Photosynthesis & Cellular Resp.

By: Prajna Vootukuri and Ritthikha Vijayaragavan



-6H20+6CO2+ ATP----> 6O2 + C6O12H6

^Sunlight Rays

-water enters through roots of plant and goes through the roots via xylem.

-photosynthesis occurs in chloroplast in leaves

-Light Dependent cycle and Calvin cycle

Light Dependent Cycle

- In the light-dependent reactions, energy from sunlight is absorbed by the molecule chlorophyll and converted into stored chemical energy in the form of the electron carrier molecule NADPH and ATP.

- take place in the thylakoid membrane(granum)

Calvin Cycle(AKA Light Independent Cycle)

-the energized electrons from the light-dependent reactions provide energy to assemble carbohydrates from carbon dioxide molecules

-do not use light as a reactant, but use products of light independent reactions.

- depend on the energy carrier molecules to drive the construction of new carbohydrate molecules.

- After the energy is transferred, energy carrier molecules return to the light-dependent reactions to get more energized electrons

Cellular Respiration

We eat a sandwich⇾ it is broken down into smaller and smaller units until it becomes small enough to be used in our cells as glucose molecules. At the same time, we are breathing in oxygen

that travels from our lungs through our bloodstream into small and smaller blood vessels until it reaches our cells. The small intestine and villi also help- they help with digesting the food. When the glucose and oxygen reaches our cells, we have the materials we need to perform cellular respiration. This process starts in the cells’ cytoplasm and is completed in the mitochondria. There, one molecule of glucose with 6 molecules of oxygen are changed into 36 molecules of ATP – the energy cells can use for all functions and processes.

***Cellular respiration is going on in every cell in both animals and plants.

Equation : C6H12O6 + 602 = 6CO2 + 6H2O + energy(36 ATP)

  • Cellular respiration is the process by which the chemical energy of "food" molecules is released and partially captured in the form of ATP.

  • There are two types : Aerobic and Anaerobic

  • Aerobic respiration is when there is enough oxygen, while anaerobic is when there isn’t enough oxygen(AKA Fermentation)


Raw Materials

  • Glucose , Oxygen, Water

  • Plants make own glucose and and recapture oxygen during photosynthesis(through the stomata), while animals get glucose from the food they eat and oxygen from breathing(lungs)

  • Plants and animals use the water from their own bodies for this process.


There are 3 stages: Glycolysis, Krebs Cycle, Electron Transport Chain


  • 1 glucose molecule, in the cell’s cytoplasm, is broken down into 2 molecules of

pyruvate, which is then used in the Kreb’s Cycle(stage 2).

  • This breakdown also releases 2 ATP + 2 H2O + 2 NADH molecules

Krebs Cycle

  • At the beginning, pyruvate is pulled into the cell’s mitochondria and converted to Acetyl-CoA.

  • The Acetyl-CoA molecule is then converted into 4 CO2 molecules, 6 NADH molecules, 2 ATP molecules and 2 FADH2 molecules.

Electron Transport Chain

  • The final stage – the Electron Transport Chain (ETC) is found in the mitochondria (in animals) and in the chloroplasts (in plants) and releases 32-34 ATP molecules when the electron transport chain produces a concentration gradient through which hydrogen moves across the membrane releasing energy as ATP .

Photosynthesis and Cellular Respiration

Photosynthesis creates glucose molecules (instead of eating) → this fuels cellular respiration in the plant cells → which creates ATP → which fuels plant growth and reproduction → which provides carbohydrates to animals for their cellular respiration. The energy cycle continues.


  • without presence of oxygen

  • happens in cell’s cytoplasm, not mitochondria.

  • can only get 2 ATP molecules per glucose molecule(less than aerobic)

  • uses the pyruvate molecules made by glycolysis from glucose.

  • Equation: C6H12O6(glucose)CO2+ 2C2H5OH(alcohol) and some energy

  • In the making of wine and beer (alcohol), yeast cells generate ATP by the fermentation of the sugars in fruit and grain (in the absence of oxygen). Yeast can also release carbon dioxide in this process, which is what causes bread to rise.

  • In animals, the lack of oxygen will drive muscle cells to carry on lactate fermentation which creates lactic acid causing sore and cramping muscles. Ex: Running


Source: Boundless. “The Two Parts of Photosynthesis.” Boundless Biology. Boundless, 14 Sep. 2015. Retrieved 05 Dec. 2015 from

Source: Exploring Nature
"Cellular Respiration." Encyclopedia of Metalloproteins (2013): 587. Web. 4 Dec. 2015.