lowered

Question 50

Nutrition

Answer 50

• Nutrients are chemical substances in food that body cells use for growth, maintenance, and repair
  
  • There are 6 main types of nutrients
    
    • water , which is needed in the largest amount
    • carbohydrates
    • lipids
    • proteins
    • minerals
    • vitamins

Question 51

Nutrition

Answer 51

• Guidelines for nutritious eating are not known with certainty. Different populations around the world eat radically different amounts and types of carbohydrates, fats and protein in their diets. Basic guidelines include:
  
  • Eat a variety of foods
  • Maintain a healthy weight
  • Choose foods low in fat, saturated fat and cholesterol
  • Eat plenty of vegetables, fruits and grain products
  • Use sugars in moderation only

Question 52

Nutrition:

**Essential minerals **

Answer 52

• Essential minerals are those inorganic elements that occur naturally in the earth’s crust and are needed to maintain life. The major role of minerals is to help regulate enzymatic reactions and build bone
  
  • Recommendations are to eat foods that contain enough calcium, phosphorus, iron and iodine
    
    • Excess amounts of most minerals are excreted in urine and feces

Question 53

Nutrition:

Vitamins

Answer 53

• Vitamins are organic nutrients required in small amounts to maintain growth and normal metabolism - they do not provide energy or serve as the body’s building materials
  
  • Most cannot be synthesized by us, and no single food contains all the required vitamins
  • They are divided into those that are water soluble (several B vitamins and vitamin C), and those that are fat soluble (A, D, E, K)
    
    • Most vitamins serve as coenzymes

Question 54

Vitamin Deficiencies

Answer 54

• Vitamin A is needed to make the visual pigment retinal
  
  • Deficiency leads to night blindness and a weakened immune system
• Vitamin D is needed for calcium absorption
  
  • Deficiency results in impaired bone mineralization, and leads to bone softening diseasess such as rickets in children and osteomalacia in adults
• Vitamin K is needed to make clotting factors II, VII, and IX, X
  
  • A deficiency such as due to long-term antibiotic therapy or taking anticoagulant medications leads to delayed clotting times
• Vitamin C is necessary for proper growth of connective tissues like collagen
  
  • Deficiency manifests as a disease called Scurvy
• Niacin (B3) is a precursor to NAD (NADH), which plays essential metabolic roles in living cells
  
  • A deficiency (which is called Pellagra) results from an all corn diet, and manifests as dermatitis, diarrhea, and dementia
• Thiamine (B1) is essential for neural function and carbohydrate metabolism
  
  • A deficiency (called Beriberi) results from a polished rice diet, and manifests with muscle wasting, and impaired reflexes
• Folic Acid (vitamin B9) is needed to synthesize the bases used to replicate DNA
  
  • A deficiency manifests as a macrocytic anemia without nerve involvement
• Cyanocobalamin (B12 ) is important for normal nerve function and for the formation of blood
  
  • A deficiency manifests as pernicious anemia, ataxia, memory loss, weakness, personality and mood changes

Question 55

Obesity

Answer 55

• Obesity is defined as a body weight 10-20% (or more) above the desirable level because of excess fat
  
  • An explanation for the prevalence of obesity in our society is not universally agreed upon. In a complex interplay, many psychosocial and physiological issues appear to contribute
  • Obesity puts an individual at risk for a large number of diseases and conditions – cardiovascular disease predominant

Question 56

Factors of Obesity

Answer 56

• Factors that are especially prevalent in western society include:
  
  • An abundance of good-tasting food
  • Working longer hours (less time preparing good food)
  • Fast-foods
  • Super-size portions
  • Sedentary jobs
  • Lack of Exercise

Question 57

The thermostat and food intake regulating center of the body is in the ________ of the brain.

Answer 57

Hypothalamus

Question 58

The three key molecules of metabolism are ________, ________, and ________

Answer 58

1. glucose
2. Pyruvic Acid
3. Acetyl CoA

Question 59

**T or F: **Vitamins A, B, D, and K are fat‐soluble vitamins.

Answer 59

False

Question 60

T or F: Foods that we eat are used to supply energy for life processes, serve as building blocks for synthesis reactions, or are stored for future use.

