A short discussion on the topic and its easy to understand

1. By,
Dhaneshwar.S
B.sc OD
THE CELL

2. THE CELL

3. THE CELL
• The cell is the smallest unit of all living organism
• Cells of different tissue perform the different action
• The cells are made up of the following structures:
 Cell wall
 Nucleus
 Cytoplasm
 Microsomes

4. CELL WALL

5. CELL WALL
• External boundary of the lining
• Three layered structure made up of lipids and proteins
• Measures appox 70Å in thickness
• It allows the diffusion of substance into and out of the cell

6. NUCLEUS

7. NUCLEUS
• Largest structure
• Present in the center of the cell
• More or less spherical in shape
• Bounded by nuclear membrane
• It contain
 Nucleolus
 chromatin

8. CYTOPLASM

9. CYTOPLASM
• Between the cell membrane and nucleus.
• Contains cell organelles like,
Microsomes:
Endoplasmic reticulum
Golgi apparatus
Mitochondria
Lysosomes
Centrosome

10. MICROSOMES
• Extremely small bodies present inside the cytoplasm
• Complex structure with high content of lipids and nucleoproteins
• Concerns with protein synthesis

11. ENDOPLASMIC RETICULUM

12. ENDOPLASMIC RETICULUM
• Most extensive cell organelle
• Consists of two membranes
 Granular
 Agranular
Granular
 Rough surfaced EPR
 Contains ribosomes
 Ribosomes are the sites of protein synthesis
Agranular
 Smooth surfaced EPR
 Does not contains ribosomes
 It concern with fatty acid and steroid
 Also store and release calcium

13. GOLGI APPARATUS

14. GOLGI APPARATUS
• Cup shaped structures
• Contains vesicles
• Situated between the nucleus and the apex of the cell
• Concerned with the concentration of protein prior to their secretion

15. MITOCHONDRIA

16. MITOCHONDRIA
• Occurs in cytoplasm at variable numbers
• Composed of two layers of membranes they are:
An outer layer which is smooth
An inner layer folded into sheets of tubules called cristae
• It concerns with cellular oxidation
• It is made up of proteins, phospholipids and some ribonucleic acid
• It also contains some important enzyme systems

17. LYSOSOMES

18. LYSOSOMES
• Small or oval bodies surrounded by single membrane
• Vary in number and contains a variety of hydrolytic enzyme
• It breakdown bacteria and cell debris engulfed by the cell
• Damaged intercellular organelles are also breakdown and digested by
lysosomes

19. CENTROSOMES

20. CENTROSOMES
• Small
• Rod shaped
• Found near the nucleus
• Plays important role during cell division
• Damaged intercellular are surrounded by radiating thread like structure
• Contains two centrioles

21. MICROTUBLES

22. MICROTUBULES
• Straight
• Hollow cylinders with a diameter a about 200Å.
• Concerned with the maintenance of cell shape
• Also associated with the movement of cilia,flagella,and mitotic
spindles.

23. FUNCTIONS OF CELL
• Important functions performed by the cells are,
Ingestion and assimilation
Growth and repair
Metabolism
Respiration
Excretion
Irritability and contractility

24. • Ingestion and assimilation
 The cell ingests chemical substance like amino acids from
intercellular or interstitial fluid
 These substance are used to build up complicated
substances like protein
• Growth and repair
 The ingested and assimilated materials are used to
synthesis new protoplasm
 Leads to increase in size and growth of the cell
 Also worn out parts of the cells are replaced by this process

25. • Metabolism : This involves in two processes
Anabolism in which the ingested and assimilated food
material is used for growth and repair
Catabolism in which food material is broken down to release
energy for various functions of the cell
• Respiration
 Transport of oxygen from lungs to blood to the tissues
 Removal of waste product like carbondioxide
 This is the essential for the survival and functions of the cell

26. • Excretion
 The cell eliminated waste products resulting from catabolism
into the interstitial fluid
 These products are carried by blood for elimination through
lungs and kidneys
• Irritability and contractility
 The cells are active by means for these two functions
 The cell responds to any stimulus by contracting
 The impulse is conducted as that occurs in the nerve cells