B3 - Living Together - Food Ecosystems Flashcards
Enzymes
living things produce enzymes which act as biological catalysts. Reduces the need for higher temperature and speeds up useful chemical reactions in body
lock and key model
substrate: molecule changed in the reaction
Every enzyme has an active site; the part where it joins on to the substrate to catalyse.
Enzymes have a high specificity, so the sub needs to fit like a lock and key
Things that affect the rate of reaction (enzymes)
temperature: higher temp increases rate as the sub and enz have more energy + optimum temp
pH: if pH is too low/high, it interferes the bonding holding the enzyme + optimum pH
The higher the substrate concentration, the faster the reaction
photosynthesis
Energy from the sun is used to make glucose. Some of it is used for cellular respiration/ stored/ growth.
endothermic
which subcellular structure does photosynthesis occur and how?
Chloroplasts; contains enzymes which catalyse reactions and chlorophyll which absorbs light energy
Equation for photosynthesis?
carbon dioxide + water →glucose + oxygen
6CO2+6H2O→C6H12O6+6O2
starch test which shows if photosynthesis is taking place
oxygen production shows the rate of photosynthesis
limiting factors of photosynthesis
- light slows down the rate of photosynthesis, will go straight when at highest point due to another limiting factor
- co2 same as light will increase but wont coz of limiting factor
- temp enzymes could get denatured after optimum temp 45
diffusion
net overall movement of particles from an area of higher concentration to an area of lower concentration
osmosis
the net movement of water molecules across a partially permeable membrane from a region of higher water concentration to a region of lower water concen….
active transport
movement of particles across a membrane against a concentration gradient, using energy transferred during respiration
