BM : Proteins Flashcards
(16 cards)
What are the 2 types of proteins
- globular
- fibrous
what are globular proteins
- soluble proteins
- specific 3D shape
Examples of globular proteins
Enzymes
hormones
antibodies
What are fibrous protiens
- strong
- insoluble
- inflexible material
Examples of fibrous proteins
collagen
keratin
what are the building blocks for proteins
amino acids
Structure of amino acid
- central carbon
- carboxyl group to the right ( COOH )
- amine group to the left ( NH2 )
- hydrogen above
- r group below
how do amino acids differ?
Have different R groups
How are amino acids joined together
By condensation reaction Between carboxyl group of one and the amine group of another
- leaves a bond between carbon and nitrogen (peptide bond) forming a dipeptide
What is primary structure
Sequence of amino acids
- polypeptide chain
- Held by peptide bonds
What is secondary structure
The primary structure (polypeptide chain)
- coiled to form a helix
- held by hydrogen bonds
What is tertiary structure
Secondary structure
- folds again to form a final 3D shape
- held by hydrogen/ ionic/ disulfide bonds
what is Quaternary structure
made of more than one polypeptide chain
Examples of quaternary structure proteins
- collagen
- antibodies
- haemoglobin
Structure of collagen
- strong material, many together build tendons/ ligaments/ connective tissue
Primary structure - mainly made up of glycine
Secondary structure - forms a tight coil (not much branching)
Tertiary structure - coils again
Quaternary Structure - made from 3 tertiary structures wrapped around each other like rope = collagen molecules
What is the test for proteins?
Add biuret, turns purple
