Exam 2 Flashcards
List 2 functions of proteins in the body
Enzymes
Hormones
What is the difference between essential amino acids and nonessential amino acids?
Essential cannot be made by body
Nonessential can be made by body
List the 10 essential amino acids
Phenylalanine
Valine
Tryptophan
Threonine
Isoleucine
Methionine
Histidine
Arginine
Lysine
Leucine
What type of bonds link amino acids together?
Peptide bonds
Write 1 interesting feature of fibrous proteins
Do not dissolve in water
Name a metalloprotein that is found inside red blood cells.
Hemoglobin
What effect does stomach acid have on protein digestion?
Makes stomach highly acidic
What protein digesting enzyme is found in the stomach?
Pepsin
List the 3 pancreatic enzymes that aid in protein digestion .
Trypsin
Chymotrypsin
Carboxypeptidase
What happens to di-peptides that enter epithelial cells of the small intestine?
Broken down by intracellular enzymes to produce free amino acids
Name 2 organs in the body where first pass utilization of amino acids can occur.
Small intestine
Liver
What happens to unused or excess amino acids in the body?
Delivered to liver for break down and conversion into urea
Name the chemical reaction that involves the formation of an unbreakable bond between an amino acid and a sugar in the presence of heat.
Browning
Name the compound in cottonseed plants that can be problematic to livestock
Gossypol
Describe in detail the process of protein digestion in the rumen
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
What can ammonia molecules be used for in the rumen?
Used to make microbial protein
What are the 2 types of proteins reaching the small intestine of ruminant animals?
Undigested dietary protein
Microbial protein
List 2 ways that urea can be recycled back to the rumen
Diffusion from blood (85%)
By saliva (15%)
Name 2 types of fatty acids that can only be produced by bacteria.
trans form fatty acid
odd numbered
Describe 2 differences between saturated fatty acids and unsaturated fatty acids.
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
What is the difference between fats and oils?
Fats - solid at room temp (more saturated)
Oils - liquid at room temp (more unsaturated)
How many fatty acids are found in a triglyceride?
3
What type of bonds link fatty acids to glycerol?
ester bonds
Of the 5 types of lipoproteins, which type are least dense (most bulky)?
Chylomicrons
List the 2 essential fatty acids needed for ALL animals.
Linoleic
Linolenic
Name an animal that specifically requires arachidonic acie in the diet.
Cats
List 2 broad functions of fat in the body.
Energy storage
Protect vital organs
Name one hormone that can be made from cholesterol.
Testosterone
Describe in detail the process of lipid digestion and absorption in monogastrics.
- When fat enters the small intestine, the gallbladder secretes bile
- Bile will react with fat droplets to form a water-lipid interface. This is called Emulsification
- The pancreas secretes enzymes lipase and colipase
- Colipase binds to the water-lipid interface and acts as an anchor for lipase
- Lipase enzyme cuts 2 out of 3 ester bonds to produce monoglyceride and 2 FFAs
- Monoglyceride, FFAs, phospholipids, and bile salts combine to form micelles
- The micelles transport the lipids to the cell membrane of the intestine
- Once at membrane, micelles break apart. The monoglycerides and FFAs then diffuse into the intestinal cell
- Inside the cell, the monoglycerides and FFAs are remade into triglycerides
- The triglycerides combine with proteins to form chylomicrons. The chylomicrons diffuse into nearby lymph vessels
What enzyme is responsible for triglyceride digestion in the rumen?
Microbial lipase
How does microbial lipase in the rumen differ from pancreatic lipase?
Microbial breaks all three ester bonds, pancreatic only breaks two ester bonds
What is biohydrogenation?
process of adding H atoms to unsaturated FAs
Write 1 human health benefit of the biohydrogenation product cis-9-trans-11 CLA.
Decrease risk of cancer
What is energy?
The ability to do work
What does the first law of thermodynamics state?
Energy cannot be created or destroyed
Which nutrient has the most energy (in kcal) per gram?
Lipids
Write 1 function that falls under net energy of maintenance.
Breathing
Write 1 function that falls under net energy of production
Growth
Lactation
What energy comes after gross energy?
Digestible energy
What 2 energies are lost from digestible energy?
Urinary
Gas
What is lost from metabolizable energy?
Heat increment
What energy comes after metabolizable energy?
Net energy
What is the net gain of ATP produced directly by glycolysis?
2 ATP, 2 NADH
How are NADH and FADH2 important for ATP production?
donate hydrogen atoms for electron transport chain
In total, how many ATP are produced from 1 molecule of glucose? (Assume 1 NADH yields 3 ATP and 1 FADH2 yields 2 ATP)
38 ATP
List 2 molecules that. can be used to make glucose.
Lactic Acid
Glycerol
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)
32 ATP
