Proteins Flashcards
(77 cards)
1
Q
6 Nutrient Classes
A
Water Carbohydrates Proteins Lipids Vitamins Minerals
2
Q
6 roles/functions of Proteins
A
- ) Structural elements (hair, wool, collagen, muscle)
- ) Enzymes
- ) Hormones
- ) Carriers in the blood (hemoglobin)
- ) Associated with genes (hereditary factors)
- ) Antibodies
3
Q
In protein digestion, the digesting enzymes are secreted as…?
A
Inactive Zymogens
4
Q
What is the principle protein-digesting enzyme in the stomach (abomasum in ruminants)?
A
Pepsin
5
Q
What activates the inactive zymogen into this active enzyme?
A
HCl
6
Q
What is the distinction between an endopeptidase and an exopeptidase?
A
- Endopeptidase attacks internal peptide bonds
- Exopeptidase attacks terminal peptide bonds
7
Q
Name some examples of an exopeptidase.
A
- Carboxypeptidase
- A&B
- Aminopeptidase
- Dipeptidase
8
Q
10 amino acids classified as dietary essentials for pigs, rats, dogs, and growing humans.
A
Phenylalanine Valine Tryptophan Threonine Isoleucine Methionine Histidine Arginine Lysine Leucine
9
Q
If you were feeding a diet of poor amino acid balance to a growing nonruminant animal, would you expect the blood urea level to be higher, lower, or the same as that of an animal fed a diet of perfect amino acid balance for muscle growth?
What would you expect if the animal was a ruminant?
A
Higher
The same results
10
Q
The linkage between one amino acid and another in a protein…?
A
Peptide bond
11
Q
Protein quality of the diet is a function of WHAT aspects of the amino acid in that protein?
A
Qualitative (Balance)
Quantitative (Total Amount)
12
Q
Name the physiological process that is a protein quality that is extremely critical to the biological value of a protein.
A
Rate and Extent of Digestion/Absorption
13
Q
What two amino acids has it been shown that man does not need for maintenance? What about for growing?
A
- Maintenance: Histidine and Arginine NOT NEEDED
- Growing: need all 10
14
Q
Proteins comprise about ____ of the dry, fat-free body.
A
80%
15
Q
Name the elements that protein contains? (5)
A
C, H, O, N, S
16
Q
The N content in protein content of tissues and feedstuffs? (%)
A
14-20% (Avg. 16%)
17
Q
These yield ONLY amino acids or their derivatives on hydrolysis. (5)
A
Simple proteins:
- Albumin
- Globulin
- Albuminoids
- Histones
- Protamins
18
Q
Simple proteins combined with a non-protein radical…?
A
Conjugated proteins
19
Q
There are 5 conjugated proteins. They are…?
A
- ) Nucleoproteins
- ) Glycoproteins
- ) Phosphoproteins
- ) Metalloproteins
- ) Lipoproteins
20
Q
Nucleoprotein
A
1 or more protein molecules with NUCLEIC ACID
21
Q
Glycoprotein
A
Protein molecule & substance(s) containing CHO group (ex: mucin in saliva)
22
Q
Phosphoprotein
A
Protein molecule & a P containing substance other than a nucleic acid (ex: casein)
23
Q
Metalloprotein
A
Protein molecule and a METAL (ex: cytochrome oxidase (Cu))
24
Q
Lipoprotein
A
Protein molecule & a LIPID (ex: VLDL)
25
Consist of altered and degraded products of naturally occuring proteins -- produced by action of heat, enzymes or chemical agents
Derived proteins
26
Non-protein Nitrogen Compounds
Not all of the N present in palnts, feeds or tissues are in the form of protein.
A portion may be non-protein such as:
-amides, amino acids, nitrogenous glucosides and fats, alkaloids and ammonium salts
27
The end product of protein digestion (hydrolysis)/ building blocks for body protein
Amino Acids
28
Aliphatic AAs. Name the 4 subcategories
1. ) Monoamino-monocarboxylic acids - neutral AAs
2. ) Monoamino-dicarboxylic acids - acidic AAs
3. ) Diamino-monocarboxylic acids - basic AAs
4. ) Sulfu-containing AAs
29
3 Types of AAs
Aliphatic, Aromatic, Heterocyclic
30
Amino acids are _______.
