1What are amino acids?
The basic building blocks of proteins
2What does every amino acid have?
Amine, carboxyl group, an R group, and an alpha carbon
3What is a carboxyl group?
COOH (double bond between the C=O)
5What is an essential amino acid?
An indispensable amino acid that cannot be synthesized by the body in a sufficient amount to meet the animal's requirements
6Where must EAA be absorbed?
The small intestine
7Which animals must consume EAA in their diet?
Non-ruminants/monogastrics
8What happens when you overfeed an animal EAAs?
The animal turns that excess EAA into glucose, then energy
9Which type of amino acid is very expensive?
Essential amino acids
10What are non-essential amino acids?
Amino acids synthesized by the body in sufficient amounts to meet the animal's requirements
11Which type of AA is required in greater amounts for normal metabolism?
Non-essential amino acids
12What is the bond between two amino acids?
Peptide bond
13Which animals do not generally require EAAs in their diet?
Ruminants
14Why do ruminants not generally require EAAs in their diet?
Ruminal microbes have the capacity to synthesize all AAs
15Where do ruminants require AAs to be absorbed?
The small intestine
16What is required for microbes to synthesize AAs?
A carbon skeleton (VFAs) and ammonia
17What are carbon skeletons also known as?
VFAs
18What is special about the synthesis and degredation of AAs?
More ATP is required for synthesizing than degrading
19What can microbes use AAs to make?
Microbial Crude Proteins (MCP)
20What are the two types of cattle (non-nursing/wean) that require EAAs in excess of the ruminal microbes ability to synthesize them?
High producing dairy cows (methionine) and growth implanted cattle
21Why do high producing dairy cattle need excess methionine?
They have increased milk production and must protect methionine from microbial degredation
22How do you protect a protein from ruminal degredation?
You coat it in fat
23What EAA do high producing dairy cattle need?
Methionine
24Why do growth implanted cattle need more EAAs than normal?
They are rapidly growing, so we must supply them with a source of ruminally undegradable protein
25What is the acronym to remember the EAAs?
MATT HILL VP
26How many EAAs are there?
10
27How many AAs are there?
20
28What is MATT?
Methionine, Argenine, Threonine, Tryptophan
29What is HILL?
Histidine, Isoleucine, Leucine, Lysine
30What is VP?
Valine, Phenylalanine
31What is nitrogen balance (NB)?
Nitrogen Intake - Nitrogen excretion (NI-NE)
32What does a positive nitrogen balance indicate?
Growth or the retention of amino acids
33What does a negative nitrogen balance indicate?
Tissue mobilization or amino acid loss
34What is tissue mobilization?
Decreased protein synthesis and protein degredation, with a greater decrease in PS relative to PD, so the body begins using protein stored in tissues for maintenance
35When does tissue mobilization occur?
During starvation, gestation, or lactation (when NB is less than 0)
36When is the body at maintenance?
When PS = PD or NB = 0
37When does growth occur?
When there is an increase in protein synthesis and protein degredation, with a greater increase in PS relative to PD (NB is greater than 0)
38What are amino acid requirements?
Maintenance requirement and production requirement
39When does the maintenance requirement increase?
With an increase in size, lean muscle fat (sex), age, and production potential (dairy > beef)
40When does the production requirement increase?
With muscle growth, gestation, lactation, fiber (wool/mohair), and work (excercise)
41What does maintenance + production (m+p) equal?
Protein requirement
42When is there a peptide bond?
Every 2 amino acids (connects 2 amino acids together)
43Where does the peptide bond occur?
Between the OH of a carboxyl group and one of the Hs of the amine group (will be turned into H2O)
44How does the peptide bond form?
A proteolytic enzyme hydrolizes the bond (creates an H2O with molecules and atoms within the amino acids)
45What are polypeptides?
Amino acid chains that have greater than or equal to 10 AAs
46What are tripeptides?
Contains 3 amino acids and 2 peptide bonds
47What are dipeptides?
Contains 2 amino acids and 1 peptide bond
48How many peptide bonds are there in an amino acid?
None
49How many levels of proteins structure are there?
four
50What is the primary structure of proteins?
A sequence of amino acids determined by peptide bonds (AA order equates to what its purpose is)
51What is the secondary structure of proteins?
Determined by the hydrogen bonding between the peptide backbone, which causes them to fold into a repeating pattern
52What is the tertiary structure of proteins?
Created by interactions between the R groups of the amino acids and the clustering of the hydrophobic regions (folding is dependent on them)
53What is the quaternary structure of proteins?
When the protein consists of more than one peptide/amino acid chain and the interactions between the polypeptides (more than one amino acid chain)
54Which structures of a protein can be denatured by HCl?
2-4
55What must a protein have to be fully functional?
Up to a tertiary structure
56What is denaturation?
