enzymes Flashcards
What are the 5 variables that affect enzymes?
Changes in pH Changes in temperature Changes in enzyme concentration Changes in substrate concentration Presence of inhibitors
What is the effect of pH on enzymes?
Enzymes work best at a specific pH called the optimum pH. We can measure how well an enzyme works in different pHs when we are looking for the optimum pH
What is the effect of temperature on enzymes?
Enzymes work at their best as the temperature increases until the optimum temperature. Once the temperature reaches above the optimum, it destroys the shape of the enzyme so the substrate cannot fit. The enzyme has now denatured.
What is the effect of inhibitors on enzymes?
They decrease the rate of enzyme catalysed reactions. They can either be competitive or non-competitive.
What is a competitive inhibitor?
It fits in the enzyme where the substrate goes
What is a non-competitive inhibitor?
It changes the shape of the enzyme so the substrate can no longer fit.
What is the food test for starch and describe the colour change?
Iodine. The colour changes from yellow/brown to blue/black
What is the food test for sugar and describe the colour change?
Benedicts solution. The colour changes from blue to orange/red
What is the food test for protein and describe the colour changes?
Biuret solution (or sodium hydroxide). The colour changes from blue to purple.
What is the test for fat and what happens when it is present?
We use filter paper. If fat is present the paper goes clearer/translucent.
Describe the uses of enzymes in the digestive system.
- hydrochloride acid provides the highest pH to break down the enzyme.
- the liver makes an alkaline substance called bial
- bial is stored in the gall bladder to neutralise the acid.
- the pancreas secretes pancreatic juice and there are lipids so that the food flora through the intestine easily.
- in the small intestine the small particles of food can travel through the bloodstream via diffusion and gets transported around the body to the places it needs
What is an enzyme?
An enzyme is a biological catalyst that speeds up the rate of a reaction. Enzymes are forms of proteins and they require specifically shaped substrates to fit in then and cause a reaction in an area called the active site.
What is the substrate with carbohydrates and what do they form?
Carbohydrase, glucose
What is the substrate for lipids and what do they form?
Lipase, glycerol and fatty acids
what is the substrate for protein and what do they form?
Protease, amino acids
