CELLULAR RESPIRATION 

Catabolic pathways yield energy by oxidizing organic fuels 

- CATABOLIC PATHWAYS: molecules are broken down and their energy is released 

   1. FERMETATION: the partial degradation of sugars that occur without the use of oxygen 

   2. AEROBIC RESPIRATION: most efficient and is when oxygen is consumed as a reactant along with organic fuel 

- OXYDATION REDUCTION: electrons are transferred from one reactant to another. The loss of one of more electrons oxidation (loss of energy) 

- REDUCTION: the gain of one of more electrons (gain of energy) 

Glycolysis harvest chemical energy by oxidizing glucose to pyruvate 

- GLYCOLYSIS: (occurs in the cystol) the degradation of glucose begins as it is broken down into two pyruvate molecules. The result is two three-carbon sugars 

After pyruvate is oxidized the citric acid cycle completes the energy yielding oxidation of organic molecules 

- after glycolysis pyruvate is oxidized to acetyl COA

- CITRIC ACID CYCLE: the cycle that breaks down glucose and releases CO2 as a waste product products of each cycle: 2CO2, 3NADH, 1FADH, 1ATP 

During oxidative phosphorylation, chemiosmosis, couples electron transport to ATP synthesis

- ELECTRON TRANSPORT CHAIN: electron transport and pumping of protons which create an H+ gradient across the membrane

- CHEMIOSMOSIS: energy-coupling mechanism that uses energy stored in the form of an H+ gradient to drive cellular work

Fermentation and anaerobic respiration enable cells to produce ATP without the use of oxygen

- ANAEROBIC RESPIRATION: by certain prokaryotes generates ATP without oxygen using an electron transport chain 

- FERMENTATION: an expansion of glycolysis in which ATP is generated by substrate level phosphorylation 

   1. ALCOHOL FERMENTATION: pyruvate is converted to ethanol releasing CO2 and oxidizing NADH in the process to create more NADH+

   2. LACTIC ACID FERMENTATION: pyruvate is reduced by NADH (NAD+ is formed in the process) and lactate is formed as a waste product 

- FACULATIVE ANAEROBES: can make ATP with oxygen and then switch to fermentation 

- OBLIGATE ANAEROBES: cannot survive in the presence of oxygen glycolysis and the citric acid cycle connect to many other metabolic pathways

- PHOSPHOFUCTOCKINASE: allosteric enzyme that functions early in the pathway of glycolysis and acts as a regulator of respiration it is inhibited by high levels ATP