Answer 60

True

Question 61

NAD+ and FAD (1) are both derivatives of B vitamins, (2) are used to carry hydrogen atoms released during oxidation reactions, (3) become NADH and FADH2 in their reduced forms, (4) act as coenzymes in the Krebs cycle, (5) are the final electron acceptors in the electron transport chain.

a. 1, 2, 3, 4, and 5
b. 2, 3, and 4
c. 2 and 4
d. 1, 2, and 3
e. 1, 2, 3, and 4

Answer 61

e. 1, 2, 3, and 4

Question 62

During glycolysis, (1) a 6‐carbon glucose is split into two 3‐carbon pyruvic acids, (2) there is a net gain of two ATP molecules, (3) two NADH molecules are oxidized, (4) moderately high levels of oxygen are needed, (5) the activity of phosphofructokinase determines the rate of the chemical reactions.

 a. 1, 2, and 3
 b. 1 and 2
 c. 1, 2, and 5
 d. 2, 3, 4, and 5
 e. 1, 2, 3, 4, and 5

Answer 62

c. 1, 2, and 5

Question 63

If glucose is not needed for immediate ATP production, it can be used for (1) vitamin synthesis, (2) amino acid synthesis, (3) gluconeogenesis, (4) glycogenesis, (5) lipogenesis.

a. 1, 3, and 5
 b. 2, 4, and 5
 c. 2, 3, 4, and 5
 d. 1, 2, and 3
 e. 2 and 5

Answer 63

b. 2, 4, and 5

Question 64

Which of the following is the correct sequence for the oxidation of glucose to produce ATP?

 a. electron transport chain, Krebs cycle, glycolysis, formation of acetyl CoA
 b. Krebs cycle, formation of acetyl CoA, electron transport chain, glycolysis
 c. glycolysis, electron transport chain, Krebs cycle, formation of acetyl CoA
 d. glycolysis, formation of acetyl CoA, Krebs cycle, electron transport chain
 e. formation of acetyl CoA, Krebs cycle, glycolysis, electron transport chain.

Answer 64

d. glycolysis, formation of acetyl CoA, Krebs cycle, electron transport chain

Question 65

Which of the following would you not expect to experience during fasting or starvation?

  a. decrease in plasma fatty acid levels
  b. increase in ketone body formation
  c. lipolysis
  d. increased use of ketones for ATP production in the brain
  e. depletion of glycogen

Answer 65

a. decrease in plasma fatty acid levels

Question 66

If core body temperature rises above normal, which of the follow‐ing would occur to cool the body? (1) dilation of vessels in the skin, (2) increased radiation and conduction of heat to the environment, (3) increased metabolic rate, (4) evaporation of perspiration, (5) increased secretion of thyroid hormones.

  a. 3, 4, and 5
  b. 1, 2, and 4
  c. 1, 2, and 5
  d. 1, 2, 3, 4 and 5
  e. 1, 2, 4, and 5

Answer 66

b. 1, 2, and 4

Question 67

In which of the following situations would the metabolic rate increase? (1) sleep, (2) after ingesting food, (3) increased secretion of thyroid hormones, (4) parasympathetic nervous system stimulation, (5) fever.

  a. 3 and 4
  b. 1, 3, and 5
  c. 2 and 3
  d. 2, 3, and 4
  e. 2, 3, and 5

Answer 67

e. 2, 3, and 5

Question 68

Which of the following are absorptive state reactions? (1) aerobic cellular respiration, (2) glycogenesis, (3) glycogenolysis, (4) gluconeogenesis using lactic acid, (5) lipolysis.

a. 1 and 2
b. 2 and 3
c. 3 and 4
d. 4 and 5
e. 1 and 5

Answer 68

b. 2 and 3

Question 69

Match the hormones with the reactions they regulate (answers may be used more than once; some reactions have more than one answer):

___ a.____gluconeogenesis

___ b.____glycogenesis

___ c.____glycogenolysis

___ d.____lipolysis

___ e.____lipogenesis

___ f.____protein catabolism

___ g.____protein anabolism

1. insulin
2. cortisol
3. glucagon
4. thyroid hormones
5. epinephrine
6. insulinlike growth factors

Answer 69

2,3 a.____gluconeogenesis

1 b.____glycogenesis

3,5 c.____glycogenolysis

2,4,5,6 d.____lipolysis

1 e.____lipogenesis

2 f.____protein catabolism

1,2,4,6 g.____protein anabolism

Question 70

Match the following:

___ a. ____deliver cholesterol to body cells for use in repair of membranes and synthesis of steroid hormones and bile salts

___ b. ____remove excess cholesterol from body cells and transport it to the liver for elimination

___ c. ____organic nutrients required in small amounts for growth and normal metabolism

___ d. ____the energy‐transferring molecule of the body

___ e. ____nutrient molecules that can be oxidized to produce ATP or stored in adipose tissue

___ f. ____transport endogenous lipids to adipocytes for storage

___ g.____the body’s preferred source for synthesizing ATP

___ h.____composed of amino acids and are the primary regulatory molecules in the body

___ i.____acetoacetic acid, beta‐hydroxybutyric acid, and acetone

___ j.____hormone secreted by adipocytes that acts to decrease total body‐fat mass

___ k.____neurotransmitter that stimulates food intake

___ l.____inorganic substances that perform many vital functions in the body

___ m.____carriers of electrons in the electron transport chain

1. leptin
2. minerals
3. glucose
4. lipids
5. proteins
6. neuropeptide Y
7. cytochromes
8. ketone bodies
9. low‐density lipoproteins
10. ATP
11. vitamins
12. high‐density lipoproteins
13. very‐low‐density lipoproteins

Answer 70

Match the following:

9 a. ____deliver cholesterol to body cells for use in repair of membranes and synthesis of steroid hormones and bile salts

12 b. ____remove excess cholesterol from body cells and transport it to the liver for elimination

11 c. ____organic nutrients required in small amounts for growth and normal metabolism

10 d. ____the energy‐transferring molecule of the body

4 e. ____nutrient molecules that can be oxidized to produce ATP or stored in adipose tissue

13 f. ____transport endogenous lipids to adipocytes for storage

3 g.____the body’s preferred source for synthesizing ATP

5 h.____composed of amino acids and are the primary regulatory molecules in the body

8 i.____acetoacetic acid, beta‐hydroxybutyric acid, and acetone

1 j.____hormone secreted by adipocytes that acts to decrease total body‐fat mass

6 k.____neurotransmitter that stimulates food intake

2 l.____inorganic substances that perform many vital functions in the body

7 m.____carriers of electrons in the electron transport chain

Question 71

Match the following:

___ a.____the mechanism of ATP generation that links chemical reactions with pumping of hydrogen ions

___ b.____the removal of electrons from an atom or molecule resulting in a decrease in potential energy

___ c.____the transfer of an amino group from an amino acid to a substance such as pyruvic acid

___ d.____the formation of glucose from noncarbohydrate sources

___ e.____refers to all the chemical reactions in the body

___ f.____the oxidation of glucose to produce ATP

___ g.____the splitting of a triglyceride into glycerol and fatty acids

___ h.____the synthesis of lipids

___ i.____the addition of electrons to a molecule resulting in an increase in potential energy content of the molecule

___ j.____the formation of ketone bodies

___ k.____the breakdown of glycogen back to glucose

___ l.____exergonic chemical reactions that break down complex organic molecules into simpler ones

___ m.____overall rate at which metabolic reactions use energy

___ n.____the breakdown of glucose into two molecules of pyruvic acid

___ o.____removal of CO2 from a molecule

___ p.____endergonic chemical reactions that combine simple molecules and monomers to make more complex ones

___ q.____the addition of a phosphate group to a molecule

___ r.____the removal of the amino group from an amino acid

___ s.____the cleavage of one pair of carbon atoms at a time from a fatty acid

___ t.____the conversion of glucose into glycogen

1. metabolism
2. catabolism
3. beta oxidation
4. lipolysis
5. phosphorylation
6. glycolysis
7. cellular respiration
8. transamination
9. anabolism
10. lipogenesis
11. glycogenolysis
12. glycogenesis
13. metabolic rate
14. ketogenesis
15. oxidation
16. reduction
17. chemiosmosis
18. deamination
19. gluconeogenesis
20. decarboxylation

Answer 71

17 a.____the mechanism of ATP generation that links chemical reactions with pumping of hydrogen ions

15 b.____the removal of electrons from an atom or molecule resulting in a decrease in potential energy

