Question

1. Describe in detail the functions of the following organelles: Ribosomes, endoplasmic reticulum (rough and smooth), golgi complex, lysosomes, peroxisomes, mitochondria, and chloroplasts.
2. What are the differences between Plant and Animal cells?

Answer 1

Ribosomes: Ribosomes are granular structures.They provide space as well as enzymes for the synthesis of proteins.

Endoplasmic reticulum: Endoplasmic reticulum are thread like structures in the cell.It has two types 1.smooth endoplasmic reticulum 2.Rough endoplasmic reticulum.

Rough endoplasmic reticulum frequently observed in the cells actively involved in protein synthesis and secretion.

Smooth endoplasmic reticulum is the major site for synthesis of lipid.

Golgi complex:They are located near nucleus.They consist of many flat,disc shaped sacs or cisternae.It is the important site of formation of glycoproteins and glycolipids.

In plant cells golgi complex involves in the synthesis of cell wall materials and also plays a role in the formation of cell plate during cell division.

Lysosomes:These are membrane bound vesicular structures formed by the process of packaging in the golgi complex.

Under starvation conditions lysosomes digest cellular contents by releasing hydrolyzing enzymes and cause death of cells.This is called autolysis.

Lysosomes also called as suicidal bags.

Peroxisomes:These are located in cytoplasm.They break down fatty acids.They involved in lipid production.

Mitochondria:These are double membrane organelles.These are sites of aerobic respiration.They produce cellular energy in the form of ATP.Hence they are called ''Power houses of the cell''.

Chloroplasts:Chloroplasts are plastids.They contain chlorophyll.

These are play very important role in photo synthesis.

Animal cells do not have chloroplasts.

Differences between plant and animal cells:

Plant cells are rectangular and animal cells are round.

Plant cells have chloroplasts but animal cells do not have.

Plant cells have cell wall but animal cells do not have.