Bio2 Chapter 8 - Chap 8 PDF

Preview

Summary

Chap 8...

Description

Chapter 8 Photosynthesis Homework #3 (20 Points)

1. The overall reaction for Photosynthesis is: 6 CO2 +12 H 2 O →C 6 H 12 O 6 +6 H 2 O + 6 O 2 2. Define: a. Light dependent reaction (1)  A light dependent reaction requires light energy. This reaction makes ATP and reduces NAD+ NADH. b. Light independent reaction (1)  A light independent reaction doesn’t require light energy and it uses ATP and NADPH to synthesize molecules from CO2 . c. electron carriers and give examples (2)  An electron carrier is a compound that can accept a pair of high-energy electrons and transfer them, along with most of their energy, to another molecule. Example are NADP+ and NAD+ since they reduce to NADPH and NADH. 3. What is the role of pigments in Photosynthesis? (2)  Plants use pigments to gather the sun's light energy. For instance, they are affected by wavelengths. 3. Sketch a chloroplast and label the: outer membrane, inner stroma, thylakoid (4)

4. The following are structures found in a photosystem, what is the function of: (4) a. antenna complex  Antenna Complex is a light-harvesting complex that captures photons from sunlight and channels them to the reaction center chlorophylls. It is made up of hundreds of pigments. b. reaction center  The reaction center is a transmembrane protein complex. It contains pigments such as chlorophyll and phaeophytin. These absorb light, promoting an electron to a higher energy level within the pigment. c. chlorophyll  Chlorophyll is embedded in the thylakoid membrane and it absorbs light. d. water

Water provides electrons to replace those removed from chlorophyll in photosystem II. Water also produces oxygen as well as reduces NADP to NADPH by liberating H+ ions. 5. What does water provide for the light reaction? (1)  In light reactions, water is split to satisfy the electron debt in the chlorophyll molecules in the reaction center of photosystem II. ...