enzymes- 1.4

what are enzymes

• proteins

• biological catalysts

• speed up chemical reactions in all living things but don’t get used up

the 2 types of enzymes

• intrcellular

• extracellular

intercellular enzymes

found inside cells (eg respiration and photosynthesis)

extracellular enzymes

found outside cells (eg digestive enzymes that work in the gut lumen)

what enzyme turns carbohydrates into simple sugars

carbohydrases

what enzyme converts fats/lipids into fatty acids and glycerol

lipases

what enzyme converts proteins into amino acids

protease

what is carbohydrase

an enzyme that turns carbohydrates into simple sugars (eg amylase converts start into glucose)

what is lipases

an enzyme that converts fats/lipids into fatty acids and glycerol

what is protease

an enzyme that converts proteins into amino acids

what is it called when an enzyme and a substrate molecule collide

substrate complex

what is the spot where the substrate molecules collide to

active site

key things in an enzyme question

• enzymes are specific

• based off lock and key model

• substrate and active site are complementary

• form an enzyme substrate complex

• products are formed

• enzyme can be used again

what causes the effect of enzymes

• pH level

• temperature

• enzyme concentration

• inhibitors

why must the pH be correct

• if it’s too alkaline or acidic the activity of the enzyme is reduced because the active site has changed and now is denatured

the effect of temperature

• increases kinetic energy

• more collisions

• high temps make the enzyme become denatured by change the active site

the effect of enzyme concentration

• faster because there is more active sites to attach to

• implies to a limit as the rate levels off when there isn’t enough substrate molecules

effect of an inhibitor

• some molecules fit loosely and don’t break down

• the occupy the site without doing anything which lead to a reduced rate of reaction

examples of commercial enzymes

• protease

• lipase

• pectinase

why are protease and lipase used in washing powders

there are thermostable and work at a range of temperatures

what is pectinase used in food and drink

helps fruit release more juice