2 Think back to Energy Transfer… Living things use energy forGrowthRepairReproductionMetabolismThe collection of reactions that occur in a cell
3 Metabolism Involves either: Using energy to build molecules (condensation reactions)orBreaking down molecules to release the stored energy (hydrolysis)
4 Building Molecules That Store Energy Photosynthesis is the process by which light energy is converted to chemical energyOrganisms that use energy from sunlight (or from chemical bonds in inorganic substances) to make organic compounds are called autotrophs
5 Breaking Down Food for Energy Organisms that must get energy from food instead of directly from sunlight (or inorganic substances) are called heterotrophsHeterotrophs get energy from food through the chemical process of cellular respiration, remember that autotrophs perform cellular respiration also!
9 The chlorophyll inside the chloroplast of leaves absorb light Absorption of lightIn addition to water and carbon dioxide, photosynthesis requires light and chlorophyllThe chlorophyll inside the chloroplast of leaves absorb lightChlorophyll does not absorb all the wavelengths of visible light equally
10 Inside the Chloroplast Chloroplast – organelle in plants where photosynthesis takes placeThylakoids – Saclike photosynthetic membranesGrana- Stacks of thylakoidsStroma- aqueous region outside the grana
12 Step 1 - Light-Dependent Reactions Breaks apart H2O to produce oxygen gasConvert ADP and NADH+ into ATP and NADPHTakes place within the thylakoid membranes in the chloroplast
13 Step 2 - Calvin Cycle ( aka light-INdependent reactions) Uses ATP and NADPH from the light dependent reactionsProduces high-energy sugarsTakes place in the stroma of the chloroplastsDoes not require light
14 Factors Affecting Photosynthesis WaterTemperatureDepends on enzymes that function best between 0oC and 35oCIntensity of lightIncreasing light intensity increases the rate of photosynthesis to a pointCarbon Dioxide ConcentrationNutrients
16 Cellular Respiration 3 Stages of Aerobic Cellular Respiration: Glycolysis does not require oxygen.Aerobic respiration: oxygen is present, glycolysis is followed by the Krebs cycle and then the electron transport chain.Anaerobic respiration: no oxygen, glycolysis is followed by fermentation3 Stages of Aerobic Cellular Respiration:Glycolysisthe Krebs cyclethe electron transport chainEach of the 3 stages of cellular respiration uses energy from food to produce ATP
17 1.Glycolysis Respiration begins with a pathway called Glycolysis. Glycolysis releases a small amount of energy.Uses 2 ATP to make 4 ATP and 2 pyruvic acids
18 Next step to the Mitochondria The “power house” of the cell, because most of the ATP is produced here.
19 2. The Krebs Cycle Oxygen is required During the Krebs cycle, pyruvic acid is broken down into:CO2NADHFADH2ATP: The Krebs Cycle makes 2 ATP
20 3. Electron TransportEach pair of high-energy electrons moves down the electron transport chain (ETC) and provides the energy to produce more ATP.The break down of glucose by aerobic cellular respiration results in the production of 36 molecules of ATP.
21 What happens when there is NO OXYGEN? When oxygen is not present, glycolysis is followed by a different pathway.2 types of fermentation: anaerobic (no oxygen)Lactic Acid FermentationAlcoholic Fermentation
22 What happens during fermentation? No ATP are producedLactic Acid FermentationPyruvic acid lactic acid (lactate)Alcoholic FermentationPyruvic acid ethanol & CO2DURING ANAEROBIC RESPIRATION ONLY 2 ATP ARE MADE
23 Why ATP Adenine Triphosphate? A high energy molecule that stores energy needed by cellsMade in the mitochondriaComposed of:Ribose (5 carbon Sugar)Adenine (nitrogenous base)3 phosphate groups (group of molecules made up of phosphorous and oxygen)
24 Releasing Energy from ATP The removal of 1 phosphate group from ATP produces ADP (Adenosine DiPhosphate)This reaction releases energy in a way that enables cells to use the energy
25 PLANTS ALSO PERFORM RESPIRATION Plants also contain the organelle, mitochondria, which converts the high energy carbohydrates made by the plant through photosynthesis in the chloroplast into ATP for the plant to use to perform cellular functions.