TCA Cycle Overview

Study Notes

TCA Cycle Overview

The TCA (Tricarboxylic Acid) cycle, also known as the citric acid cycle or Krebs cycle, is a series of chemical reactions that occur within the mitochondria of cells. It is a crucial step in cellular respiration, as it generates energy for the cell by converting acetyl-CoA into carbon dioxide and coenzyme A.

Steps of the TCA Cycle

Acetyl-CoA: The cycle begins with the conversion of acetyl-CoA, a product of fatty acid breakdown and glycolysis, into citrate.
Citrate: Citrate is converted into isocitrate through the enzyme aconitase.
Isocitrate: Isocitrate is converted into α-ketoglutarate through the enzyme isocitrate dehydrogenase, producing NADH and CO2.
α-Ketoglutarate: α-Ketoglutarate is converted into succinyl-CoA through the enzyme α-ketoglutarate dehydrogenase, producing NADH and CO2.
Succinyl-CoA: Succinyl-CoA is converted into succinate through the enzyme succinyl-CoA synthetase, producing ATP and CoA.
Succinate: Succinate is converted into fumarate through the enzyme succinate dehydrogenase, producing FADH2.
Fumarate: Fumarate is converted into malate through the enzyme fumarase.
Malate: Malate is converted into oxaloacetate through the enzyme malate dehydrogenase, producing NADH.
Oxaloacetate: Oxaloacetate is converted back into citrate, completing the cycle.

Products of the TCA Cycle

ATP: 2 ATP molecules are produced per glucose molecule
NADH: 6 NADH molecules are produced per glucose molecule
FADH2: 2 FADH2 molecules are produced per glucose molecule
CO2: Carbon dioxide is produced as a byproduct

Importance of the TCA Cycle

Energy production: The TCA cycle produces energy for the cell through the generation of ATP, NADH, and FADH2.
Intermediary metabolism: The TCA cycle plays a central role in intermediary metabolism, connecting glycolysis, fatty acid breakdown, and the electron transport chain.
Regulation of cellular metabolism: The TCA cycle is regulated by various enzymes and feedback mechanisms to ensure proper cellular metabolism.

TCA Cycle Overview

The TCA cycle is a series of chemical reactions that occur within the mitochondria of cells.
It generates energy for the cell by converting acetyl-CoA into carbon dioxide and coenzyme A.

Steps of the TCA Cycle

The cycle begins with the conversion of acetyl-CoA into citrate.
Citrate is converted into isocitrate through the enzyme aconitase.
Isocitrate is converted into α-ketoglutarate, producing NADH and CO2.
α-Ketoglutarate is converted into succinyl-CoA, producing NADH and CO2.
Succinyl-CoA is converted into succinate, producing ATP and CoA.
Succinate is converted into fumarate, producing FADH2.
Fumarate is converted into malate.
Malate is converted into oxaloacetate, producing NADH.
Oxaloacetate is converted back into citrate, completing the cycle.

Products of the TCA Cycle

2 ATP molecules are produced per glucose molecule.
6 NADH molecules are produced per glucose molecule.
2 FADH2 molecules are produced per glucose molecule.
Carbon dioxide is produced as a byproduct.

Importance of the TCA Cycle

The TCA cycle produces energy for the cell through the generation of ATP, NADH, and FADH2.
It plays a central role in intermediary metabolism, connecting glycolysis, fatty acid breakdown, and the electron transport chain.
The TCA cycle is regulated by various enzymes and feedback mechanisms to ensure proper cellular metabolism.

Laminar Flow of Blood in Vessels

Blood flowing at a steady rate through a long smooth vessel forms streamlines, with each layer maintaining a consistent distance from the vessel wall.
In laminar flow, the centralmost portion of the blood remains in the center of the vessel.
Laminar flow is characterized by a smooth, continuous, and organized flow of blood.
This type of flow is in contrast to turbulent flow, where blood flows in all directions and continually mixes in the vessel.

Description

The TCA cycle is a series of chemical reactions in cellular respiration, generating energy for cells by converting acetyl-CoA into carbon dioxide and coenzyme A. It occurs in the mitochondria and is a crucial step in cellular respiration.