Protein Structure Flashcards
1
Q
Describe the primary structure of a protein
A
- ‘basic chain’ the sequence of amino acids
- amino group and carboxyl groups stick out the ends
2
Q
Describe the secondary structure of a protein
A
- ’ initial folding’ of primary structure
- hydrogen bonds form between the amine group and the carboxyl group
- form alpha helix or beta - pleated sheet
3
Q
Describe the tertiary structure of a protein
A
- provides 3D shape
- hydrogen bonds form between amine group and carboxyl group
- ionic bonds formed - maintains the shape
- disulphide bridges are formed - for further support
4
Q
Describe the strength of the 3 bonds: disulphide bridges, ionic bonds and hydrogen bonds
A
- disulfide bridges - strong and not easily broken
- ionic bonds - easily broken down by changes in pH (carboxyl/ amino groups)
- hydrogen bonds - numerous but very easily broken
5
Q
Describe the quaternary structure
A
- made of 2 or more polypeptides (tertiary proteins) joined together
6
Q
What are the two types of proteins?
A
Fibrous
Globular
7
Q
What is the shape of globular proteins usually?
A
Usually spherical shape
8
Q
Describe a globular protein
A
- molecules which have a chemical function in living organisms
- and take part in specific reactions e.g. enzymes, hormones
9
Q
What is the shape of a fibrous protein?
A
Fibrous (or filamentous) structure
10
Q
Describe a fibrous protein
A
- molecules which have a structural role in living organisms
- e.g. they may give strength or elasticity to tissue
- e.g. keratin in hair and skin, collagen in cartilage and bone
