Topic 4 - Bioenergetics Flashcards
What is the definition of respiration?
the process of transferring energy fro glucose (this happens in every living cell continuously)
What happens in respiration?
Energy is transferred from the breakdown of glucose
Is respiration exothermic or endothermic?
Exothermic (energy is transferred to the surroundings)
Why do plants and animals need to respire?
to transfer energy from their food to their cells
Give 3 ways of how organisms use the energy transferred by respiration?
1) to build up larger molecules from smaller ones (proteins fro amino acids)
2) In animals, it is used to allow the muscles to contract
3) In mammals and birds, energy is used to keep body temperature steady in cooler surroundings
What is the metabolism of a cell or body?
The sum of all the reactions that happen in a cell or body
What controls chemical reactions in cells?
enzymes
- these reactions are linked to form bigger reactions
What two things can happen in reactions in cells?
- larger molecules are made from smaller ones
- larger molecules are broken into smaller ones
Give two examples of larger molecules breaking into smaller ones
- glucose is broken down in respiration (energy transferred powers the reactions in the body that make molecules)
- excess protein is broken down to produce urea - this is excreted in urine
Give 3 examples of larger molecules being made from smaller one?
- small glucose molecules are joined to form starch, glycogen and cellulose
- lipid molecules are each made from one molecule of glycerol + 3 fatty acids
- glucose is combined with nitrate ions to make amino acids (these then make proteins)
What is starch?
a storage molecule in plant cells
What is glycogen?
a storage molecule in animal cells
What is cellulose?
a component of plant cell walls
What is aerobic respiration?
respiration using oxygen (this is the most efficient way to transfer energy from glucose) - this happens all the time in animals and plants
Where does aerobic respiration take place?
in the mitochondria
