B5 - Plant nutrition Flashcards
define photosynthesis
Is the process by which plants manufacture carbohydrates from raw materials using light energy.
where does photosynthesis occur?
Photosynthesis occurs in the leaves of the plant, specifically in the chloroplasts of a leaf
what is the word equation for photosynthesis?
Carbon dioxide + Water → glucose + oxygen (in the presence of light and chlorophyll)
what is the balanced chemical formula for photosynthesis?
6CO2 + 6H2O —> C6H12O6 + 6O2
what does photosynthesis require for the reaction to take place?
light and chlorophyll
what type of reaction is photosynthesis and how?
Endothermic reaction: Energy is transferred from the environment to chloroplasts by light endothermic reaction
how do plants use glucose?
Cellular respiration: breaks glucose apart to release energy. Photosynthesis traps the sun’s light energy in glucose molecules and other cells around the plant can break the glucose apart again and use that energy when they need it
Combining glucose molecules to form larger molecules of carbohydrates. Can be combined to make cellulose which is a complex carbohydrate that plants use to strengthen their cell walls. Glucose molecules can also be combined to form starch which is another complex carbohydrate and is used as a long term storage for glucose because it is more compact so a lot more glucose can fit within a cell and it is insoluble which means that it won’t draw water into the cell through osmosis like glucose would
in what forms is glucose stored and what are the differences between the forms?
cellulose and starch
cellulose is used to strengthen the plants cell walls
starch is used as a long term storage because it is compact so a lot more glucose can fit within a cell and it is insoluble which means that it won’t draw water into the cell through osmosis like glucose molecules would.
why do plants need good stores of starch?
Most plant cells need good stores of starch so it can be broken down into glucose later when photosynthesis is not occurring as much as during the night or in the winter.
how is the magnesium deficiency managed?
Making chlorophyll: specialised soil containing magnesium can be used to produce chlorophyll and used for plants that lack chlorophyll which is shown by the colour of their leaves.
how is the nitrogen deficiency managed?
Making amino acids: glucose molecules can be combined with nitrate ions from the soil and the amino acids can combine to form protein. Protein can then be used to help the plant grow such as plants with stunted growth which are small plants that grow slowly.
what are factors that affect the rate of photosynthesis?
light, carbon dioxide concentration and temperature
how does the amount of light affect the rate of photosynthesis?
- Without light, a plant is unable to photosynthesise as it is a required factor.
- As the light intensity increases, the rate of photosynthesis will increase until it reaches a maximum point
- From the maximum point, the rate of photosynthesis will remain constant.
how does the amount of carbon dioxide concentration affect the rate of photosynthesis?
- Photosynthesis is unable to occur without a sufficient amount of carbon dioxide
- As the amount of carbon dioxide concentration increases the rate of photosynthesis increases until a maximum point is reached
- From the maximum point onwards, the rate of photosynthesis remains constant.
how does the temperature affect the rate of photosynthesis?
- The graph is an upside down U.
- As temperature increases, the rate of photosynthesis will increase until it reaches an optimum temperature.
- Plants are unable to photosynthesise if it gets too hot (40 degrees is around the optimum temperature). After this the enzymes will denature causing the rate of photosynthesis to decrease.
