U1B protein

what are proteins made of ?

small molecules called Amino acids

what are the 4 main structures of proteins

• primary

• secondary

• tertiary

• quaternary

what is an primary structure

a polypeptide long chain of amnio acid

how is a dipeptide molecule produced

covalent bond forms between 2 amino acids bond formed 2 amino acids is called a peptide bond the molecule produced is a dipeptide molecule

what is the primary structure broken by

broken by hydrolysis

what is a secondary structure

alpha helix and beta pleated sheets

what is a secondary structure held by

held in shape by hydrogen bonds

what is a tertiary structure

3D folded structure of a single polypeptide chain formed by interactions of side chains

what are tertiary structures

ionic

• opposite charges attract and form a bond

what do tertiary structures have

• disulphide bonds

• van der waals forces

what are disulphide bonds

sulphur atoms on 2 chains bond covalently to form strong bonds

what are van der waals forces

weak bonds due to temporary charge distributions

what is a Quaternary structure

4th and final level made up of 2 polypeptide chains it has a 3d shape which is essential for function

what is an example of a quaternary structure

• Haemoglobin

• made of 4 polypeptide chains that come together to form functional protein

what is a globular protein

perform metabolic functions such as enzymes/hormones/antibodies

name me 3 structures of globular protein

• compact

• spherical

• water soluble

what are fibrous proteins

provide structural roles and provide strength and support

what are fibrous proteins found in

found in keratin (hair/nails) and collagen(tissue/tendon/bone)

give me 3 facts about fibrous proteins

• long

• insoluble

• strand like

function of muscle contractions

filamentous proteins that slide past each other

function of antibodies

bind to specific antigens on the surface of a pathogen to provoke a immune response

function of carrier proteins

carrier proteins that bind to vitamins and minerals/transport them around body

function of transport of other components

various proteins transport different substances around body

function of blood clotting

platelets and proteins needed in order to clot

steps for how to test proteins using biuret solution

1) add sodium hydroxide to test sample

2) add few drops of copper sulfate

3) result if positive is violet if negative stays same

how do you test proteins

biuret solution