Cellular Energy

Learning targets: understand that ATP is the source of cellular energy Understand how ATP is formed and how it provides energy

ATP is the fuel for cells Adenosine triphosphate 4.1 ATP is the fuel for cells Adenosine triphosphate 3 phosphates Bond with 3rd phosphate is a high energy bond ADP: adenosine diphosphate 2 phosphates Low energy

ATP is made from glucose by respiration Glucose is made by photosynthesis In absence of sunlight, organisms can make food by chemosynthesis

ATP

4.2: Photosynthesis Learning targets: Understand how plants turn CO2 into food by photosynthesis

Chlorophyll: the pigment that absorbs light energy Photosynthesis 6CO2 + 6H2O  C6H12O6 + 6O2 Photosynthesis: the process that captures energy from sunlight to make food (glucose) Chlorophyll: the pigment that absorbs light energy Chloroplast: the structure in plants that contains chlorophyll and where photosynthesis occurs

Thylakoid: membrane bound coinlike structures that contain chlorophyll Chloroplast Thylakoid: membrane bound coinlike structures that contain chlorophyll Grana: stacks of thylakoids Stroma: fluid in the chloroplast outside the thylakoids

Light dependent reactions Photosystem II Chlorophyll absorbs light energy Water is split into H+, electron, and oxygen Photosystem I NADP+ + electrons  NADPH Note the purple and red compounds. They appear in the next step

Photosystem II comes first because photosystem I was discovered first.

Light Independent reactions: Calvin Cycle 3CO2 added to 3-5C molecule  3-6 C Requires enzyme RUBISCO 3-6C  6-3C ATP  ADP NADPH  NADP+ 6-3C  5-3C + 1-3C 5-3C  3-5C ATP  ADP

Photosynthesis

Stomata shut during the day Fix carbon at night Examples: CAM photosynthesis Arid conditions Stomata shut during the day Fix carbon at night Examples: Pineapples Cacti

Drought, high temperature, low nitrogen Examples: C4 Photosynthesis 4C intermediate Drought, high temperature, low nitrogen Examples: Corn Sugar cane Oxaloacetic acid (3C) + CO2  Malate = 4C

Cellular Respiration Learning Target: Understand how glucose is broken down to produce energy (ATP)

Requires oxygen (aerobic) Cellular respiration C6H12O6 + 6O2  6CO2 + 6H2O Produces ATP Requires oxygen (aerobic)

6C glucose  2-3C pyruvates Glycolysis 6C glucose  2-3C pyruvates Occurs in cytoplasm Does not require oxygen (anaerobic) Requires 2 ATP Produces 4 ATP Net gain = 2 ATP

Glycolysis

Aerobic: requires oxygen Krebs cycle Aerobic: requires oxygen Pyruvate (3C) + CoEnzyme A  1CO2 + acetyl CoA (2C) 2C + 4C  6C 6C – 1CO2  5C (NAD+  NADH) 5C – 1CO2  4C (NAD+  NADH) 4C  4C (NAD+  NADH, FAD2+ FADH2) Produces 1 ATP per pyruvate (2 per glucose)

Electron Transport System Aerobic: requires oxygen Electrons removed from NADH and FADH2 H+ ions transported across membrane H+ ions flow back, produce ATP (34) Oxygen acts as final electron receptor. Oxygen + electrons + H+  water

Cellular respiration

Comparison

Comparison

Learning Targets: Explain how ATP can be made in the absence of oxygen Fermentation Learning Targets: Explain how ATP can be made in the absence of oxygen Give examples of practical economic uses of anaerobic respiration

Pyruvate  lactic acid + 2ATP Pyruvate  alcohol + CO2 + 2ATP Fermentation No oxygen: anaerobic Pyruvate  lactic acid + 2ATP Animals Pyruvate  alcohol + CO2 + 2ATP yeasts

Medical indicator of muscle damage Causes soreness Lactic acid Medical indicator of muscle damage Causes soreness Lactobacillus produces yogurt

Alcoholic fementation Brewing industry Beer, wine, champagne Baking industry Yeast rolls