STRUCTURE AND FUNCTIONS OF DIFFERENT CELL ORGANELLES

Cell WallCell wall is a

rigid outer covering present outside plasma membrane. It is found in plant cell. Animal cell lack cell wall.

Structure of Cell wallIt is made up of

cellulose .Cell walls are a strong collection of laminated fibers. Each fiber contains hundreds of strands of cellulose.

Functions of Cell wall

It gives turgidity to the cell.

It provides shape to the cell.

It provides mechanical strength to the cell.

It provides rigidity to the cell.

It protects cell from damages.

It is freely permeable to water and allows exchange of materials between living cell contents through pores.

NucleusStructure The nucleus is a large

roundish organelle. It is bounded by a double membrane which has numerous pores. Inside the nucleus are chromosomes and a dark region called a nucleolus which makes ribosomes. 

Functions It controls all the

metabolic functions of the cell.

It helps in cell division.

It helps in proteins synthesis.

It helps in cell cycle. It is responsible for

transfer of heridatory characters from parents to next generation.

It is the brain of the cell.

Plasma Membrane

Structure The plasma membrane is made up of

phospholipids. This makes the membrane selectively permeable to molecules. It allows only the entry and exit of selective material in and out of the cell.

FunctionThe plasma membrane is also

a vital component of cellular control. Its responsibility is to restrict what can enter or leave the cell. 

Cytoplasm

Structure It is the fluid content present inside

the plasma membrane. It contains specialized cell organelles.

Functions It acts as the store of important

chemicals. It is a physical basis of all metabolic

activities. It keeps the cell fully expanded and

provides turgidity.

Endoplasmic ReticulumStructure Endoplasmic reticulum is a large

network of membrane bound tubes and sheets. It looks like long tubules or bags. Its structure is similar to plasma membrane. It encloses fluid filled lumen.

There of 2 types : Smooth Endoplasmic

reticulum[they do not have ribosomes]

Rough Endoplasmic reticulum[ribosomes are attached to its surface]

Functions It is associated with the synthesis, storage

and transport of metabolic products.

It gives internal support to colloidal matrix.

Rough endoplasmic reticulum is concerned with protein synthesis.

It helps in formation of new cell membrane.

Ribosomes

Structure Ribosomes are dense spherical

granular particles which move freely in the matrix. They are present in cytoplasm as well as inside the nucleus.  A ribosome is made of numerous proteins and RNA.

Functions They play important role in protein

synthesis.

It helps in storage modification and packaging of products in vesicles.

It is involved in synthesis of lysosomes.

Golgi bodies/apparatusStructure It consists of smooth

flatted cisterns. They are usually together in parallel rows. There membranes have connections with the membrane of endoplasmic reticulum. The Golgi complex looks like a stack of pancakes made of membranes with smaller vacuoles or vesicles on either side of the main structure.

Function It is involved in synthesis of proteins, liquids

and carbohydrates. It is involved in the process of lysosomes and

peroxisomes. It complex sugars from simple sugar. It packages and dispackages the material

synthesis near targets inside and outside the cells.

It helps in storage modification and packaging of products.

Lysosomes Structure

They are small spherical bodies bounded by single membrane. they contain digestive enzymes which can break all organic material. They act as digestive system for the cell so they are also called digestive bags.

They cause digestion of worn out cells organelles and even can digest entire damage cell containing them so they are also called suicidal bags.

Functions They help in inter cellular and

intra cellular digestion of food particles.

They cause digestion of worn out and damages cell organelles.

They destroy foreign substances.

They help in the digestion of bones by digesting cartilage.

MitochondriaStructure

They are rod shaped structure bounded by double membrane .outer membrane is very porous while inner is deeply folded. These folds create a large surface area for ATP generating chemical reaction. They are called strange organelles because they have there own DNA and ribosome. Therefore they are able to make some of their proteins. It is called power house of cell because they release energy required for various activities in the cell.

Functions Second largest organelle with unique genetic structure. Double-layered outer membrane with inner folds

called cristae Energy-producing chemical reactions take place on

cristae Controls level of water and other materials in cell Recycles and decomposes proteins, fats, and

carbohydrates, and forms urea

VacuolesStructureThey are the

solid sacs for solid and liquid contents. They are of small size animal calls and very large in plant cell.

Functions They help in storage of food ,water

and waste substance. Contractile vacuoles help in the

eliminations of excess water from the cell.

PlastidsStructure Plastids consists of numerous membrane

layers embedded in a material called the strome.

Plastids are of three types:

1) Chromoplast-they are colored plastids except green. They are present in flavors to attract insects for pollination.

2) Leucoplast-They are colorless or white plastids. They store strach,oils and proteins granules.

3) Chloroplast-They are green colored plastids which are important for photosynthesis for plants. They contain green colour pigments chlorophyll. They are known as kitchen of cell.

FunctionsThey manufacture food through photosynthesis.

They provide colors to fruits and flowers to attract insect for pollination.

It store strach,oil and proteins granules.

Presented by:Vishwajeet

Singh Bajwan

Thank you