Cellular Respiration Lesson Objectives

Cell Respiration and Photosynthesis

• Cellular respiration is a complex process that releases energy in the form of ATP from food molecules.

Photosynthesis

• No information provided in the text.

Cellular Respiration

• Cellular respiration is a process that converts stored energy in food into chemical energy.

Steps in Cellular Respiration

• Glycolysis: occurs in the cytoplasm of the cell.
• Glycolysis Events:
  • One glucose molecule (C6H12O6) is broken down into 2 pyruvate acid molecules, generating 2 net ATPs.
  • Phosphate groups from 2 ATP molecules are transferred to glucose molecules.
  • The resulting 6-carbon compound is broken down into 2 three-carbon compounds containing phosphate groups.
  • 2 NADH molecules are produced, and a phosphate group is transferred to each 3-carbon compound.
  • The 3-carbon compounds are converted into 3-carbon pyruvate.
  • Glycolysis is a process of harvesting energy by breaking down glucose to pyruvate, producing 2 ATP molecules.

Krebs Cycle

• Occurs in the inner matrix of the mitochondria.
• Krebs Cycle Preparation: 3-carbon pyruvate is converted into 2-carbon molecules called Acetyl-CoA.
• Krebs Cycle Step 1: Acetyl-CoA combines with a 4-carbon compound to form a 6-carbon compound.
• Krebs Cycle: Produces NADH and FADH2.

Electron Transport Chain

• Occurs in the inner membrane of the mitochondria.
• A series of oxidation processes where electrons (in the form of H-) carried by NADH and FADH are transferred to electron receptors.
• Transfer of electrons from coenzymes NADH and FADH to receptors found in the protein complex.
• ATP Synthase: an enzyme that adds phosphate to ADP to produce ATP, producing water as a byproduct.
• Electron Transport Chain Byproducts:
  • ATPs are released with water as byproducts.
  • 3 ATPs are produced for every molecule of NADH.
  • 2 ATPs are produced for every 3 molecules of FADH2.
  • 36 ATPs are produced for every molecule of glucose (C6H12O6).