Biology Bioenergetics YR9 EOY

define the term catalyst

something that increases the rate of a chemical reaction without being used up/changed

define the term metabolic reaction

chemical reactions in cells/organisms

define metabolism

the sum of all metabolic reactions in cells/organisms

give 2 examples of metabolic reactions

respiration, protein synthesis

use lock and key theory to describe how metabolic reactions are controlled by enzymes

- enzyme (lock) and substrate (key)
- substrate fits into enzyme's active site
- enzyme helps reaction happen (breaking/joining molecules)
- then product is released and enzyme can be used again

explain why enzymes are known as biological catalysts

they speed up chemical reactions

why are enzymes so important to living things?

they speed up chemical reactions - without, the body's reactions would be too slow to survive

they help with digestion, respiration, protein synthesis - all vital processes

why do enzymes have 'preferred' conditions

they have a specific shape only working in certain environments. they need right shape to fit into substrate (lock & key)

where does respiration in cells occur

mitochondria

word equation for aerobic respiration

oxygen + glucose -> CO2 + H2O + energy

word equation for anaerobic respiration

animals: glucose -> lactic acid

plants/fungi: glucose -> CO2 + ethanol

why is respiration different to breathing

breathing brings oxygen into the body. respiration uses that oxygen to create energy

what is connection with anaerobic respiration and acidity in yoghurt

Anaerobic respiration by bacteria produces lactic acid, which makes yoghurt sour and thick

write word equation for photosynthesis

carbon dioxide+ water -> oxygen + glucose

write symbol equation for photosynthesis

6CO2 + H2O -> C6H12O6 + 6O2