B3.4 catalysts and enzymes

Question 1

Define each of the following terms

a catalyst

Answer 1

substance that speeds up a chemical reaction but is not used up or involved in the reaction and can be used many times over

Question 2

Define each of the following terms

a enzyme

Answer 2

large protein molecule that acts as biological catalyst

Question 3

Define each of the following terms

the active site of an enzyme

Answer 3

area in structure of enzyme with unique shape that binds to specific
substrate

Question 4

Explain what enzymes are made of

Answer 4

protein

Question 5

Explain in detail how enzyme act to speed up reactions in your body

Answer 5

Substrate of reaction to be catalysed fits into active site of enzyme like
a lock and key.
Once in place, enzyme and substrate bind together.
Reaction takes place rapidly
and products are released from active site.
Enzyme then ready to catalyse another reaction.

Question 6

give three clear examples of the type of reactions that are catalysed by enzymes

Answer 6

building large molecules from smaller ones
changing one molecule into another
breaking down large insoluble molecules into smaller soluble ones

Question 7

Explain how enzymes are important in the metabolism of a cell or organism

Answer 7

Chemical reactions needed for life could not take place fast enough
without enzymes to speed them up.
Each reaction controlled by specific enzyme
so that many metabolic reactions can take place in same small space
without interfering with one another.
Enzymes enable cells to perform basic reactions (e.g., respiration)
and specific reactions to carry out particular functions
simultaneously.