AP Ch 7 Photosynthesis Outline Quiz

Plants appear green because they reflect green wavelengths of light. This is due to the presence of chlorophyll, a pigment that absorbs light energy for photosynthesis. Chlorophyll absorbs red and blue wavelengths of light more efficiently, while reflecting green light. The reflected green light is then detected by our eyes, making plants appear green to us.

Sunlight arrives at a plant in units of light energy called photons. Photons are particles of light that carry energy and are responsible for the transfer of energy from the sun to the plant during photosynthesis. This energy is then converted into chemical energy, which the plant uses for growth and other metabolic processes. Electrons and wavelengths are not units of light energy, and protons are not directly involved in the transfer of energy from sunlight to plants.

Grana refers to a stack of thylakoid membrane structures in the chloroplast. Thylakoid membranes are where the light-dependent reactions of photosynthesis occur, and they are organized into stacks called grana. These stacks increase the surface area available for light absorption and provide a more efficient arrangement for the photosynthetic process. Therefore, the correct answer is "a stack of thylakoid membrane structures."

The term stroma refers to the central fluid-filled space of the chloroplast. This is where the Calvin cycle, which is the process of photosynthesis that converts carbon dioxide into glucose, takes place. The stroma also contains enzymes, DNA, and ribosomes, which are necessary for the synthesis of proteins within the chloroplast. It acts as a medium for various metabolic reactions and is essential for the functioning of the chloroplast as a whole.

The energy content of photons is inversely proportional to the wavelength of the radiation. This means that as the wavelength of the radiation increases, the energy content of the photons decreases, and vice versa. This relationship is described by the equation E = hc/λ, where E is the energy, h is Planck's constant, c is the speed of light, and λ is the wavelength. Therefore, the statement is true.

In the noncyclic electron pathway of photosynthesis, the first step involves the removal of electrons from water molecules. This process, known as photolysis, occurs in the thylakoid membrane of the chloroplasts. The energy from sunlight is used to split water molecules, releasing oxygen and generating electrons that are then used in the electron transport chain to produce ATP and NADPH. Therefore, the statement "The first part of the noncyclic electron pathway involves the removal of electrons from water" is true.

Most food plants, such as wheat, oats, and rice, belong to the group of C3 plants. C3 plants are characterized by the C3 carbon fixation pathway, where the first stable product of photosynthesis is a three-carbon compound. These plants directly fix carbon dioxide into a three-carbon compound during photosynthesis. C3 plants are adapted to cooler and moister environments and are the most common type of plants. CAM plants and C4 plants have different carbon fixation pathways and are typically found in arid and hot environments.

Chlorophyll is a pigment found in plants that is responsible for absorbing light energy during photosynthesis. It specifically absorbs photons from certain portions of the visible light spectrum, mainly in the red and blue regions. This is because chlorophyll molecules have specific structures that allow them to capture and utilize light energy within these wavelengths. Therefore, only photons from portions of visible light that fall within the absorption spectrum of chlorophyll can be taken up by it, making the statement true.

C3 plants make glucose in the mesophyll cells, not in the bundle sheath cells. In C3 plants, the initial fixation of CO2 occurs in the mesophyll cells through the Calvin cycle, where glucose is produced. In contrast, C4 plants fix CO2 in the mesophyll cells to form a four-carbon compound, oxaloacetate, which is then transported to the bundle sheath cells where it is decarboxylated to release CO2 for the Calvin cycle. Therefore, the statement that C3 plants make glucose in the bundle sheath cells is not true.

Photorespiration is a metabolic pathway that occurs in C3 plants, where oxygen is taken up and carbon dioxide is released. This process is considered to be a wasteful and inefficient side reaction of the main process of photosynthesis. It occurs when the concentration of carbon dioxide is low and oxygen is high, leading to the binding of oxygen instead of carbon dioxide by the enzyme RuBisCO. This results in the release of carbon dioxide and the consumption of energy, ultimately reducing the efficiency of photosynthesis in C3 plants.