Cell Respiration

Energy from ATP: Chemical Energy from organic molecules used Plants make sugars to use as source of chemical energy Animals eat food to get organic molecules as a source of chemical energy Cellular Respiration releases energy from organic molecules slowly through a step-by-step process so it can be used to make ATP

Glycolysis: First step BREAKING GLUCOSE in the cytoplasm (p. 229) 2 ATP drop off their high energy phosphates onto glucose unstable and high energy Glucose breaks in half to make 2 PGAL (G3P) PGAL is converted to Pyruvate H are pulled off the PGAL (G3P) Phosphates are pulled off the PGAL

PGAL is converted to Pyruvate: H are pulled off the PGAL NAD+ carries them away Breaking the bonds that hold H gives off some energy to put a phosphate on to ADP Phosphates are pulled off the PGAL Phosphates are put onto ADP ATP Each PGAL makes 2 ATP so each glucose makes 4 ATP 2 ATP used so net gain is 2 ATP 2 NADH2/Glucose carry H into mitochondria 2 pyruvate sent into mitochondria

Overall Glycolysis Reaction Glycolysis Requires Produces 1 Glucose 2 3GP  2 Pyruvate 2 ATP 4 ATP 2 NAD+ 2 NADH2 **in order for glycolysis to continue the H must be dropped off and NAD+ must come back. (happens in the first step of Kreb’s Cycle)

An-aerobic Metabolism: without oxygen Fermentation=anaerobic metabolism

Lactic Acid Fermentation Lactic Acid Fermentation: (Animals) NADH drops off H onto pyruvate NAD goes back to keep gylycolysis running Pyruvate becomes lactic acid when the H is added to it.

Alcohol Fermentation: Pyruvate converted to alcohol +CO2 as NADH drops off hydrogen NAD+ returns to continue glycolysis Done by yeast and bacteria

Aerobic Respiration=with oxygen in mitochondria NADH drops off H at mitochondria NAD+ returns to keep glycolysis going

Krebs Cycle: inside the mitochondria NADH drops off the H at the outer membrane of the mitochondria NAD returns to continue glycolysis The H diffuses into the inter membrane space

Krebs Cycle: inside the mitochondria Pyruvate diffuses into the matrix of the mitochondria where it is stripped of H and CO2 H is added to NAD inside the matrix to form NADH that transports the H to the E-chain CO2 is released from the cell through diffusion Breaking the bonds releases energy forming 2 ATP NET GAIN: 2 ATP, NADH for the chain, CO2

Electron Transport Chain: in the inner mitochondrial membrane NADH drops off H to an electron acceptor that takes the E through the chain, forming a H+ in the matrix The H+ diffuses through a protein channel into the inter-membrane space forming a high concentration of H+.

Electron Transport Chain: in the inner mitochondrial membrane H+ diffuses through an ATPase channel creating ATP The H+ bonds with the electron from the chain forming a hydrogen atom inside the matrix The hydrogen bonds with an O2 that has diffused into the matrix and forms water Water leaves the cell through osmosis NET GAIN: 32 ATP, CO2, H2O

OVERALL REACTION: One glucose molecule + H2O + O2= 2 ATP from Glycolysis 2 ATP from Krebs Cycle CO2 released from the cell 32 ATP from E-transport Chain H2O released from the cell