The document provides an overview of the cell as the fundamental unit of life, detailing its three main components: the plasma membrane, cytoplasm with organelles, and the nucleus. Key organelles such as the endoplasmic reticulum, Golgi apparatus, mitochondria, lysosomes, and peroxisomes are described along with their functions in protein synthesis, energy production, and waste digestion. Additionally, the nucleus is highlighted as the control center containing DNA and involved in replication and transcription processes.

1. Cell and its function
What is cell??
• Cell is the basic structural and
functional unit of organism.
•The organelles within cell are the
structure required for biological
processes, which include making protein
and extacting and utilizing usable energy
from food.

2. A cell has three major components:
•1. Plasma membrane or cell membrane.
•2. Cytoplasm with its organelles.
- Endoplasmic reticulum
- Golgi appratus
- Mitochondria
- Lysosome
- Peroxisome
•3. Nucleus

3. Plasma membrane
•It is composed of lipid bilayered membrane and
protein molecules with small proportion of
carbohydrate and forms a thin, tough, pliable
hyrophobic barrier around the cell.
•It functions are:-
. - Transport of molecules in
and out of cell.
- Has receptors for hormone
and neurotransmitters.

4. Cytoplasm and its organelles
•Cytoplasm is the internal volume bounded by
the plasma membrane.
•The clear fluid portion of the Cytoplasm in which
organelles are suspended is called Cytosol, which
contain dissolved proteins, electrolytes and
glucose.
• Five important organelles that are suspended in
the cytosol are:-

5. 1. Endoplasmic reticulum
•The Endoplasmic reticulum is the interconnected,
folded network of tubular strucutres in the
cytoplasm.
• Functions:-
- Rough Endoplasmic reticulum is the site for
synthesis of proteins.
- Smooth endopasmic reticulum is involved in Lipid
synthesis, biosynthesis of steroid hormones and
removal of toxic substances.

6. 2. Golgi Appratus
•It is a flat, membranous sac in which proteins are
processed, modified and prepared for export from
cell.
• Functions:-
- Protein which are synthesized in the endoplasmic
reticulum passed throught layers of the Golgi
appratus where enzymes in Golgi membranes catalyze
transfer of carbohydrates units to Protein to form
glycoprotein or to lipids to make glycolipids.

7. 3.Mitochondria:-
•Mitochondria are organelle that supply energy for all
cellular metabolic activities, that's why known as
power plant of cell
• Muscle of the heart contains large number of
mitochondria.
•Erythrocytes are an exception which derive their ATP
from glycolysis due to lack of mitochondria.
•Its matrix is the site of most of the reactions of the
citric acid cycle and fatty acid oxidation. In contrast
Oxidative phosphorylation takes place in inner
mitochondrial membrane

8. 4.lysosomes
•Lysosomes are organelles formed from Golgi
appratus.
• It is membrane bounded sacs containing as
many as forty different hydrolytic enzyme
include proteases, nucleases, glycosidases,
lipases, phosphates and sulfatases.
•All these enzymes works at acidic pH, so pH of
its matrix is about 5.

9. Function of Lysosome:-
•During development of foetus, lysosomes digest
the webbed tissues that join fingers and toes in
embryo.
•Involved in digestion of intra and extracellular
substances that must be removed.

10. 5.Peroxisome:-
•They are membranous sacs containing enzyme. The
enzyme content of cellular Peroxisome varies
according to the need of the tissues.
• Functions:-
. - Contain enzymes used for detoxification.
- Also participates in degradation of very long chain
fatty acids and synthesis of glycerolipids,
plasmalogens and isoprenoid.

11. Nucleus:-
•Nucleus is the control center of the cell; it contain
the DNA organized into chromosomes which carry
genetic information.
•Surrounded by double membrane called nuclear
envelope, containing nuclear pores.
•Nuclear pores facilitate transport of molecules
between the Cytoplasm and nucleus.
• The space enclosed by Nuclear envelope is called
nucleoplasm, in which nucleolus is present.

12. •Nucleolus is an organized structure of DNA,RNA
and Protein and major site for RNA synthesis.
•The major functional role of
the nucleus is that of
replication (synthesis of new
DNA) and transcription
(synthesis of rRNA, tRNA and
mRNA).
• All of the RNA molecule
operates functionally outside
the nucleus and seems to
leave via nuclear pore.

13. Thank you