When HCl breaks the weak interactions or bonds in the secondary, tertiary, and quaternary structure of a protein (unfolding)
57What does HCl denaturation expose?
The peptide bonds of the primary structure
58What are the steps of nonruminant protein digestion?
Denaturation, hydrolisis of the peptide bonds, and absorption of the AA, di, and tripeptides
59What is the purpose of HCl denaturation?
To expose the peptide bonds so they can be hydrolized
60What occurs during the denaturation step of nonruminant protein digestion?
Acid (HCl) in the stomach denaturesnfolds the protein in order to expose the peptide bond
61Where does denaturation occur in nonruminants?
Stomach
62Where does denaturation occur in ruminants?
Abomasum
63What occurs during the hydrolisis step of nonruminant protein digestion?
A proteolytic enzyme (ME) hydrolizes peptide bonds to separate amino acid chains into individual AAs
64Where does peptide bond hydrolisis occur in nonruminants?
The stomach and small intestine
65Where does peptide bond hydrolisis occur in ruminants?
The abomasum and small intestine
66Where does absorption of AA, dipeptides, and tripeptides occur?
The small intestine (for all animals)
67What occurs in the mouth of a nonruminant?
Decreasing particle size
68What is released in the stomach and abomasum of animals?
HCl and pepsinogen
69What is pepsinogen?
A zymogen/inactive enzyme that turns into pepsin when activated (endopeptidase)
70What activates pepsinogen?
HCl or pepsin
71What is the site of activity for pepsin?
The stomach/abomasum
72What are endopeptidase enzymes?
A category of enzymes that hydrolyze peptide bonds on the inside of the protein that result in oligopeptides
73What are exopeptidase enzymes?
A category of enzymes that hydrolize peptide bonds on the exterior of proteins
74Which type of proteins result in oligopeptides?
Endopeptidase
75What is enteropeptidase?
A molecule produced by the enterocyte in response to CCK ans secritin that activates trypsinogen into trypsin
76Where is enteropeptidase produced?
Enterocytes
77What is trypsinogen?
Pancreatic zymogen that is activated into trypsin by enteropeptidase or trypsin that acts in the small intestine as an endopeptidase
78What activates trypsinogen?
Enteropeptidase or trypsin
79What type of enzyme is trypsin?
Endopeptidase
80What does pepsin act on?
Hydrolyzes pepsin bonds (1°)
81What does trypsin act on?
Hydrolyzes pepsin bonds (1°)
82What is chymotrypsinogen?
Pancreatic zymogen that is activated into chymotrypsin by trypsin
83What activates chymotrypsin?
Trypsin
84What is the site of activity for chymotrypsin?
Small intestine
85What is the site of activity for trypsin?
Small intestine
86What does chymotripsin do?
Hydrolyzes peptide bonds (1°)
87What type of enzyme is chymotrypsin?
Endopeptidase
88What is procarboxypeptidase?
Pancreatic zymogen that is activated by trypsin into carboxypeptidase A&B
89Where is the site of activity for carboxypeptidase A&B?
Small intestine
90What does procarboxypeptidase A&B do?
Hydrolyzes peptide bonds (1°)
91What type of enzyme is procarboxypeptidase A&B?
Endopeptidase
92How many enzymes are made by the enterocyte?
5
93What enzymes are made by the enterocyte?
Amino peptidase, dipeptidyl amino peptidase, tripeptidase, peptidase, and enteropeptidase
94What are S cells?
Enteroendocrine cells in the small intestine that produce secretin in response to digesta with a low pH and denatured peptides
95Where are S cells?
The small intestine
96What do S cells provide and to where?
Secretin to the pancrease and enterocytes
97What are I cells?
Enteroendocrine cells in the small intestine that produce CCK in response to digesta with a low pH and denatured peptides
98Where are I cells?
The small intestine
99What do I cells provide and to where?
CCK to the pancreas and enterocytes
100What is secretin?
A hormone produced by S cells that results in the production of enteropeptidase and pancreatic zymogens
101What is CCK?
A hormon produced by I cells that results in the production of enteropeptidase and pancreatic zymogens
102What is aminopeptidase?
A brush border peptidase/enzyme, produced by enterocytes, that cleaves one AA from oligopeptides
103What are oligopeptides?
Short chains of AAs, normally 2-20 in length
104What produces aminopeptidase?
Enterocytes
105What is dipeptyl aminopeptidase?
A brush border peptidase/enzyme, produced by enterocytes, that cleaves dipeptides from oligopeptides
106What produces didpetyl aminopeptidase?
Enterocytes
107What is tripeptidase?
A brush border peptidase/enzyme, produced by enterocytes, that cleaves specific AA from tripeptides
108What produces tripeptidase?
Enterocytes
109What is special about the synthesis of tripeptides?
