BIOA01H3 Lecture 26: BIOA01 Lecture 23
2 Nov 2018
School
Department
Course
BIOA01 Lecture 23: Anaerobic Metabolism, Intro to Photosynthesis
- Glucose can be broken down in the absence of oxygen via fermentation
o 2 forms: Lactic acid and ethanol
o 1: Lactic Acid Fermentation: occurs in animals and bacteria
▪ Electrons from NADH are transferred to pyruvate
▪ Yields NAD and lactic acid
▪ Process begins with glycolysis
• Yields 2 ATP and 2 NADH
o In this case the NADH doesn’t move to enter the ETC
o Instead it is used to reduce pyruvate
▪ Forms lactic acid in the process
▪ NADH is oxidized to NAD in the process
• NADH can then be used to oxidize another
glucose
▪ Final products per glucose: 2 ATP, 2 Lactic Acid, 2 water
o 2: Ethanol fermentation: occurs in animals and fungi
▪ Pyruvate releases CO2 yielding acetaldehyde
• Electrons are then transferred to this molecule from NADH to
form ethanol and NAD
▪ Process again begins with glycolysis
• Glucose is converted to pyruvate
o 2 CO2’s are removed to yield an acetaldehyde molecule
o Molecule is then reduced
o NADH is oxidized to form NAD
▪ Final products per glucose: 2 ATP, 2 Ethanol, 2 O2
o Both processes function to regenerate NAD for use in glycolysis
▪ Used to oxidize glucose into pyruvate, process that releases ATP without
the need for O2
▪ Both processes produce relatively low energy
o Storage forms of glucose: excess glucose is stored in 2 forms
▪ Both forms involve large branched polymers of glucose
• Allows for glucose regulation
▪ 1: stored as glycogen in animals
• Stored in liver and muscle cells
o Muscles: use it to give ATP for muscle contractions
o Liver: stores it for the whole body, releases it when
needed
▪ 2: stored as starch in plants
▪ Glucose molecules are released from glycogen via enzymatic reactions
• Cleavage occurs at the end of the glycogen chains
18
BIOA01H3 Full Course Notes
Verified Note
18 documents
