Cell Respiration All living things do cell respiration (including plants!) Basically, reverse of photosynthesis Carbohydrates and O 2 are used to make ATP (energy). CO 2 and H 2 O are waste products. Happens in the cytoplasm and mitochondria of the cell 3 steps

1. Glycolysis Happens in cytoplasm Glucose (6 C) is broken down into 2 pyruvic acid (3 C) Makes 2 NADH and 4 ATP, but uses 2 ATP, for a net gain of 2 ATP Is anaerobic (does not require oxygen) GTjQTqUuOwhttp:// GTjQTqUuOw

1. Glycolysis

2. Kreb’s Cycle Is aerobic, must have oxygen Happens in the mitochondrial matrix (open area inside) Pyruvic acid is converted into other compounds (Acetyl CoA, citric acid…C 6, C 5, C 4 ) This makes 1 ATP, 4 NADH and 1 FADH 2, per pyruvic acid (double that for each glucose molecule) Releases CO 2 as waste

2. Kreb’s Cycle youtube.co m/watch?v= KAjUsiZWyw k&feature=r elated youtube.co m/watch?v= KAjUsiZWyw k&feature=r elated

3. Electron Transport Chain Is aerobic and makes most of the energy in cell respiration Happens in cristae (inner membrane) of mitochondria The NADH and FADH 2 from glycolysis and Kreb’s cycle are made into ATP 3 ATP for each NADH and 2 ATP for each FADH 2 Uses oxygen, and gives off water as a waste product

3. Electron Transport Chain utube.com/wa tch?v=kN5Mtq AB_Yc&feature =related utube.com/wa tch?v=kN5Mtq AB_Yc&feature =related

Total ATP Glycolysis: 2 ATP (+ 6 from the 2 NADH* (in ETC)) Kreb’s cycle: 2 ATP (+ 24 from 8 NADH (in ETC)) (+ 4 from FADH 2 (in ETC)) Total: 38* ATP from each glucose molecule * some cells (brain and muscle) are not as efficient and will only make 36 ATP 2 2

Summary of Cell Respiration Glycolysis: –1 glucose (C 6 H 12 O 6 ) is broken down into 2 pyruvic acid + 2 ATP (net) + 2 NADH Kreb’s cycle – Each pyruvic acid is changed into other molecules –Makes 1 ATP, 4 NADH and 1 FADH 2 (per pyruvic acid….x 2 per glucose) –Releases CO 2 as a waste

Summary of Cell Respiration Electron transport chain –Takes all the NADH and FADH 2 and converts them into ATP – ATP in this step –H 2 O is waste

Relate to photosynthesis? Pretty much the reverse of photosynthesis (with 1 difference*) P: starts with CO 2 and H 2 O and energy and makes CH 2 O and O 2 CR: Starts with O 2 and C 6 H 12 O 6 and makes energy and H 2 O and CO 2 *difference: P doesn’t make C 6 H 12 O 6

Anaerobic Respiration If there’s not enough oxygen in the cell after glycolysis to perform the Kreb’s cycle, the cell automatically uses fermentation Pyruvic acid is converted into either lactic acid or ethyl alcohol Makes no ATP, but reuses the NADH from glycolysis, so glycolysis can occur and make 2 ATP GnKxv2_AEghttp:// GnKxv2_AEg

Anaerobic Respiration Makes no ATP, but reuses the NADH from glycolysis, so glycolysis can occur and make 2 ATP

Summary of Cell Respiration Glycolysis: –1 Carbohydrate is broken down into 2 pyruvic acid + 2 ATP + 2 NADH –Water is a waste product

Summary of Cell Respiration Kreb’s cycle