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Where It Starts: Photosynthesis. Chapter 5. Sunlight and Survival. Autotrophs use nonliving sources to build their own food Heterotrophs feed on living organisms or their remains. Sunlight and Survival.
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Where It Starts: Photosynthesis Chapter 5
Sunlight and Survival • Autotrophs use nonliving sources to build their own food • Heterotrophs feed on living organisms or their remains
Sunlight and Survival • Photoautotrophs use sunlight and CO2 to produce sugar in the process of photosynthesis • plants, algae and photosynthetic bacteria
Visible Light • Wavelengths humans perceive as different colors • Violet (380 nm) to red (750 nm) • Longer wavelengths, lower energy
Pigments • Color you see is the wavelengths not absorbed So, Why do we see plants as green? Why do we see plants as other colors in fall and winter?
Variety of Pigments Chlorophylls Carotenoids Anthocyanins Phycobilins
Photosynthesis Equation LIGHT ENERGY 12H2O + 6CO2 6O2 + C6H12O6 + 6H2O water carbon dioxide oxygen glucose water
Two-Step Process Light-dependent reactions • formation of ATP Light-independent reactions • Synthesis part of photosynthesis (synthesis of glucose) • Can proceed in the dark using energy stored in the light reactions • Calvin-Benson cycle
sunlight energy H2O (water) CO2 (carbon dioxide) ATP light- dependent reactions light- independent reactions ADP + Pi glucose O2 H2O (metabolic water)
Chloroplast Organelle of photosynthesis in plants and algae two outer membranes stroma inner membrane system (thylakoids connectedby channels)
Summary of Photosynthesis sunlight Light Dependent Reactions 6O2 12H2O ATP ADP + Pi NADP+ NADPH 6CO2 Calvin- Benson cycle Light Independent Reactions 6 RuBP 12 PGAL 6H2O phosphorylated glucose P end products (e.g., sucrose, starch, cellulose)
Carbon and Energy Sources • Photoautotrophs • Carbon source is carbon dioxide • Energy source is sunlight • Heterotrophs • Get carbon and energy by eating autotrophs or one another
How Cells Release Chemical Energy Chapter 6
ATP Is Universal Energy Source • Photosynthesizers get energy fromthe sun • Animals get energy second- or third-hand from plants or other organisms • Regardless, the energy is converted to the chemical bond energy of ATP
Making ATP • Plants make ATP during photosynthesis • Cells of all organisms make ATP by breaking down carbohydrates, fats, and protein
Aerobic pathways Require oxygen Anaerobic pathways No Oxygen required Main Types of Energy-Releasing Pathways
Summary Equation for Aerobic Cellular Respiration C6H1206 + 6O2 6CO2 + 6H20 + ATP glucose oxygen carbon water dioxide
Glucose • A monosaccharide or simple sugar (C6H12O6) • Why is Glucose so important in the blood of animals?
CYTOPLASM glucose ATP 4 Overview of Aerobic Respiration 2 ATP Glycolysis e- + H+ (2 ATP net) 2 pyruvate 2 NADH e- + H+ 2 CO2 2 NADH e- + H+ 4 CO2 8 NADH Krebs Cycle e- + H+ 2 ATP 2 FADH2 e- Electron Transfer Phosphorylation 32 ATP H+ water e- +oxygen Typical Energy Yield: 36 ATP
Fermentation Pathways • Begin with glycolysis • Are anaerobic: don’t require oxygen • Yield only the 2 ATP from glycolysis
Lactate Fermentation GLYCOLYSIS C6H12O6 ATP 2 energy input 2 NAD+ 2 ADP NADH 2 ATP 4 2 pyruvate energy output 2 ATP net LACTATE FORMATION electrons, hydrogen from NADH 2 lactate
GLYCOLYSIS C6H12O6 Alcoholic Fermentation 2 ATP 2 NAD+ energy input 2 ADP NADH 2 ATP 4 2 pyruvate energy output 2 ATP net ETHANOL FORMATION 2 H2O 2 CO2 2 acetaldehyde electrons, hydrogen from NADH 2 ethanol
Photosynthesis Energy-storing pathway Releases oxygen Requires carbon dioxide Aerobic Respiration Energy-releasing pathway Requires oxygen Releases carbon dioxide Linked Processes