2D: Proteins & Amino Acids

Amino Acids

The monomers that make up proteins.

Peptide Bonds

The kind of bond that connects amino acids.

Nitrogen content

What distinguishes proteins from fats, carbohydrates, & other organic compounds.

7% H, 55% C, 23& O, & 15% Other

The elemental compositions of proteins.

Growth & tissue repair & maintenance

2 reasons why proteins are needed.

Muscle contractions

The general responsibility of proteins.

Enzymes, hormones, & antibodies

Proteins are components of these 3 classifications of substances.

Maintenance, growth, & reproduction

The 3 roles of continuous protein supply in aquatic animals.

Globular & Fibrous

The 2 classifications of proteins based on form & solubility.

Globular Proteins

A classification of proteins that are compact spherical or globularly shaped. They are mostly soluble in aqueous systems.

Enzymes, protein hormones, proteins of serum fraction of blood, & antibodies

4 examples of globular proteins.

Fibrous Proteins

A classification of proteins that are long chains of polypeptides & are highly insoluble & resistant to action of digestive enzymes.

Collagen, blood vessels, elastin, & keratin

4 examples of fibrous proteins.

Simple, Conjugated, & Derived Proteins

The 3 classifications of proteins based on physical properties.

Simple Proteins

A classification of proteins that consist of only amino acids or their derivatives. When hydrolyzed by acids, alkalis, or enzymes they only yield amino acids or their derivatives.

Albumins, albuminoids, globulins, glutelins, histones, protamines, & prolamines.

7 examples of simple proteins.

Conjugated Proteins

A classification of proteins that is made of a simple & non-protein prosthetic group.

Nucleoproteins, glycoproteins, phosphoproteins, & chromoproteins

4 examples of conjugated proteins.

Lipoproteins & metalloproteins

2 examples of prosthetic groups.

Derived proteins

A classification of proteins that consist of compounds representing altered & degraded products of naturally occurring proteins. Produced by the action of heat, enzymes, or chemical agents.

Peptones, peptides, & proteases

3 examples of derived proteins.

Primary, Secondary, Tertiary, & Quaternary

The 4 levels of protein structure.

Primary Structure

The level of protein structure defined as being the linear sequence in which constituent amino acids are covalently linked VIA amide/peptide bonds. Any change in amino acid may produce drastic effect. Determines the 3D conformation of protein molecule & its role.

Sickle Cell Disease

The effect of a change in the primary structure of hemoglobin in the 6th amino acid from GLU to VAL.

Secondary Structure

The level of protein structure defined as being the periodic spatial arrangement of amino acids residues at certain segments of polypeptide chain.

Coiled (alpha) Helices or Extended beta sheets/pleated sheet forms

The 2 forms of secondary structures of proteins.

Tertiary Structure

The level of protein structure defined as being the spatial arrangement when a linear chain with secondary structure folds further into a compact 3D form.

Quaternary Structure

The level of protein structure defined as being the spatial arrangement of a protein when it contains more than one polypeptide chain.

Chemical & Biological Method

The 2 ways to evaluate protein quality.

Chemical Method

The way to evaluate protein quality through determining the quantity of protein or amino acid in feedstuff.

Killdall method, Liquid chromatography, & High-performance chromatography

3 examples of chemical methods of evaluating protein quality.

Biological Method

The way to evaluate protein quality through determining how fish react to the protein in terms of growth & survival. Measures the body weight gain & nitrogen retention in fish at the end of the experiment. The longer method which takes 6-8 weeks. More expensive.

Maximum growth

What the optimum protein requirement of fish looks at based on the level of high quality dietary protein needed.

Highest weight gain & survival

The 2 things which the best diet is considered to give.

27% - 60%

The range of the minimum amount of dietary protein needed for optimum growth of most cultured aquatic species.

Carnivorous fish

The kind of fish that have a higher protein requirement & optimum levels.

Higher metabolism & protein levels

The metabolism & protein levels in small or younger fish compared to older or larger ones.

Fish fed at feeding rates below satiation levels & fish that are fed poor quality protein

2 instances wherein fish need to be fed higher levels of protein.

a-carbon at the center, Hydrogen atom, Amino group, Carboxyl group, & Side chain R-group

The 5 components of amino acids.

Seleonocysteine

The 21st highly reactive amino acid.

Pyrolysine

The 22nd amino acid found in archaea for the production of methane.

Essential or Indispensable & Non-Essential or Dispensable

The 2 general classifications of amino acids.

Essential or Indispensable Amino Acids

The classification of amino acids that include those that cannot be synthesized in amounts that are enough to support maximum growth and thus have to be present in the diet.

Arg, His, Ile, Leu, Lys, Met, Phe, Thr, Trp, & Val

The 10 essential or indispensable amino acids required by fish for growth & maintenance.

Met

An essential/indispensable amino acid that supplies methyl groups for creatine, choline & other substances.

Thr

An essential/indispensable amino acid that is needed to form hormones thyroxine, epinephrine, norepinephrine, & melanin.

Trp

An essential/indispensable amino acid that is the precursor of serotonin which regulates fish intestinal movement & nicotinic acid/niacin.

Non-Essential or Dispensable Amino Acids

The classification of amino acids that include those that have nutritional significance as they conserve energy required for protein synthesis. Some can partially replace/spare essential amino acids. They are adequately synthesized or formed from amino acids & are not necessary in the diet.

Cys

A non essential or dispensable amino acid that can partially replace Met.

Tyr

A non essential or dispensable amino acid that can partially replace Phe.

Aliphatic, Aromatic, & Heterocyclic

3 other classifications of amino acids based on their side chains.

Aliphatic Amino Acids

A classification of amino acids that have linear side chains and 3 sub groups based on acidity.

Arg & Lys

2 basic aliphatic amino acids.

Asp & Glu

2 acidic aliphatic amino acids.

Leu, Ile, Val, Ala, Gly, Met, Cys, Thr, & Ser

9 neutral aliphatic amino acids.

Aromatic Amino Acids

A classification of amino acids that have a benzene ring.

Phe & Tyr

2 aromatic amino acids.

Heterocyclic Amino Acids

A classification of amino acids that have cyclic compounds or a ring.

His, Trp, & Pro

3 heterocyclic amino acids.

65% - 75%

The percentage range of protein in fish tissues.

Intestinal tract

Where the digestion & absorption of amino acids from proteins occur.

Energy sources or converted to fat

The 2 fates of excess amino acids.

Expensive so impractical

The downside to using crystalline amino acid supplements.

Minimize leeching so they do not break down through efficient binders & feeding practices

The importance of using water stable diets.

Feed ingredients lack essential amino acids, Excessive heating during feed preparation, chemical affecting feed ingredients, & nutrient leaching

4 causes of amino acid deficiencies.

Amino Acid Antagonism & Amino Acid Toxicity

2 causes of excess dietary amino acids.

Amino Acid Antagonism

When some amino acids are fed in excess causing an increase in the requirement for another amino acid of similar structure.

Amino Acid Toxicity

When excess amounts of certain amino acids are fed to fish. Detrimental to their health.