Q.23 Another name for cardio lipin is
1. Phosphatidyl choline
2. Phosphatidyl serine
3. Phosphatidyl inositol
4. Diphosphatidyl glycerol

Correct Answer: 4. Diphosphatidyl glycerol

Cardiolipin, also known as diphosphatidylglycerol, is a unique dimeric phospholipid abundant in mitochondrial inner membranes, essential for respiratory chain function.

Option Analysis

1. Phosphatidyl choline
Major plasma membrane phospholipid (PC/lecithin); single glycerol backbone with choline head. Not dimeric structure of cardiolipin.

2. Phosphatidyl serine
Negative charge carrier in membranes, involved in apoptosis signaling. Single phosphatidic acid lacks cardiolipin’s four acyl chains.

3. Phosphatidyl inositol
Signaling lipid (PI, PIP2, PIP3) in second messenger pathways. Single chain structure, not mitochondrial-specific diphosphatidylglycerol.

4. Diphosphatidyl glycerol
Correct: Cardiolipin = two phosphatidic acids linked by central glycerol (four fatty acids total). Synonyms confirmed across biochemical literature.

Cardiolipin another name diphosphatidyl glycerol identifies this mitochondrial signature lipid crucial for oxidative phosphorylation and energy metabolism. This cardiolipin another name diphosphatidyl glycerol guide clarifies phospholipid nomenclature for GATE Life Sciences, CSIR NET, and molecular biology students.

Cardiolipin Structure

Two phosphatidic acid molecules esterified to central glycerol → four acyl chains (often linoleic acid) → conical shape stabilizes cristae curvature. 15-20% of inner mitochondrial membrane.

Phospholipid Comparison Table

Cardiolipin another name diphosphatidyl glycerol distinguishes its unique dimeric architecture.

Biological Significance

Binds complexes I-V, cytochrome c; peroxidation triggers mitophagy/apoptosis. Barth syndrome mutations disrupt remodeling. Exam tip: “Cardiolipin = double PA = diphosphatidylglycerol.”