Proteins Flashcards
6 Nutrient Classes
Water Carbohydrates Proteins Lipids Vitamins Minerals
6 roles/functions of Proteins
- ) Structural elements (hair, wool, collagen, muscle)
- ) Enzymes
- ) Hormones
- ) Carriers in the blood (hemoglobin)
- ) Associated with genes (hereditary factors)
- ) Antibodies
In protein digestion, the digesting enzymes are secreted as…?
Inactive Zymogens
What is the principle protein-digesting enzyme in the stomach (abomasum in ruminants)?
Pepsin
What activates the inactive zymogen into this active enzyme?
HCl
What is the distinction between an endopeptidase and an exopeptidase?
- Endopeptidase attacks internal peptide bonds
- Exopeptidase attacks terminal peptide bonds
Name some examples of an exopeptidase.
- Carboxypeptidase
- A&B
- Aminopeptidase
- Dipeptidase
10 amino acids classified as dietary essentials for pigs, rats, dogs, and growing humans.
Phenylalanine Valine Tryptophan Threonine Isoleucine Methionine Histidine Arginine Lysine Leucine
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?
Higher
The same results
The linkage between one amino acid and another in a protein…?
Peptide bond
Protein quality of the diet is a function of WHAT aspects of the amino acid in that protein?
Qualitative (Balance)
Quantitative (Total Amount)
Name the physiological process that is a protein quality that is extremely critical to the biological value of a protein.
Rate and Extent of Digestion/Absorption
What two amino acids has it been shown that man does not need for maintenance? What about for growing?
- Maintenance: Histidine and Arginine NOT NEEDED
- Growing: need all 10
Proteins comprise about ____ of the dry, fat-free body.
80%
Name the elements that protein contains? (5)
C, H, O, N, S
The N content in protein content of tissues and feedstuffs? (%)
14-20% (Avg. 16%)
These yield ONLY amino acids or their derivatives on hydrolysis. (5)
Simple proteins:
- Albumin
- Globulin
- Albuminoids
- Histones
- Protamins
Simple proteins combined with a non-protein radical…?
Conjugated proteins
There are 5 conjugated proteins. They are…?
- ) Nucleoproteins
- ) Glycoproteins
- ) Phosphoproteins
- ) Metalloproteins
- ) Lipoproteins
Nucleoprotein
1 or more protein molecules with NUCLEIC ACID
Glycoprotein
Protein molecule & substance(s) containing CHO group (ex: mucin in saliva)
Phosphoprotein
Protein molecule & a P containing substance other than a nucleic acid (ex: casein)
Metalloprotein
Protein molecule and a METAL (ex: cytochrome oxidase (Cu))
Lipoprotein
Protein molecule & a LIPID (ex: VLDL)
Consist of altered and degraded products of naturally occuring proteins – produced by action of heat, enzymes or chemical agents
Derived proteins
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
The end product of protein digestion (hydrolysis)/ building blocks for body protein
Amino Acids
Aliphatic AAs. Name the 4 subcategories
- ) Monoamino-monocarboxylic acids - neutral AAs
- ) Monoamino-dicarboxylic acids - acidic AAs
- ) Diamino-monocarboxylic acids - basic AAs
- ) Sulfu-containing AAs
3 Types of AAs
Aliphatic, Aromatic, Heterocyclic
Amino acids are _______.
Amphoteric - behave as both an acid and base