Photosynthesis and Photorespiration Quiz

A waxy, waterproof layer covering the external walls of the upper and lower epidermis of a leaf, protecting it from water loss and infection.

Tiny pores on the lower epidermis of a leaf that allow for gas exchange (CO2 in, O2 out).

Specialized cells surrounding each stoma that control its opening and closing, regulating gas exchange.

Column-shaped cells in the mesophyll layer of a leaf, packed with chloroplasts for maximum photosynthesis.

Irregularly shaped cells in the mesophyll layer, creating air spaces for gas diffusion and containing fewer chloroplasts than palisade cells.

Green pigments that absorb light energy for photosynthesis.

Pigments that capture light energy and transfer it to chlorophyll, expanding the range of light used in photosynthesis.

The spectrum of wavelengths of light absorbed by a pigment.

The portion of the electromagnetic spectrum that our eyes can detect, ranging from approximately 400 to 700 nanometers in wavelength.

Packets of energy that make up electromagnetic radiation.

Pigments that absorb specific wavelengths of light, allowing plants to capture energy for photosynthesis.

Pigments that absorb mainly blue-violet light and transfer that energy to chlorophyll, expanding the range of light used for photosynthesis.

A graph illustrating the rate of photosynthesis at different wavelengths of light.

The process where light energy is converted into chemical energy in the form of glucose, using carbon dioxide and water as reactants.

The first stage of photosynthesis, where light energy is captured and used to split water and produce ATP and NADPH.

The second stage of photosynthesis, where carbon dioxide is fixed and converted into glucose using energy from ATP and NADPH.

A factor that limits the rate of photosynthesis when its amount is insufficient, even if other factors are optimal.

The intensity of light that determines the rate of photosynthesis.

Specific wavelengths of light that are most effective in driving photosynthesis.

The amount of carbon dioxide in the air that determines the rate of photosynthesis.

The temperature that determines the rate of photosynthesis, as enzymes involved in the process have optimal temperatures.

Photosynthesis in these plants begins with fixing carbon dioxide into a four-carbon compound, hence the name. They are more efficient in hot, dry climates.

Plants that directly fix carbon dioxide into a three-carbon compound, glyceraldehyde 3-phosphate, during photosynthesis.

A process where plants use oxygen instead of carbon dioxide to fix carbon, resulting in a net loss of energy. It occurs when stomata are closed to conserve water, limiting CO2 uptake and increasing O2.

C4 plants have specialized cells called bundle sheath cells that contain chloroplasts where the Calvin cycle occurs. These chloroplasts are structurally different from those in mesophyll cells.

C4 plants have a special structure within their leaves where carbon fixation occurs, called the kranz anatomy, which includes mesophyll cells and bundle sheath cells with different chloroplasts.

These plants open their stomata at night to take in carbon dioxide, store it as an acid, and then release it during the day for photosynthesis when it's hot and dry, minimizing water loss.

These occur when a factor limits the rate of photosynthesis, even if other factors are optimal. For example, a lack of light will limit photosynthesis, even if there's plenty of water and carbon dioxide.

The loss of carbon dioxide during photorespiration, which is unproductive as it doesn't contribute to sugar production.

The energy used in photorespiration is not used for growth or other essential processes, making it a wasteful process.

When photorespiration is active, it competes with photosynthesis for the same resources, reducing the overall efficiency of the process.

A type of leaf anatomy found in C4 plants, characterized by two concentric layers of cells: mesophyll cells and bundle sheath cells.

A type of photosynthesis where carbon dioxide is first incorporated into a 4-carbon compound before entering the Calvin cycle, reducing photorespiration.

The outer layer of cells in Kranz anatomy, where the initial fixation of carbon dioxide occurs in C4 plants.

In C4 plants, the light-dependent reactions occur in the mesophyll cells, while the Calvin cycle occurs in the bundle-sheath cells. This spatial separation allows for more efficient carbon fixation.

In C4 plants, the enzyme PEP carboxylase is used to initially fix carbon dioxide into a 4-carbon organic acid called oxaloacetate. This enzyme does not bind with oxygen, preventing photorespiration.

Oxaloacetate, a 4-carbon molecule produced in the mesophyll cells, is converted into malate. Malate then moves into the bundle-sheath cells, where it releases carbon dioxide and pyruvate.

C4 plants have specialized chloroplasts in both mesophyll and bundle sheath cells, each with different functions. Mesophyll chloroplasts have large grana for efficient light-dependent reactions, while bundle sheath chloroplasts lack grana and have high levels of rubisco for carbon fixation.

The Hatch-Slack pathway is the specific metabolic pathway utilized by C4 plants for carbon fixation. In this pathway, CO2 is initially fixed into a 4-carbon compound, facilitating efficient carbon fixation.

The movement of metabolites between mesophyll and bundle sheath cells is facilitated by plasmodesmata, creating continuous connections and enabling molecule exchange for efficient photosynthesis.

C4 plants are characterized by Kranz anatomy, where the bundle sheath cells are large and closely surrounded by mesophyll cells. This structural arrangement optimizes the flow of metabolites and ensures efficient photosynthesis.

While mesophyll chloroplasts have high rates of light-dependent reactions generating abundant ATP, NADPH, and oxygen, bundle sheath chloroplasts focus on carbon fixation. This specialization improves the overall efficiency of photosynthesis.