B4 Flashcards
what is photosynthesis?
where does it take place?
what type of reaction is it?
what is the word equation?
what is the symbol equation?
-Photosynthesis uses energy to change carbon dioxide and water into glucose and oxygen
-It takes place in chloroplasts in green plant cells-contain pigments like chlorophyll that absorb light
-Energy is transferred to the chloroplasts from the environment by light
-Endothermic reaction-means energy is transferred from the environment in the process
word equation:
carbon dioxide+water—-light–glucose+oxygen
symbol equation
6co2+6h20—–light—–c6h12o6+6o2
what are 5 main ways plant use glucose?
-For respiration-transfers energy from glucose and converts the rest of the glucose to other useful substances
-Making cellulose-glucose is converted into cellulose for making strong plant cell walls
-Making amino acids-glucose is combined with nitrate ions to make amino acids which are made into proteins
-Stored as oils and fats-glucose is turned into lipids
what are three things the rate of photosynthesis is affected by?
what do these 3 factors become?
which factor limiting at a particular time depends on environmental conditions?
how can chlorophyll be a limiting factor?
-Affected by light intensity,concentration of co2 and temperature
-They become the limiting factor this means it stops photosynthesis from happening any faster
Factor limiting at a particular time depends on environmental conditions:
-at night light is the limiting factor
-in winter it’s often the temperature
-if it’s warm enough and bright enough amount of co2 is usually limiting
-Chlorophyll can be a limited factor the amount of chlorophyll in a plant can be affected by a disease (tmv) or enivrionmental stress such as lack of nutrients.These factors can cause chloroplasts to become damaged or not to make enough chlorophyll.The rate of photosynthesis is reduced because they can’t absorb as much light
Light:
how does light affect the rate of photosynthesis?
what happens as the light level is raised?
what happens if the light intensity increases?
how can we change the light intensity in the lab?
what happens if we just plot the rate of photosynthesis against..?
how to get a graph like the one (flashcard)?
Carbon dioxide:
what does carbon dioxide do in photosynthesis?
what does amount of co2 do?
what happens after graph flattens out?
what is now limiting factor?
Not enough light slows down the rate of photosynthesis
-Light provides energy needed for photosynthesis
-As light level is raised rate of photosynthesis increases-only at a certain point
-As the light intensity increases rate will no longer increase this is because it will be either the temperature or c02 which now the limiting factor not light
-In the lab you can change the light intensity by moving the light closer or further away from the plant
-If you just plot the rate of photosynthesis against the ‘distance of lamp from the plant’ you get a weird shaped graph
-To get a graph (flashcard) you either need to measure light intenstiy at the plant using a light meter or maths
Carbon dioxide:
-Co2 is one of the raw materials needed for photosynthesis
-Amount of co2 will increase rate of photosynthesis up to a point.After this graph flattens out- amount of co2 increases rate no longer increases which makes co2 no longer limiting factor
-As light and co2 are in plentiful supply factor limiting photosynthesis must be temperature
Temperature:
what happens if the temperature is the limiting factor?
what happens if the plant gets to hot?
what degree does it happen about?
-If the temperature is the limiting facotr it’s because it’s too low- enzymes needed for photosynthesis work more slowly at low temperatures
-If the plant gets too hot enzyme it needs for photosynthesis and it’s other reaction will be damaged
-Happens at about 45 celcius
