1 Organisation 2 Flashcards
What do enzymes do?
Control the speed of almost all chemical reactions in our bodies, mostly in the cytoplasm of our cells
It acts as a biological catalyst
What do digestive enzymes do?
Break down large, insoluble molecules into smaller, soluble ones that can be absorbed
How ads molecules absorbed during the digestive system?
They’re absorbed into the blood through the walls of the small intestine
Explain how enzymes work?
- a type of protein, protein is formed of a,ink acids which fold and coil into shapes
- enzymes fold into a shape which has an indentation called active site
- which allows a substrate to fit into it as they’re complementary
When an active site fits with a substrate what’s it called?and what have they formed?
Complementary
And form enzyme-substrate complex
How do enzymes work?
-By lowering the activation energy, which is needed for a reaction to begin
What do carbohydrate do?
Break down large carbohydrates into smaller sugars
What do protease do?
Break down protein into amino acids
What sort of enzyme is amylase?
A carbohydrase
Why does enzyme activity increase as the temperature rises?
- the substrate molecules have more kinetic energy
- the frequency of enzyme-substrate collisions increases
Where is protease produced?
Stomach, pancreas and small intestine
Where does amylase break down starch into glucose?
Mouth abs small intestine
Where is protein made?
In cell ribosomes
What does lipase do?
It breaks down lipids into (fats and oils) into fatty acids and glycerol
Where is lipase produced?
In the pancreas and small intestine
Why is the shape of an enzyme so important?
- the shape of the active site is important because it fits with 1 particular substrate, meaning each enzyme can only catalyse 1 reaction
- it also means that any condition that changes the shape of the active site can prevent the enzyme from working
What 2 things affect the shape of the active site?
Temperature and pH
Explain why increasing the temperature affects the shape of the active site?
- increasing the temperature gives molecules more kinetic energy, which increases the rate of collisions & allows the reaction to happen faster
- but if the temperature is too high, it damages the shape of the active site this is called denaturing, which stops the reaction
- a denatured enzyme is permanent?
Explain why changing the pH affects the shape of the active site?
- each enzyme has an optimum pH at which it operates
- if the solution becomes too acidic or alkaline the H+ or OH- ions change the forces that hold the active site in its specific shape
- which prevents the substrate from binding, slowing the reaction until the enzyme is denatured
Why can’t we digest fibres?
Because we don’t have the right enzymes
Why does bile emulsify fat?
To increase the surface area so enzymes work faster
What are enzymes made of?
Proteins and amino acids
What’s lost when an enzyme is denatured?
The shape of the active site
Name 2 processes catalysed by enzymes?
Photosynthesis and digestion
Give 2 reasons why starch isn’t digested in the stomach
- the stomach does make amylase
- the pH of the stomach is too low and could denature the amylase
Define fermentation
The conversion of sugar into acids occurs in yeast
What’s the use if bile in the digestive system?
- made in the liver stored in the gall bladder
- it’s alkaline to neutralise the hydrochloric acid from the stomach
- emulsifies fat into small pieces to increase its surface area
- the alkaline And large surface area increases the rate of fat breakdown by lipase