Amphoteric - behave as both an acid and base
31
A monoamino-monocarboxylic amino acid (ex: glycine) exists as a dipolar ion...
- "Zwitterion" where both acidic and basic groups are IONIZED and the molecule is electrically NEUTRAL.
- Said to be ISOELECTRIC
32
The 1840's showed that all proteins are not of equal value and revealed that...
Gelatin would not take the place of meat protein in the diet
33
In the period of 1870-1900, scientists proposed that...
Amino acids were probably the building blocks of protein
34
In the early 1900's, many workers began to make use of...
The purified diet technique to study the effects of a single source of dietary protein on N balance and growth
-Mendel and Osborne
35
The most critical understanding of protein nutrition resulted from the studies of...
W.C. Rose in the 1930's
36
W.C. Rose and his Illinois coworkers were able to...
Classify the 10 amino acids as dietary essentials
37
Name the AAs that are NOT synthesized in animal tissue.
The 10 essential amino acids
38
The AAs synthesized from limited substrates (2)
Tyrosine (phenylalanine)
| Cystine (methionine)
39
The AAs readily synthesized by animal tissue (9)
```
Glycine
Alanine
Serine
Glutamic acid
Aspartic acid
Proline
Hydroxyproline
Asparagine
Glutamine
```
40
How many essential AAs are there for poultry?
12 Essential AAs, the extra 2 are:
- Glycine
- Serine
41
"Sparing Effect" on the requirements for other AAs
- Cystine can meet requirement of methionine+cystine
| - Tyrosine can meet requirement of phenylalanine+tyrosine
42
In metabolism there is no such thing as...
A nonessential amino acid
43
Plants can synthesize all te AAs found in nature by their capacity to... and their ability to...
- Utilize ammonia
| - Fabricate the carbon structures (skeletons) to each AAs
44
Mammals LACK the ability to..
Make about 1/2 the carbon structures and their AAs that plants can make
45
Two aspects of protein nutrition/quality are of concern:
1. ) Qualitative Phase - balance
| 2. ) Quantitative Phase - gross amount
46
If there is a marked lag in the digestion of an AA, _________ is reduced due to the "________" for protein synthesis.
-Protein quality is reduced due to the "time factor" for protein synthesis
47
Name the aromatic amino acid to which iodine is added to make T4
Tyrosine
48
The group of amino acids in relatively greater need in poultry due to their high content in feathers.
S-containing AAs
49
Name 3 basic amino acids
- Lysine
- Arginine
- Citrulline
50
When amino acids are present in excess, the excess is catabolized for the energy in the carbon skeleton and the nitrogen is excreted. In what form is the nitrogen excreted in mammals?
Urea
51
Name 3 factors affecting microbial protein synthesis
- Available energy
- Available nitrogen
- Available other nutrients (BCFA, S, Co, Fe)
52
What activates the inactive zymogen pepsinogen into the active pepsin in the stomach?
HCl
53
What activates the inactive zymogen trypsinogen into the active trypsin in the small intestine?
Enterokinase
54
Name some examples of an endopeptidase.
Trypsin, Chymotrypsin, Pepsin, Enterokinase
55
The formula for True Biological Value is...
[NI - (FN-MFN)] - (UN-EUN) / [NI-(FN-MFN)] x 100 = B.V.
OR
(true N absorbed) - (true urinary N) / (true N absorbed) x 100 = B.V.
56
What is Biological Value?
Measures how well the N absorbed is used; % of digested N that is utilized
57
A pig consumes 4 kg of a ration containing 15% crude protein. It excretes 1000 gm of feces containing 20% crude protein.
What is the CONSUMED N?
