Chapter 7

Question 1

Energy

Energy and Metabolism Basics

Answer 1

Energy: Capacity to perform work in various forms—heat, mechanical, electrical, and chemical.

Question 2

Metabolism

Energy and Metabolism Basics

Answer 2

Metabolism: Total chemical reactions in living cells.

Energy metabolism includes all reactions used to extract and use energy from food.

Question 3

Liver cells

Cellular Metabolic Processes

Answer 3

Liver cells: Most metabolically active, essential for various metabolic reactions.

Question 4

Anabolism

Cellular Metabolic Processes

Answer 4

Anabolism: Small molecules combine to form larger ones, consuming energy.

Question 5

Catabolism

Cellular Metabolic Processes

Answer 5

Catabolism: Large molecules break down, releasing energy.

Question 6

ATP

Energy Transfer with ATP

Answer 6

ATP (Adenosine Triphosphate): High-energy compound crucial for cellular activities. Contains three phosphate groups, with energy released when bonds break.

Question 7

Coupled reactions

Energy Transfer with ATP

Answer 7

Coupled reactions: Energy is consumed and produced simultaneously in the body, with some lost as heat.

Question 8

Enzymes

Metabolic Helpers

Answer 8

Enzymes: Protein catalysts aiding reactions without being altered.

Question 9

Coenzymes

Metabolic Helpers

Answer 9

Coenzymes: Organic molecules (often B vitamins) that help enzymes function properly.

Question 10

Carbohydrates

Nutrient Breakdown for Energy

Answer 10

Carbohydrates: Digested into glucose/monosaccharides.

Question 11

Fats

Nutrient Breakdown for Energy

Answer 11

Fats: Broken down into glycerol and fatty acids.

Question 12

Proteins

Nutrient Breakdown for Energy

Answer 12

Proteins: Broken into amino acids, supporting both energy production and storage.

Question 13

Glycolysis

Energy-Yielding Pathways

Answer 13

Glycolysis: Glucose splits into two pyruvate molecules, leading to energy release.

Pyruvate to Lactate (Anaerobic): Fast energy release without oxygen.
Pyruvate to Acetyl CoA (Aerobic): Slower, oxygen-requiring pathway that feeds into the TCA cycle.

Question 14

Fatty Acid Oxidation

Energy-Yielding Pathways

Answer 14

Fatty Acid Oxidation: Fatty acids yield acetyl CoA, with hydrogen and electrons transported to the electron transport chain.

Question 15

Amino Acid Metabolism

Energy-Yielding Pathways

Answer 15

Amino Acid Metabolism: Amino acids must undergo deamination to enter energy pathways, becoming pyruvate or acetyl CoA.

Question 16

TCA Cycle

TCA Cycle and Electron Transport Chain

Answer 16

TCA Cycle: Circular process within mitochondria, crucial for energy production, involving oxaloacetate.

Question 17

ETC

TCA Cycle and Electron Transport Chain

Answer 17

Electron Transport Chain (ETC): High-energy ATP synthesis; oxygen accepts electrons, forming water.

Question 18

Feasting

Feasting vs. Fasting

Answer 18

Feasting (Excess Energy): Excess nutrients, especially fat, are stored post-meal.

Question 19

Fasting

Feasting vs. Fasting

Answer 19

Fasting: Glycogen and fat stores provide energy initially, but prolonged fasting depletes glycogen, using body proteins for glucose. Hormones slow metabolism to conserve energy.

Question 20

Gluconeogenesis

Adaptations to Fasting

Answer 20

Gluconeogenesis: Formation of glucose from non-carbohydrates (e.g., amino acids).

Question 21

Ketosis

Adaptations to Fasting

Answer 21

Ketosis: Produces ketone bodies as alternative fuel for the brain, decreasing protein breakdown and inducing appetite loss.

Question 22

Physical

Starvation Symptoms

Answer 22

Physical: Muscle wasting, reduced heart and metabolic rates, low body temperature, impaired vision, organ failure.

Question 23

Psychological

Starvation Symptoms

Answer 23

Psychological: Depression, anxiety, food-centered thoughts.

Question 24

Low-Carb, Ketogenic Diet Side Effects

Answer 24

Potential side effects include nausea, fatigue, constipation, low blood pressure, elevated uric acid, bad breath, and risks for pregnant women (fetal harm).