Proteins and enzymes

Question 1

protein basics
- how are they formed
how many proteins and genes in body

Answer 1

• sourced from our genome/genetic code - DNA (transcription to) -> mRNA (translation to)-> proteins
• roughly 75,000 proteins with around 20,000 genes

Question 2

basic structure of a protein
- what is their monomer
- the structure of each monomer
- bonds between monomers and how they formed
- what is the part of the chain within the bond
- what do you call 2 and many monomers joined

Answer 2

• amino acids
• Charged amino group on one side (H2N+)
• Charged carboxyl group on other side (COOH-)
• Central carbon
• Repeating hydrogen
• Variable R group/side chain determines different amino acids
• Peptide bonds forms between 2 amino acids (covalently) via condensation reaction
• the residue
• dipeptide and polypeptide

Question 3

levels of organisation-
- what is a proteome
- what is primary structure
- what is secondary structure
- what is tertiary structure
- what causes denaturing of these bonds
- what is quaternary structure

Answer 3

• The entire set of proteins in an organism, tissue, cell type, or biological fluid
• the order of amino acids
• the folding of polypeptides, created by individually weak, but collectively strong hydrogen bonds, into alpha helix or beta pleated sheet. bonds created by a hydrogen atom with a partial positive charge and an atom usually o or n with a partial negative charge.
• the 3d shape of a polypeptide chain. stabilised by hydrogen bonds, electrostatic bonds/ionic bonds, van der waals interaction, disulfide bonds and hydrophobic (mutual repulsion) interactions.
• Environmental factors such as heat and acidity can alter/break these forces irreversibly
• multiple polypeptides/subunits interact via the previously discussed interactions to form a protein

Question 4

examples of functions of proteins in the body

Answer 4

• Antibodies (defensive)
• Keratin (structural)
• Enzymes (catalytic)
• Haemoglobin (transport)
• Hormones (messenger)
• Insulin receptors (receptors)
• Many proteins have more than 1 function

Question 5

enzymes-
- what do they do
- what are their reactants called
- 2 theories of ESC binding

Answer 5

• accelerate metabolic reactions
• called substrates
  lock and key and induced fit

Question 6

3 main features of enzymes

Answer 6

• speed up reactions
• they are highly specific/complementary
• speed of reaction is subject to substrate and enzyme availability, temperature, and ph

Question 7

cofactors and coenzymes
- what do cofactors do to enymes
- what are they
- what are metalloenzymes

Answer 7

• in their active sites to catalyse reactions
• metal ions and organic compounds
• metal ions embedded in organic compounds, eg. heme