What is Respiration? The process of respiration is where organisms convert chemical energy into cellular energy, which is known as ATP. Adenine Ribose P P P

Cellular Respiration high energy sugar low energy CO 2 + H 2 O P i + ADP low energy ATP high energy

Where does respiration occur? In both autotrophs and heterotrophs that depend on chemical energy to make ATP. The actual process occurs inside a cell s cytoplasm and the mitochondria.

What does cellular respiration require? 1) Carbohydrates, Sugars, Starches (C 6 H 12 O 6 ) 2) Oxygen (O 2 )

Eat carbs Absorb Polysaccharides Hydrolysis breaks down Polysacch. Produce ATP Cellular Respiration Form Monosaccharides (Glucose) Transport ATP in the blood Break bond to form ADP & phosphate Release ENERGY in cells!!!

How? Fermentation (anaerobic) Oxygen absent Organic Compounds Glycolysis Oxygen present The process of respiration is divided into different stages depending on whether or not oxygen is present. Aerobic Respiration When oxygen is present much more ATP can be made (up to 20 times more). ATP ATP

Process: Glucose is split into two 3- carbon pyruvic acid molecules. Energy from the glucose molecule is stored as ATP and NADH Note: ATP must be invested to get the process started Glycolysis General Information: Takes place in the cytoplasm of cell Does not require O 2 Glycolysis animation: http://www.science.smith.edu/departments/biology/bio231/glycolysis.html

Glycolysis Summary 2 ATP were used to start the process. 4 ATP were produced from this process. This gives a total net yield of 2 ATP.

Aerobic Respiration If oxygen is present the pyruvic acid produced during glycolysis continues on to aerobic respiration. Aerobic respiration takes place within the mitochondria. Aerobic Respiration has 2 stages: Krebs Cycle Electron Transport Chain (ETC)

Prep for the Krebs Cycle General Information: Takes place in the matrix of the mitochondria. Pyruvic Acids from Glycolysis must be modified before they can enter the Krebs Cycle. Process: Pyruvic acids (3-carbon molecules) are converted to Acetic Acids (2-carbon molecules). Co-enzyme A is attached to form Aceytl-CoA

The Krebs Cycle Process: 1. Acetic acid from acetyl-coa joins a 4-C molecule to form a 6-C molecule. General Information: 2. For every acetic acid, 2 CO 2 are produced. Takes place in the matrix 3. Some energy is transferred directly into ATP s. of the mitochondria 4. Most energy is trapped by NADH. Produces many energycarrier molecules (NADH 5. Some is also captured in FADH 2 molecules. 6. The 4-C molecule which remains after the CO & FADH 2 ) 2 s are produced is recycled to begin the process again.

Intermembrane space Electron Transport Chain Mitochondrial Matrix Process: 1. Electrons donated by NADH enter the electron transport chain. 2. Energy from these electrons pumps H + ions out of the inner mitochondria (matrix). Hydrogen builds up outside the inner membrane and creates a concentration gradient. 3. H + diffuses back to the inside of the mitochondrion by passing through a carrier protein (ATP Synthase) 4. As it passes through the ATP Synthase, the H + causes the protein to attach a phosphate (P i ) to ADP, producing ATP. 5. Hydrogen that has re-entered the mitochondrion combines with used up electrons and oxygen to form H 2 O.

Intermembrane space Electron Transport Chain Mitochondrial Matrix Notes: NADH molecules enter the ETC at the first transport protein and cause the production of 3 ATP molecules. FADH 2 molecules enter the ETC at the second transport protein and cause the production of 2 ATP molecules. The ETC can produce up to 34 ATP s for each glucose that undergoes aerobic respiration. Electron Transport Chain Animation Cellular Respiration Overview Animation

Cellular Respiration Summary

Cellular Respiration Summary Glycolysis: Produces 2 ATP directly. Produces 2 NADH, which get converted to 6 ATP in ETC. Total of 8 ATP from glycolysis. Acetyl CoA: Produces 2 NADH, which get converted to 6 ATP in ETC. Total of 6 ATP from Acetyl CoA. Krebs Cycle: Produces 2 ATP directly. Produces 6 NADH, which get converted to 18 ATP in ETC. Produces 2 FADH 2, which get converted to 4 ATP in ETC. Total of 24 ATP from Krebs Cycle.