B5 - Enzymes Flashcards
Where are enzymes located? [1]
Inside cells
What are enzymes? [3]
Proteins that are involved in all metabolic reactions, where they function as biological catalysts
Enzymes have a particular _____ [1]
Shape
What is the special region in an enzyme called? [1]
Active site
What does an active site have? [2]
Specific shape that fits with other molecules
Where does the chemical reaction take place in an enzyme? [1]
Active site
What is the molecule(s) that fit into the active site called? [1]
Substrate
What is a catalyst? [2]
A substance that speeds up a reaction without being used up
What is a substrate? [2]
A substance acted on by an enzyme. The substrate molecules become product molecules
What is an enzyme-substrate complex? [2]
When a substrate molecule fits into the active site
What does the lock in a lock and key model represent? [1]
Enzyme
What does the screw represent in a screwdriver and screw model? [1]
Substrate
What must happen for an enzyme to work? [2]
- come into physical contact with its substrate
- have an active site which fits the substrate
What does increasing temperature increase? [1]
Kinetic energy of the molecules
What is an optimum temperature? [2]
When the rate of reaction is highest
What does the temperature rise cause amino acids to do? [1]
It causes the amino acid chains in the protein to unravel
What does the temperature rise result in? [1]
The active site changing shape
Why does the rate of reaction decrease after the active site changes shape? [1]
The substrate can no longer bind
When does the reaction stop? [1]
When all the enzymes are denatured
Is enzymes being denatured permanent or temporary? [1]
Permanent
What is pH the measure of? [1]
acidity
pH 2 is very ______ and is found in the _______ [2]
- acidic
- stomach
pH 7 is _______ and is found in the _____ [2]
- neutral
- mouth
What is the saliva enzyme? [1]
Amylase
What does each enzyme have its own of? [1]
Optimum pH
What happens to the enzyme if the pH is above or below the optimum pH? [2]
- enzyme is denatured
- active site changes shape
What type of reactions do enzymes speed up? [2]
- break up larger molecules to smaller ones
- put smaller molecules to make bigger molecules
What does an increased kinetic energy in molecules mean? [2]
- molecules move around more rapidly
- they collide more
pH 9 is ________ and is found in the _____ _________ [2]
- alkaline
- small intestine
An active site is _____________ to it’s substrate [1]
complementary
What happens to the rate of an enzyme-controlled reaction when the temperature increases? [1]
INCREASES
