Exam 2

Question 1

List 2 functions of proteins in the body

Answer 1

Enzymes
Hormones

Question 2

What is the difference between essential amino acids and nonessential amino acids?

Answer 2

Essential cannot be made by body
Nonessential can be made by body

Question 3

List the 10 essential amino acids

Answer 3

Phenylalanine
Valine
Tryptophan
Threonine
Isoleucine
Methionine
Histidine
Arginine
Lysine
Leucine

Question 4

What type of bonds link amino acids together?

Answer 4

Peptide bonds

Question 5

Write 1 interesting feature of fibrous proteins

Answer 5

Do not dissolve in water

Question 6

Name a metalloprotein that is found inside red blood cells.

Answer 6

Hemoglobin

Question 7

What effect does stomach acid have on protein digestion?

Answer 7

Makes stomach highly acidic

Question 8

What protein digesting enzyme is found in the stomach?

Answer 8

Pepsin

Question 9

List the 3 pancreatic enzymes that aid in protein digestion .

Answer 9

Trypsin
Chymotrypsin
Carboxypeptidase

Question 10

What happens to di-peptides that enter epithelial cells of the small intestine?

Answer 10

Broken down by intracellular enzymes to produce free amino acids

Question 11

Name 2 organs in the body where first pass utilization of amino acids can occur.

Answer 11

Small intestine
Liver

Question 12

What happens to unused or excess amino acids in the body?

Answer 12

Delivered to liver for break down and conversion into urea

Question 13

Name the chemical reaction that involves the formation of an unbreakable bond between an amino acid and a sugar in the presence of heat.

Answer 13

Browning

Question 14

Name the compound in cottonseed plants that can be problematic to livestock

Answer 14

Gossypol

Question 15

Describe in detail the process of protein digestion in the rumen

Answer 15

1 ) dietary protein is broken down by microbial protease enzyme to produce peptides
2 ) The peptides are broken down by microbial peptidase enzyme to produce amino acids
3 ) microbial deaminase enzyme breaks down amino acids to ammonia and Carbon skeletons

Question 16

What can ammonia molecules be used for in the rumen?

Answer 16

Used to make microbial protein

Question 17

What are the 2 types of proteins reaching the small intestine of ruminant animals?

Answer 17

Undigested dietary protein
Microbial protein

Question 18

List 2 ways that urea can be recycled back to the rumen

Answer 18

Diffusion from blood (85%)
By saliva (15%)

Question 19

Name 2 types of fatty acids that can only be produced by bacteria.

Answer 19

trans form fatty acid
odd numbered

Question 20

Describe 2 differences between saturated fatty acids and unsaturated fatty acids.

Answer 20

Saturated:
- do not have double bonds between carbons
- more stable
- solid at room temperature

Unsaturated:
- do have double bonds between carbons
- less stable
- liquid at room temperature

Question 21

What is the difference between fats and oils?

Answer 21

Fats - solid at room temp (more saturated)
Oils - liquid at room temp (more unsaturated)

Question 22

How many fatty acids are found in a triglyceride?

Answer 22

3

Question 23

What type of bonds link fatty acids to glycerol?

Answer 23

ester bonds

Question 24

Of the 5 types of lipoproteins, which type are least dense (most bulky)?

Answer 24

Chylomicrons

Question 25

List the 2 essential fatty acids needed for ALL animals.

Answer 25

Linoleic Linolenic

Question 26

Name an animal that specifically requires arachidonic acie in the diet.

Answer 26

Cats

Question 27

List 2 broad functions of fat in the body.

Answer 27

Energy storage Protect vital organs

Question 28

Name one hormone that can be made from cholesterol.

Answer 28

Testosterone

Question 29

Describe in detail the process of lipid digestion and absorption in monogastrics.

Answer 29

1. When fat enters the small intestine, the gallbladder secretes bile 2. Bile will react with fat droplets to form a water-lipid interface. This is called Emulsification 3. The pancreas secretes enzymes lipase and colipase 4. Colipase binds to the water-lipid interface and acts as an anchor for lipase 5. Lipase enzyme cuts 2 out of 3 ester bonds to produce monoglyceride and 2 FFAs 6. Monoglyceride, FFAs, phospholipids, and bile salts combine to form micelles 7. The micelles transport the lipids to the cell membrane of the intestine 8. Once at membrane, micelles break apart. The monoglycerides and FFAs then diffuse into the intestinal cell 9. Inside the cell, the monoglycerides and FFAs are remade into triglycerides 10. The triglycerides combine with proteins to form chylomicrons. The chylomicrons diffuse into nearby lymph vessels

Question 30

What enzyme is responsible for triglyceride digestion in the rumen?

Answer 30

Microbial lipase

Question 31

How does microbial lipase in the rumen differ from pancreatic lipase?

Answer 31

Microbial breaks all three ester bonds, pancreatic only breaks two ester bonds

Question 32

What is biohydrogenation?

Answer 32

process of adding H atoms to unsaturated FAs

Question 33

Write 1 human health benefit of the biohydrogenation product cis-9-trans-11 CLA.

Answer 33

Decrease risk of cancer

Question 34

What is energy?

Answer 34

The ability to do work

Question 35

What does the first law of thermodynamics state?

Answer 35

Energy cannot be created or destroyed

Question 36

Which nutrient has the most energy (in kcal) per gram?

Answer 36

Lipids

Question 37

Write 1 function that falls under net energy of maintenance.

Answer 37

Breathing

Question 38

Write 1 function that falls under net energy of production

Answer 38

Growth Lactation

Question 39

What energy comes after gross energy?

Answer 39

Digestible energy

Question 40

What 2 energies are lost from digestible energy?

Answer 40

Urinary Gas

Question 41

What is lost from metabolizable energy?

Answer 41

Heat increment

Question 42

What energy comes after metabolizable energy?

Answer 42

Net energy

Question 43

What is the net gain of ATP produced directly by glycolysis?

Answer 43

2 ATP, 2 NADH

Question 44

How are NADH and FADH2 important for ATP production?

Answer 44

donate hydrogen atoms for electron transport chain

Question 45

In total, how many ATP are produced from 1 molecule of glucose? (Assume 1 NADH yields 3 ATP and 1 FADH2 yields 2 ATP)

Answer 45

38 ATP

Question 46

List 2 molecules that. can be used to make glucose.

Answer 46

Lactic Acid Glycerol

Question 47

In total, how many ATP are produced from 1 molecule of glucose? (Assume 1 NADH yields 2.5 ATP and 1 FADH2 yields 1.5 ATP)

Answer 47

32 ATP