8.2 Photosynthesis: An Overview
What role do pigments play in the process of photosynthesis?- What are electron carrier molecules?
- What are the reactants and products of photosynthesis?
pigment • chlorophyll • thylakoid • stroma • NADP+ • light-dependent reactions • light-independent reactions
Outline Make an outline using the green and blue headings in this lesson. Fill in details as you read to help you organize the information.
THINK ABOUT IT How would you design a system to capture the energy of sunlight and convert it into a useful form? First, you'd have to collect that energy. Maybe you'd spread out lots of flat panels to catch the light. You might then coat the panels with light-absorbing compounds, but what then? How could you take the energy, trapped ever so briefly in these chemical compounds, and get it into a stable, useful, chemical form? Solving such problems may well be the key to making solar power a practical energy alternative. But plants have already solved all these issues on their own terms—and maybe we can learn a trick or two from them.
Chlorophyll and Chloroplasts
What role do pigments play in the process of photosynthesis?
Our lives, and the lives of nearly every living thing on the surface of Earth, are made possible by the sun and the process of photosynthesis. In order for photosynthesis to occur, light energy from the sun must somehow be captured.
Light Energy from the sun travels to Earth in the form of light. Sunlight, which our eyes perceive as “white” light, is actually a mixture of different wavelengths. Many of these wavelengths are visible to our eyes and make up what is known as the visible spectrum. Our eyes see the different wavelengths of the visible spectrum as different colors: shades of red, orange, yellow, green, blue, indigo, and violet.
Pigments Plants gather the sun's energy with light-absorbing molecules called pigments. Photosynthetic organisms capture energy from sunlight with pigments. The plants' principal pigment is chlorophyll (KLAWR uh fil). The two types of chlorophyll found in plants, chlorophyll a and chlorophyll b, absorb light very well in the blue-violet and red regions of the visible spectrum. However, chlorophyll does not absorb light well in the green region of the spectrum, as shown in Figure 8–4.
FIGURE 8–4 Light Absorption
Table of Contents
- Formulas and Equations
- Applying Formulas and Equations
- Mean, Median, and Mode
- Estimation
- Using Measurements in Calculations
- Effects of Measurement Errors
- Accuracy
- Precision
- Comparing Accuracy and Precision
- Significant Figures
- Calculating With Significant Figures
- Scientific Notation
- Calculating With Scientific Notation
- Dimensional Analysis
- Applying Dimensional Analysis