write the major function of the -plasma membrane,mitochondria, ribosomes, chloroplast
Answers
Answer:
mitochondria is known as the power house of the cell it acts as a digestive system that takes in nutrient breaks them down and creates energy for the cell
I worked a lot so please mark me the brainliest
Functions of plasma membrane:-
(1) A Physical Barrier
The plasma membrane surrounds all cells
and physically separates the cytoplasm, which is the material that makes up the cell, from the extracellular fluid outside the cell. This protects all the components of the cell from the outside environment and allows separate activities to occur inside and outside the cell. The plasma membrane provides structural support to the cell. It tethers the cytoskeleton, which is a network of protein filaments inside the cell that hold all the parts of the cell in place. This gives the cell its shape. Certain organisms such as plants and fungi have a cell wall in addition to the membrane. The cell wall is composed of molecules such as cellulose. It provides additional support to the cell, and it is why plant cells do not burst like animal cells do if too much water diffuses into them.
(2) Selective Permeability
Plasma membranes are selectively permeable (or semi-permeable), meaning that only certain molecules can pass through them. Water, oxygen, and carbon dioxide can easily travel through the membrane. Generally, ions (e.g. sodium, potassium) and polar molecules cannot pass through the membrane; they must go through specific channels or pores in the membrane instead of freely diffusing through. This way, the membrane can control the rate at which certain molecules can enter and exit the cell.
(3) Endocytosis and Exocytosis
Endocytosis is when a cell ingests relatively larger contents than the single ions or molecules that pass through channels. Through endocytosis, a cell can take in large quantities of molecules or even whole bacteria from the extracellular fluid. Exocytosis is when the cell releases these materials. The cell membrane plays an important role in both of these processes. The shape of the membrane itself changes to allow molecules to enter or exit the cell. It also forms vacuoles, small bubbles of membrane that can transport many molecules at once, in order to transport materials to different places in the cell.
(4) Cell Signaling
Another important function of the membrane is to facilitate communication and signaling between cells. It does so through the use of various proteins and carbohydrates in the membrane. Proteins on the cell “mark” that cell so that other cells can identify it. The membrane also has receptors that allow it to carry out certain tasks when molecules such as hormones bind to those receptors.
Functions of mitochondria:-
The most important function of mitochondria is to produce energy through the process of oxidative phosphorylation. It is also involved in the following process:
(1) Regulates the metabolic activity of the cell
(2) Promotes the growth of new cells and cell multiplication
(3) Helps in detoxifying ammonia in the liver cells
(4( Plays an important role in apoptosis or programmed cell death
(5) Responsible for building certain parts of the blood and various hormones like testosterone and oestrogen
(6) Helps in maintaining an adequate concentration of calcium ions within the compartments of the cell
(7) It is also involved in various cellular activities like cellular differentiation, cell signalling, cell senescence, controlling the cell cycle and also in cell growth.
Functions of ribosomes:-
(1) It assembles amino acid to form proteins that are essential to carry out cellular functions.
(2) The DNA produces mRNA by the process of DNA transcription.
(3) The mRNA is synthesised in the nucleus and transported to the cytoplasm for the process of protein synthesis.
(4) The ribosomal subunits in the cytoplasm are bound around mRNA polymers. The tRNA then synthesises proteins.
(5)The proteins synthesised in the cytoplasm are utilised in the cytoplasm itself, the proteins synthesised by bound ribosomes are transported outside the cell.
Functions of chloroplast:-
(1) The most important function of the chloroplast is to synthesize food by the process of photosynthesis.
(2) Absorbs light energy and converts it into chemical energy.
(3) Chloroplast has a structure called chlorophyll which functions by trapping the solar energy and used for the synthesis of food in all green plants.
(4) Produces NADPH and molecular oxygen (O2) by photolysis of water.
(5) Produces ATP – Adenosine triphosphate by the process of photosynthesis.
(6) The carbon dioxide (CO2) obtained from the air is used to generate carbon and sugar during the Calvin Cycle or dark reaction of photosynthesis.