Citric Acid Cycle 2 C483 Spring 2013.

Slides:

Advertisements

Similar presentations

Tricarboxylic Acid Cycle

Advertisements

Citric Acid Cycle 1 C483 Spring The net effect of the eight steps of the citric acid cycle is to A) completely oxidize an acetyl group to carbon.

The Citric Acid Cycle II 11/17/2009. The Citric acid cycle It is called the Krebs cycle or the tricarboxylic and is the “hub” of the metabolic system.

KEY CONCEPTS: Section 14-1

12.3 The Citric Acid Cycle Oxidizes AcetylCoA Table 12.2.

Three Fates of Pyruvate Pyruvate  acetyl-CoA Occurs in mitochondria Produce CO 2 and NADH + H + Pyruvate Dehydrogenase Aerobic **Acetyl-CoA used in the.

Kreb’s Cycle (aka, tricarboxylic acid (TCA)cycle, citric acid cycle) “The wheel is turnin’ and the sugar’s a burnin’”

Prentice Hall c2002Chapter 121 Chapter 12 - The Citric Acid Cycle The citric acid cycle is involved in the aerobic catabolism of carbohydrates, lipids.

Overview of Citric Acid Cycle The citric acid cycle operates under aerobic conditions only The two-carbon acetyl group in acetyl CoA is oxidized to CO.

Chapter 12 (part 1) Citric Acid Cycle. Gylcolysis TCA Cycle Electron Transport and Oxidative phosphorylation.

Chapter 12 (part 1) Citric Acid Cycle.

Lecture 24½ Krebs Cycle. Overview Condensation Formation of citrate –One of the methyl-Hs can easily come off acetyl CoA –Gives a very reactive species.

Average = 76.4 = B- A = 96+ A-=90-95 B+ = B= B- = C+ = C=

Krebs Cycle. Glycolysis Extracts a Small Portion of Energy Stored in Glucose ~10% getting to pyruvate.

Biochemical Energy Production

1 24.1The Citric Acid Cycle Chapter 24 Metabolism and Energy Production.

Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Chapter 18 Metabolic.

Oxidative Phosphorylation and ATP 24.5 ATP Energy from Glucose Chapter 24 Metabolism and Energy Production.

Chapter 13 - The Citric Acid Cycle The citric acid cycle (tricarboxylic acid cycle) is amphibolic (both catabolic and anabolic) The cycle is involved in.

Citric Acid Cycle Pratt & Cornely, Ch 14. Overview Compartmentalization – Glycolysis: Cytosol – Citric Acid Cycle: mitochondria.

Chapter 16.2: The Citric Acid Cycle CHEM 7784 Biochemistry Professor Bensley.

Tricarboxylic Acid Cycle

Citric Acid Cycle. General Considerations What is the importance of citric acid cycle? final common pathway for oxidation of fuel molecules provides intermediates.

BRIDGING REACTION STEP 2 Fall 2013 BIOT 309. TRANSITION OR BRIDGING REACTION Connects glycolysis to citric acid/Kreb’s Cycle OVERALL REACTION 2 pyruvate.

Metabolism and Energy Production

Citric Acid Cycle What is it? Series of rxns that oxidize acetyl CoA to 2CO 2 in a manner that conserves the liberated free energy for ATP production Breakdown.

چرخه کربس مرکز سوخت و ساز سلولي مي شناسند، چرا که افزون بر کوشندگي هاي سوخت و سوزي براي کربوهيدراتها، فرآيند سوخت و ساز اسيدهاي چرب و اسيدهاي آمينه.

Stages of Metabolism.

Biochemistry department

Chapter 16 The Citric Acid Cycle: CAC Kreb’s Cycle

CITRIC ACID CYCLE- discovered by Sir Hans Krebs in He was awarded Nobel Prize in Medicine Sir Hans KrebsSir Hans Krebs 1. The citric acid cycle (also.

SURVEY OF BIOCHEMISTRY Citric Acid Cycle

FERMENTATION: Anaerobic Glycolysis. CATABOLIC FATES OF PYRUVATE.

Glycolysis 1. From glucose to pyruvate; step reactions; 3

CHAPTER 23: Metabolism & Energy Production

INTER 111: Graduate Biochemistry.  To discuss the function of the citric acid cycle in intermediary metabolism, where it occurs in the cell, and how.

Citric Acid Cycle. Figure 17-2 Citric Acid Cycle.

Harvesting Electrons from the Citric Acid Cycle

After pyruvate is oxidized, the citric acid cycle completes the energy-yielding oxidation of organic molecules. Chapter 9, Section 3.

Citric Acid Cycle: A Two Stage Process

Draw a reaction map of glucose completely metabolized to CO 2 + H 2 O in the presence of oxygen25 Points Reference:

Citric Acid Cycle Chapter 19 Stryer Short Course.

