Anaerobic Respiration: Fermentation PDF

Anaerobic Respiration: F ermentation General Biology I Objectives: identify the pathway of electron flow when oxygen is unavailable; explain the advantages and disadvantages of fermentation; and prepare simple fermentation setup using common fruits to...

Anaerobic Respiration: F ermentation General Biology I Objectives: identify the pathway of electron flow when oxygen is unavailable; explain the advantages and disadvantages of fermentation; and prepare simple fermentation setup using common fruits to produce wine.  Anaerobic Respiration organisms convert energy in the absence of oxygen uses all three parts of cellular respiration, but uses a different final electron acceptor instead of oxygen gas  Anaerobic Respiration: F ermentation An example of anaerobic respiration process that uses glycolysis only Processes that regenerate NAD+ from NADH are collectively referred to as fermentation.  Anaerobic Respiration: F ermentation Fermentation begins with glycolysis It allows glucose to be continuously broken down to make ATP due to the recycling of NADH to NAD+.  Anaerobic Respiration: F ermentation Microorganisms like yeast and bacteria usually play a role in the fermentation process, creating beer, wine, bread, kimchi, yogurt and other foods.  Lactic Acid F ermentation This is carried out by yogurt bacteria and by your own muscle cells when you work them hard and fast.  Lactic Acid F ermentation The chemical reaction of lactic acid fermentation is the following: Pyruvate + NADH → lactic acid + NAD+  Lactic Acid F ermentation In lactic acid fermentation, NADH transfers its electrons directly to pyruvate Pyruvate becomes lactate and NADH is regenerated back into NAD+.  Alcohol F ermentation This kind of fermentation produces ethanol Carried out by living yeast cells under anaerobic conditions Used to make bread, wine, and biofuels  Alcohol F ermentation The chemical reaction of alcohol fermentation is the following: Pyruvate → CO2 + acetaldehyde + NADH → ethanol + NAD+  Alcohol F ermentation First, a carbon is removed from pyruvate, releasing CO2 as a gas and forming acetaldehyde Second, NADH passes its electrons to acetaldehyde, oxidizing into NAD+ and reducing acetaldehyde to ethanol  Lactic Acid Fermentation Alcohol Fermentation Occurs in bacteria, yeast, and muscle cells Produces lactic acid from pyruvate Used in the production of yogurt and cheese Occurs in yeast and other microorganisms Produces ethanol from pyruvate Used in the production of bread, beer, and wine Advantages and Disadvantages of F ermentation ADVANTAGES Energy is still extracted Fermented foods 01 from glucose when oxygen is unavailable 03 have longer shelf life Certain bacteria produce Fermented foods are rich in 02 chemicals that are important in the chemical, food, and 04 probiotics, the good bacteria pharmaceutical industries that can improve digestion Fermentation 05 enhances nutrient absorption Advantages and Disadvantages of F ermentation DISADVANTAGES Energy from ethanol and Many fermented foods 01 are at risk of contamination 03 lactate cannot be extracted by organisms using anaerobic respiration Human muscle cells 02 The energy produced is insufficient 04 feel pain when lactate accumulates  Short-answer Questions 1. Differentiate lactic acid fermentation and alcohol fermentation. 2. Why is fermentation useful? Thank you for Listening!