2. DEFINATION
“
KEY POINTS-
Cells carry out basic functions of life GROWTH, METABOLISM AND REPRODUCTION.
Amoeba consists of single cell.
Multicellular organisms have multiple cells.
Atoms --> molecule --> cells --tissue -->organ- organ system- body.
Humans contain about 10 trillion 1013 .
8/25/2017 2
3. Who gave the cell theory ?
{in 1665}
The word cell comes from the Latin
cellula, meaning "small compartment".
Two types of cells :
A) Prokaryotes (Pro- before ; karyon- nucleus)
B) Eukaryotes (Eu-true ; karyon- nucleus)
8/25/2017 3
4. COMPARISON
PROKARYOTES CHARACTERISTIC EUKARYOTES
Bacteria, algae Typical organisms Animal , plant, fungi
~ 1–10 µm size ~ 10–100 µm
rigid cell wall Cell membrane flexible plasma membrane
No real nucleus Nucleus real nucleus with double
membrane
Binary fission Cell division mitosis
Flagella Cell movement Flagella and cilia
8/25/2017 4
6. CELL MEMBRANE
Also known as
“ plasma membrane “.
Cell enveloped by thin membrane.
75-100 A0 thick.
Fluid outside cell membrane called
as extracellular fluid.
Fluid inside cell membrane called
as intracellular fluid.
Made up of lipid, proteins and fat.
8/25/2017 6
7. Functions-
• Transport of molecules in and out.
• Secretes waste products.
• It keeps out toxic materials.
• Maintenance of proper shape and size.
• As a semi permeable membrane.
8/25/2017 7
8. CYTOPLASM
•It is internal volume of cell.
•Cytosol – clear fluid portion of cytoplasm in which particles are
suspended.
•Contains dissolved proteins, glucose, electrolyte etc….
The cytoplasm / protoplasm
Nucleus
Endoplasmic reticulum
Golgi appartaus
Mitochondria
Vacuoles
Lysosomes.
8/25/2017
8
9. NUCLEUS
• Cells with nucleus- Eukaryotes.
• Cells without nucleus- prokaryotes.
• Most heaviest organells.
Structure-
∞ Spherical in shape.
∞ Attached with ER and ribosomes.
∞ Nucleus contain DNA (genetic information)
∞ Nucleolus- organized structure- DNA, RNA and proteins.
∞ Involved in the synthesis of r-RNA.
Nuclear membrane.
Nucleolus
chromatin
Most cells have single nucleus but SKELETAL MUSCLES have many
nucleus and RBC’s do not have nucleus.
8/25/2017 9
11. MITOCHONDRIA
(Greek : Mitos- thread ; Chondron-
granules)
Powerhouse of the cell.
Rod like or filamentous body.
Strange organell as it has its own
DNA and ribosomes hence it can
produce its own proteins.
Structure-
Outer membrane
Inner membrane
• Cristae (folds called cristae)
• Matrix (DNA and ribosomes in matrix)
• granules
8/25/2017 11
12. • Site for ATP production
• ATP [energy currency of the cell]
• Inner membrane-
-Components of ETC, oxidative
phosphorylation.
• matrix-
-Enzymes required for metabolism of
Carbohydrates, lipids and amino acids.
- Matrix enzymes participate in the
synthesis of heme and urea.
8/25/2017 12
13. ENDOPLASMIC RETICULUM
• Interconnected network
• Thread like structure
• Wall made up of lipids which contains
• Proteins Like cell membrane.
• Also known as “INTRACELLULAR SUPPORTING FRAMEWORK”
Two types of ER-
Rough ER
Smooth ER
8/25/2017 13
14. Functions-
Rough/Granular ER-
Rough nature is due to ribosomes present on it.
Functions- Ribosomes consist of mixture of RNA and
proteins hence helps in PROTEIN SYNTHESIS.
Smooth ER-
Smooth nature is due to absence of ribosomes.
Functions-
• Provide mechanical support to cytoplasmic matrix.
• Helps in maintaining the position of various organelles in the cell.
• Glycogen and lipids are synthesized and stored in ER.
• Smooth ER plays a role in detoxification in the liver.
• Smooth ER plays a role in synthesis & secretion of lipids & steroid hormones by
mammalian gonads & adrenal glands.
8/25/2017 14
15. GOLGI APPARATUS
• Present in all cells except RBC.
• Closely related with ER.
Functions-
• It secrets & stores protein, carbohydrates and
lipids.
• They synthesize complex carbohydrates from
simple sugar.
• Takes proteins made by the ER and exports them
out of the cell as needed.
• It modifies proteins and fats built in the ER and
prepare them for export to the outside of the cell.
8/25/2017 15
16. RIBOSOMES
Small granules either attached to ER or
Scattered into cytoplasm.
It contains RNA-protein complex
Synthesis of proteins.
Also known as “PROTEIN FACTORIES”
8/25/2017 16
17. LYSOSOMES
• “Digestive tract of cells”.
• Spherical vesicles.
• Hydrolytic enzyme take part in
Digestion of proteins, carbohydrates,
Lipids and nucleic acid.
• Also known as SUICIDE BAGS OF CELL.
8/25/2017 17
18. 8/25/2017 18
CELL MEMBRANE Controls what comes into and out of a cell
CYTOPLASM Gel-like fluid where the organelles are found
MITOCHONDRIA Produces the energy a cell needs to carry out its
functions
LYSOSOMES
Uses chemicals to break down food and
worn out cell parts
ENDOPLASMIC
RETICULUM
Has passageways that carry proteins and other
materials from one part of the cell to another
RIBOSOMES Assesembles amino acids to create proteins
NUCLEUS Controls center of cell, contains DNA
GOLGI COMPLEX Receives proteins & materials from the ER, packages
them, & distributes them