Photosynthesis FRQ
Explain in detail, the light independent reactions. Include location, reactants, and products.
Also known as the Calvin cycle. In the first stage, chemical reactions use energy from light to produce ATP and NADPH. In the second stage, carbon dioxide and water are converted into organic molecules, such as glucose. Takes place in the stroma of the chloroplast. The reactants are carbon dioxide, NADPH, and ATP. The products are ADP, phosphate, NADP+, and glucose.
Explain the effect of carbon dioxide concentration on rate of photosynthesis
Carbon dioxide is one of the reactants in photosynthesis. If the concentration of carbon dioxide is increased, the rate of photosynthesis will increase, which will lead to in increase in growth.
1. Explain why the Calvin Cycle (dark reactions) rely on the light reactions.
The ATP provides the energy, and the NADPH supplies the electrons for the Calvin cycle, which converts carbon dioxide to sugar. The ADP and NADP+ that result from the Calvin cycle shuttle back to the light reactions, which regenerate ATP and NADPH.
Explain why the dark reactions can only continue in the darkness for a limited time.
The Calvin cycle is also called the dark reactions because it is doesn't need energy from the sun to happen. Dark reactions will fail to continue if the plants are deprived of light for too long because it is fueled by products from the light reaction.
Write the balanced equation for synthesis, then describe where each reactant and product come from and leaves from.
6CO2 + 6H2O → C6H12O6 + 6O2 Plants get water from the soil, and the water gets to the leaves through the xylem. Plants extract the carbon dioxide from the air. The carbon dioxide enters the leaves of the plant through small pores called stomata. Once the carbon dioxide enters the plant, the process begins with the help of sunlight and water. Light energy converts carbon dioxide and water into glucose and oxygen. Glucose is the result of solar energy to chemical energy. The oxygen molecules released into the atmosphere come from the original water molecules.
Explain the effect of temperature on rate of photosynthesis
At low temperatures, the enzymes that carry out photosynthesis do not work efficiently, and this decreases the photosynthetic rate. This leads to a decrease in glucose production and will result in stunted growth. At medium temperatures, the photosynthetic enzymes work at their optimum levels, so photosynthesis rates are high. At high temperatures, rate of photosynthesis decreases because enzymes that carry out photosynthesis lose their shape and functionality.
Transpiration is when water escapes through stomata of leaves. Explain the relationship between temperature and water-loss in plants. What two protective mechanisms do plants have against water-loss?
At very cold and very hot temperatures cause the plant cells which control the openings (stomata) to close. At optimum temperature, the stomata opens. Two protective mechanisms include thorns and poison.
Describe the physical structure of a chloroplast.
Chloroplasts are plant cell organelles that convert light energy into chemical energy via the photosynthesis. Chloroplast are oval-shaped and contains a double membrane. The interior contains flattened sacs of photosynthetic membranes called thylakoids. Thylakoids are usually arranged in stacks called grana that contain chlorophyll which are photosynthetic pigment. The lumen is the inner surface of the thylakoid membrane. The stroma is the fluid of the chloroplast surrounding the thylakoid membrane
Explain the effect of light intensity on rate of photosynthesis
Increasing the light intensity increases the rate of photosynthesis, until a limiting factor becomes in short supply. At very high light intensities, photosynthesis is slowed and then inhibited.
Explain in detail, the light dependent reactions. Include location, reactants, and products.
Light dependent reactions convert light energy into chemical energy. Light dependent reactions collect energy from the sun and break down water molecules to produce ATP and NADP. This reaction occurs in the thylakoid membrane of the chloroplasts. The reactants are sunlight, water, NADP+, ADP, and phosphate. Products are ATP, NADPH, and O2.
Describe why plants will die if only provided green light.
The plants will die because they reflect green light, and they would not be able to collect enough light to perform photosynthesis. Green light is the least effective for plants because the plants are green due to the pigment chlorophyll.
Explain in detail, how the rate of photosynthesis could be measured in the lab. Include any limitations of your experimental design.
The rate of photosynthesis can be measured by 1) measuring the O2 production 2) measuring the CO2 consumption. In the photosynthesis lab with the leaf disks, the accumulation of the oxygen was measured. The Oxygen production level can be measured by the number of floating disks in the beaker in the controlled and uncontrolled solutions.
