KrebsCycleII2010SRS

KrebsCycleII2010SRS - Citric Acid Cycle II Lecture 27...

Info iconThis preview shows pages 1–20. Sign up to view the full content.

View Full Document Right Arrow Icon
Citric Acid Cycle II Lecture 27 Chapter 17-4, 17-5
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Figure 17-2
Background image of page 2
CAC is an Amphibolic Pathway Amphibolic: both catabolic and anabolic functions. – Catabolic: oxidation of acetate to CO 2 . Anabolic: intermediates serve as precursors to other molecules. Depletion of intermediates for anabolic pathways creates a problem for catabolism: slows CAC.
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Figure 17-17 Cataplerotic reactions: “empty” CAC Anaplerotic reactions: “fill” CAC
Background image of page 4
Page 589 Cataplerotic reactions: Glutamate dehydrogenase:
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Page 589 Cataplerotic reactions: Aspartyl aminotransferase
Background image of page 6
Anaplerotic reactions Amino acid breakdown Odd-chain fatty acid breakdown Pyruvate carboxylase (biotin): Pyruvate + CO 2 + ATP + H 2 O --> OAA + ADP + Pi If insufficient OAA in cycle, Acetyl-CoA builds up. Acetyl-CoA activates pyruvate carboxylase, makes more OAA.
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Figure 17-17 Cataplerotic reactions: “empty” CAC Anaplerotic reactions: “fill” CAC
Background image of page 8
Page 553 β-keto acid: decarboxylation is energetically favorable OAA -----> Pyr + CO 2 G o’ < 0
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Figure 16-16 part 1 Pyruvate carboxylase (biotin) Coupled reaction: use energy in ATP to drive forward the carboxylation of pyruvate. Acetyl-CoA is a required allosteric activator (signifies high energy state in cell). + Acetyl-CoA
Background image of page 10
Figure 16-17 Biotin: Functions in carboxylation reactions “Activated” CO 2 carrier. Covalently linked to lysine in enzyme, creating a 14 angstrom flexible arm between the enzyme and the functional group, similar to lipoamide in pyruvate dehydrognase. 14 angstroms
Background image of page 11

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Figure 16-18 Pyruvate carboxylase has two distinct catalytic sites. Biotin carries the product from the first reaction to the second active site.
Background image of page 12
Figure 16-18 part 1 Activation of CO 2 CO 2 dissolves in water as carbonic acid: CO 2 + H 2 O <==> HCO 3 - + H + (active site 1)
Background image of page 13

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Figure 16-18 part 2 Carboxylation of pyruvate to form OAA: (active site 2)
Background image of page 14
Pyruvate carboxylase Site 1 Site 2
Background image of page 15

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Pyruvate carboxylase Site 1 Site 2 ATP + CO 2 ADP + Pi
Background image of page 16
Pyruvate carboxylase Site 1 Site 2
Background image of page 17

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Pyruvate carboxylase Site 1 Site 2 Pyr OAA
Background image of page 18
Pyruvate carboxylase Site 1 Site 2
Background image of page 19

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 20
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 11/19/2010 for the course BIO 361 taught by Professor Lake during the Fall '08 term at SUNY Stony Brook.

Page1 / 49

KrebsCycleII2010SRS - Citric Acid Cycle II Lecture 27...

This preview shows document pages 1 - 20. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online