Metabolism

Question 1

Define metabolism

Answer 1

The process of transformation and use of energy and materials that occur within the cells of living organisms

Question 2

___ is the source for most energy-requiring processes

Answer 2

ATP hydrolysis

Question 3

Define anabolism

Answer 3

Using energy to build complex structures

Question 4

Define catabolism

Answer 4

Molecules being broken down to yield energy

Question 5

The most abundant molecule in the body __

Answer 5

Water

Question 6

Hydroxyl group: properties

Answer 6

Polar, soluble

Question 7

Carbonyl groups: properties

Answer 7

Polar, soluble over 6C

Question 8

Carboxyl groups: properties

Answer 8

Polar, may ionize to release H+

Question 9

Amino groups: properties

Answer 9

Polar, may accept H+

Question 10

Formation of macromolecules occurs as a ___ reaction

Answer 10

Condenstation

Question 11

Breakdown of macromolecules occurs as a ___ reaction

Answer 11

Hydrolysis

Question 12

What is major form of dietary lipids

Answer 12

Triglycerides

Question 13

Describe the structure of a triglyceride

Answer 13

1 x glycerol
3 x fatty acids

Question 14

What are the 3 components of an amino acid

Answer 14

1. Amino group
2. Carboxyl group
3. Carbon-containing R side chain (this determines the amino acid’s properties)

Question 15

What is an example of nucleotide

Answer 15

ATP (major energy transfer molecule)

Question 16

Define a vitamin

Answer 16

An organic compound that cannot be synthesized and are required in small amounts in the diet

Question 17

Give an example of a vitamin that is a dietary requirement for dogs and cats but not humans

Answer 17

Vitamin D

Question 18

What is the function of an enzyme

Answer 18

It lowers the activation energy of a reaction

Question 19

Define a committing enzyme

Answer 19

An enzyme that catalyzes one of the first, essentially irreversible, steps in a reaction

Question 20

Committing enzymes are often regulated by __

Answer 20

Hormones

Question 21

Define reciprocal control

Answer 21

The conditions promoting one process inhibits the reverse process

Question 22

What is the energy source for most cellular processes

Answer 22

ATP hydrolysis

Question 23

The formation of ATP from ADP is achieved by…?

Answer 23

Catabolism of dietary nutrients

Question 24

Explain the term oxidation in the sense of nutrient catabolism

Answer 24

Carbon compounds (nutrients) are oxidized to release energy, this involves the loss of electrons
Ex. C compound to CO2

Question 25

What is reduced when carbon compounds are oxidized?

Answer 25

Electron carriers (NAD, FAD, NADP)

Question 26

The ultimate electron acceptor is ___?

Answer 26

Molecular oxygen (it is reduced to H20)

Question 27

Where does glycolysis occur

Answer 27

The cytosol

Question 28

How much ATP does glycolysis yield

Answer 28

2 ATP

Question 29

What is different about NAD regeneration in aerobic vs anaerobic glycolysis

Answer 29

Aerobic - NAD is regenerated by cellular respiration Anaerobic - NAD is regenerated through the formation of lactate

Question 30

Where does the TCA cycle occur?

Answer 30

Mitochondrial inner matrix

Question 31

What part of acetyl-coA goes into the TCA cycle

Answer 31

The 2-C acetate (coA just carry's it)

Question 32

What are the outputs of one turn the TCA cycle?

Answer 32

2 x CO2 5 x co-enzymes (reduced) 1 x ATP

Question 33

How many ATP does the ETC generate?

Answer 33

34 ATP

Question 34

What are the 4 major metabolic fuels

Answer 34

Glucose, amino acids, fatty acids, and ketone bodies

Question 35

Why are amino acid carbon skeletons important?

Answer 35

They are used as metabolic intermediates

Question 36

What is the process of breaking a fatty acid hydrocarbon chain into 2-carbon units, yielding ATP, AcetylCoA and reduced coenzymes

Answer 36

Beta-oxidation

Question 37

Abnormally elevated ketone bodies in the blood can lead to __

Answer 37

Acidosis

Question 38

In an aerobic organism, metabolic rate =

Answer 38

Rate of oxygen consumption

Question 39

Define BMR

Answer 39

The minimum power requirement to maintain tissues and essential life functions

Question 40

When is an animal in energy balance?

Answer 40

When the chemical energy within its body remains constant

Question 41

In the absorptive phase, carbohydrates and proteins are absorbed into the __

Answer 41

Portal vein

Question 42

In the absorptive phase, lipids, are absorbed into the __

Answer 42

Bloodstream

Question 43

What two things are made from glucose in the liver

Answer 43

1. Glycogen 2. Triglyceride

Question 44

What is adipose lipoprotein lipase promoted by?

Answer 44

Insulin

Question 45

What does LDL do?

Answer 45

Transports cholesterol into tissues

Question 46

What does HDL do?

Answer 46

Transports cholesterol out of tissues (good)

Question 47

ALL glucose in carnivores (50% in ruminants) is formed from what?

Answer 47

Amino acids

Question 48

Name 3 things that carbon skeletons from amino acids are used for

Answer 48

1. Oxidation (energy) 2. Glucose 3. Fat/glycogen

Question 49

Name two tissues for which glucose is essential

Answer 49

1. Brain/nervous tissue 2. Renal medulla

Question 50

Name 3 ways the liver directly maintains plasma glucose in the post absorptive phase

Answer 50

1. Stops taking up glucose 2. Mobilization of glycogen stores 3. New production of glucose from non-carb substrates (gluconeogenesis)

Question 51

Only tissues that express ___ can release free glucose into the plasma

Answer 51

Glucose-6-phosphatase enzyme

Question 52

Muscle glucose in hydrolyzed in response to __

Answer 52

Exercise

Question 53

What is the major source of plasma glucose when there is no GI absorption

Answer 53

Gluconeogenesis

Question 54

Define gluconeogenesis

Answer 54

The production of glucose from non-carbohydrate sources

Question 55

What are 4 precursors for gluconeogenesis

Answer 55

1. Lactate 2. Amino acids 3. Glycerol 4. Propionate

Question 56

To act as a gluconeogenic precursor, a substrate needs to ___

Answer 56

Form pyruvate, or otherwise generate oxaloacetate

Question 57

What is the cori cycle

Answer 57

When lactate from muscle is converted to glucose by the liver and taken up/used by muscles and other tissue

Question 58

When can fatty liver occur

Answer 58

If mobilization of fatty acids from adipose exceeds the liver's capacity to synthesize and export lipoproteins

Question 59

Where does ketone body synthesis occur

Answer 59

In the mitochondria of hepatocytes

Question 60

The breakdown of glycogen yields __

Answer 60

Glucose-6-phosphate

Question 61

___ is a key metabolite in GNG

Answer 61

Oxaloacetate