KREB’S CYCLE. Discovered by Hans Adolf Krebs who won the nobel prize in 1953 Occurs in the mitochondrial matrix A cyclical metabolic pathway with 8 steps.

Reminder From glycolysis, 2 ATP net were produced, along with 2 NADH and 2 pyruvate molecules. If oxygen is present, pyruvate will move on with aerobic.

Cellular Respiration Part 1 Harvesting Chemical Energy from Glucose.

2. The Citric Acid Cycle (CAC) Pyruvate CO The Citric Acid Cycle (CAC) The sequence of events: Step 1: C-C bond formation to make citrate Step 2:

Aerobic Respiration Section 9:2. Overview Krebs Cycle: In the presence of O2, Pyruvic Acid oxidizes, the reduction of NAD + to NADH, and FAD to FADH,

Introduction to the Krebs Cycle Hans Kreb discovered its cyclic nature Goes by three names – Citric acid cycle – Tricarboxylic cycle – Krebs cycle.

3. CITRIC ACID CYCLE. The citric acid cycle (Kreb’s cycle, Tricarboxylic acid cycle) is a series of reactions in mitochondria that bring about the catabolism.

Oxidative Decarboxylation of pyruvate and TCA cycle

Chapter 23 Metabolism and Energy Production

Oxidative Decarboxylation of pyruvate and TCA cycle

Citric Acid Cycle Pratt & Cornely, Ch 14.

Chapter 9 Chem 341 Suroviec Fall 2016.

TRICARBOXYLIC ACID CYCLE (TCA)

Aerobic Metabolism: The Citric Acid Cycle

Tricarboxylic Acid Cycle

Acetyl-CoA and the Citric Acid Cycle

Kreb’s Cycle Tricarboxylic Acid (TCA) Cycle, citric acid cycle)

Presentation on Kreb’s Cycle

Metabolism: TCA Cycle.

Matrix Reactions The Fun Begins.

Krebs Cycle Tricarboxylic Acid Cycle

Chapter 23 Metabolism and Energy Production

Chapter 10 The Citrate Cycle.

The Citric Acid Cycle 11/25/2008

Citric Acid Cycle.

Cellular Respiration Part III:

Aerobic Respiration Section 9:2.

Presentation transcript:

Citric Acid Cycle 2 C483 Spring 2013

1. A metabolic pathway that is involved in both energy production and biosynthesis is Anaplerotic amphibolic C) Duplibolic Cataplerotic 2. Carbons from acetyl CoA are transferred to the citric acid cycle. Which is the first round of the citric acid cycle that could possibly release a carbon atom originating from this acetyl CoA? A) First round. B) Second round. C) Third round. D) Fourth round. 3. What type of enzyme is involved in all four redox reactions of the citric acid cycle?

What is the thermodynamic driving force for formation of citrate? High levels of oxaloacetate C-C bond formation through condensation Loss of carbon dioxide Hydrolysis of a high energy bond 5. True or false? Both glycolysis and the citric acid cycle produce a high energy bond starting from inorganic phosphate through a process called substrate level phosphorylation.

Overview

Carbon Flow Each cycle is net oxidation of acetyl CoA C-13 incorporation experiments 4-carbon compounds act “catalytically” in oxygen consumption Cyclic pathway!

Anaplerotic Reactions “Filling up” reactions Formation of oxaloacetate by pyruvate carboxylase No net carbohydrates from Acetyl CoA in mammals

1. Citrate Synthase Highly exothermic—lysis of high energy bond Used to drive reaction in presence of small [oxaloacetate]

2. Aconitase Citrate is achiral and prochiral Green represents carbon from acetyl CoA How can enzyme distinguish prochirality?

Prochirality Only one compound produced X

3. Isocitrate Dehydrogenase Oxidative decarboxylation Spontaneous in b-ketoacids NADH

4. a-Ketogluterate Dehydrogenase Complex Analogous to pyruvate dehydrogenase complex Second decarboxylation, but this is a-decarboxylation High energy bond retained

5. Succinyl CoA Synthetase Synthetase means ATP (GTP) involved High energy bond used to do substrate-level phosphorylation Good leaving group to activate Pi Covalent catalysis GDP  GTP

Notice: symmetrical Product! We lose track of which carbons are from acetyl CoA!

6. Succinate Dehydrogenase Oxidation to form C=C releases less energy FAD is bound redox reagent In turn, Q is reduced Membrane enzyme—revisit in chapter 14!

7. Fumarase Another prochiral molecule Hydration reaction sets up another oxidation

8. Malate Dehydrogenase Large standard free energy Driven by low [oxaloacetate]

Carbon Flow Practice C-14 labeling problems given basic chart

Answers B Dehydrogenase D T