1 / 9

Anaerobic Respiration

Anaerobic Respiration. Lactic Acid Fermentation Oxygen is not present Conversion of 2 molecules of pyruvate into lactic acid when oxygen is not present Happens during vigorous muscle exercise Liver converts lactic acid back into glucose . Lactic Acid Fermentation.

thea
Télécharger la présentation

Anaerobic Respiration

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Anaerobic Respiration • Lactic Acid Fermentation • Oxygen is not present • Conversion of 2 molecules of pyruvate into lactic acid when oxygen is not present • Happens during vigorous muscle exercise • Liver converts lactic acid back into glucose

  2. Lactic Acid Fermentation • Occurs in humans when • Demand for ATP exceeds the rate at which O₂ can be supplied • Process • Pyruvate is converted into lactate • NAD⁺ reduced to NADH • Lactate regeneratesNAD⁺ (oxidizes) • Glycolysis continues

  3. Lactic Acid Fermentation • Final reaction pyruvate + NADH + H⁺ → NAD⁺ + lactate • Glycolysis included glucose + 2 ADP + 2Pi → lactate + 2ATP Fermentation only produces 2 ATP!!!

  4. Anaerobic Respiration • Alcohol Fermentation • Does not occur in humans • Occurs in yeast when oxygen is not available • Facultative anaerobes • Conversion of 2 molecules of pyruvate into ethanol

  5. Alcohol Fermentation Facultative anaerobes - survive with or without oxygen • Occurs in • Bacteria, yeasts • Process • Pyruvate is decarboxylated • NAD⁺ is reduced to NADH • Produces acetaldehyde • Acetaldehyde oxidizes NADH to NAD⁺ • Ethanol is produced • Products • CO₂ • Ethanol • NAD⁺

  6. Alcohol Fermentation • Final reaction: pyruvate + NADH + H⁺ → NAD⁺ + CO₂ + ethanol • Glycolysis included (2 pyruvate molecules) glucose + 2 ADP + 2 Pi → 2 ATP + 2CO₂ + 2 ethanol Fermentation produces only 2 ATP!!!

  7. Anaerobic Respiration • Obligate anaerobes • Cannot survive in the presence of oxygen • Lack mitochondria • Have electron transport chains • Inorganic terminal electron acceptor • Sulfate SO₄²⁻ • Nitrate NO₃⁻ • Iron ion Fe³⁺ • Many prokaryotes, protists

  8. Cells that produce HEAT rather than ATP • Uncoupling • Proteins in mitochondria provide a different path for H⁺ • Instead of producing ATP, thermal energy is released • Brown adipose tissue • burns energy in order to maintain internal temperature • Hibernating mammals

  9. Alternatives to Glucose • Disaccharide carbohydrates • Hydrolyzed into glucose, fructose, galactose • Glycogen is hydrolyzed by enzymes in liver • Produce glucose-6-phosphate • Fats • Triglycerides • Hydrolyzed into glycerol • Converted into glyceraldehyde-3-phosphate • Fatty Acids • Split into 2 carbon fragments • Become acetyl groups – attach to CoA • Proteins • Hydrolyzed into amino acids • -NH₂ is removed and the rest enters as pyruvate, acetyl groups

More Related