biological molecules Flashcards
what are proteins
sequences of amino acid joined by peptide linkages formed from condensation reactions
why are hydrogen and sulphur bonding important in proteins
the hydrogen bonds help to stabilise both secondary and tertiary structure, the sulphur bonding are only important when amino acid cysteine is part of the protein structure
describe the structure of protein
there are 3 levels of protein, primary is the sequence of amino acids in the polypeptide chains, secondary is the way the amino acid interact with each other to form alpha helix or beta pleated sheets, tertiary is the 3d structure into which alpha helix and beta pleated sheets are folded
what are enzymes
proteins are biological catalyst
how do enzymes act as a catalyst
they have a concept of stereospecific active site that binds to a substrate molecules, each enzyme has an active site that is 3d tertiary protein structure of enzymes and is responsible for the catalytic activity.
what does the lock and ket theory suggest
it states that the substrate must fit perfectly in order for the reaction to take place, the wrong stereoisomer will not be catalysed
what are enzyme inhibitors
they have a similar shape to the substrate and prevent the substrate from binding to the enzyme
what is the structure of deoxyribose acid
phosphate group, deoxyribose pentose sugar and nitrogenous organic base
how is a sugar phosphate polymer chain
single strand of dna is a polymer of nucleotides linked by phosphodiester bond between phosphate group of one nucleotide linked by covalent bonds between phosphate group of 1 nucleotides and deoxyribose of another nucleotide
what is pt complex cisplatin used as
as an anti cancer drug
what is the role of cisplatin
prevents dna replication in cancer cells by ligand replacement reaction with dna in which bond is formed between platinum and nitrogen atom
how does cisplatin stop dna replication
the dna strands are kinked so they can’t unravel properly to replication
what are the side effects of cisplatin
can also bind to healthy cells, it is used as the advantages outweigh the disadvantages
