GCSE Biology – Photosynthesis, Respiration and Enzymes

Photosynthesis and respiration are two of the key topics within the GCSE Biology and combined Science specifications. From the photosynthesis equation, both word and symbol, to aerobic respiration and enzymes, this topic is tricky and contains a wealth of information you have to learn. You will look at respiration in the context of exercise and how the human body responds to different intensities of exercise and how this impacts on the use of glucose.

Photosynthesis, Respiration and Enzymes Revision

What is aerobic respiration?

– Aerobic respiration is the breakdown of glucose using oxygen. This process releases energy, water and carbon dioxide. For your GCSE Biology exam you can simply write the word equation below as a definition.

Glucose + Oxygen -> Carbon Dioxide + Water + Energy

What is the difference between aerobic respiration and anaerobic respiration?

– Aerobic respiration uses oxygen and anaerobic doesn’t. Anaerobic results in the partial break down of glucose.

What is an enzyme?

– It is a protein which is a biological catalyst. This means it speeds up reactions without being used up. Enzymes play important roles in all living organisms.

What factors affect metabolism?

– Both genetic and lifestyle factors can impact on metabolism. In your GCSE Biology exam you may be asked to list some specific examples such as age, weight, gender along with lifestyle choices such as exercise.

What do I need to know about photosynthesis for my GCSE Biology exam?

– You will need to know the word and symbol equation as well as the factors the affect photosynthesis.

What are the factors that affect the rate of photosynthesis?

– Temperature, light intensity and carbon dioxide all impact on the rate of photosynthesis. The most common incorrect exam answer is water.

What are the uses of Glucose in animals and humans?

– We store glucose as glycogen. We use it in respiration to release energy to make proteins and complete other cellular processes. Glucose is also used in muscle contraction as well as active transport.