Biology B2/ENZYMES

?
What are Enzymes?
Catalysts produced by living things. They are proteins
1 of 12
What is a catalyst?
A substance which increases the speed of a reaction without being changed or used up during it.
2 of 12
3 ways enzymes can be used?
1.) DNA replication- enzymes help copy DNA before division 2.)protein synthesis- enzymes hold amino acids in place and form bonds between them 3.)digestion- enzymes are secreted into the gut to digest food molecules
3 of 12
What do chemical reactions usually involve?
things either splitting or joining
4 of 12
What is a substrate?
the molecule changed in the reaction
5 of 12
What is an active site?
the part where the enzyme joins on to its substrate to catalyse the reaction
6 of 12
What is the lock and key mechanism?
for an enzyme to work, the substrate has to fit into the active site.
7 of 12
How do you measure the rate of an enzyme controlled reaction?
1.) use amylase as the enzyme and starch as the substrate 2.) time how long it takes for the starch to disappear 3.)to do this- regularly drop starch/amylase mix onto iodine solution 4.) record colour change. blue/black=starch & record time when oran
8 of 12
What happens to an enzyme when temperature increases?
the rate will increase AT FIRST due to more energy. If it gets too hot the enzyme's bonds will break- enzyme loses shape and substrate won't fit in active site therefore can't catalyse. Enzyme becomes denatured
9 of 12
What happens to an enzyme when pH isn't optimum
it will interfere with bonds, this changes the active site's shape and the enzyme will become denatured
10 of 12
what is pepsin and what is its optimum pH?
an enzyme used to break down proteins in the stomach. Works best at pH2
11 of 12
How does substrate concentration affect rate of reaction?
The higher, the faster and it's more likely the enzyme will meet the substrate. However if there are too many substrates the enzymes can't cope and adding more makes no difference.
12 of 12

Other cards in this set

Card 2

Front

What is a catalyst?

Back

A substance which increases the speed of a reaction without being changed or used up during it.

Card 3

Front

3 ways enzymes can be used?

Back

Preview of the front of card 3

Card 4

Front

What do chemical reactions usually involve?

Back

Preview of the front of card 4

Card 5

Front

What is a substrate?

Back

Preview of the front of card 5
View more cards

Comments

No comments have yet been made

Similar Biology resources:

See all Biology resources »See all Enzymes resources »