Proteins and Their Structures

These flashcards cover key vocabulary related to proteins, their structures, and functions.

Protein

Large, complex molecules made from chains of amino acids that play a role in the structure and metabolism of living organisms.

Amino Acid

The basic building blocks of proteins, which join via peptide bonds to form polypeptides.

Peptide Bond

The bond formed between the amino group of one amino acid and the carboxyl group of another, creating a dipeptide or polypeptide.

Primary Structure

The linear order of amino acids in a polypeptide, determining the properties and shape of the protein.

Secondary Structure

The way amino acids fold or twist into structures such as alpha helices or beta pleated sheets due to hydrogen bonding.

Alpha Helix

A common secondary structure in proteins where hydrogen bonds form between amino acids, causing the chain to twist into a spiral.

Beta Pleated Sheet

A secondary structure formed by adjacent polypeptide chains that are arranged in opposite directions, stabilized by hydrogen bonds.

Tertiary Structure

The overall three-dimensional structure of a protein, formed by interactions between R groups of amino acids.

Quaternary Structure

The arrangement of multiple polypeptide chains into a single functional protein.

Denaturation

The process by which proteins lose their structure due to changes in temperature, pH, or other environmental factors, resulting in loss of function.

Fibrous Proteins

Proteins that form long fibers or sheets; typically provide structural support and are not soluble in water.

Globular Proteins

Proteins that are compact and soluble in water, often involved in metabolic processes.

Hydrophobic Interaction

The tendency of non-polar R groups to orient away from water in aqueous environments, stabilizing protein structure.

Van der Waals Forces

Weak attractions that occur between atoms that are close together, contributing to protein structure stability.

Hydrogen Bonding

The interaction between the electronegative oxygen of a carboxyl group and the electropositive hydrogen of an amino group, important for stabilizing protein structures.