BIO-1801 Lecture Notes - Lecture 9: Electron Acceptor, Facultative Anaerobic Organism, Anaerobic Respiration
Aerobic versus Anaerobic Respiration
- All eukaryotes and many prokaryotes use
oxygen as the terminal electron acceptor for
the ETC. (aerobic respiration) Some
prokaryotes use other electron acceptors
(anaerobic respiration)
- -Alternate electron acceptors such as
nitrate, sulfate, carbon dioxide
- Anaerobic Respiration: In Prokaryotes
Glycolysis, breakdown of Pyruvate, Citric
Acid Cycle, & Electron Transport Chain**.
- Aerobic Respiration is the Most efficient.
Oxygen is the most effective electron
acceptor (highest electronegativity). Aerobic
organisms grow and reproduce faster.
-Fermentation: is a metabolic pathway that occurs in the cytoplasm, it
regenerates NAD+ from NADH. Electrons from NADH are transferred to
pyruvate. Enables ATP production from glycolysis only.
-When there is no electron acceptor, fermentation occurs. NADH builds up
and there is no NAD+ available to accept electrons. Glycolysis, pyruvate
processing, and the citric acid cycle stop.
Different Fermentation Pathways Exist
-Muscle cells deprived of oxygen convert to lactic acid fermentation.
Lactate and NAD+ are produced. Lactate can be recycled later.
- Alcohol fermentation: Pyruvate is converted to acetaldehyde and CO2.
Ethanol and NAD+ are produced.
-Other Fermentation are used to make soy sauce, tofu, yogurt, cheese,
etc.
-Prokaryotes that rely on fermentation are present in our intestines.
-Fermentation produces 2 ATP per glucose, compared with about 29 ATP
per glucose in cellular respiration.
-Facultative anaerobes can switch between fermentation and aerobic
respiration.
-In Fermentation NADH DOES NOT donate electrons to electron transport
chain.
Fermentation
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
All eukaryotes and many prokaryotes use oxygen as the terminal electron acceptor for. Fermentation: is a metabolic pathway that occurs in the cytoplasm, it regenerates nad+ from nadh. Enables atp production from glycolysis only. the etc. (aerobic respiration) some prokaryotes use other electron acceptors (anaerobic respiration) When there is no electron acceptor, fermentation occurs. Nadh builds up and there is no nad+ available to accept electrons. Glycolysis, pyruvate processing, and the citric acid cycle stop. Different fermentation pathways exist nitrate, sulfate, carbon dioxide. Oxygen is the most effective electron acceptor (highest electronegativity). Muscle cells deprived of oxygen convert to lactic acid fermentation. Alcohol fermentation: pyruvate is converted to acetaldehyde and co2. Other fermentation are used to make soy sauce, tofu, yogurt, cheese, etc. Prokaryotes that rely on fermentation are present in our intestines. Fermentation produces 2 atp per glucose, compared with about 29 atp per glucose in cellular respiration. Facultative anaerobes can switch between fermentation and aerobic respiration.