Question

State the major functions of the following.
a) Plasma membrane
b) Ribosome
c) Lysosome
d) Mitochondria
e) Golgi-apparatus
f) Cytoplasm
g) Asters of chromosome
h) Chromosomes
i) Glycogen granule
j) Vacuoles

Answer 1

Hint: Cell is the basic structural and functional unit of life. An organism consists of one or more cells. Based on the number of cells, there are two types of organisms. The cell consists of several cell organelles that help in performing various metabolic activities in cells.

Complete answer: Functions of the organelles mentioned below are as follows:
a) Plasma membrane: Plasma membrane is a double-layered structure made up of proteins and lipids. Lipids are arranged in the membrane as a bilayer. Polar head of the lipid is placed towards the outside and the hydrophobic tail towards the inner side. It also contains several carbohydrates.
b) Ribosome: They are spherical bodies made up of RNA and proteins. Two types of ribosomes are seen. They are 70S ribosomes and 80S ribosomes.
c) Lysosome: They are spherical bodies containing digestive enzymes produced from the Golgi complex.
d) Mitochondria: These are double membrane-bound cell organelles. Mitochondria perform the function of aerobic respiration. So, they are called the powerhouse of the cells.
e) Golgi-apparatus: These are sac-like structures made up of individual units called cisternae. It also consists of tubules and vesicles. They are involved in the packing of substances inside the cell.
f) Cytoplasm: It is a fluid in which all cell organelles are immersed. It harbours all the organelles of a cell.
g) Asters of chromosomes: These are star-like structures that consist of centrosomes and microtubules. They are seen at the time of cell division.
Chromosomes: Structures made up of coiling of DNA, RNA, histone proteins and non-histone proteins.
h) Glycogen granule: These are granules of glycogen seen in the cytoplasm of cells.
i) Vacuoles: They are membrane-bound cell organelles seen in certain cells. They perform several functions like maintaining water balance, turgor pressure, accumulation of waste materials, etc.

Note: Structure of a cell is different in prokaryotes and eukaryotes. Prokaryotes lack a membrane-bound nucleus and membrane-bound cell organelles. Both can be seen in a eukaryotic cell. The size of the cell also differs, i.e. prokaryotic cells are much smaller than eukaryotic cells.