BIOZONE: 85-87 Text: 102 Digital Text: 47 Sponge: Set up Cornell Notes on pg. 23 Topic: 8.2 Other Aspects of Cellular Respiration Essential Question: None. 2.8 Other Aspects of Cellular Respiration Key Vocabulary: Alcoholic Fermentation Lactic Acid Fermentation BIOZONE: 85-87 Text: 102 Digital Text: 47

Objective SWU: SW:

P. 20 Alcoholic Fermentation picture Lactic Acid Fermentation picture

Understandings: Anaerobic respiration gives a small yield of ATP from glucose

Anaerobic Respiration All pathways of cellular respiration start with glycolysis

Anaerobic Respiration

Anaerobic Respiration Fermentation: the breakdown of organic molecules for ATP production in an anaerobic way (without the use of oxygen) Aerobic Draw a small picture on p. 21 Anaerobic Cellular Respiration

Aerobic Respiration In the presence of oxygen, the pyruvate will enter the link reaction and Kreb’s cycle ETC

Anaerobic Respiration If NO oxygen is available there are two anaerobic pathways that the pyruvate can enter: Alcoholic fermentation Yeast Higher plant cells Lactic acid fermentation Animals

Alcoholic Fermentation 1. Glycolysis occurs first (net gain 2 ATP- 2 pyruvate) 2. The 3-carbon pyruvates are converted into molecules of ethanol Ethanol is a 2-carbon molecule that will be released as waste 3. A carbon atom is “lost” Given off as a waste CO² molecule

Alcoholic Fermentation Draw on top of p. 20 Ethanol glycolysis Ethanol

Ex: Yeast is added to baker’s bread as the generation of CO² molecules helps the dough rise- the CO² and ethanol are both given off as waste products It is also common to use yeast in the production of ethanol as drinking alcohol

Understandings: Lactate production in humans when anaerobic respiration is used to maximize the power of muscle contractions

Lactic Acid Fermentation Organisms that use an aerobic cell respiration pathway sometimes find themselves in a metabolic situation where they cannot supply enough oxygen to their cells

Lactic Acid Fermentation Ex: A person pushing beyond their normal exercise pattern or routine In this situation, the person’s pulmonary and cardiovascular systems (lungs and heart) supply as much oxygen to their cells as is physically possible If a person’s exercise exceeds their capacity of supplying oxygen, then at least some of the glucose entering into cellular respiration will follow the anaerobic pathways called lactic acid fermentation

Lactic Acid Fermentation Glycolysis first (net gain 2 ATP- 2 pyruvate) In a low-oxygen situation excess pyruvate molecules are converted into lactic acid molecules Lactic acid molecules are 3-carbon molecules (so there is no production of CO²)

Lactic Acid Fermentation What benefit does this serve? It allows glycolysis to continue with the small gain of ATP generated in addition to the ATP which is already being generated through the aerobic pathway

Lactic Acid Fermentation Draw on bottom of p. 20

Aerobic Cell Respiration is the most Efficient!!! Which type of respiration is the MOST efficient? Aerobic v Anaerobic. Aerobic Cell Respiration is the most Efficient!!! v.

Application: Use of anaerobic cell respiration in yeasts to produce ethanol and carbon dioxide in baking

Anaerobic cell respiration demo Materials Yeast Balloons Water bottles Sugar

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