likewise, our body is made up of thousands and thousands of

cells

What is a cell? Cell is a basic structural

and functional unit of life. It is the smallest unit of life

and is often called, the building block of life

the cell was discovered by Robert hooke in 1665

he examined (under coarse, compound microscope)

very thin slices of cork and saw a multitude of tiny pores that he remarked looked

like the walled compartments

and named them cells

Matthias Jakob Schleiden and Theodore

Schwann proposed cell theory in 1839

which states that all plants and animals are made up of cells

and cell is the basic unit of life.

unicellular organisms

they are formed of one cell example amoeba,

paramecium etc multicellular organisms

they are formed of many cells examples

we human beings etc

take a look at the structure of

an animal cell

and now

the structure of a plant cell

let's talk about the components of a cell, cell membrane

it is the outermost elastic covering of the cell

it is made up of lipids and proteins

it protects the cell from injury and allows

osmosis it is selectively permeable

and allows endocytosis membrane has carrier proteins

for active transport

cell wall it is a rigid semi elastic

protective and permeable covering present outside the cell membrane

only in plant cells it is made up of cellulose ,

hemicellulose and pectin . it gives strength to plants

and prevents cell from bursting.

nucleus it is made up of four

parts nuclear membrane nucleoplasm

nucleolus and chromatin material

it controls all cell functions and brings

about cell differentiation DNA

of chromosome transfers the hereditary characters

from parents to off springs

cytoplasm it is a Jelly like semi fluid substance

it is present between cell membrane and nucleus

various cell organelles are present in it

cell organelles these

are tiny sub-cellular structures specialized to perform specific

functions

and hence are very important as they Carry out important functions

the various cell organelles

and their functions are endoplasmic recticulum, Golgi apparatus

they are membrane-bound vesicles arranged

parallel to each other in tiny sacs

called cisternae, it helps in formation of cell wall, cell membrane and lysosomes

complex sugars may be made from simple sugars in golgi

apparatus Lysosomes

they are smaller vesicles covered by single membrane

and contain digestive enzymes they are known

as a suicide bags of the cell. they destroy foreign particles

and remove dead and wornout cells Mitochondria

these are rod shaped covered by double membrane

it is the site for respiration

it provides the energy in the form of

adenosine triphosphate for various chemical

activities hence it is called the power house

of the cell plastids

these are present only in plant cells

and are of two types: leucoplast and chromoplast

green coloured plastids called chloroplast contain

chlorophyll and are important for photosynthesis

chromoplast give colour to flowers

and fruits leucoplast store starch,

oil and proteins ,

ribosomes

this is a structure of a ribosome

vacuole animal cells have small sized Vacuoles

while plant cells have very large vacuoles

they are covered by single membrane called tonoplast

Turgidity and rigidity of plant cell

is due to cells sap. thank you.