Organisms and Energy
Biology: AQA GCSE Higher, topic 4.2.1
Energy
Organisms need energy for many reasons:
Growth
- To make larger molecules from smaller molecules. For example:
- Glucose molecules can be joined together to produce starch (in plants).
- Proteins can be made from amino acids in plants and animals.
Contraction
- To contract the muscles of animals, allowing them to move.
Homeostasis
- To keep the body temperature of warm-blooded animals (mammals and birds) relatively constant.
Test yourself on Organisms and Energy
What molecule can be joined together to produce starch in plants?
A bird fluffs up its feathers to trap heat and stop its body losing warmth. Which reason for needing energy does this best represent?
A seedling grows taller as it produces new cells and tissues. Which reason for needing energy does this best represent?
What happens to smaller molecules when organisms use energy for growth?