Chapter 24 - Nutrition, Metabolism, and Temperature Regulation

Question 1

Nutrient

Answer 1

A substance in food that is used to promote normal growth, maintenance, and repair

Question 2

H2O

Answer 2

is the major nutrient, 60% comes from food

Question 3

Carbohydrates

Answer 3

Almost all are derived from plants. Glucose is the major one, we use it for body fuel. Used to make ATP, mostly needed in the brain and RBC’s. Need 125-175g lately.

Question 4

Lipids

Answer 4

Sourced from plants and animals, most abundant are the neutral fats.

Question 5

Uses of Lipids

Answer 5

Phospholipids -cell membrane components
Triglycerides -energy source for hepatocytes and muscle
Adipose tissue-protection, insulation, and energy source
Lecithin -used to build the plasma membrane
Cholesterol -Not an energy source, but builds bile salts and steroids

Question 6

Proteins

Answer 6

For high quality proteins, animals are the best source for essential amino acids. Used for structural components, production of enzymes, production of hormones, production of plasma proteins and antibodies.

Question 7

Vitamins

Answer 7

Organic compound needed for growth and good health. Never used for energy. Without vitamins, proteins, fats, and carbs would be completely useless. Most are coenzymes or a component of a coenzyme. Vitamins K, B, and D may be produced in the body.

Question 8

Effects of:

Vitamin A

Answer 8

Important in retinal function, deficiency leads to night blindness

Question 9

Effects of:

Vitamin D

Answer 9

Deficiency can lead to Rickets in children

Question 10

Effects of:

Vitamin E

Answer 10

Excess can lead to thrombopoiesis

Question 11

Effects of:

Vitamin K

Answer 11

Deficiency can lead to prolonged clotting

Question 12

Effects of:

Vitamin C

Answer 12

Deficiency leads to scurvy

Question 13

Effects of:

Vitamin B1

Answer 13

Deficiency leads to beri-beri

Question 14

Effects of:

Vitamin B2

Answer 14

Deficiency leads to dermititis

Question 15

Effects of:

Vitamin B12

Answer 15

Deficiency leads to pernicious anemia

Question 16

Effects of:

Niacin

Answer 16

Deficiency leads to pellagra

Question 17

Fat Soluble Vitamins

Answer 17

Vitamins A, D, E, K

Question 18

Water Soluble Vitamins

Answer 18

Vitamins C, B1, B2, B12, and niacin

Question 19

Anabolism

Answer 19

A reaction where larger molecules are built from smaller ones. Ex: Amino acids being builts into proteins

Question 20

Catabolism

Answer 20

The breaking down of complex structures to simpler structures. Ex: Food being broken down by hydrolysis

Question 21

Stages of Metabolism

Answer 21

• Digestion in the gastrointestinal tract
• Nutrients are transported by the blood to the cell
• In the mitochondria, O2 makes a complete breakdown of food
• The electron transport chain

Question 22

Redox Reactions

Answer 22

• Oxidation: when oxygen is gained or H, or e-, is lost

- Reduction: when oxygen is lost or H, or e-, are gained

Question 23

H+ Acceptors

Answer 23

FAD and NAD

Question 24

Glycolysis

Answer 24

Ten chemical steps where glucose is converted into 2 pyruvic acid molecules. It occurs in the cytoplams, is anaerobic, and results in 2 ATP per glucose molecule

Question 25

Kreb's Cycle

Answer 25

The aerobic pathway, occurs in the mitochondria. 2 pyruvic acid molecules are converted into acetyl CoA. It's then oxidized, decarboxylated yielding 6 CO2, 8 NADH, H+, 2 FADH2, and 2ATP.

Question 26

e- Transport Chain

Answer 26

Coenzymes deliver H+ to redox acceptors, H2 is split into H+ and e-. H+ and ATP synthase uses the energy to produce ATP. O2 is the terminal e- acceptor. ETC doesn't make ATP directly, it generates a proton gradient across the membrane which uses the energy to phosphorylate ADP into ATP.

Question 27

Net ATP Production

Answer 27

Glycolysis = 2 ATP net Krebs Cycle = 2 ATP net ETC = 32 or 34 ATP Total 36 or 38 ATP per glucose molecule.

Question 28

Glycogenesis

Answer 28

Glucose catabolism being inhibited by high amounts of ATP. Glucose is then converted to glycogen. The liver and skeletal muscle will synthesize and store glycogen.

Question 29

Glycogenolysis

Answer 29

When glycogen is broken down into glucose

Question 30

Gluconeogenesis

Answer 30

The formation of sugar from non-carbohydrate molecules, occurs in the liver when blood glucose levels drop.

Question 31

Beta Oxidation

Answer 31

Fatty acids are broken down into 2-carbon acetic acid chains and coenzymes. When 2 bind, they enter the Kreb's cycle as acetyl CoA. Lipid products are transported in the lymph as fatty protein droplets called chylomicrons. Only neutral fats are oxidized for energy. Happens in the mitochondria.

Question 32

Lipogenesis

Answer 32

Triglyceride synthesis.

Question 33

Lipolysis

Answer 33

The breakdown of stored fats into glycerol and fatty acids

Question 34

Ketones

Answer 34

When carbohydrates are deficient, oxaloacetic acid is converted to glucose, and the liver will convert CoA into ketones, this is called Ketogenesis.

Question 35

Oxidation of Amino Acids

Answer 35

The NH2 must be removed first, it is transferred to glutamic acid. It is then removed as NH3, and combines with CO2 to produce water and urea.

Question 36

Promotion of Amino Acid Oxidation

Answer 36

There needs to be: 1) A lack of essential amino acids 2) inadequate fat or carbs to produce ATP 3) An excessive amount of proteins in the diet.

Question 37

Metabolic Rate

Answer 37

The total rate of kilocalorie consumption. The energy expended by the body per unit of time.

Question 38

Basal Metabolic Rate

Answer 38

The energy needed to perform only the basic, most integral activities

Question 39

Measuring the Basal Metabolic Rate

Answer 39

It can be measured under standard conditions of: 1) Not eating for 12 hrs or more 2) Be resting of reclined 3) Have the room at room temperature, 35 C.

Question 40

Thyroxine

Answer 40

The hormone produced by the thyroid. It's the most important hormone affecting BMR.

Question 41

Body Temperature

Answer 41

Usually maintained between 97-100 F.

Question 42

Heat Promoting Mechanisms

Answer 42

(1) Vasoconstriction (2) Increased metabolic rate (3) Muscular activity (4) Thyroxine effect

Question 43

Heat Loss Mechanisms

Answer 43

(1) Radiation (2) Conduction/Convection (3) Evaporation

Question 44

Role of the Hypothalamus

Answer 44

The major center for temperature regulation.

Question 45

Fever

Answer 45

Infection, cancer, injury, etc ----> WBC's arrive ----> Macrophages enter tissues ----> release pyrogens ----> cause neurons to release prostaglandins ----> reset the hypothalamus to a higher temperature ----> cause heat promoting mechanisms

Question 46

Hypothermia

Answer 46

Low body temperature, due to overexposure to cold

Question 47

Kwashiorkor

Answer 47

Severe protein deficiency in children. Leads to failure to grow and eventually mental retardation