Zusammenfassung der Ressource
Structure and function in proteins
- Globular
Proteins
- Haemoglobin
- Ball shaped molecule
- Soluble in water
- Contains many R groups containing hydrophilic side chains on the outside of the 'ball'
- Insulin
- Shape allows it to form bonds with other protein molecules
- In the membranes of liver cells
- Complementary shape
- Respond by setting off a sequence of events
- Culminates in the joining of glucose molecules to cause glycogen
- Enzymes
- Active site
- Precise shape that allows the enzyme to bind with other molecules
- Causing a reaction
- Fibrous Proteins
- Long, thin, molecules
- Keratin
- Found in hair, wool, nails and skin
- Keratin forms long molecules that coil
- These associate with each other
- To form filaments
- Very strong
- Held together by disulphide bridges
- Chains of amino acids
- Regular pattern of hydrogen bonds
- Causes them to coil into long helices
- Insoluble
- Structural roles
- Collagen
- Gives bone and cartilage strength
- 3 twisted polypeptide chains
- More tightly bound than Keratin
- Can form more rigid structures
- Often grouped together to from almost rigid rods
- Simple Protein Strucutre
- Primary Structure
- Secondary Strucutre
- Tertiary Structure
- Quaternary Structure
- The function of a protein depends on its 3D shape.
- The 3D shape is determined by its primary structure