Chapter 8 Adenosine Triphosphate ATP Energy Powers chemical

  • Slides: 14
Download presentation
Chapter 8

Chapter 8

Adenosine Triphosphate ATP • Energy • Powers chemical reactions in your cells.

Adenosine Triphosphate ATP • Energy • Powers chemical reactions in your cells.

ATP => ADP • ATP releases energy when the bond between one of the

ATP => ADP • ATP releases energy when the bond between one of the 3 phosphates breaks, forming ADP • Sunlight or food (chemical energy) is used to reform the bond.

Energy Flows Between Living Things • Photosynthesis-process by which autotrophs convert light energy to

Energy Flows Between Living Things • Photosynthesis-process by which autotrophs convert light energy to chemical energy.

Photosynthesis- Light Reactions 1. Sunlight strikes the thylakoid and energy is transferred to electrons

Photosynthesis- Light Reactions 1. Sunlight strikes the thylakoid and energy is transferred to electrons in chlorophyll (and other pigments. ) 2. This activates a system that splits H 2 O into hydrogen and oxygen; oxygen is released as waste or a by-product.

Light Reactions continued 3. “Excited” electrons move through the electron transport chain and produce

Light Reactions continued 3. “Excited” electrons move through the electron transport chain and produce molecules of ATP and NADPH.

Photosynthesis- Dark Reactions (Calvin Cycle) (light independent) 1. Plant absorbs CO 2 from the

Photosynthesis- Dark Reactions (Calvin Cycle) (light independent) 1. Plant absorbs CO 2 from the surroundings. 2. In the stroma, CO 2 is “fixed” using energy from ATP and NADPH to form a simple 3 carbon sugar. 3. Two of these simple sugars combine to form glucose.

Calvin Cycle (Carbon in) • Carbon Dioxide comes in: produces sugar molecules (aka glucose!)

Calvin Cycle (Carbon in) • Carbon Dioxide comes in: produces sugar molecules (aka glucose!) • NADPH loses its H – Converts to NADP+ • ATP is converted to ADP

The Equation for Photosynthesis • Reactants: – CO 2(carbon dioxide) + H 2 O

The Equation for Photosynthesis • Reactants: – CO 2(carbon dioxide) + H 2 O (water) • Products: – C 6 H 12 O 6(glucose) + O 2 (oxygen) • Light energy is used to convert water and carbon dioxide to high energy sugars and oxygen.

Summary of Photosynthesis SUNLIGHT H 2 O O 2 lightdependent reactions CO 2 NADPH,

Summary of Photosynthesis SUNLIGHT H 2 O O 2 lightdependent reactions CO 2 NADPH, ATP NADP+, ADP lightindependent reactions sugars CHLOROPLAST Fig. 7 -6 c, p. 111

IV. Why? • Plants use glucose for growth, they create molecules such as cellulose

IV. Why? • Plants use glucose for growth, they create molecules such as cellulose by linking chains of glucose molecules. • Most plants store glucose as starches. Starches are found in plant foods such as wheat and potatoes. 12

Factors Affecting Rate of Photosynthesis 1. Temperature: Enzymes function between 0° and 35° C

Factors Affecting Rate of Photosynthesis 1. Temperature: Enzymes function between 0° and 35° C 2. Light Intensity 3. Water: must be available

• 1. Why is ATP important for cells? • 2. What is photosynthesis?

• 1. Why is ATP important for cells? • 2. What is photosynthesis? Does it store or release energy? • 3. What are autotrophs and why are they important? • 4. What is the formula for photosynthesis? Is it balanced? • 5. Describe the 2 cycles that make up photosynthesis. 14