PPT on Structure and Functions of Different Organelles

1. STRUCTURE AND FUNCTIONS OF
DIFFERENT ORGANELLES
MADE BY – AARUSH AGGARWAL
GRADE - 9A

2. MITOCHONDRIA
Structure
The mitochondria is also called powerhouse of the cell. It
is surrounded by two membranes. The outer membrane is
porous where the inner membrane has deep folds that
provides a large surface to perform the chemical reactions
required for the generation of ATP.
Functions
• They provide important intermediates for the synthesis of
several biochemical substances like chlorophyll,
cytochromes and steroids.
• Synthesis of many amino acids occurs in mitochondria.
• Mitochondria can manufacture some of their own
proteins.
• Mitochondria are miniature biochemical factories where food is oxidized and energy is released. This energy
is stored in the form of ATP. Hence, mitochondria are called the powerhouses of the cell.

3. ENDOPLASMICRETICULUM
Structure
It is a series of connected flattened sacs having several
ribosomes on its outer surface, hence the name. It
synthesizes and secretes proteins in the liver, hormones and
other substances in the glands.
Functions
• Endoplasmic reticulum divides the cytoplasm into small
compartments. It gives rigidity to the cell, thus, acts as a
skeletal framework of the cell.
• It acts as a cytoplasmic framework and provides a large
surface area inside the cells for various biochemical activities.
• It serves as a channel and helps in transporting different materials such as proteins between various regions
of the cytoplasm as well as between the cytoplasm and the nucleus. As it helps in intracellular transport, it is
also known as the circulatory system of the cell.
• The membranes of endoplasmic reticulum contain a number of enzymes for various metabolic activities.

4. GOLGI Body
Structure
Golgi apparatus consists of a system of membrane-bound fluid-
filled vesicles (flattened sacs) arranged parallel to each other.
They arranged in the form of stacks called as cisternae. These
cisternae are smooth and flattened in structure. Vesicles membranes
have connections with the membranes of Endoplasmic reticulum.
Functions
• It helps in the storage, modification and packaging of secretory
products in the vesicles.
• In some cases, Golgi apparatus also helps in the manufacture of
complex sugars from simple sugars.
• The Golgi apparatus also helps in the formation of lysosomes.
• Golgi apparatus helps in the secretion of mucus, enzymes and hormones. The material synthesized near the
endoplasmic reticulum is transported to various targets inside and outside the cell through the Golgi
apparatus.

5. LYSOSOMES
Structure
“Lysosomes are sphere-shaped sacs filled with hydrolytic
enzymes that have the capability to break down many types of
biomolecules.” In other words, lysosomes are membranous
organelles whose specific function is to breakdown cellular wastes
and debris by engulfing it with hydrolytic enzymes.
Functions
• Lysosomes help in intracellular digestion.
• They provide energy during starvation by controlled breakdown
of stored food.
• Lysosomes bring about cellular breakdown and are associated
with ageing.

6. RIBOSOMES
Structure
A ribosome is a complex of RNA and protein and is,
therefore, known as a ribonucleoprotein. It is composed
of two subunits – smaller and larger. The smaller
subunit, where the mRNA binds and is decoded, and in
the larger subunit, the amino acids get added.
Functions
• Ribosomes are a cell structure that makes protein.
• Protein is needed for many cell functions such as
repairing damage or directing chemical processes.
• Ribosomes can be found floating within the cytoplasm or attached to the endoplasmic reticulum.
• Protein synthesis is very important to cells, therefore large numbers of ribosomes are found in cells.
• Ribosomes float freely in the cytoplasm, and are also bound to the endoplasmic reticulum (ER).
• Ribosomes are where RNA is translated into protein.
• This process is called protein synthesis.

7. Chloroplast
Structure
There are two distinct regions present inside a chloroplast
known as the grana and stroma. Grana are made up of stacks
of disc-shaped structures known as thylakoids or lamellae. The
grana of the chloroplast consists of chlorophyll pigments and are
the functional units of chloroplasts.
Functions
• The most important function of the chloroplast is to synthesize
food by the process of photosynthesis.
• Absorbs light energy and converts it into chemical energy.
• Produces ATP – Adenosine triphosphate by the process of photosynthesis.
• Chloroplast has a structure called chlorophyll which functions by trapping the solar energy and is used for the
synthesis of food in all green plants.
• The carbon dioxide (CO2) obtained from the air is used to generate carbon and sugar during the Calvin Cycle
or dark reaction of photosynthesis.

8. Vacuole
Structure
A vacuole is a membrane bound structure found in the
cytoplasmic matrix of a cell. The membrane surrounding the
vacuole is known as tonoplast. The components of the
vacuole, known as the cell sap, differ from that of the
surrounding cytoplasm. The membranes are composed of
phospholipids.
Functions
• Vacuoles help the plant cells to remain turgid.
• They play an important role in growth by helping in the
elongation of cells.
• They provide an aqueous environment for the accumulation and storage of water-soluble compounds (sugars,
minerals, pigments, etc.)
• In protozoans like Amoeba and Paramecium, vacuoles help in digestion and excretion.

9. Thank You