Chapter 9 Cellular Respiration

Heterotrophs Vs. Autotrophs Autotrophs/ Producers-Make Their Own Food Using the sun’s energy (i.e. Plants) Heterotrophs/ Consumers-Obtain Energy From the food they eat (i.e. Animals)

Production of Energy in heterotrophs Cellular Respiration – Process by which living organisms harvest energy from food they eat. C 6 H 12 O 6 + O 2 -> H 2 O + CO 2 + energy(ATP) Do you notice anything about this equation?

Forms of Respiration Oxygen gas makes the production of ATP very efficient. Although it is not required all of the time. Anaerobic respiration – The process of making ATP without the use of Oxygen. Aerobic respiration – The process of making ATP with the use of Oxygen.

Cell Respiration Flow Chart

Glycolysis Glycolysis – Break down of sugar in the cytoplasm. Glucose -> 2 pyruvates 2 ATP used 2 ATP used + 4 ATP made 2 net ATP made 2 net ATP made

Stage 2: Krebs Cycle The Krebs Cycle AKA The Citric Acid Cycle is a form of Aerobic Respiration. The Krebs Cycle requires the pyruvate and an NADH from Glycolysis, a CO 2, and a molecule called Acetyl-CoA which is made from 1 pyruvate once it releases a CO 2 molecule.

Take home message! For each pyruvate made 2 CO 2 molecules are produced. 3 NADH molecules produced. 1 FADH 2 molecule is made. 1 ATP molecule is made. How many ATP molecules are made per Glucose molecule?

E.T.C. Between Glycolysis and the Krebs Cycle only 4 ATP molecules in total are made. Our body needs a total of about ATP molecules. The rest come from an electron transport chain that gets the remaining energy from NADH & FADH 2. The ETC also produces 2 water molecules that are released. The ETC makes a total of about ATP. O 2 is the final e- acceptor.

E.T.C.

Anaerobic Respiration Fermentation – A form of anaerobic Respiration that uses leftover NAD+ to make energy. Fermentation occurs when there is not enough O 2. Being that O 2 is the final e- acceptor from the e.t.c. an organism that is out of O 2 needs to do something else for energy. There are two types of fermentation that you should know.

Lactic Acid Fermentation After a cell goes through all of Glycolysis and The Krebs Cycle if there in no O 2 around it will not go through the E.T.C. The first type of fermentation produces a chemical called Lactic Acid. Humans go through this type of fermentation when their O 2 level is depleted. When you exercise you’re forcing your body to work beyond the amount of O 2 and energy that you have available to you. Your body will switch to fermentation to gain a quick burst of energy. C 6 H 12 O 6 → 2 CH 3 CHOHCOOH (lactic acid)

Alcoholic (Ethanol) Fermentation Another type of fermentation results in the production of Ethyl alcohol and CO 2. An example of an organism that ferments is Yeast. C 6 H 12 O 6 → C 2 H 5 OH (ethanol) + CO 2 C 6 H 12 O 6 → C 2 H 5 OH (ethanol) + CO 2