Consumed N (g) = 4000g *15%*16% = 96g
58
A pig consumes 4 kg of a ration containing 15% crude protein. It excretes 1000 gm of feces containing 20% crude protein.
What is the FECAL NITROGEN?
Fecal N (g) = 1000g*20%*16% = 32g
59
A pig consumes 4 kg of a ration containing 15% crude protein. It excretes 1000 gm of feces containing 20% crude protein.
Urinary N = 63 g
Metabolic Fecal N = 6 g
Endogenous Urinary N = 2 g
Fecal N = 32 g
Consumed N = 96 g
What is the TRUE DIGESTIBILITY COEFFICIENT (DC)?
True Digestibility Coefficient = (96-(32-6)) / 96 = 72.92%
| Formula: (Consumed N - (Fecal N - Metabolic Fecal N)) / (Consumed N) x 100
60
```
A pig consumes 4 kg of a ration containing 15% crude protein. It excretes 1000 gm of feces containing 20% crude protein.
Urinary N = 63 g
Metabolic Fecal N = 6 g
Endogenous Urinary N = 2 g
Fecal N = 32 g
Consumed N = 96 g
What is the NITROGEN RETENTION?
```
Nitrogen Retention = 96-(32+63)= 1g/d
| Formula: Consumed N - (Fecal N + Urinary N) = NR
61
```
A pig consumes 4 kg of a ration containing 15% crude protein. It excretes 1000 gm of feces containing 20% crude protein.
Urinary N = 63 g
Metabolic Fecal N = 6 g
Endogenous Urinary N = 2 g
Fecal N = 32 g
Consumed N = 96 g
What is the BIOLOGICAL VALUE?
```
Biological Value = ((96-(32-6))-(63-2)) / (96-(32-6)) = 12.86%
(Formula: ((Consumed N - (Fecal N - Metabolic Fecal N))-(Urinary-Endogenous Urinary N)) / (Consumed N - (Fecal N-Metabolic Fecal N)) = BV)
62
Apparent Digestibility Coefficient Formula (Apparent DC)
(NI-FN) / NI
63
True Digestibility Coefficient Formula (True DC)
(NI - [FN-MFN] ) / NI)
64
Nitrogen Retention Formula
NI - (FN + UN)
65
Acronyms for evaluating proteins from a nutritional standpoint
```
EUN = Endogenous urinary nitrogen
DC = Digestibility coefficient
NI = Nitrogen intake
FN = Fecal nitrogen
MFN = Metabolic fecal nitrogen
```
66
With regard to NPN content of the feedstuff:
| Which is higher? Mature or Immature Corn
Immature Corn
67
With regard to NPN content of the feedstuff:
| Which is higher? Fresh-chopped or Ensiled Corn
Ensiled Corn
68
With regard to NPN utilization:
| Which is higher? Increased energy content of the diet or to a low energy diet
Increased Energy Content
69
With regard to NPN utilization:
| Which is higher? Less frequent feeding compared to more frequent feeding
More frequent feeding
70
With regard to NPN utilization:
| Which is higher? High roughage diet compared to a high concentrate diet
High concentrate diet
71
With regard to N recycling:
| Which is higher? Higher dietary crude protein content compared to lower crude protein content.
Lower crude protein content
72
With regard to the extent of degradation of protein in the rumen.
High or low
High: Increased time that the feed spends in the rumen
73
With regard to the extent of degradation of protein in the rumen.
Which is higher? A lower rumen pH compared to the normal rumen pH.
Normal rumen pH.
74
With regard to the extent of degradation of protein in the rumen.
Which is higher? The heat treatment of a protein supplement compared to no heat treatment
No heat treatment
75
Of the four protein types found in corn, two are very poor quality (zein and glutelin). Name the two primary protein types
Globulin and Albumin
76
An amino acid which cannot be synthesized at a rate rapid enough to meet the body needs is defined as...
Essential or Indispensable
77
What dietary compound often fed to ruminants is clearly enhanced the most (given that if it was absorbed directly with no alteration, it would have a BV = 0%)?
NPN or Urea
