what do enzymes do?
they play an essential part in all metabolic reactions.
what are enzymes?
they’re biological catalysts - speeds up reactions in a cell.
what does the binding
of a substrate to the active site depend on?
- the shape of active site
- bond formation
why is the shape of the active site important?
the shape of the active site is complimentary to the shape of substrate and this is required for chemical reactions to take place.
what is the effect of temperature on enzyme activity?
the rate of chemical reactions increases as the temperature increases.
however the optimum temperature is 40oc so if the temperature exceeds this, the bonds weaken which denatures the active site so substances can’t bind.
what happens to the enzyme when the temperature increases too much?
it denatures. bonds weaken and shape of the protein and active shape change so the substrate can’t fit.
it cant go back to its original shape.
what are intracellular reactions?
reactions in the cell.
what is the lock and key hypothesis?
a substrate is complimentary to the active site of an enzyme - the active site is only complimentary to certain substrates.
what is reducing activation energy in regards to enzymes?
the way in which all catalysts increase rate of reactions.
this is due to induced fit - the active site of an enzyme can change shape and mould around the substrate, it doesn’t therefore denature.
what is the effect of enzyme concentration on rate of reaction?
as you increase the enzyme concentration, the rate of reaction increases and DOESNT DENATURE.
what are examples of enzymes?
- proteases
- carbohydrases
- lipase
what do proteases do? give examples.
they break down proteins by converting them into smaller polypeptides, dipeptides and/or amino acids.
e.g. trypsin aids digestion in the small intestine.
what do carbohydrases do? give examples.
they break down carbohydrates by converting long chains of polysaccharides into disaccharides or monosaccharides.
e.g. amylase turns starch into sugars.
what do lipase do?
they break down fats in food by converting triglycerides into glycerol and fatty acids.
they are absorbed in intestines.
