BIOLOGY
                           CONCEPTS & CONNECTIONS
                                      Fourth Edition
     Neil A. Campbell  •  Jane B. Reece  •  Lawrence G. Mitchell  •  Martha R. 
                                            Taylor 
                                 CHAPTER 7
                              Photosynthesis:
                  Using Light to Make Food
                                     Modules 7.1 – 7.5
                  From PowerPoint® Lectures for Biology: Concepts & Connections
                           Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
   Life in the Sun
   • Light is central to the life of a plant
   • Photosynthesis is the most important 
      chemical process on Earth
       – It provides food for 
         virtually all organisms
   • Plant cells convert light 
      into chemical signals 
      that affect a plant’s 
      life cycle
   Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
    • Light can influence the architecture of a 
      plant
       – Plants that get adequate light are often 
         bushy, with deep green leaves 
       – Without enough light, plants 
         become tall and spindly with 
         small pale leaves 
    • Too much sunlight can 
      damage a plant
       – Chloroplasts and carotenoids 
         help to prevent such damage
   Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
    AN OVERVIEW OF PHOTOSYNTHESIS
    • Photosynthesis is the process by which 
       autotrophic organisms use light energy 
       to make sugar and oxygen gas from 
       carbon dioxide and water 
                   Carbon    Water                   Glucose       Oxygen
                   dioxide                                          gas
                                    PHOTOSYNTHESIS
    Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings