Making ATP in the presence of oxygen… Aerobic Respiration Making ATP in the presence of oxygen…

Quick Quiz: The purpose of photosynthesis is to provide what for the plant cell? The purpose of respiration for BOTH plant and animal cells is to provide what? What is the starting molecule for Respiration? What happens after Glycolysis if there is no O2 available?

(continued…) Glucose (a monosaccharide!) ATP (the cell’s energy currency) Glucose Fermentation (anaerobic respiration)

Where does aerobic respiration occur? In the mitochondria! (the “powerhouse” of the cell!)

After Step 1: Glycolysis…. The pyruvic acid joins with an enzyme called Coenzyme A to form Acetyl CoA.

Fidgety -- like this guy Acetyl CoA (a very “fidgety” molecule) that is not very stable chemically. It enters the Kreb’s Cycle and changes its composition several times producing... Fidgety -- like this guy

Step 2: Kreb’s Cycle

Products of the Kreb’s Cycle 1) CO2 2) NADH 3) ATP

A word about the products: CO2 is a waste product for animal cells, but is reused in plant cells for… you guessed it- PHOTOSYNTHESIS! NADH is an electron carrier, much like NADPH is in photosynthesis. It carries electrons to electron transport chain ATP are produced in Krebs Cycle

Step 3: The Electron Transport Chain This ETC is VERY similar to the one in photosynthesis!!!! But where does it occur? (remember, we’re not in the chloroplast any more!)

The electron transport chain Electron carrier H+ Phospholipids H+ H+ H+ H+ H+ H+ H+ H+ Caught by oxygen!! Electrons (from NADH) H+

The ETC consists of proteins embedded in the inner membrane of the mitochondrion. H+ ions are pushed out of the mitochondrial matrix, creating an electrical charge difference similar to the one in the light reactions of photosynthesis. The H+ ions naturally diffuse back through the ATP synthase, creating more ATP for a total of 36!

ATP synthase (an enzyme)uses this energy to make lots of ATP!!!!

The final acceptor of the electron is Oxygen. 4H+2O --> 2H2O So the final products of aerobic respiration are: H2O (from ETC) CO2 (from Krebs cycle) 36 ATP per molecule of glucose

total!!