1. Metabolic Pathways (a)
Revise your knowledge on the properties of enzymes
State what is meant by metabolism and metabolic pathway
State what is meant by an anabolic pathway (and make reference to energy)
State what is meant by a biosynthetic reaction
State what is meant by an catabolic pathway (and make reference to energy)
Give an example of an anabolic and catabolic reaction

3. What is Activation Energy?
Video
What is Activation Energy?
Reaction Rate

4. Properties of enzymes…
Enzymes are found in all living cells
Enzymes speed up the rate of a reaction
Enzymes remain unchanged after the reaction, so can be re-used
Enzymes lower the activation energy required for a chemical reaction to proceed
The molecule which an enzyme acts on is known as a substrate

5. You now need to learn this in HIGHER level language…
What is metabolism?
You may have heard metabolism as the term used to describe the sum of all chemical reactions in the body
You now need to learn this in HIGHER level language…

6. What is metabolism?
Metabolism encompasses the integrated and controlled pathways of enzyme-catalysed reactions within a cell.

7. Metabolic Pathways
Metabolic pathways refer to reactions in the body that are linked together.
Metabolic pathways can have reversible and irreversible steps.
Alternative metabolic pathways may exist that can bypass steps in a pathway.

8. What are the two types of enzyme-catalysed reaction?
Anabolic reactions involve biosynthetic reactions (synthesis). This refers to the build up of substrates.
Catabolic reactions involve the breakdown of substrates.

9. What are the two types of enzyme-catalysed reaction?

10. Biosynthetic reactions
Example: GPS glucose-1-phosphate phosphorylase starch This reaction requires the input of energy to proceed (anabolic reaction).

11. Breakdown reactions Example: SAM and HPCOW starch amylase maltose
Hydrogen Peroxide catalase water + oxygen
This reaction releases energy (catabolic reaction).