Photosynthesis and Cellular Respiration

ATP: The Fuel of LifeCellular respiration produces ATP, the fuel of

life. C6H12O6 + 6O2 -> 6CO2 + 6H2O + ATPCellular respiration can be broken down into

three parts:GlycolysisThe Krebs Cycle (Citric Acid Cycle)Electron Transport Chain

GlycolysisGlycolysis occurs in the cytoplasm. It needs

two molecules of ATP to begin, and results in a net gain of two molecules of ATP.

Glycolysis begins with a six-carbon sugar, and produces pyruvic acid in addition to ATP.

The Krebs CycleThe chemical bonds in pyruvic acid are

broken in a series of reactions known as the Krebs cycle. The Krebs cycle takes place in the mitochondria. The cycle produces 2 molecules of carbon dioxide, and 1 molecule of ATP. For each glucose molecules, the cycle takes place twice.

Electron Transport ChainThe electron transport chain occurs in the inner membrane of the mitochondria. NAD+ and FAD take the high energy electrons from Kreb cycle to the inner membrane of the mitochondria. The high energy electrons are then passed from various molecules in the electron transport chain: cytochromes. The energy of these electrons is used to produce ATP.

The electron transport chain produces 32 or 36 ATP molecules, depending on the electron carrier.

OXYGEN is the final recipient of the electrons

FermentationCellular respiration requires oxygen. When oxygen

is not present, fermentation occurs.There are two types of fermentation: lactic acid

fermentation and alcoholic fermentation.In lactic acid fermentation, pyruvic acid is

converted into lactic acid. Lactic acid is produced in the muscles. This is what makes muscles “sore” after exercise

In alcoholic fermentation, pyruvic acid is broken down to produce alcohol and carbon dioxide. This is how whiskey and other alcohols are produced

Photosynthesis

The Process of PhotosynthesisPhotosynthesis is the process by which green

plants use the energy in sunlight to produce carbohydrates.

Plants contain pigments. Pigments are colored substances that reflect or absorb light. One such pigment is chlorophyll.

When chlorophyll absorbs light, much of that light energy is transferred to electrons in the chlorophyll molecule.

Light-Dependent ReactionsLight-dependent reactions require direct

involvement of light. They use SUNLIGHT to excite electrons. These excited electrons move to an electron acceptor. At the end of the light-dependent reaction, ATP and NADP+ are produced.

Light-Independent (Calvin Cycle) ReactionsLight-independent reactions use the energy

from ATP to make sugars. Water is split. (Hydrogen is needed)Carbon (from CO2) is used for the Carbon

molecules needed in a sugarEach turn of the Calvin cycle uses 1 molecule

of carbon dioxide and 2 atoms of hydrogen.The products of the light-independent

reaction are simple sugars.

Plant Cells

Cell Wall Chlorophyl

Stomata Guard cells

PhotorespirationRuBisCo fixes OxygenWastefullEvolutionary left over

Cam PlantsStomata open at NIGHTCO2 stored as organic acids in the vacuolesCO2 focused around RuBisCo by TIME

C4 PlantsUses PEP to fix CO2 in mesophyll cells and

move it to Bundle Sheath cells (as Malate)Focus CO2 around RuBisCo SPATIALLYVery little O2 in the bundle sheath