Protein (NUTR 150)

essential amino acid

an amino acid that cannot be synthesized by the body in sufficient amounts and must be consumed in the diet

nonessential amino acid

An amino acid that can be synthesized in the body in sufficient amounts.

Conditionally essential amino acid

A nonessential amino acid which cannot be synthesized in sufficient amounts under certain conditions.

Phenylketonuria (PKU)

A genetic condition when phenylalanine cannot be metabolized normally, causing it to build up in the blood.

Peptide bond

Bond that holds amino acids together

Dipeptide

Two amino acids bonded together

Tripeptide

Three amino acids bonded together

Polypeptide

Many amino acids bonded together

Denaturation

A change in a proteins three-dimensional structure. Often is caused by heat or acid.

Pepsin

Enzyme found in stomach that begins the chemical digestion of proteins

Proteases

A general name for protein digesting enzymes.

Active transport

An absorption process which requires a carrier molecule (transporter) and ATP. Amino acids require this type of absorption.

Amino acid pool

All the amino acids in body tissues that are available for use by the body.

Genes

The part of DNA that contains the information needed to make a protein

Gene expression

The activation or turning on of a gene that results in its transcription and the production of a specific protein

Transamination

When the amino group from one amino acid is transferred to a carbon compound to form a new amino acid

Limiting amino acid

The essential amino acid that is available in the lowest concentration relative to the body's needs

Transcription

Transferring the code for a protein from DNA into a messenger RNA (mRNA).

Translation

The process of synthesizing a protein from messenger RNA (mRNA).

Edema

When water leaks out of blood vessels and accumulates in body tissues, due to low blood proteins

Deamination

The process of removing the amino group from an amino acid

Urea

The nitrogen containing waste product from the breakdown of proteins. Excreted in urine.

Gluconeogenesis

The synthesis of "new" glucose in the body. Glucose may be made from some of the amino acids.

Protein-energy malnutrition

Insufficient amounts of protein/energy to meet the body's needs, resulting in loss of muscle and fat mass

Kwashiorkor

A form of protein-energy malnutrition where protein intake is deficient and caloric intake is moderately deficient.

Marasmus

A form of protein-energy malnutrition in which protein and caloric intake are severely deficient. This causes severe body wasting.

Allergy

An adverse immune response to a specific food protein

Food intolerance

An adverse reaction to a food that does not involve production of antibodies by the immune system.

Celiac disease

A disorder that causes damage to the intestines when gluten is consumed. People with Celiac disease need to avoid wheat, rye, and barley.

Protein balance

The amount of protein in the body remains the same. The protein consumed in the diet is the same as the protein broken down by the body

Negative protein balance

There is protein in the body decreases. The amount of protein consumed is less than the amount of protein lost in the body.

Positive protein balance

A person loses less protein in the body than is consumed in the diet. There is an increase of protein in the body.

Complete dietary proteins

Proteins that supply essential amino acids in the proportions needed by the body.

Incomplete dietary protein

Proteins lower in one or more essential amino acids.

Complementary protein

Combining a protein from a different food sources so they provide the proportion of essential amino acids needed by the body

Vegetarian

An eating pattern that includes plant-based foods and eliminates some or all animal based foods

Vegan

A plant-based diet that eliminates all animal products

Pescetarian

An eating pattern that excludes all animal flesh except fish

Lacto-ovo vegetarian

An eating pattern that excludes all animal flesh but does include eggs and dairy products