Chapter 4.2 Overview of Photosyntheis
and the increasing complexity of systems. SB3. Students will derive the relationship between single-celled and multi-celled organisms and the increasing complexity of systems. a. Explain the cycling of energy through the processes of photosynthesis and respiration. b. Compare how structures and function vary between the six kingdoms (archaebacteria, eubacteria, protists, fungi, plants, and animals). c. Examine the evolutionary basis of modern classification systems. d. Compare and contrast viruses with living organisms.
KEY CONCEPT The overall process of photosynthesis produces sugars that store chemical energy.
Photosynthetic organisms are producers. Producers make their own source of chemical energy. Plants use photosynthesis and are producers. Photosynthesis captures energy from sunlight to make sugars.
ENERGY ULTIMATELY COMES FROM THE SUN AND THEN BECOMES PART OF OUR FOOD
Chlorophyll is a molecule that absorbs light energy.
In plants, chlorophyll is found in organelles called chloroplasts. leaf cell leaf
Chloroplasts
Photosynthesis in plants occurs in chloroplasts. Photosynthesis takes place in two parts of chloroplasts. grana (thylakoids) stroma
Two phases of the photosynthesis reaction Light Dependent Capture energy from the sunlight! Phase 2 Light Independent This captured energy is used to make sugars!
The light-dependent reactions capture energy from sunlight. take place in thylakoids water and sunlight are needed chlorophyll absorbs energy energy is transferred along thylakoid membrane then to light-independent reactions oxygen is released
Light Dependent Reactions. Look How Complex This Process Is!
The light-independent reactions make sugars. take place in stroma needs carbon dioxide from atmosphere use energy to build a sugar in a cycle of chemical reactions
The equation for the overall process is: 6CO2 + 6H2O C6H12O6 + 6O2 C6H12O6 granum (stack of thylakoids) thylakoid sunlight 1 six-carbon sugar 6H2O 6CO2 6O2 chloroplast 1 2 4 3 energy stroma (fluid outside the thylakoids)
What is the equation for the chemical reaction of photosynthesis? Six molecules of carbon dioxide react with six molecules of water to form 1 molecule of glucose and six molecules of oxygen.
1 2 4 3 granum (stack of thylakoids) chloroplast sunlight 6H2O 6O2 C6H12O6 granum (stack of thylakoids) thylakoid sunlight 1 six-carbon sugar 6H2O 6CO2 6O2 chloroplast 1 2 4 3 energy stroma (fluid outside the thylakoids)
Stage 3 is also known as the Calvin Cycle
The Calvin Cycle
Melvin Calvin at Lawrence Berkeley Laboratory