20 May 2013

# 79 Respiration realeases energy from food

Respiration is the chemical reactions that break down  nutrient molecules in living cells to release energy.

In humans, our cells need energy (ATP) for:
  • muscle contraction
  • making protein molecules: linking together amino acids into long chains
  • cell division: to repair damaged tissues and so that we can grow
  • active transport
  • transmitting nerve impulses
  • maintenance of constant body

All this energy comes from the food we eat. Water soluble molecules are absorbed from the intestine into the blood.

The main energy–providing nutrient: glucose (contains a lot of chemical energy).

There are 2 types of respiration:

1 comment: