Chapter 23- Metabolism

Question 1

What is a calorie?

Answer 1

The amount of heat required to raise the temperature of one gram of water by one degree Celsius

Question 2

What is metabolism?

Answer 2

The sum of the bodies chemical reactions

Question 3

What is catabolism? What are 3 nutrients that are catabolized to generate ATP?

Answer 3

A series of reactions in which one substance is broken down into smaller parts

Releases energy to be used for other processes

Glucose
Fatty acids
Amino acids

Question 4

What is anabolism? What are some of the larger macromolecules?

Answer 4

Series of reactions in which smaller molecules are combined to make larger molecules such as:

Proteins
Nucleic acids
Lipids
Carbohydrates

Question 5

What is anaerobic catabolism? Where does it occur?

Answer 5

Process that releases only a low amount of ATP

Occurs in cytosol

Question 6

What is aerobic catabolism?

Answer 6

Process that releases a large amount of APT

occurs in the mitochondria

Question 7

What is glycolysis?

Answer 7

Break down of glucose to pyruvic acid

Occurs in cytosol
No O2 required
Nets 2 ATP, pyruvate and Acetyl-CoA

Question 8

What is gluconeogenesis?

Answer 8

Synthesis of glucose from noncarbohydrate precursors such as amino acids

Question 9

What is glyconeogenesis?

Answer 9

Formation of glycogen from glucose

Question 10

What is glycogenolysis?

Answer 10

Break down of glycogen

Question 11

What is lipolysis?

Answer 11

An enzyme cataloged process that liberates fatty acids and glycerol

Question 12

What is ketogenesis?

Answer 12

A process that occurs primarily in liver cells in the mitochondrial matrix In which ketone bodies are produced through the breakdown of amino acids and fatty acids

This supplies energy during times of caloric restriction

Question 13

What are ketone bodies?

Answer 13

Molecules produced by the liver from fatty acids during periods of low food intake or starvation When glucose is in short supply

Question 14

What organ cannot metabolize ketone bodies? Which organs can?

Answer 14

The liver cannot metabolize them

Skeletal muscle the brain and the heart can metabolize them

Question 15

Describe the absorptive state?

Answer 15

Time immediately following a meal when the body is absorbing nutrients

Oxidation of nutrients occurs to provide the cells with fuel, glucose and triglycerides are stored

Question 16

Describe the post absorptive state

Answer 16

Period in which no nutrient absorption is occurring. Body relies on stored nutrients

Question 17

What is the dominant hormone in the absorptive state?

Answer 17

Insulin

Question 18

What are the dominant or major hormones in the post absorptive state?

Answer 18

Glucagon and glucocorticoids

Question 19

How are lipids transported and distributed in the body?

Answer 19

They are packaged with cholesterol into Lipoproteins. Lipoproteins provide transportation in the bloodstream

Question 20

What are the five classes of Lipoproteins?

Answer 20

Chylomicron
Very low density lipoprotein
Intermediate density lipoprotein
Low density lipoprotein
High density lipoprotein

Question 21

How does the body produce energy when glucose and lipid reserves are in adequate?

Answer 21

Liver cells break down internal proteins and absorb additional amino acids from the blood. Amino acids are deaminated

Question 22

What is deamination?

Answer 22

Removing an amino group and breaking down the carbon chain to provide ATP. Removes the amino group and hydrogen atom and generates an ammonium ion

Question 23

What is Transamination?

Answer 23

Transfer of an amino group from one molecule to another.

Question 24

What happens to ammonium generated from deamination?

Answer 24

Extra ammonium is synthesized into urea by enzymes in the liver and is then excreted in the urine

Question 25

How is heat produced and eliminated from the body?

Answer 25

The body produces heat as a byproduct of metabolism. It is retained by water in the body and then released through radiation, convection, evaporation or conduction

Question 26

How are heat loss and heat gain regulated?

Answer 26

Regulated by negative feedback loops in response to the increase or decrease in temperature from normal range.

Sweating/shivering

Question 27

Where is the heat center?

Answer 27

Hypothalamus

Question 28

What is the difference between thermal regulation of infants and adults?

Answer 28

Infants have a larger surface area and lose heat rapidly. They are much less adaptable to temperature changes than adults

Question 29

Where does the citric acid cycle occur? What are its reactants and products?

Answer 29

Occurs in the mitochondrial matrix. Starts with acetyl CoA produced by the oxidation of pyruvate and ends with NADH, FADH2, carbon dioxide and 2 ATP

Question 30

Where does oxidative phosphorylation occur? What are its reactants and products?

Answer 30

Occurs in the inner mitochondrial membrane. Forms ATP as electrons are transferred from reduced NADH and FADAH2 to oxygen by the ETC

Question 31

Where does the electron transport chain occur what are its reactants and products?

Answer 31

Occurs in the mitochondrial membrane. Starts with oxygen and ends with water molecules and ATP