The glyoxylate cycle is a metabolic pathway in plants and microorganisms that converts fats into carbohydrates, as animals cannot synthesize carbohydrates from fats. This cycle occurs in glyoxysomes, where acetyl CoA from fatty acid oxidation combines with oxaloacetate to form citrate, which is then transformed through a series of reactions that ultimately produce glucose. It serves as an anabolic variant of the citric acid cycle, allowing organisms to convert two-carbon fragments into four-carbon compounds.

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
ketoglutartatesuccinate
fumarate
malate
oxaloacetate
glyoxylate
Citrate synthase
Aconitase
Isocitrate lyase
Malate
dehydrogenase
succinateglucose