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Structure of a Cell
By Ms Sushma SureshMs. Pritam Bhise
Pawar Public SchoolKandivali
STRUCTURE OF A CELL
Three essential basic parts:
Cell membrane [plasma membrane]
Cytoplasm
Nucleus
Plasma membrane(gate)
selectively permeable thin, delicate
Plant cells have a cell wall surrounding the plasma membrane.
Cell wall is made of cellulose.It gives shape, protects the cell.
Cytoplasm
colourless
semi-liquid
translucent
Includes everything inside the cell except nucleus
NUCLEUS(CAPITAL / CONTROL CENTRE)
DISCOVERED BY ROBERT BROWN
HAS A DELICATE NUCLEAR MEMBRANE WITH NUCLEAR PORES
FILLED WITH NUCLEOPLASM
HAS NUCLEOLUS
CHROMATIN FIBRES FOUND IN NUCLEOPLASM WHICH BECOME RIBBON SHAPED [CHROMOSOMES] DURING CELL DIVISION
ORGANELLES
• Organelle is a specialsed subunit within a cell that has specific function.
• They are the finer, functional parts of the cell.
• The name organelle comes from the idea that these structures are to cells what organs are to the body.
Endoplasmic Reticulum(Highway)
• Irregular network of fine, tubular structure.
• Distributed in the entire cytoplasm.
• Provides framework and distribution of products from one part of cell to another.
Ribosomes(protein factory)
• Granules which synthesize proteins.• Scattered or attached to ER.• Scattered ribosomes make protein
for the cell, whereas the attached ribosome synthesize protein which is exported from the cell.
Golgi Bodies(Post Office)
• A Golgi complex is composed of flat sacs known as cisternae. The sacs are stacked in a bent, semicircular shape.
• Molecules synthesized in the ER (highway) exit via special transport vesicles (truck) which carry their contents to the Golgi complex(post office) where they are assembled and distributed to other parts of the cell.
Mitochondria(Power House)
• It is made up of two membranes.
• Outer membrane and Inner membrane.
• Inner membrane is folded inward to form cristae.
• It consists of necessary enzymes to release energy from the food.
• This chemical energy is stored in the form of ATP(adenosine triphospate).
Lysosomes(Trash Bin)
• Enzyme- containing bodies capable of digesting various materials.
• They engulf foreign bodies like germs and also digest or dissolve the old or injured cell parts.
Centrosome(found only in animal cells)
• Located near the nucleus.
• Initiates and regulates cell division.
Plastids(found only in plant cells)
Chloroplast
Amyloplast
Chromoplast
Plastids
Vacuoles
• In plant cell vacuole is large as compared to animal cells.
• It has water and some enzymes.
• It helps to remove the toxic and waste products of the cells.
Cytoskeleton
It is found throughout the cell
It is made up of filaments and tubules.
It helps shape and support the cell.
