PROTEINS Flashcards
what is proteins made up of
amino acids
what does the NH2 represent in an amino acid
amine group
what does the COOH represent in an amino acid
carboxylic group
what bond is formed in a condensation reaction between amino acids
peptide bonds
what are dipeptides
two amino acids joined together
what are polypeptides
multiple amino acids joined together
what is the structure of a primary protein
it is a straight chain of amino acids
structure of secondary protein
its is joined by hydrogen bonds when straight chain of amino acids have folded
structure of tertiary protein
3d structure when the the secondary protein has folded again causing ionic bonds disulphide bridges and more hydrogen bonds.
structure of quaternary protein
when two or more polypeptide chains have joined together held together by more ionic bonds , disulphide bridges,
how do you test for proteins
biuret test
explain the test for protein method
place biuret solution into a test tube with substance
what result do you expect to see if a protein is present
it will turn purple
what is the function of protein in relation to its structure.
it is involved in metabolic reactions. eg an enzyme has a tertiary structure which has a specific shape
what do enzymes do
they are biological catalysts which lower the activation energy.
- increase rate of reaction
list the properties of an enzyme
it has a tertiary structure so it is able to change shape
what affect does the – enzyme concentration have on the rate of reaction `
what happens after a few minutes to the ror
enzyme concentration increases the rate of reaction
- this is because there is more active sites to fit with the substrate
- over time is decreases as the substrates have all been used up and is in excess
what affect does the substrate concentration have on the rate of reaction
increases rate of reaction
- as there are more substrates to fit into the active sites.
- enzyme limiting factor- as there might not be enough active sites to fit into substrates so rate of reaction decreases.
what affect does the concentration of competitive inhibitors on the rate of reaction
it decreases rate of reaction as competitive:
- bind to active site as it has a similar substrate shape so less enzyme substrate complexes are formed so less reactions
what affect does the concentration of the non competitive inhibitors rate of reaction
non competitive:
changes the shape of active sites so less substrates can fit into it.
so less substrates will fit into the active site
what affect does the PH have on the rate of reaction
the ph. increases the rate of reaction until it has reached its optimum level
- after optimum level the rate of reaction decrees as the enzymes denature
what affect does the temperature have on the rate of reaction.
it increases as there are more kinetic energy causing more collisions
after optimum temp the rate of reaction decreases as the enzymes denature.
what is competitive and non competitive inhibitors
competitive:
- bind to active site as they have a similar substrate shape
- this causes less substrates to bind to the active site of enzymes.
non competitive:
- bind to other site of enzyme
- causes active site to change shape
- less substrates can fit into active site as there are different shapes.
