3.3.13 Amino acids, proteins and DNA Flashcards
What are the functional groups of a zwitterion
NH3+ and COO-
Amino acid in acidic solution functional groups
COOH and NH3+
Amino acid in alkaline solution functional groups
COO- and NH2
Protein definition
Sequences of amino acids joined by peptide bonds
Primary structure of a protein
A single polypeptide chain of amino acids
Secondary structure of a protein
Folding due to hydrogen bonds resulting in either an a helix or B pleated sheet
Tertiary structure of a protein
3D folding of a protein due to disulfide bdirges, ionic bonds and hydrogen bonds
How are amino acids located on a chromatagram
Ninhydrin or UV light
Then calculate Rf values
How are amino acids identified
Thin Layer Chromatography
What are enzymes
Proteins with a specific tertiary structure and a stereospecific active site. They can act asbological catalysts
How do enzyme inhibitors work
By blocking the active site
What is a nucleotide made up of
A phosphate ion bonded to 2-deoxyribose which is in turn bonded to one of the four bases adenine, cytosine, guanine and thymine.
Structure of DNA
Double helix made up of two complimentary strands. Both strands are polymers of nucleotides.
How do Guanine and Cytosine form hydrogen bonds
N-H and C=O bonds are polar and the O and N both have lone pairs of electron, so there is a strong force of attraction between these groups and hydrogens
Cisplatin structure
Cl
l
Cl - Pt - NH3
l
NH3
How does cisplatin prevent DNA replication
By a ligand replacement reaction with DNA in which a bond is formed between platinum and a nitrogen atom on guanine.
Negatives of cisplatin
Also affects human cells such as hair, so must be used in small doses
