LG 4 Cellular Energy Flow Cellular Energy ATP – Cellular Respiration Glycolysis – The Citric Acid Cycle – The Electron Transport System – The Cellular Respiration Reaction – Photosynthesis The Light Reactions of Photosynthesis – The Calvin Cycle – The Photosynthesis Reaction -

Describe the flow of energy and matter in cellular function. Unit III Cells Learning Goal 4 Describe the flow of energy and matter in cellular function.

Cellular Energy ATP Adenosine Triphosphate A high energy molecule that drives all cellular function Produced by the mitochondria in process called cellular respiration.

Cellular Respiration Glycolysis This part actually occurs in the cytoplasm of the cell. Glucose (which has 6 carbon atoms) is split into two 3 carbon molecules.

The Citric Acid Cycle (Also known as the Krebs Cycle) The 3-carbon molecules from glycolysis move into the mitochondrial membranes and are used to produce three types of molecules: NADH, FADH2, and ATP. Carbon Dioxide (CO2) is produced as a bi-product of this process and is removed from the cell.

The Electron Transport System The NADH and FADH2 provide energy to produce ATP. They do this by passing electrons to special proteins in the inner mitochondrial membrane. Left over hydrogen ions (H+) are then taken up by oxygen atoms from the oxygen we breathe, producing water.

The cellular respiration reaction: 6O2 + C 6H12O6  6CO2 + 6H2 O (Glucose) ATP is produced as a result of this process, but is not part of the reaction.

so where does the glucose come from?

Photosynthesis Light Reactions of Photosynthesis Sunlight strikes the chlorophyll molecules in the chloroplasts of plant cells. This energizes electrons in the chlorophyll and provides the energy to make two important molecules: NADPH and ATP. These electrons are replaced when water molecules are split, resulting in the production of atmospheric oxygen (O2).

The Calvin Cycle (Also known as the Dark Reactions) The NADPH and ATP from the light reactions are used to build carbohydrates (glucose) out of CO2 taken in by the plant.

The photosynthesis reaction: 6CO2 + 6H2O  C6H12O6 + 6O2 Light and chlorophyll are also needed