PROTEINS

Protein

Naturally occurring unbranched polymer made of amino acids, accounting for 15% of a cell's mass.

Daily Protein Intake

Recommended daily intake for adults is 0.8 grams of protein per kg of body weight.

Catalytic Proteins

Enzymes that act as biochemical catalysts to speed up biochemical processes.

Defense Proteins

Immunoglobulins or antibodies that help protect the body.

Transport Proteins

Proteins like hemoglobin and lipoproteins that transfer chemicals in the body.

Messenger Proteins

Proteins such as insulin and glucagon that transmit signals in the body.

Contractile Proteins

Proteins like actin and myosin that control muscle contractions.

Structural Proteins

Proteins such as collagen and α-keratin that provide structure to tissues.

Transmembrane Proteins

Proteins that form channels in cell membranes.

Storage Proteins

Proteins like myoglobin that store essential substances like oxygen.

Regulatory Proteins

Proteins such as proteolytic enzymes and zymogens that regulate biological processes.

Nutrient Proteins

Proteins like casein and ovalbumin that provide amino acids.

Buffer Proteins

Proteins like hemoglobin that help maintain blood pH by absorbing acidity.

Amino Acids

Building blocks of proteins, containing carboxylic acid and amino groups.

Chiral Amino Acids

All α-amino acids are chiral except glycine, which has two identical groups.

Peptide Bond

A bond formed between the carboxyl group of one amino acid and the amino group of another.

Dipeptide

A molecule formed from two amino acids linked by a peptide bond.

Tripeptide

A molecule formed from three amino acids linked by peptide bonds.

Polypeptide

A macromolecule containing many amino acids linked by peptide bonds.

C-terminal Amino Acid

The amino acid at the end of a peptide chain with a free -COO- group.

N-terminal Amino Acid

The amino acid at the start of a peptide chain with a free -NH3+ group.

Enkephalins

Pentapeptides that act as painkillers and sedatives by binding to pain receptors.

Oxytocin

A cyclic nonapeptide hormone that stimulates uterine contractions and milk production.

Vasopressin

An antidiuretic hormone that helps regulate body fluids during dehydration.

Primary Structure

The unique sequence of amino acids in a protein held together by peptide bonds.

Secondary Structure

The arrangement of amino acids in a polypeptide chain, including α-helices and β-pleated sheets.

Tertiary Structure

The three-dimensional shape of a protein determined by interactions between side chains.

Quaternary Structure

The combination of two or more polypeptide subunits in a protein.

Denaturation

The process of destroying a protein's structure through chemical or physical means.

Sickle Cell Anemia

A genetic mutation causing a change in hemoglobin that leads to sickle-shaped red blood cells.

Conantokins

small family of helical peptides that are derived from the venom of predatory marine snails of the genus conus