Nutrition Chapter 6: Proteins

Total Flash Cards » 34
Text Size: S | M | L
proteins large, complex molecules made up of amino acids and found as essential components of living cells
amino acids nitrogen-containing molecules that combine to form proteins
essential amino acids amino acids not produced by the body that must be obtained from food
non-essential amino acids amino acids that can be manufactured by the body in sufficient quantities and therefore do not need to be consumed regularly in our diet
transamination the process of transferring the amine group from one amino acid to another to manufacture a new amino acid
peptide bonds unique types of chemical bonds in which the amine group of one amino acid binds to the acid group of another 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 mRNA copies genetic information from DNA in the nucleus
translation the process that occurs when the genetic information carried by mRNA is translated into a chain of amino acids at the ribosome
denaturation a change in the shape of a protein caused by heat, acids, bases, heavy metals, alcohol, or other substances; results in protein loosing its ability to function
limiting amino acid the essential amino acid that is missing or in the smallest supply in the amino acid pool and is thus responsible for slowing or halting protein synthesis
incomplete proteins proteins that do not contain all the essential amino acids in sufficient amounts to support growth and health
complete proteins proteins that contain all nine essential amino acids. Proteins from animal sources are complete proteins. Soybeans are the only complete source of plant protein
mutual supplementation the process of combining two or more incomplete protein sources to make a complete protein
complementary proteins 2 or more foods together contain all nine essential amino acids necessary for a complete protein. it is not necessary to eat complementary foods at the same meal
pepsin an enzyme in the stomach that begins the breakdown of proteins into shorter polypeptide chains and single amino acids
proteases a set of enzymes secreted by cells in the pancreas that hydrolyze (break apart) the peptide bonds in shorter polypeptides splitting them into oligopeptides, tripeptides, dipeptides, and free amino acids
peptidases a set of enzymes on the surface of intestinal cells that hydrolyze peptide bonds in oligopeptides, tripeptides, and dipeptides, splitting them into single amino acids for absorption
protein digestibility-corrected amino acid score (PDCAAS) a measurement of protein quality that considers the balance of essential amino acids as well as the digestibility of the protein in the food
Edema a disorder in which fluids build up in the tissue spaces of the body, causing fluid imbalances and sollen appearance
transport proteins protein molecules that help to transport substances throughout the body and across cell membranes
pH stands for percentage of hydrogen. it is a measure of the acidity - or level of hydrogen - f any solution, including human blood
acidosis a disorder in which the blood becomes acidic; that is, the level of hydrogen in the blood is excessive. It can be caused by respiratory or metabolic problems
alkalosis a disorder in which the blood becomes basic; that is, the level of hydrogen in the blood is deficient. it can be caused by respiratory or metabolic problems
buffers proteins that help maintain proper acid-base balance by attaching to, or 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 and allergens
deamination the process by which an amine group is removed from an amino acid. The nitrogen is then transported in a special form to the kidneys for excretion in the urine, while the carbon skeleton is metabolized for energy or used to make other compounds
vegetarianism the practice of restricting the diet to foods of plant origin, including vegetables, fruits, grains, and nuts
carcinogens cancer-causing agents, such as certain pesticides, industrial chemicals, and pollutants
protein-energy malnutrition a disorder caused by inadequate consumption of protein energy and other nutrients. It is characterized by severe wasting.
marasmus a form of protein-energy malnutrition that results from grossly inadequate intakes of protein, energy, and other nutrients
kwashiorkor a form of protein-energy malnutrition that is typically seen in developing countries in infants and toddlers who are weaned early because of the birth of the subsequent child. Denied breast milk, they are fed a cereal diet that provides adequate energy but inadequate protein
sickle cell anemia a genetic disorder that causes red blood cells to be sickle or crescent shaped. These cells cannot travel smoothly through blood vessels, causing cell breakage and anemia
cystic fibrosis a genetic disorder that caused an alternation in chloride transport leading to the production of thick, sticky mucus that causes life-threatening respiratory and digestive problems