Energy: Chemical vs. Light Cell Respiration Vs. Photosynthesis

1. Releasing energy…this is respiration Cellular respiration banks energy in ATP molecules The reactants O 2 and glucose regroup to form the products CO 2 and H 2 O Energy from glucose is released and stored in ATP

Where does respiration take place and who does it? Cytoplasm and mitochondria The mitochondria’s design-many membranes folded inside the mitochondria, allows for lots of chemical reactions to take place. These generate the energy to put ADP + P -> ATP Any living organisms do respiration since all living things require energy!

LE 6-11 NADH FAD FADH 2 NAD + Electron Transport Chain Chemiosmosis ATP ADP P + H2OH2O O2O H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ Cyanide, carbon monoxide Rotenone Oligomycin DNP ATP synthase 2

LE 6-3 EnergyWaterCarbon dioxide Oxygen gasGlucose 2. Here’s the formula again!

3. Aerobic vs. Anaerobic respiration… Aerobic=with oxygen All 3 steps of respiration occur=38 ATPs Anaerobic=no oxygen Only glycolysis occurs=2 ATPs

What do you know about photosynthesis? 1. Who does photosynthesis-autotrophs, heterotrophs, or both? 2. What carbohydrate is a product of photosynthesis? (be specific) 3. What pigment is used for photosynthesis to absorb light? 4-5. What two things does the Calvin Cycle need to produce sugar? (hint-one is a product of the light reactions)

Photosynthesis…using “Light” energy… Plant Power 1. Photosynthesis makes sugar and oxygen gas from carbon dioxide and water Carried out by plants, algae, and some bacteria The ultimate source of all food eaten by animals A major source of heat, light, and fuel

2. Here’s the formula…

Who can photosynthesize? 7.1 Autotrophs are the producers of the biosphere –Autotrophs produce their own food –Autotrophs produce the food supply for the global ecosystem –Photoautotrophs produce organic molecules using light energy Plants, algae, and photosynthetic bacteria Video: Cyanobacteria (Oscillatoria) Video: Cyanobacteria (Oscillatoria)

Where does photosynthesis take place? Photosynthesis occurs in chloroplasts –In plants, photosynthesis occurs primarily in leaves CO 2 enters and O 2 exits through stomata –Chloroplasts are the site of photosynthesis Concentrated in mesophyll cells of leaves

LE 7-2 Leaf Leaf Cross Section Mesophyll Cell Vein Mesophyll Chloroplast Stoma Stroma Chloroplast CO 2 O2O2 Granum Grana Stroma TEM 9,750  Thylakoid Thylakoid space Intermembrane space Inner membrane Outer membrane LM 2,600 

More on the chloroplast… Like the mitochondria, it has many folded sacs (they are called thylakoids) that contain a special pigment (chlorophyll) for photosynthesis. There are a lot of chemical reactions that occur within the chloroplast that convert solar energy (light) into chemical energy (ATP). This energy is needed to complete photosynthesis (the making of sugar).

3. So…photosynthesis happens in 2 stages First, the light reactions where light energy is converted in chemical energy (ATP, NADP) and oxygen gas is given off. Second, with the help of this chemical energy, the Calvin cycle occurs. Here’s where sugar (C6H12O6) is assembled from CO2 with the help of the energy produced in the light reactions.

LE 7-5 Light Chloroplast H2OH2O LIGHT REACTIONS (in thylakoids) ATP NADPH Electrons O2O2 CO 2 Sugar P  ADP NADP  CALVIN CYCLE (in stroma)

PHOTOSYNTHESIS REVIEWED AND EXTENDED 7.11 Review: Photosynthesis uses light energy to make food molecules –The light reactions Capture light energy Generate NADPH and ATP Release O 2 and water –The Calvin cycle Manufactures sugar –Cells use many of the same mechanisms in photosynthesis and cellular respiration

Combining the two processes…cell respiration and photosynthesis These two processes are connected and are important for all living things to have enough energy to survive. (Even though not every organism can photosynthesize)! The fuel from photosynthesis eventually powers cell respiration. These two processes are even significant concerning the phenomena known as global warming-how?

Cell Respiration and Photosynthesis… C6H12O6 + 6 O2 -> 6 CO2 + 6 H2O + ATP (energy) 6 CO2 + 6 H2O -> C6H12O6 + 6 O2 light/chlorophyll

LE 7-11 Light H2OH2O CO 2 Chloroplast NADP  ADP  P RUBP CALVIN CYCLE (in stroma) NADPH ATP G3P 3-PGA Stroma Photosystem II Electron transport chains Photosystem I Thylakoid membranes O2O2 LIGHT REACTIONS Sugars CALVIN CYCLE Cellular respiration Cellulose Starch Other organic compounds

How does photosynthesis moderate global warming? What is global warming? Does cell respiration contribute to global warming? Anything else? What role does photosynthesis play in global warming? Is global warming real?

Photosynthesis and global warming… Photosynthesis moderates global warming –The greenhouse effect Like a greenhouse, the atmosphere traps CO 2 and other gases that absorb heat radiated from Earth's surface Excess greenhouse gases in the atmosphere contribute to global warming –Photosynthesis, which removes CO 2 from the atmosphere, moderates warming Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings

LE 7-13b Sunlight Radiant heat trapped by CO 2 and other gases Atmosphere Some heat energy escapes into space

Assignment…. On a piece of poster board, create a Venn Diagram to compare and contrast the processes of cell respiration and photosynthesis. Use words, descriptive phrases, pictures, diagrams, etc. to show what these processes involve and what they have in common Goal: We should be able to learn and understand from your poster what these 2 processes are and how they are related. 20 pts. (graded for accuracy, completeness with detail, appearance-quality, neatness, pictures, etc) Work days:____________ Due:_________

Cell Respiration vs. Photosynthesis