Enzymes

define the term catalyst

something that speeds up the rate of a reaction

define the term metabolic

a chemical reaction within a cell

enzymes are

biological catalysts

what do enzymes do?

speed up rate of reaction

lower activation energy

react with a substrate

what are enzymes made out of?

proteins

name three functions of an enzyme

respiration, photosynthesis, washing powder

why are enzymes important?

without them reactions would be too slow to support life

where is pepsin found?

stomach

where is amylase found?

saliva/mouth

name the class of enzyme that breaks down carbohydrates and give the product of this reaction

carbohydrases, produces sugars

name the enzyme that breaks down starch and give the product of this reaction

amylase, produces maltose

name the enzyme that breaks down maltose and give the product of this reaction

maltase, produces glucose

name the class of enzyme that breaks down protein and give the product of this reaction

proteases, produces amino acids

name the class of enzyme that breaks down lipids (fats) and give the product of this reaction

lipases, produces glycerol and fatty acids

where does enzyme activity take place

active site

name the first model of enzyme action.

lock and key

how many different types of substrate molecules can most enzymes react with?

one

to help the substrate bind to the active site, what happens?

enzyme slightly changes its shape to best fit the substrate

name the model of enzyme action where the enzyme alters its shape to fit the substrate.

induced fit model

define the term optimum conditions

best conditions for maximum enzyme efficiency

name the environmental conditions that play a role in enzyme activity.

pH and temperature

what happens when conditions are less than optimal for enzymes?

rate of reaction slows

why does rate of reaction slow in less than optimal conditions?

enzyme loses shape (denatures)

define the term denaturation

the loss of the shape of the active site. Substrate is no longer complementary and cannot bind.

explain why enzyme activity increases up to a point (optimum temperature), then decreases.

as temperature increases, there is more kinetic energy therefore more collisions between active sites and substrates. At … (insert whatever number is on the graph) is the optimum temperature. As we increase temperature further, the enzyme denatures. This is because the hydrogen bonds break and the shape of the active site is lost. The substrate is no longer complementary and cannot bind.

when a substrate binds to the active site, what is formed?

enzyme-substrate complex

explain why rate of reaction decreases at extreme pH’s.

at both extremes of pH, enzymes denature. This is because hydrogen bonds are broken. This means that the shape has changed and the substrate will no longer be complementary and cannot bind.

what does pepsin do and where is it found?

breaks down proteins to peptides, produced in stomach wall, acts in the stomach

what does trypsin do and where is it found?

breaks down proteins to peptides. Produced in pancreas, acts in the small intestine

what do peptidases do and where is it found?

breaks down peptides into amino acid. Produced in wall of small intestine, acts in small intestine

what does amylase do and where can it be found?

breaks down starch into maltose. Produced in salivary glands/pancreas, acts in mouth/small intestine

what does maltase do and where is it found?

breaks down maltose into glucose. Produced in wall of small intestine, acts in small intestine

what does lipase do and where is it found?

breaks down lipids into glycerol and fatty acids. Produced in the pancreas, acts in the small intestine.