Citric Acid Cycle: A Two Stage Process

Slides:

Advertisements

Similar presentations

Tricarboxylic Acid Cycle

Advertisements

KEY CONCEPTS: Section 14-1

CITRIC ACID CYCLE Student Edition 11/8/13 version

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’”

KREBS CYCLE. Introduction Let us review fates of Pyruvate Depending on the oxidation state of the cell: Aerobic – converted to acetyl-CoA via TCA cycle.

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

Chapter 12 (part 1) Citric Acid Cycle.

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.

1 The Citric Acid Cycle (Tricarboxylic Acid Cyle) 1. The link between gycolysis and citric acid cycle 2. TCA cycle oxidizes 2 –C units 3. Entry and metabolism.

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

Citrate Cycle: Energy conversion through redox reactions, a cycle with eight renewable reactants, and regulation Bioc 460 Spring Lecture 28 (Miesfeld)

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 2 C483 Spring 2013.

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.

Ashadi Sasongko. Essential facts of the citric acid cycle The citric acid cycle is an eight-step reaction. It requires 8 enzymes. The final product is.

Oxidative Decarboxylation of pyruvate and TCA cycle

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.

CITRIC ACID CYCLE -Anaplerosis Reading: l Harper’s Biochemistry Chapter 18 l Lehninger Principles of Biochemistry 3rd Ed. pp

Part 2: Transition Reaction

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.

Krebs cycle. Krebs Cycle (Citric acid cycle) Series of 8 sequential reactions Matrix of the mitorchondria Synthesis of 2 ATP Generation of 8 energetic.

Biochemistry department

Tricarboxylic Acid Cycle (TCA), Krebs Cycle Occurs totally in mitochondria Pyruvate (actually acetate) from glycolysis is degraded to CO 2 Some ATP is.

Oxidative Decarboxylation and Krebs Cycle By Reem M. Sallam, M.D.; Ph.D. Clinical Biochemistry Unit, Pathology Dept. College of Medicine, King Saud University.

Ch. 20 Tricarboxylic acid cyle Student Learning Outcomes:

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.

Tricarboxylic acid cycle (TCA Cycle) [Kreb’s cycle] [Citric acid cycle] Is the final common oxidative pathway for carbohydrates, fats and amino acids Along.

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

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.

Reactions of the citric acid cycle. Formation of citrate.

Citric acid cycle Production of acetyl-CoA Reactions of citric acid cycle Regulation of the citric acid cycle.

Harvesting Electrons from the Citric Acid Cycle

KREBS CYCLE (Tricarboxylic Acid Cycle) (Citric Acid Cycle)

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.

The Citric Acid Cycle: Tricarboxylic Acid Cycle Dr. M. Zeeshan Hyder Chapter 17 Biochemistry, Lubert Stryer, 5 th Edition Roundabouts, or traffic circles,

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.

Figure 7.8 Pyruvate Oxidation and the Citric Acid Cycle

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:

Pyruvate Oxidation: Pyruvate Dehydrogenase and the TCA Cycle.

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.

The Citric Acid Cycle & Oxidative phosphorylation.

Oxidative Decarboxylation of pyruvate and TCA cycle

Chapter 23 Metabolism and Energy Production

Oxidative Decarboxylation of pyruvate and TCA cycle

Chapter 9 Chem 341 Suroviec Fall 2016.

TRICARBOXYLIC ACID CYCLE (TCA)

Aerobic Metabolism: The Citric Acid Cycle

Acetyl-CoA and the Citric Acid Cycle

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

Metabolism: TCA Cycle.

Matrix Reactions The Fun Begins.

Krebs Cycle Tricarboxylic Acid Cycle

The Citric Acid Cycle Hans Krebs, 1900–1981.

Citric Acid Cycle.

Cellular Respiration Part III:

TCA Cycle Presented By, Mrs. Lincy Joseph Asst. Prof

Presentation transcript:

Citric Acid Cycle Generates Reductive Equivalents Utilized in Respiration

Citric Acid Cycle: A Two Stage Process Stage One: C4 + C2 condensation C6 tricarboxylic acid Oxidative decarboxylation 2 CO2 Succinyl CoA Net Result: 2NADH + 2CO2 + Succinyl CoA

C4 + C2 Condensation Reaction Condensation catalyzed by enzyme dimer Citrate Synthase RxN Driver

Citrate Synthase Reaction

Citrate Synthase Reaction

Citrate Synthase Reaction

Citrate Synthase Reaction

Citrate to Isocitrate Conversion via Aconitase Hydroxyl shift for subsequent oxidative decarboxylation

Isocitrate Dehydrogenase: Oxidation and Decarboxylation Oxalosuccinate not released from the enzyme

α-Ketoglutarate Dehydrogenase: Oxidation and Decarboxylation How similar is α-ketoglutarate dehydrogenase with pyruvate dehydrogenase in terms of substrate components? Reaction mechanism?

Citric Acid Cycle Part Two: Oxaloacetate Regeneration Succinyl Coenzyme A Synthetase couples hydrolysis of Coenzyme A (-33 kJ/mol) with GTP formation (-30 kJ/mol) The energetics works but what about the reaction mechanism?

Succinyl CoA-Sythetase Generates GTP What is the Nu:-, E, and leaving group with GTP generation?

Oxaloacetate Enzyme Regeneration from Succinate Succinate Dehydrogenase Fumerase Malate Dehydrogenase

A Color-Coded Citric Acid Cycle Isocitrate is prochiral Succinate is a symmetric molecule Generated products include: 2CO2 + 3NADH + 1FADH2 + GTP + CoA

Citric Acid Energetics

Citric Acid Cycle Regulation Points ATP and NADH are indicators of a high energy state ADP an indicator of a low energy state Regulatory sites include: Isocitrate dehydrogenase α-Ketoglutarate dehydrogenase Pyruvate dehydrogenase

Citric Acid Cycle is a Source for Biosynthetic Precursors

Transamination Reaction

Citric Acid Cycle Intermediates: Replenished as Metabolites are Drawn Off for Biosynthesis Anapleurotic reactions lead to a replenishment of pathway components (e.g. pyruvate carboxylase).

Problems: 1, 3, 5, 7 and 9