1 Photosynthesis Chapter 8

2 Autotrophs Autotrophs include organisms that make their own foodAutotrophs include organisms that make their own food Euglena

3 Autotrophs Plants and some other types of organisms that contain chlorophyll are able to use light energy from the sun to produce food.

4 Heterotrophs Heterotrophs are organisms that can NOT make their own foodHeterotrophs are organisms that can NOT make their own food Heterotrophs obtain energy from the food they eat.Heterotrophs obtain energy from the food they eat.

5 ATP – Cellular Energy Adenosine Triphosphate:Adenosine Triphosphate: –a chemical coumpound used to store and release energy. Contains:Contains: – two, high-energy phosphate bonds –the nitrogen base adenine – a ribose sugar

6 ATP releases energy : ATP releases energy by breaking the bond between its second and third phosphate. One phosphate bond has been removed

7 Releasing Energy From ATP ATP is constantly being used and remade by cellsATP is constantly being used and remade by cells ATP provides all of the energy for cell activitiesATP provides all of the energy for cell activities Adding A Phosphate Group To ADP stores Energy in ATPAdding A Phosphate Group To ADP stores Energy in ATP Removing A Phosphate Group From ATP Releases Energy & forms ADPRemoving A Phosphate Group From ATP Releases Energy & forms ADP Lose Gain

8 Glucose Glucose is a sugar.Glucose is a sugar. Its formula : C 6 H 12 O 6Its formula : C 6 H 12 O 6 Glucose Stores 90 Times More Energy Than ATPGlucose Stores 90 Times More Energy Than ATP

9 ATP and Glucose Cells Have Enough ATP To Last For A Few Seconds.Cells Have Enough ATP To Last For A Few Seconds. ATP must constantly be made.ATP must constantly be made. ATP is made using energy from foods like glucose.ATP is made using energy from foods like glucose. Glucose is made during photosynthesis for use as an energy source.Glucose is made during photosynthesis for use as an energy source.

10 Photosynthesis SUNLIGHT converts:SUNLIGHT converts: Water (H 2 0) + Carbon Dioxide (CO 2 ) into Water (H 2 0) + Carbon Dioxide (CO 2 ) into Oxygen (O 2 ) + Glucose (C 6 H 12 O 6 ) Oxygen (O 2 ) + Glucose (C 6 H 12 O 6 )

11 The Photosynthesis Equation

12 Pigments Chlorophyll is found inside the chloroplasts of plant cells. It absorbs the light necessary for photosynthesis to occur.

13 Inside A Chloroplast

14 Structure of the Chloroplast Inner membrane forms stacks of connected sacs called thylakoidsInner membrane forms stacks of connected sacs called thylakoids A Thylakoid stack is called the granum (grana-plural)A Thylakoid stack is called the granum (grana-plural) The gel-like material around the grana is called the stroma.The gel-like material around the grana is called the stroma.

15 Photosynthesis has two steps: Light Dependent ReactionLight Dependent Reaction Light Independent Reaction (also called the Calvin Cycle)Light Independent Reaction (also called the Calvin Cycle)

16 The Light Dependent Reaction Occurs on the thylakoid membrane.Occurs on the thylakoid membrane. Light energy strikes a leaf and is captured by chlorophyll.Light energy strikes a leaf and is captured by chlorophyll. This energy is used to split water into hydrogen and oxygen. This oxygen is released back into the atmosphere.This energy is used to split water into hydrogen and oxygen. This oxygen is released back into the atmosphere. The hydrogen is used in the Calvin Cycle.The hydrogen is used in the Calvin Cycle. ATP is produced during the light reaction.ATP is produced during the light reaction.

The Light Independent Reaction Also called the Calvin Cycle Occurs in the stroma and uses the ATP produced in the Light Dependent Reaction. Carbon Dioxide enters the leaf and passes into the stroma. The carbon dioxide combines with the hydrogen from the light reaction to form glucose. The glucose is then used throughout the plant for growth and development.

18 Photosynthesis Overview