educake - Photosynthesis; Aerobic and anaerobic respiration and Exercise and metabolism Flashcards
photosynthesis definition
- It is the process by which green plants use sunlight energy to make their own food.
- convert carbon dioxide and water into glucose (a type of sugar) and oxygen.
- takes place inside the chloroplasts of plant cells.
What is the chemical in leaves that absorbs light?
Chlorophyll
Chlorophyll is a green pigment found inside chloroplasts in the leaves of green plants.
What sugar is formed in photosynthesis?
glucose (C₆H₁₂O₆).
What gas is needed by plants for photosynthesis?
The gas carbon dioxide, found in the atmosphere
What gas is produced by plants as a waste product of photosynthesis? Give the name, not the symbol or formula.
oxygen
What substance is tested for to see if photosynthesis has occurred in a leaf?
In order to see if photosynthesis has occurred in a green plant, a leaf can be removed from the plant and tested for the presence of starch.
When leaves are tested for starch with iodine, what colour indicates the presence of starch?
the iodine will change from orange to blue-black.
Photosynthesis is controlled by three environmental factors. name them
- light intensity
- availability of carbon
- dioxide and temperature
What name is given to a factor which is preventing any increase in photosynthesis?
limiting factor
limiting factor defenition
any factors which, when in short supply, affects the rate of reaction.
In order to make proteins from glucose, what other substance do plant cells need?
nitrate ions is needed. These are found in the soil.
What substance produced in photosynthesis is used in plants to make fats and oils?
The glucose
The glucose made in photosynthesis can be converted into fats and oils in the plant.
Plant cells store food in three main ways. what are they?
starch, fats and oils
chemical equation for photosynthesis
6 CO₂ + 6 H₂O (light energy) → C₆H₁₂O₆ + 6 O₂
chemical equation for respiration
C₆H₁₂O₆ + 6 O₂ → 6 CO₂ + 6 H₂O + energy
Why is glucose unsuitable for storage in plants?
because it is soluble in water
this would draw in water, making it difficult for cells to store in large quantities without affecting cell structure and function.
plants in the dark for 24–48 hours receive no light. what happens to them
they undergo a process called respiration where they break down stored starch to release energy.
eventually it removes starch from the plant
potentially leading to wilting or yellowing of leaves.
On a sunny summer day, what factor is likely to limit the rate of photosynthesis in plants?
carbon dioxide (CO₂) availability because the demand for CO₂ increases with light intensity.
Some plant cells contain oil droplets which stores…
food and energy
Plant cells may contain starch granules. The function of starch granules is to… what?
Starch granules provide a plant with a store of food. The starch can be converted into glucose.
In plants, nitrogen is absorbed in the form of __________.
nitrate ions
What product from photosynthesis is used to make cellulose?
glucose
Glucose is the product of photosynthesis that can be converted into the cellulose found in a plant’s cell walls.
what happens if a plant becomes deficient in nitrate ions?
it will be unable to make amino acids and proteins. This will result in stunted growth.
What product of photosynthesis is used to make starch?
glucose
The glucose made in photosynthesis is converted into starch in the leaves of plants.
By counting the number of bubbles released per minute, a student can measure the…
rate of photosynthesis
Light intensity follows the inverse square law. This means that when you double the distance between a plant and its source of light, the light intensity what?
reduces to 1/4
what does the inverse square law state?
The inverse square law states that “when you double the distance between a plant and its light source, the light intensity reduces by a quarter”.