Biology-Living Organisms?

Question

why do living organisms need the following substances: protein, carbohydrates, lipids.
thankyou

Answer 1

Protein - growth and repair (makes other proteins such as muscle, enzymes, hormones etc)
Carbohydrates - for energy (made by using them in respiration)
Lipids - store of energy and insulation in some animals

Answer 2

Proteins:
1. build parts of living things like hair, horns, fingernails, ...
2. are important components of all membranes
3. carry oxygen
4. convey immunity
5. are enzymes that catalyze chemical reactions
6. contract muscles

Carbohydrates
1. store and provide energy
2. cellulose makes up cell walls in plants and algae

Lipids
1. store energy
2. provide insulation and padding
3. make protective coatings
4. make up the bilayer of membranes

You need a fourth group: the nuclei acids which have the code for how to build the proteins.