Ch 6 - Proteins Flashcards
(34 cards)
Proteins
Large, complex molecules made up of amino acids and found as essential components of all living cells.
Amino acids
Nitrogen-containing molecule that combine to form proteins.
Essential amino acid
Cannot be produced by our body, must be obtained from food. 9 of 20 amino acids in body are essential.
Nonessential amino acids
can be made by our body in sufficient quantities and therefore do not need to be consumed regularly in our diet.
Conditionally essential amino acids
Amino acids considered nonessential but become essential under certain circumstances when the body’s need for them exceeds the ability to produce them.
Peptide bonds
chemical bonds in which the amine group of one amino acid binds to the acid group of another in order to manufacture dipeptides and all larger peptide molecules.
Gene expression
The process of using a gene to make a protein.
Transcription
The process through which messenger RNA copies genetic information from DNA in the nucleus.
Translation
The process that occurs when genetic info carried by messenger RNA is translated into a chain of amino acids at the ribosome.
Denaturation
The process by which proteins uncoil and lose their shape and function when they are exposed to heat, acids, bases, heavy metals, alcohol, and other damaging substances.
Limiting amino acids
The essential amino acid that is missing or in the smallest supply in the amino acid pool and it thus responsible for slowing or halting protein synthesis.
Incomplete proteins (low-quality)
Foods that do not contain all of the essential amino acids in sufficient amounts to support growth and health.
Complete proteins (high quality protein)
Foods that contain all 9 essential amino acids.
Mutual supplementation
combining 2 or more incomplete proteins to make a complete protein.
Complementary proteins
2/more foods that together contain all 9 essential amino acids necessary for a complete protein. It’s not necessary to eat complementary proteins at the same meal. (Beans, rice)
Edema
A disorder in which fluids build up in the tissue spaces of the body, causing fluid imbalances and a swollen appearance.
Transport proteins
Protein molecules that help transport substances throughout the body and across cell membrane.
Acidosis
blood becomes acidic; the level of hydrogen in the blood is excessive. It can be caused by respiratory / metabolic problems.
Alkalosis
blood becomes basic; the level of hydrogen in the blood is deficient. It can be caused by respiratory /metabolic problems.
Buffers
Proteins that help maintain proper acid-base balance by attaching to / releasing hydrogen ions as conditions change in the body.
Antibodies
Defensive proteins of the immune system. Their production is prompted by the presence of bacteria, viruses, toxins, allergens, and other antigens.
Deamination
Liver removes the amine group from the amino acid.
Neurotransmitters
Chemicals that transmit messages from one nerve cell to another.
Pepsin
An enzyme in the stomach that begins the breakdown of proteins into shorter polypeptide chains and single amino acids.