Biology - Photosynthesis

Chapter 8 Page 200 - 212

8 -- 1 Energy and life

1. Organisms such as plants, which make their own food, are called autotrophs.

2. These organisms, known as heterotrophs obtain energy from the foods they consume.

3. One of the principal chemical compounds that cells use to store and release energy is adenosine triphosphate abbreviated ATP.

4. Adenosine diphosphate (ADP) is a compound that looks like ATP, except that it has two phosphate groups instead of three.

8 -- 2 An Overview

1.  In the process of Photosynthesis, Plants use the energy of sunlight to convert water and carbon dioxide into high-energy carbohydrates---sugars and starches--and oxygen, a waste product.

2. Plants gather the sun’s energy with light absorbing molecules called pigments.

3. The Plants’ principal pigment is chlorophyll.

8 -- 3 The Reaction of photosynthesis

1.      The Chloroplasts, shown in figure 8-6 contain saclike photosynthetic membranes called thylakoid.

2.      Proteins in the thylakoid membranes organize chlorophyll and other pigments into clusters known as photosystems.

3.      The Calvin cycle takes place in the stroma, the region outside the thylakoid membranes.

4.      NADP (nicotinamide adenine dinucleotide phosphate).

5.      The light - dependent reactions require light. The light dependent reaction use energy from light to produce ATP & NADPH.

6.      However, the membrane contains a protein called ATP Synthase.

7.      Calvin Cycle, plants use the energy that ATP and NADPH contain to build high energy compounds that can be stored for a long time.