8 c.____the transfer of an amino group from an amino acid to a substance such as pyruvic acid

19 d.____the formation of glucose from noncarbohydrate sources

1 e.____refers to all the chemical reactions in the body

7 f.____the oxidation of glucose to produce ATP

4 g.____the splitting of a triglyceride into glycerol and fatty acids

10 h.____the synthesis of lipids

16 i.____the addition of electrons to a molecule resulting in an increase in potential energy content of the molecule

14 j.____the formation of ketone bodies

11 k.____the breakdown of glycogen back to glucose

2 l.____exergonic chemical reactions that break down complex organic molecules into simpler ones

13 m.____overall rate at which metabolic reactions use energy

6 n.____the breakdown of glucose into two molecules of pyruvic acid

20 o.____removal of CO2 from a molecule

9 p.____endergonic chemical reactions that combine simple molecules and monomers to make more complex ones

5 q.____the addition of a phosphate group to a molecule

18 r.____the removal of the amino group from an amino acid

3 s.____the cleavage of one pair of carbon atoms at a time from a fatty acid

12 t.____the conversion of glucose into glycogen

Question 72

Before the nutrients in a cheeseburger can be absorbed in the small intestine, the complex carbohydrates, fats, and proteins contained in it must undergo

a. exergonic catabolic reactions
b. endergonic catabolic reactions
c. exergonic anabolic reactions
d. endergonic anabolic reactions
e. endergonic reactions which are both catabolic and anabolic.

Answer 72

a. exergonic catabolic reactions

Question 73

Glucose is stored in the liver and muscle in the form of

a. starch.
b. cellulose
c. triglycerides.
d. glycogen
e. glucagon

Answer 73

a. starch

Question 74

Which of the following places the events of glucose catabolism in the correct order?

a. glycolysis, formation of acetyl coA, Krebs cycle, electron transport chain reactions
b. glycolysis, Krebs cycle, formation of acetyl coA, electron transport chain reactions
c. glycolysis, anaerobic respiration, Krebs cycle, electron transport chain reactions
d. glycolysis, Krebs cycle, anaerobic respiration, electron transport chain reactions
e. formation of acetyl coA, glycolysis, electron transport chain reactions.

Answer 74

a. glycolysis, formation of acetyl coA, Krebs cycle, electron transport chain reactions

Question 75

High-density lipoproteins

a. remove excess cholesterol from the blood.
b. transport dietary lipids to adipose tissue for storage.
c. transport triglycerides to adipose tissue for storage.
d. remove fatty acids from chylomicron triglycerides.
e. deposit cholesterol in and around arteries.

Answer 75

a. remove excess cholesterol from the blood.

Question 76

Fatty acids may be converted to acetyl CoA through a process called ________.

a. dehydrogenation
b. gluconeogenesis
c. beta oxidation
d. ketogenesis
e. transamination

Answer 76

c. beta oxidation

Question 77

Essential amino acids

1. are found in complete proteins.
2. include phenylalanine and tryptophan.
3. are found only in animal protein sources.

a. 1 only
b. 2 only
c. 3 only
d. 1 and 2 are correct.
1, 2, and 3 are correct.

Answer 77

d. 1 and 2 are correct.

Question 78

Which of the following may be used to produce ATP without utilizing glucose?

a. oxidation of fatty acids
b. oxidation of lactic acid
c. oxidation of amino acids
d. oxidation of ketone bodies
e. all of these choices

Answer 78

e. all of these choices

Question 79

The bulk of your total energy expenditure is due to your

a. voluntary exercise.
b. nonexercise activity thermogenesis.
c. basal metabolic rate.
d. food-induce thermogenesis.
e. energy homeostasis.

Answer 79

c. basal metabolic rate.

Question 80

Vitamins

a. serve as coenzymes
b. provide energy
c. serve as building materials within the body
d. serve as coenzymes and provide energy are correct
e. serve as coenzymes, provide energy, and serve as building materials within the body are correct

Answer 80

a. serve as coenzymes

Question 81

What is the role of oxygen in metabolism?

a. it provides energy to cells
b. it is needed in all oxidation reactions
c. it is a catalyst in the Krebs cycle
d. it is needed to produce ATP
e. it is the final electron acceptor in the electron transport system

Answer 81

e. it is the final electron acceptor in the electron transport system