Why is chlorophyll green? a. It absorbs all wavelengths in the visible spectrum. b. It absorbs wavelengths only in the red portions of the spectrum (680–700 nm). c. It absorbs wavelengths only in the blue part of the visible spectrum (450–480 nm). d. It absorbs wavelengths in only the blue and red parts of the visible spectrum.

Verified step by step guidance

1. Step 1: Understand the question. The question is asking why chlorophyll, the pigment responsible for photosynthesis in plants, appears green.
2. Step 2: Recall that the color we see is the color that is reflected, not absorbed. So, if chlorophyll appears green, it means it is reflecting green light.
3. Step 3: Look at the answer choices. We can eliminate option a because if chlorophyll absorbed all wavelengths, it would appear black, not green.
4. Step 4: We can also eliminate options b and c because they suggest that chlorophyll only absorbs either red or blue light, which would mean it reflects the other colors, including green. But we know that chlorophyll appears green, so it must be reflecting green light, not absorbing it.
5. Step 5: The correct answer is option d. Chlorophyll absorbs wavelengths in the blue (450–480 nm) and red (680–700 nm) parts of the visible spectrum, and reflects the green part, which is why it appears green to us.

Key Concepts

Chlorophyll Structure and Function

Chlorophyll is a pigment found in plants, algae, and cyanobacteria that plays a crucial role in photosynthesis. It primarily absorbs light energy from the sun, which is essential for converting carbon dioxide and water into glucose and oxygen. The structure of chlorophyll includes a porphyrin ring with a magnesium ion at its center, which allows it to capture light energy effectively.

Light Absorption Spectrum

The light absorption spectrum refers to the specific wavelengths of light that a pigment can absorb. Chlorophyll mainly absorbs light in the blue (around 450-480 nm) and red (around 680-700 nm) regions of the spectrum, while reflecting green light (around 500-550 nm). This selective absorption is why chlorophyll appears green to the human eye.

Photosynthesis

Photosynthesis is the biochemical process by which green plants, algae, and some bacteria convert light energy into chemical energy stored in glucose. This process occurs in the chloroplasts and involves two main stages: the light-dependent reactions, which capture and convert light energy, and the light-independent reactions (Calvin cycle), which use that energy to synthesize glucose from carbon dioxide and water.