- Books Name
- Yash Tyagi Coaching Science Book
- Publication
- ACERISE INDIA
- Course
- CBSE Class 9
- Subject
- Science
Cell Organelles and their Functions
Cell organelles and their functions
There are many types of organelles that help the cell in performing different functions. The different organelles are :
- Endoplasmic reticulum
- Ribosome
- Golgi bodies
- Lysosomes
- Mitochondria
- Plastids
- Vacuole
- Centrosome
Let us study them in detail:
1. Endoplasmic reticulum
It is an irregular network of membranes enclosing fluid in its cavity .they are of two types that is:
- Rough endoplasmic reticulum(RER)
- Smooth endoplasmic reticulum(SER)
The basic difference between the two is that:
- RER – It has ribosomes attached to it.
- SER : – No ribosome are attached
Functions of endoplasmic reticulum are as follows –
- SER helps in synthesizing fats etc.
- Endoplasmic reticulum forms skeleton framework of cell.
- Rough endoplasmic reticulum helps in transportation of proteins.
- Smooth endoplasmic reticulum helps in detoxification.
- Oxidative enzymes of lysosomes are produced by Rough endoplasmic reticulum.
- Endoplasmic reticulum helps in formation of membrane of cell .That is :
RER – SER – Golgi body – sec. vesicles – p membrane
2. Ribosomes
They are present in plant as well as in animal cell. They are spherical particles found free or attached to Rough Endoplasmic Reticulum. They contain their own genetic material that is RNA & proteins .Their function is protein synthesis. Due to the reason they are called as factory of proteins.
3. Golgi bodies
This organelle is present in plant and animal cells both. They are membrane bound fluid filled vesicles and flattened membranes stacked over one another called cisternae. In plant cells it is called by a special name that is Dictyosome. Function: They secrete, packages and dispatch the cellular secretions and also helps in the formation of cell membrane.
4. Lysosomes
They are present in plant as well as in animal cell. They are membrane bound vesicle containing powerful digestive enzymes. These enzymes can carry out the catabolic function
Function: Its functions are:
- They can destroy foreign material.
- They can remove worn out parts of the cell.
It acts as suicidal bags as they can even eat up their own cells if in case it gets damaged.
5. Mitochondria
They are rod shaped structures having a double membrane.
- Its outer membrane is – porous
- Its inner membrane is folded to form cristae & contain small bodies called oxysomes.
- It has a cavity that is filled with matrix (fluid) containing DNA and ribosomes.
- Its function is to produce energy in the form of ATP (Adenosine triphosphate) and is also designated as called as Power House of cell (due to production of energy).
6. Plastids
These are only found in plant cells. They are of three types: –
- Leucoplast – It is colorless plastid.
- Chromoplast – It is colored plastid.
- Chloroplast –It is green colored plastid.
As you all know that plants have the ability to synthesize their own food. They do so with the help of pigment chlorophyll. This chlorophyll is present in organelle chloroplast.
Chloroplasts are double membrane organelles containing liquid stoma and stacked structures called lamellae. When lamellae are stacked over one another they give rise to grana. Grana contain green pigment chlorophyll. This chlorophyll actually helps in capturing solar energy and converting it to chemical energy of food.
Functions of plastids are as follows –
- Chloroplast helps in photosynthesis
- Leucoplast – stores food, fats etc.
- Chromoplast impart colour to flowers.
7. Vacuole
They are fluid filled membrane bound spaces. They are prominent and large in plants but in animal cell they are either absent or if present they are small and temporary. In animal cell it helps in storing substances. In plant cell vacuole are large & permanent. Outer membrane is called as tonoplast and is filled with fluid called cell sap Functions of vacuole are as follows
- It provides turgidity & rigidity to cell.
- It stores substances.
- It maintains the osmotic pressure of cell.
8. Centrosome
It is found only in animal cell. It consists of two granules called centrioles. The function of centrioles is to help in spindle formation during cell division.
Transportation of substances
As we have seen that substances move in and out from the cell. These exchange mainly occur by two processes:
- Diffusion
- Osmosis