No enzyme specifically makes them, rather they are created as leftovers or byproducts of other reactions
110What are Sodium Dependent AA Transporters?
A category of transporters in enterocytes that use Na+ to transport AAs against their concentration gradient
111What types of amino acids doe Sodium Dependent AA Transporters prefer?
Large AAs and EAAs
112How doe Sodium Dependent AA Transporters work?
Uses Na+ to diminish the electrochmical gradient and allow AAs to enter by going agaisnt the gradient
113What are Sodium Independent AA Transporters?
A category of transporters that transport AAs with their concentration gradient (do not need Na+) via facilitated diffusion
114What is the Peptide Transporter 1?
A transporter that cotransports dipeptides and tripeptides with an H+
115What is the Amino Acid Transporter?
A transporter that transports AAs with their concentration gradient
116What is ruminal undegradable protein (RUP)?
Protein that the microbes cannot degrade that "escape" the rumen
117What is ruminal degradable protein (RDP)?
Protein that the microbes can degrade into AA or NH3 and carbok skeletons
118What does the rumen use RDP for?
To synthesize MCP
119What is RDP also known as?
Undegradable intake protein (UIP)
120What happens to RUP in the rumen?
It bypasses the rumen and goes into the abomasum to be treated like any other protein in a nonruminant
121Where does the ATP used in the rumen for MCP synthesis come from?
Fermentation of carbohydrates
122What happens to RDP in the rumen?
It is converted by microbes into ammonia, amino acids, peptides, and MCP, which allows for microbial growth and replication
123When does catabolism of AA happen?
When there is an excess of AA absorbed from the small intestines or energy requirements are not met
124What occurs during AA catabolism?
AA is turned into glucose and ketones which is used for ATP, and some NH3 is released as a byproduct
125What are proteolytic microbes?
Microbes that break down proteins
126What are celluloytic microbes?
Microbes that break down cellulose, amount increases with a low starch diet
127What are amylolytic microbes?
Microbes that break down starch, amount increases with a high starch diet
128What does endogenous mean?
From the body/the body made it
129What does exogenous mean?
From outside the body
130When is it very rare for a cow to be protein defficient?
When they are lactating or pregnant
131Which animal is most likely to use AA for energy and why?
Cows, because they get the greatest supply of AA since they need to meet microbe requirements
132What is the only type of feed protein in the cow's large intestine?
Any RUP that has not been broken down
133What happens to RDP the longer it stays in the rumen?
The more degraded it becomes
134What does urease do?
It hydrolyzes urea into NH3
135What can the NH3 pool be used to make?
AAs
136Why does the ATP used for MCP synethsis come from fermented CHO?
Because CHO are relatively cheap and easy to ferment
137What must you have both of for MCP production?
Supply of fermentable CHO and RDP supply (for NH3)
138What happens when there is no RDP in the rumen?
There will be no CHO fermentation, which means no MCP production
139What are some examples of low quality RDP?
Urea or proteins with few EAAs
140What happens when you feed a ruminant low quality RDP?
Microbes can improve the quality
141What are some high quality RDPs?
Soybean and proteins with lots of EAAs
142What happens when you feed a ruminant high quality RDP?
Microbes can lower the quality
143What enters the large intestine of a ruminant?
Feed protein, and endogenous protein (enzymes and cells)
144What enters the large intestine of a nonruminant?
Undigested feed protein and endogenous protein (enzymes and cells)
145What is absorbed in the large intestine for nonruminants?
VFAs from carbon skeletons and NH3
146What happens when RDP decreases?
So does microbial growth/enzymes, CHO degredation, fermentation, energy, MCP, performance, and intake of feed
147What is the only animal that you can acheive an optimal balance of all EAAs?
A growing pig
148What is the first limiting AA?
The EAA that the diet supplies in the lowest portion of the body, which limits performance (sort of like a limiting reagent)
149How do you know when the requirement of a limiting AA is met?
When production stops increasing
150What happens to any AAs that are fed to an animal past the requirement?
It will be absorbed and metabolized for energy, but for no need and is essentially a waste of money
151What is the limiting AA in dairy cattle?
Methionine
152What are types of Nitrogen excretions?
Reproduction, lactation, urine, feces, skin, hair, and wool
153What makes an ideal protein?
The product being produced, the diet being fed, and the efficiency of AA deposition (always <1)
154What does the product being produced mean when determining an ideal protein?
What the AA profile of the product is
155What does the diet being fed mean when determining an ideal protein?
Are all of the other nutrients provided in excess or at the requirement, bc if the energy is limiting, the animal will use AA for energy
156How does the efficiency of AA deposition work?
Must eat more AA than you want deposited, as not all AA will be deposited (must be <1)
157What is a common limiting AA?
Lysine