BRAINCAKEAmino Acids, Proteins and DNA
Revision notes for Amino Acids, Proteins and DNA in AQA Chemistry (7405). Read the start of any lesson here, then sign in free for the whole lesson, the R.E.C.I.P.E. recall steps and the quiz.
- Amino AcidsAn amino acid contains both an amine group, -NH2, and a carboxylic acid group, -COOH.
- ZwitterionsIn an amino acid the -COOH group is acidic and the -NH2 group is basic.
- Acid-Base Properties of Amino AcidsAmino acids are amphoteric: because they contain both an acidic group (-COOH) and a basic group (-NH2), they react with both acids and bases.
- Peptide LinksAmino acids join together by condensation reactions.
- Hydrolysis of ProteinsHydrolysis is the reverse of the condensation reaction that forms peptide links.
- Primary Structure of ProteinsThe primary structure of a protein is the sequence of amino acids in its polypeptide chain(s), joined by peptide links.
- Secondary Structure of ProteinsThe secondary structure is the way a polypeptide chain coils or folds in regular patterns, held in place by hydrogen bonds between peptide links.
- Tertiary Structure of ProteinsThe tertiary structure is the overall three-dimensional shape formed when the coiled or folded chain folds further.
- Enzymes and Stereospecific Active SitesEnzymes are proteins that act as biological catalysts.
- Drug Action and Enzyme InhibitorsMany drugs work as enzyme inhibitors.
- Structure of DNA NucleotidesDNA (deoxyribonucleic acid) is a polymer made of monomers called nucleotides.
- Hydrogen Bonding between DNA BasesDNA consists of two strands twisted around each other to form a double helix.
- CisplatinCisplatin is an anticancer drug.
- How Cisplatin Prevents DNA ReplicationCisplatin kills cancer cells by binding to their DNA and stopping it from being copied.
- Side Effects of CisplatinCisplatin cannot tell the difference between the DNA of cancer cells and the DNA of healthy cells.