Following are marker enzymes that would be used to identify correct sub- cellular fractions.

Column X		Column Y
ENZYME		FRACTION
A.	Lactate dehydrogenase	i.	Lysosomes
B.	Acid phosphatase	ii.	Microsomes
C.	Glucose-6-phosphatase	iii.	Cytosol
D.	Catalase	iv.	Peroxisomes

Which one of the following options correctly pairs the enzymes with the subcellular fractions? 

The correct answer is Option 3 i.e.​ A - iii, B - i, C - ii, D - iv

Explanation-

Lactate Dehydrogenase (LDH) - Cytosol: LDH is primarily located in the cytosol of the cell. It plays a central role in anaerobic respiration and is responsible for the conversion of pyruvate to lactate when oxygen is scarce. The presence of LDH would suggest that the particular fraction is from the cytoplasm of the cell.

Acid Phosphatase - Lysosomes: Acid phosphatase is most commonly found in the lysosomes, organelles responsible for breaking down waste materials and cellular debris inside the cell. The lysosome is often referred to as the cell's "recycling center". Acid phosphatase is an enzyme that functions under acidic conditions, which is a characteristic of the lysosome's environment.

Glucose-6-Phosphatase - Microsomes (Endoplasmic Reticulum): This enzyme is embedded in the endoplasmic reticulum's membrane, more specifically in the smooth endoplasmic reticulum. It plays a critical role in the process of gluconeogenesis and glycogenolysis - biochemical pathways that synthesize glucose. The term "microsome" is often used to describe fragments of the endoplasmic reticulum (and sometimes the Golgi apparatus) that form when cells are homogenized, so this enzyme can be used as a marker for this subcellular fraction.

Catalase - Peroxisomes: Catalase is a common enzyme found in nearly all organisms exposed to oxygen. It is a very important enzyme in protecting the cell from oxidative damage by reactive oxygen species (ROS). Specifically, it's located in an organelle called the peroxisome. Peroxisomes are involved in the breakdown of very long chain fatty acids, branched chain fatty acids, D-amino acids, and polyamines, the reduction of reactive oxygen species, hydrogen peroxide, and biosynthesis of plasmalogens, ether phospholipids critical for the normal function of mammalian brains and lungs.