Chapter 8, Problem 16A

Summary Introduction

To write:

Correct vocabulary term for the given definition.

Introduction:

Photosynthesis is a process in which light energy from the Sun is converted to chemical energy for use by the cell. Chloroplasts are the organelles which capture light energy. They are found in all leaves. A chloroplast has two parts; sac like structures called thylakoids and a fluid filled space called stroma.

Answer to Problem 16A

Chlorophyll

Explanation of Solution

A colored molecule that absorbs light is called a pigment. Pigments are present in the membranes of thylakoids of chloroplasts. Pigments differ in their ability to absorb specific wavelengths of light. Most important light absorbing pigment is chlorophyll. There are many types of chlorophyll but two most common ones are chlorophyll a and chlorophyll b. chlorophylls absorb mostly in the violet blue region of the visible light spectrum and reflect green light. That is why chlorophyll containing parts of plants appear green in color.

Besides chlorophyll there are other pigments called accessory pigments that trap additional light energy from other areas of visible spectrum. Carotenoid such as beta- carotene is an accessory pigment.