BIOL1130 Lecture Notes - Lecture 11: Pyruvic Acid, Triose, Glycolysis
28 May 2018
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6.1 Mitochondrial function
6.1.1 Respiration
• 3 steps : Glycolysis in cytosol, Citric Acid Cycle/Krebs Cycle at matrix of mitochondria,
Oxidative Phosphorylation in cristae of inner membrane of mitochondria.
• Glycolysis and CAC produce NADH
• NADH is electorn carrier
6.1.1.1 Glycolysis
• is an oxidative process
• net yield = 2ATP and 2NADH
• is a 10 step process
• Glucose, aka Hexose (6C) is split into 2 triose-p (3C) ,5 step, req 2 ATP
• next, Triose- P is oxidized to pyruvate, 5 step, generates 4ATP + 2NADH
•
6.1.1.2 CAC/ Krebs Cycle
• pyruvate produced from Glycolysis pass through outer membrane (pores) and get
into inner membrane, pores are highly permeable to ions/small molecules
• and then pyruvate travels to highly invaginated/twisted inner membrane aka
CRISTAE of mitochondria
• although cristae is impermeable to most ions/molecules ,its got PROTEINS that sit on
membrane that allow transportation of specific molecules/ions, in this case is
pyruvate specific proteins
• lipids (beta oxidation, the other pathway )from glycolysis must be converted into
acetyl-CoA before ATP production
• enzymes for CAC / Krebs are located at matrix (liquid part ) of mitochondria
• equation? Pyruvate + CoA + NAD+ → CO2 + NADH + acetyl-CoA
• 6CO2 is produced, CAC is an oxidation reaction, pyruvate is OXIDISED to CO2,
pyruvate LOST e-, LOST H+ .
• pyruvate is oxidized to Acetyl-CoA at the mitochondrial matrix during aerobic
respiration
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• NAD+ is reduced to NADH
• NADH is generated (Glycolysis and CAC/Krebs generate NADH rmb),
• 2FADH2, 8ATP and 2NADH are generated.
• to decarboxylase the pyruvate, pyruvate dehydrogenase , the enzyme is needed.
•
• What is the function of matrix?
• matrix is the liquid part of the mitochondria, it has soluble enzymes of CAC/Krebs ,
remember CAC/Krebs happens in mitochondria, therefore enzymes for CAC are at
matrix of mitochondria
• meanwhile, enzymes for CAC/Krebs for PHOTOSYNTHESIS is at the stroma of
chloroplast (the liquid phase)
• (oxidative phosphorylation) CRISTAE of inner membrane has ELECTRON TRANSPORT
CHAIN that drives ATP here.
• electron transport train occurs in cristae of inner membrane of mitochondria
6.1.1.3 Oxidative phosphorylation
• occurs in cristae of inner membrane of mitochondria
• oxidation of NADH donates e- to reduce to become NAD+ , e- is provided for O2 to
reduce to H2O. NADH is therefore oxidized
• rmb, respiration needs O2, is aerobic
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
6. 1. 1 respiration: 3 steps : glycolysis in cytosol, citric acid cycle/krebs cycle at matrix of mitochondria, Oxidative phosphorylation in cristae of inner membrane of mitochondria: glycolysis and cac produce nadh, nadh is electorn carrier. 6. 1. 1. 2 cac/ krebs cycle: pyruvate produced from glycolysis pass through outer membrane (pores) and get into inner membrane, pores are highly permeable to ions/small molecules, and then pyruvate travels to highly invaginated/twisted inner membrane aka. Chain that drives atp here: electron transport train occurs in cristae of inner membrane of mitochondria. 6. 1. 1. 3 oxidative phosphorylation: occurs in cristae of inner membrane of mitochondria, oxidation of nadh donates e- to reduce to become nad+ , e- is provided for o2 to reduce to h2o. Now, respiration without oxygen is called anaerobic metabolism. Aerobic exercise low intensity of o2 demand, increases capacity of blood to carry oxygen. Fermentation pathways convert pyruvate to ethanol or to lactate: plants are able to have alcohol(ethanol) and lactate fermentation.
