The Fundamental Unit of Life – Cell Organelles (Part -4)

Cell Organelles

• Each cell has got certain specific components within it, which is known as Cell Organelles.
• Each kind of Cell Organelle perform a specific function.
• All Cells are found to have same organelles, no matter what their function is or what organisms they are found in.

Endoplasmic Reticulum (ER)

• ER is a network of tube like structure’s found in the Cytoplasm.
• There are two types of ER, they are :-

1. RER (Rough Endoplasmic Reticulum)
2. SER (Smooth Endoplasmic Reticulum)

RER

• Rough Endoplasmic Reticulum (RER) is studded with ribosome’s and hence appears to be rough.
• RER is involved in Protein Sythesis.

Functions of RER

• Provides channel for quick transport of materials
• Provides surface for  the attachment of ribosome’s.
• Makes Digestive Enzymes for Lysosomes.
• It provides materials; lipids & proteins for biogenesis of membrane.
• Biogenesis: The production of new living organism or organelle.

SER

• Smooth Endoplasmic Reticulum (SER) has no ribosome’s attached to it and appears to be smooth.
• SER is involved in synthesis of fat and steroids.

Functions of SER

• Synthesis of Fat, Steroids and hormones.
• Detoxification of drugs & poisons.

Golgi Apparatus

• Golgi apparatus was discovered by Camillo Golgi.
• It consists of  a system of membrane-bound vesicles arranged
  approximately parallel to each other in stacks called cisterns.

Function of Golgi Apparatus

•  The storage, modification and packaging of products in
  vesicles
• Converting complex sugar into simple sugars.
• It is involved in the formation of lysosomes.

Lysosomes

• Lysosomes are the warriors as well as suicide bags of the cell.
• Structurally lysosomes are membrane-bound sacks filled with digestive enzymes. 
• They contain powerful digestive enzymes capable of breaking down all organic materials.

Function of Lysosomes

• Lysosomes help to keep the cell clean by digesting any foreign material as well as worn-out cell organelles.
• Foreign materials entering the cell, such as bacteria or food, as well as old organelles end up in the lysosomes, which break them up into small pieces.
• When the cell gets damaged or when it is out of use, lysosomes may burst and the enzymes will digest their own cell, therefore they are also known as "
  suicide bags" of a cell.

Mitochondria

• Mitochondria are known as the powerhouses of the cell.
• The energy required for the functioning of the cell is released by mitochondria in the form of ATP molecules.
• Mitochondria is double-membrane bound, and has its own DNA and Ribosome's.
• The outer membrane is very porous while the inner membrane is deeply in-folded. These folds create large are for generating chemical reactions for producing ATP molecules. 

Functions of Mitochondria

• Mitochondria produces the energy required for various chemical activities needed for life and releases it in the form of ATP (Adensine TriPhosphate) Molecules.

ATP Molecules

• ATP or Adensine Triphosphate are known as the energy currency of the cell.
• They  provide the energy stored in them for making new chemical compounds and for mechanical work in the body.

Plastids

• Plastids are found only in Plant cells.
• The internal organisation of the plastids consists of numerous membrane layers embedded in a material call the stroma.
• Like mitochrondria, plastids also have their own DNA and Ribosomes.
• There are 2 types of plastids-  Chromoplasts and Leucoplasts.
• Chromoplasts: Coloured plastids
• Chloroplasts are plastids that contain pigment chlorophyll, and give green colour to the pigment.
• Leucoplasts: White/Colourless plastids, they are primarily organelles in which materials such as starch, oil and protein granules are stored.
• Potato contains Starch in their Lecoplasts.

Vacuoles

• Vacuoles are the storage sacks for solid or liquid contents.
• Vacuoles are small sized in animal cells whereas in plant cell they are very large.
• The central vacuole of the some plant cell may occupy 50-90% of the cell volume.
• In plant cells, vacuoles are full of cell sap and provide turgidity and rigidity to the cell.
• Many important substances need for the life of the plant cell are stored in vacuoles. e.g.: Amino acids, Sugar and various other organic acids and some proteins.
• In single celled organisms