Amino Acids
Proteins
- Proteins are polypeptides (and macromolecules) made up of monomers called amino acids
- The sequence, type and number of the amino acids within a protein determines its shape and therefore its function
- Proteins are extremely important for cell growth, cell repair and structure
- They form all of the following:
- Enzymes
- Cell membrane proteins (eg. carrier)
- Hormones
- Immunoproteins (eg. immunoglobulins)
- Transport proteins (eg. haemoglobin)
- Structural proteins (eg. keratin, collagen)
- Contractile proteins (eg. myosin)
Amino acids
- Amino acids are the monomers of polypeptides
- There are 20 amino acids found in proteins common to all living organisms
- The general structure of all amino acids is a central carbon atom bonded to:
- An amine group -NH2
- A carboxylic acid group -COOH
- A hydrogen atom
- An R group (which is how each amino acid differs and why amino acid properties differ e.g. whether they are acidic or basic or whether they are polar or non-polar)
The generalised structure of an amino acid
Examiner Tip
You will be expected to recognise whether an unfamiliar molecule is an amino acid or protein so look for the functional groups (amine and carboxyl).