Protein structure function and enzyme regulation

What is a hetero dimer and a homo dimer?

• Hetero dimer - 2 different proteins in complex

• Homo dimer - 2 identical proteins in complex

how is protein structure determined?

• Nature of amino acid sequence - primary

• Interactions between amino acid - secondary

• Protein-protein interactions - tertiary, quaternary and quinary

Describe competitive inhibitors

Bind directly in an enzyme active site, preventing substrate from binding. So enzyme can't catalyse reactions. At a high substrate concentration, competitive inhibitors have minimal effect

Describe non-competitive inhibitors

Bind to the allosteric site of the enzymes. They change the shape of the active site, preventing substrates from binding. Not affected by substrate concentration.

What does erythropoietin do

Promotes cell survival and differentiation. Regulates red-cell specific genes

How does EPO regulate red blood cell–specific genes?

Binds to receptors in the cell membrane, leading to a gene cascade. This turns on RBC genes

What are the steps of cell differentiation?

1. Stem cell

2. Intermediate progenitors (expansion)

3. Fully mature cell

What does the control of gene expression involve?

1. Multiple transcriptional regulators

2. Some are controlled by extra-cellular signals