Transcript Document
PHOTOSYNTHESIS The Need For Food (Review) • Where does food come from? – Autotroph • “Own Food” • Sun as energy to create food – Heterotroph • “Others Food” • Eat other to obtain food and use energy The Need for Food (Review) • How do use light to make food? – PHOTOSYNTHESIS! • 6 CO2 + 6H2O + sunlight 6O2 + C6H12O6 (Chemical energy) • Makes glucose (basic food molecule for most living organisms) How do Plants Use Glucose? • Immediately uses the energy stored in glucose to live (through cell respiration) • Builds plant body from long chains of glucose – Cellulose (structure) – wood, bark, leaves – Starch (stored energy) – potatoes, roots What exactly is photosynthesis? • The process of converting solar energy into chemical energy. • Responsible for removal of ~ 200 billion tons of C from the atmosphere yearly. What exactly is Photosynthesis • Two step process – Light dependent reactions – Dark reactions (Calvin Cycle) • Both take place inside the chloroplasts In the chloroplast Takes Place inside chloroplast CO2 Dark Reactions ATP NADPH H2O Sugars Light Reactions O2 Light Dependent Reactions • Chlorophyll in the chloroplasts absorb light – Creates green color in plants because it DOES NOT absorb green light • Roots absorb water Chlorophyll b Chlorophyll a Light Dependent Reaction • Uses water and light and ADP to create O2 and *ATP* • ATP is stockpiled during the day or light producing times. What is ATP? • Chemical energy molecule used in: – Active Transport – Energy to move organelles – Protein synthesis • Sugar molecule stores 90x’s more energy then ATP does. Section 8-1 ADP and ATP continued ADP ATP Energy Adenosine diphosphate (ADP) + Phosphate Partially charged battery Energy Adenosine triphosphate (ATP) Fully charged battery The Calvin (DARK) Cycle • CO2 enter the plant through stomata (tiny holes in the leaf surface) The Calvin (Dark) Cycle • CO2 combines with the energy from ATP (created in light cycle) to make glucose and ADP • Where does the ADP and go? – Back to the light dependent reactions H20 CO2 Light Chloroplast Chloroplast NADP+ ADP + P LightDependent Reactions Calvin Cycle ATP NADPH Sugars O2 To sum up: • There are two parts to the photosynthesis equation – Light dependent reactions • Light + Water O2 and Chemical energy – Calvin Cycle • Chemical energy and CO2 Glucose Factors that increase/decrease Photosynthesis Rate • Water • Temperature • Light Intensity