Anaerobic Cellular Respiration

Aerobic… What? We have reviewed aerobic respiration This is the process of taking molecules of glucose and breaking them down using oxygen from the environment It provides a huge amount of energy to a cell that can do it

Aerobic… What? This process makes roughly 32 ATP (remember that number is not set in stone) It also creates H 2 O and CO 2 Remember it can only be done by some organisms

Intro to Anaerobic Respiration When no oxygen is present or when a cell does not have mitochondria a different pathway is used after glycolysis After pyruvate is formed, the cells undergo fermentation Fermentation is the process of harvesting chemical energy without using oxygen

Intro to Anaerobic Respiration Fermentation does not actually increase the amount of ATP that the cell receives We have the 2 net ATP from glycolysis… and that’s it Fermentation only produces NAD+ so glycolysis can continue This means that fermentation produces no ATP, it just helps keep glycolysis running

Intro to Anaerobic Respiration Different types of organisms perform anaerobic respiration Obligate anaerobic organisms must have anaerobic conditions – Aerobic conditions will kill them Facultative anaerobic organisms can have aerobic or anaerobic conditions

Lactic Acid Fermentation There are two main types of fermentation Lactic acid fermentation is the process of turning the pyruvate into lactate (an ionized form of lactic acid) Lactic acid fermentation happens in animal muscle cells and some bacteria

Lactic Acid Fermentation There are two main types of fermentation Lactic acid fermentation is the process of turning the pyruvate into lactate (an ionized form of lactic acid) Lactic acid fermentation happens in animal muscle cells and some bacteria

Lactic Acid Fermentation In lactic acid fermentation involves oxidizing NADH into NAD+ and converting what is left of the pyruvate into lactate The NAD+ is sent back to glycolysis to reload glycolysis with NAD+ that it needs to continue

Alcoholic Fermentation Alcoholic fermentation happens in fungi, some bacteria plant cells Yeast is the most common organism that does this It changes pyruvic acid to ethyl alcohol It also causes the loss of one molecule of CO2 and the gain of one NAD+

Alcoholic Fermentation Lactic acid fermentation takes pyruvate and converts it to a 2 carbon molecule known as ethanol This process oxidizes NADH into NAD+ and releases CO 2 into the environment

Alcoholic Fermentation Alcoholic fermentation has been used by humans for hundreds of years This process gives us bread, cheeses, yogurts and alcohols

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Other Macromolecules? Ok, we have broken down glucose… However other things can be broken down for energy Complex carbohydrates can be broken down into monosaccharides and given the same process

Other Macromolecules? Fats contain a high number of hydrogens This means they can easily be broken down in order to power oxidative phosphorylation Remember how fats contain 9kc/gram of energy

Other Macromolecules? Proteins can be used for fuel as well You body often will go through carbohydrates and fats first because they are easier to break down In order to be used, proteins must first be broken down to individual amino acids

Side By Side Comparison Type of Molecule ProducedLactic Acid Fermentation Alcoholic Fermentation Aerobic Respiration ATP232 CO H2OH2O06