Proteomics and Amino Acids

Question 1

What is a genome and proteome?

Answer 1

• A genome is the organisms complete set of DNA.

- A proteome is the entire set of proteins that an be produced from an organisms genome.

Question 2

Why is the proteome so much larger than the genome?

Answer 2

1) Alternative RNA splicing - Depending on which parts are treated as exons and introns in a primary transcript of a gene, different mature mRNA molecules are produced.
2) Post-translational modification - The polypeptide produced in translation can be cut and combined in different ways or have phosphate/carbohydrate groups added.

Question 3

Describe the structure of an amino acid.

Answer 3

Amino acids are monomers of polypeptide polymers. All amino acids have a central carbon atom bonded to am amine group (NH2), a carboxyl group (COOH), a hydrogen atom and an R group.

Question 4

What are the main classes of R groups an amino acid could have?

Answer 4

• Acidic (negitively charged in neutal solution) e.g. COOH which becomes COO- in aqueous solution.
• Basic (positively charged in neutal solution) e.g. NH2 which becomes NH3+ in aqueous solutoion.
• Polar (hydrophilic) e.g. OH group
• Non-polar (hydrophobic) e.g. methyl group

Question 5

How are amino acids joined together to form a protein?

Answer 5

Amino acid monomers undergo a condensation/dehydration reaction and a peptide bond links the two amino acids together.