Unit 2: Biology

Catabolism

• The breakdown of complex molecules into simpler ones
• This results in the release of energy 
• All living things obtain energy by a type of catabolism called respiration
• This uses oxygen to break down glucose sugar into carbon dioxide, water and energy

Anabolism

• This is the opposite of catabolism
• Anabolism uses energy from catabolism to build up complex molecules from simpler ones

Enzyme 
Substance which splits large molecules into small ones 

Active Site
Space where the reaction happens 

Catalyst
Speeds up reactions enzymes are very speciific about which reactions they catalyze

Substrate
Chemical that enzymes react with 

Specific
Enzymes only react with one substrate

Activation Energy 
Reactions happen when particles collide. The minimum energy needed for a reaction is activation energy. 

In the same way that a key fits a lock, so a substrate it thought to fit into an enzyme's active site. The enzyme is the lock and the reactant is the key.

GLUCOSE + OXYGEN -> CARBON DIOXIDE + WATER (+ENERGY)

• Aerobic respiration is one of the most important enzyme controlled reactions in living organisms
• It is the process by which we release energy from our food
• Respiration occurs within mitochondria
• These are tiny organelles are found within the cells 

• Mouth
• Oesophagus
• Stomach
• Small Intestine
• Large Intestine
• Rectum
• Anus

Amylase (carbohydrates)

breaks down
breaks it into
where it is made
where it acts