Respiration

Respiration in cells can take place aerobically or anaerobically. The energy which is released is used in a variety of ways; the human body needs to react to the increased demand for energy during exercise.

RESPIRATION =  the process of transferring energy from food molecules in every living cell. 

Aerobic respiration - USES OXYGEN

Anaerobic respiration - DOESN'T USE OXYGEN

All chemical reactions inside cells are controlled by enzymes.

• Glucose reacts with oxygen, producing carbon dioxide and water as waste products
• WORD EQUATION 

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

Aerobic respiration takes place in mitochondria.

Energy released is used for:

• building larger molecules from smaller ones
• muscle contraction to allow movement
• maintenance of a constant body temperature.

In aerobic respiration, glucose is broken down; in anaerobc respiration the breakdown of glucose can't be completed. As a result lactic acid is made instead.

Getting rid of lactic acid

• lactic acid builds up in muscles and in blood;
• oxygen is used to brake down the lactic acid to then release carbon dioxide and water
• the oxygen needed to break down the lactic acid is called oxygen debt

Much less energy is provided from anaerobic respiration and thus lots of lactic acid is produced to get enough energy. 

1) Aerobic uses oxygen, anaerobic doesn't

2) aerobic produces lots of energy, anaerobic doesn't

3) anaerobic produce lactic acid, aerobic doesn't