Components of a Cell and their functions – Class 11 | Chapter – 8 | Short Notes Series PDF

Components of a Cell and their functions: The cell comprises several smaller components termed the organelles and a fluid component called the cytoplasm. The cell comprises three major components, cell membrane, nucleus, and in between the two is the cytoplasm, embedded with the organelles.

Components of a cell and Their functions

A Cell is made up of majorly 3 components:

1. Cell membrane which surrounds the cell and acts as a gate keeper, controlling the substances which go out or into the cell structure
2. Central nucleus surrounded by Nuclear membrane
3. Cytoplasm covered by Plasma membrane containing Cytoplasmic Organelles

Plasma Membrane:

• Main function is Protection
• Prevents entry of harmful Substances holds cell together
• Transport of Metabolites cell to cell recognition and communication
• Plays an major role in Immune response
• Involved in Hormonal Action
• Helps in Conduction of Action potential

Endoplasmic Reticulum (ER):

• Rough Endoplasmic Reticulum – Protein Synthesis
• Smooth Endoplasmic Reticulum – Steroid and Lipid Synthesis

Ribosomes:

• It plays a major role n the terminal parts of Protein Synthesis

Golgi complex or Golgi apparatus:

• Stores Secretions
• Modifies Secretions
• Packages Secretions

Mitochondria:

• It is termed as the power house of the Cell
• Plays an major part in the terminal stages of Aerobic Respiration
• Synthesizes ATP – hence called the power house of cell as ATP is the primary source of Energy
• Manufactures Polysaccharides

Pinocytotic Vesicles:

• Uptake of Dissolved Materials

Lysosomes:

• These are termed as the “Disposal Units” of the cell
• Contains Hydrolytic Enzymes which Digest materials
• They are the organelles which are the center of “Autolysis” or Intracellular Breakdown.

Centrioles:

• Help in Division of Cells
• During Cell division they separate and move to form the poles of the nuclear spindle

Micro Tubules:

• Are the main organelles which help in movement and Support of the Cell
• Beating of Sperm Tail or Cilia
• Movement of Chromosomes in cell division

Micro Filaments:

• Also play part in Movement and Support
• They help in General Floating motion of Cytoplasm (Cytoplasmic Streaming)
• Contraction of Muscle Fibers
• Microvilli

Nucleus:Comprises of two parts, nuclear membrane, and nucleolus. The nuclear membrane is a thin lipid membrane characterised by the presence of pores that act as channels to transport substances. The nucleus is the organelle that stores the genetic material in the form of chromatic fibres.

Nuclear Membrane: Pores in the membrane serve as Transport Channels Site of Synthesis of RNA and DNA

Nucleoli and Chromatin Material: The information required to synthesize proteins is coded in the DNA. The DNA is copied into “Messenger RNA” molecules. These pass into the cytoplasm where the protein synthesis takes place.

---

JOIN OUR TELEGRAM CHANNELS
Biology Quiz & Notes	Physics Quiz & Notes	Chemistry Quiz & Notes

---

Follow on Facebook

By Team Learning Mantras