Glyoxylate cycle

it is bypass cycle of citric acid cycle.
it give the brief description of glyoxylate cycle.
it is the summary of glyoxylate cycle for m.sc, bsc, science students.
it is very important topic for entrance exam of biology stream.

1. Glyoxylate cycle

2. What is glyoxylate cycle The plants and many microorganisms are equipped with the metabolic machinery – namely the glyoxylate cycle. To convert the fat into carbohydrates

3. Why?????? Because the animals, including man can not carry out the net synthesis of carbohydrates from fat.

4. Location of cycle The glyoxylate cycle occurs in glyoxysomes , specialised cellular organelles , where fatty acid oxidation is also operative.

5. Reaction of cycle The glyoxylate cycle is an anabolic varient of citric acid cycle. Acetyl CoA produced from fatty acid oxidation condenses with oxaloacetate to give citrate. which is then converted to isocitrate . At this stage isocitrate bypasses the citric acid cycle and cleaved by isocitrate lyase to succinate and glyoxylate .

6. Another molecule of acetyl CoA is now utilised to combine with glyoxylate to form malate . This reaction is catalysed by malate synthase and malate so formed enters citric acid cycle. The glyoxylate cycle is cyclic pathway that results in the conversion of two 2 carbon fregments of acetyl CoA to 4-carbon compound,succinate .

7. The succinate is converted to oxaloacetate and then to glucose involving the reactions of gluconeogenesis .

8. Fatty acid Acetyl CoA citrate isocitrate ketoglutartate succinate fumarate malate oxaloacetate glyoxylate Citrate synthase Aconitase Isocitrate lyase Malate synthase Malate dehydrogenase succinate glucose