BIOLOGY - PROTEINS

Large polymers comprised of long chains of amino acids

Monomers that make up the protein polymers. All amino acids have the same basic structure and the R group is the only part that varies.

Covalent bonds that join two amino acids together

Linear chain of amino acids

Caused by hydrogen bonds forming between the =O on the carboxyl group and -H from the amino group

Twist the chain into an alpha-helix OR into a beta pleated sheet.

Give rise to strong, fibrous proteins. Keratin in wool and collagen in skin and blood vessels

Sequence of amino acids in a polypeptide chain, and joined together by peptide bonds

Formed when one polypeptide molecule twists and folds in on itself - only happens in a-helix. Makes globular proteins.

Hydrogen bonds, ionic bonds, disulfate bridges and hydrophobic interactions

Bonds that are formed from charged variable groups and can interact with water, helps a protein to dissolve

Bonds are formed from variable groups containing sulfur atoms - two of these bonds together to form disulfide bridge. These are covalent bonds that are strong and more difficult to break.

Bonds between polar variable groups

Take place when the variable groups are non-polar. They are repelled by water and are usually found on the inside of the protein; a protein rich in non-polar side groups will be less soluble in water

Peptide bond (Covalent), Disulphide bond (covalent), Ionic bond, Hydrogen bond, Hydrophobic interactions

Enzymes (active sites to bind to a substrate), antibodies (sites for binding to antigens) and Hormones (sites for binding to specific receptors)

Involves linking together of two or more polypeptide chains, each of the polypeptide chains has a primary, secondary and sometimes tertiary structure. They have a non-protein group.

Long thin molecules that are insoluble in water, therefore they have structural functions. Collagen is an example - it provides strength and toughness needed in tensions. Hydrogen bonds hold the three chains together

Compact spherical molecule, soluble, and functions include: enzymes, haemoglobin, antibodies, plasma, proteins and hormones

Little or no tertiary structure, long parallel polypeptide chains, cross linkages at intervals, long fibres and sheets formed, mostly insoluble and most have a structural role

In hair and outer layer of skin

In connective tissue

A complex tertiary structure, folded into a spherical/globular shape, usually soluble in water, some have a quarternary structure and has a role in metabolic reactions