AQA B4 Bioenergetics

What is photosynthesis?

Reaction in which plants convert carbon dioxide and water into oxygen and glucose using energy from the sun.

What is the word equation for photosynthesis?

Carbon dioxide + water -> Glucose + oxygen

What is the balanced symbol equation for photosynthesis?

6CO2 + 6H2O -> C6H12O6 + 6O2

Is photosynthesis an endothermic or exothermic reaction?

Photosythesis is an endothermic reaction because it takes in energy from the environment (sunlight).

What does a plant use the glucose from photosynthesis for?

Respiration

How does a plant store excess glucose?

Starch - such as starch grains and storage organs.

What else does a plant need in addition to glucose to make proteins?

Nitrate ions and other mineral ions

What is respiration?

reaction in which mitochondria (in cells) react glucose and oxygen producing carbon dioxide and water transferring energy

What is the word equation for aerobic respiration?

oxygen + glucose -> water + carbon dioxide

What is the balanced symbol equation for aerobic respiration?

6O2 + C6H12O6 -> 6H2O + 6CO2

Is respiration an endothermic or exothermic reaction?

Respiration is an exothermic reaction because it releases energy from glucose.

What are the differences between aerobic and anaerobic respiration?

Aerobic respiration requires oxygen and transfers more energy.

Why do organisms need energy?

synthesis of new molecules and breakdown of large molecules. Muscle contraction, maintaining body temperature, plants need energy for moving minerals.

What is the word equation for anaerobic respiration in muscles?

Glucose -> lactic acid

What are the productions of anaerobic respiration in plant and yeast cells?

Carbon Dioxide + Alcohol

How do we use the anaerobic respiration of yeast in the food and drink industry?

alcohol production, bread production.

How does the heart rate change during exercise?

Increases

How does the breathing rate change during exercise?

Increases

Why do these changes to heart and breathing rates happen when we exercise?

Due to the increased demand for energy. Cells need more oxygen and glucose.

What is oxygen debt?

The amount of oxygen that is needed to break down lactic acid.

What is metabolism?

The sum of all the reactions in the body.

Which processes occur in the cells?

Enzyme controlled processes such as respiration, production of proteins, breakdown of proteins.

What factors affect the rate of photosynthesis?

light intensity, carbon dioxide concentration and temperature

What are the limiting factors of photosynthesis?

light intensity, carbon dioxide concentration and temperature

How can you measure the rate of photosynthesis?

by measuring the amount of oxygen given off during the reaction