Chapter 12: Bioenergetics and Regulation of Metabolism

Question 1

____________ measures the overall change in heat of a system during a reaciton.

Answer 1

enthalpy

Question 2

What is the GIbbs free energy equation?

Answer 2

ΔG = ΔH - TΔS

Question 3

Spontaneous reactions proceed in the forward direction and have a negative or positive ΔG?

Answer 3

negative

Question 4

Nonspontaneous reactions have a net gain of energy and have a negative or positive ΔG?

Answer 4

positive

Question 5

Most of the ATP in a cell is produced by mitochondrial ____ ____________, but some is produced during what other pathways?

Answer 5

ATP synthase; glycolysis (indirectly from GTP) and TCA

Question 6

ATP is consumed in what two ways?

Answer 6

1. hydrolysis
2. transfer of phosphate group to another molecule

Question 7

The ________________ state, also called the absorptive or well-fed state, occurs shortly after eating. This state is marked by greater ________________ (synthesis of biomolecules) and fuel storage.

Answer 7

postprandial; anabolism

Question 8

What is the opposite of anabolism?

Answer 8

Catabolism (breakdown of molecules for energy)

Question 9

Nutrients flood in from the gut and make their way via the ____________ ________ ________ to the ____________, where they can be stored or distributed to other body tissues.

Answer 9

hepatic portal vein; liver

Question 10

________ promotes glycogen synthesis in liver and muscle.

Answer 10

insulin

Question 11

After glycogen stores are filled, the liver converts excess glucose to ____________ ____________ and ________________.

Answer 11

fatty acids and triacylglycerols

Question 12

In the fasting state, what occurs?

Answer 12

1. glycogenolysis first
2. gluconeogenesis at max velocity about 12 hours later
3. amino acids and fatty acids released due to decreased insulin and increased epinephrine

Question 13

During prolonged fasting what occurs?

Answer 13

1. increased glucagon
2. glycogen stores depleted and gluconeogenesis occurs
3. lipolysis occurring, and then eventually ketone bodies formed

Question 14

____________ is a peptide hormone secreted by the beta-cells of the pancreatic Islets of Langerhans.

Answer 14

insulin

Question 15

____________ is a peptide hormone secreted by the alpha-cells of the pancreatic Islets of Langerhans

Answer 15

glucagon

Question 16

What is the primary target of glucagon?

Answer 16

heapatocytes

Question 17

____________ from the adrenal cortex are responsible for part of the stress response. During fight or flight, ____________ must be rapidly mobilized from the liver in order to fuel actively contracting muscle cells while fatty acids are released from adipocytes.

Answer 17

glucocorticoids; glucose

Question 18

Glucocorticoids, especially ____________, are secreted with many forms of stress, including exercise, cold, and emotional stress.

Answer 18

cortisol

Question 19

Cortisol also elevates blood glucose levels and increases glucose availability for nervous tissue through what two mechanisms?

Answer 19

1. inhibits glucose uptake in tissues / increases hepatic output of glucose via gluconeogenesis
2. enhances activity of glucagon, epinephrine, and ohter catecholamines

Question 20

Catecholamines are secreted by the ____________ ____________. What are two major examples?

Answer 20

adrenal medulla; epinephrine (adrenaline) and norepinephrine (noradrenalie)

Question 21

What do catecholamines do?

Answer 21

Increase the activity of the liver and muscle glycogen phosphorylase, which promotes glycogenolysis

Question 22

What do catecholamines do for the liver?

Answer 22

Increase glucose output by stimulating glycogenolysis

Question 23

The increase in metabolic rate produced by a dose of ____________ hormone occurs after a latency of several horus but may last for several days, while ____________________ produces a more rapid increase in metabolic rate and has a shorter duration of activity.

Answer 23

thyroxine; triiodothyronine

Question 24

What are the 2 major roles of the liver?

Answer 24

1. maintain a constant level of blood glucose
2. synthesize ketones when excess fatty acids are being oxidized

Question 25

What do adipose tissues do after a meal?

Answer 25

stimulate glucose uptake

Question 26

What are the major fuels of skeletal muscle?

Answer 26

glucose and fatty acids

Question 27

What is the primary fuel of muscle contraction during HIIT vs. continuouse moderate intensity?

Answer 27

During HIIT, anaerobic glycolysis. During moderate/high intensity exercises, glucose at first then fatty acids.

Question 28

Between meals, the brain relies on blood glucose supplied by hepatic ____________ or ____________.

Answer 28

glycogenolysis or gluconeogenesis

Question 29

During prolonged fasting, the brain will use ________ ________.

Answer 29

ketone bodies

Question 30

How is the respiratory quotient calculated?

Answer 30

CO2 produced / O2 consumed

Question 31

________ is secreted by the stomach in response to signals of an impending meal, e.g. sight, sound, taste, and smell.

Answer 31

ghrelin

Question 32

____________ further increases appetite and is involved in alertness and sleep-wake cycle.

Answer 32

orexin

Question 33

________ is a hormone secreted by fat cells that decreases appetite by suppressing orexin production.

Answer 33

leptin

Question 34

How is BMI calculated?

Answer 34

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