HUMAN ANATOMY AND PHYSIOLOGY CELL CHAPTER

1. 2.Structure of cell: component
and its function
Prepare by: Yannawar P.D. ( M.Pharm)
DCOP Latur

2. Content
Introduction
Cell theory
Plant cell
Animal cell
Structure and function of cell

3. Introduction

4. Cell theory
 All living organism are composed of cells
 Cells are basic structural and functional unit of life
 New cells are produced from existing cells

5. .

8. Structure of cell
 Cell contains
1. Cell or plasma membrane cell membrane
2. Nucleus
3. Cytoplasm
A. Cytosol
B. Cell organelles nucleus
i. Endoplasmic reticulum
ii. Golgi bodies
iii. Lysosomes
iv. Vacuoles cytoplasm
v. Mitochondria
vi. Centrioles

9. Cell membrane or plasma membrane
 Definition:
 Outermost layer surrounding the cell that separate and protect the cell from external environment and
provide connecting link between cell and its environment
 Outer lipid bilayer, extremely delicate, thin, living and semipermeable membrane
 Its activity regulate internal environment of the cell
 Composition of cell membrane
• Protein – 55%
• Phospholipid – 25%
• cholesterol -3%
• Other lipids-4%
• Carbohydrates- 3%

10. Fluid mosaic model
 This model is proposed by singer and Nicolson in 1972.
 according to this model, cell membrane is made up of lipid, protein and carbohydrate
 Protein are present in form of globules and look like dot and hence called mosaic.
 Experiment on its viscosity suggest that it is of fluid consistency, like oil.
 On account of fluid and mosaic arrangement of protein and lipid it is called fluid mosaic
model.
 Cell membrane is made up of phospholipid ,it have 2 layers of phospholipid hence called
it as phospholipid bilayer

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 It is amphiphilic(amphi-both, philic-loving) in nature i.e. both water and lipid loving.
 Phospholipid divided into 2 portion
• Head( hydrophilic)(hydro-water ,philic –loving)
• Tail( hydrophobic)(phobic-hating )
 Some of the portion contain protein which are embedded and looks like globules
 This re of 2 types
• Intrinsic protein(inner protein) head(hydrophilic)
• Extrinsic protein(outer protein)
tail(lipophilic)
phospholipid

12. .
 .
phospholipid
Intrinsic
or
Extrinsic protein

13. Sandwich model
 Davson–Danielli model or sandwich model was given by Davson–Danielli in 1935
 The model describes a phospholipid bilayer that lies between two layers of globular proteins is
sandwich like structure.

14. 2.Cytoplasm
 Cytoplasm is located inside cell membrane
 Cytoplasm is gel like fluid present between plasma membrane and nucleus.
 Cytoplasm is made of 70 to 90% water and is colourless usually
 cytoplasm = inside – nucleus
 protoplasm = cytoplasm + nucleus (nucleolus)
 It is made up of
o Cytosol
o Organelles
o Inclusions
1.CYTOSOL
 Cytosol is transparent, viscous gel like fluid containing 75-90% of water and the suspended
dissolved components like protein, lipids, carbohydrates and different inorganic substance.

15. 2.Cell organelles
 Organelles meaning small organs and have individual and highly specialised functions.
 It includes
 Mitochondria
 Ribosome
 Endoplasmic reticulum
 Golgi bodies
 Lysosome
 Centrosome

16. Mitochondria :
 Powerhouse of cell
 Number of mitochondria vary from cell to cell
 Mitochondria is composed of 2 lipoprotein membrane
 Outer one which is intact and cover whole structure
 And inner one is folded internally to form shelves
 Mitochondria contain small amount of DNA called extra chromosomal DNA.
 This DNA controls all mitochondrial function.

17. Continue..
 Structure includes
 Inner membrane
 Outer membrane
 Matrix
 Cristae
 Perichondria space
 F1 particle or oxysome
 Function of MITOCHONDRIA
 It is centre of aerobic respiration, the chemical energy is made in the form of ATP.
 (ATP formation)

18. Ribosome:
 These are tiny molecules consist of rRNA and protein.
 they are made up of 2 subunit smaller one and larger one, magnesium join both subunit
 Types of RNA:
70 s 80 s
30s 40s(smaller subunit)
50 s 60s(larger subunit)
found in undeveloped prokaryote(70s) found in developed eukaryotes(80s)
Another type is one attached to EPR and other observe free in cytosol called cytoplasmic or free ribosome
 Function;
Site for Protein synthesis

19. Endoplasmic reticulum
 It is spring like structure, it start from nuclear to cell membrane.
 It is an interconnecting membranous canal in the cytoplasm and largest membrane in eukaryotic cell.
It is of two types
 Smooth endoplasmic reticulum Rough endoplasmic reticulum
It synthesis lipids and steroids hormones ribosomes are attached on surface hence appearance is granular and rough.
Because of presence of ribosomes, RER is responsible protein synthesis.
Function:
 Tighten and provide shape to cell
 Lipid and Hormone synthesis
 Exocytosis( protein supply to all organs)
cisterns

20. Golgi bodies (export house of cell)
 Structure of Golgi bodies
1. Trans phase or M phase (maturation phase) –concave
2. Cis phase or F phase (formation phase) –convex
3. Vacuoles – food material store and are always at concave site
4. Cistern and lumen
5. Transport vesicles- (transfer of protein from ER to GB )
6. secretory vesicles- secrete proteins expel outside the cell (exocytosis)
o Function
• Storage of proteins, food material, lipid,
• Supply of materials to all organs
• Export house of cell

21. PROCESS -Proteins(synthesis in ribosome)
protein transfer through transport vesicles
from ER to Golgi bodies
fuse with cis region
then carried to trans region
through secretory vesicles proteins expel outside the cell (exocytosis)

22. Lysosome (suicide bags of cells) (Lyso-separate, soma- body)
• Lysosome contain degenerative enzymes that function at pH 5 like protease( digest protein), lipase
(digest lipid)
• They vary in shape and size.
• They also contain ribonuclease, deoxyribonuclease (degrade RNA and DNA),
 Types;
 Primary – only enzyme no food
 Secondary –food inside lysosome
 Tertiary – residue after digestion
 Autophagosome ( self bomb)
 Function:
 Digestion of food material (breakdown of macromolecules like protein, carbohydrates, lipids etc)
 Removal of dead cells
 Destroy invading virus and bacteria

23. Centrosome
• It is found in every cell but not present only in RBC.
 Microtubule bundle of microtubule (9) centrioles (2) centrosomes (1)
It forms by microtubules and it consist of pair of centrioles and it play important role in cell division.
 Function :
• Help in cell division by karyokinesis.

24. 3. Nucleus
 It is control center of cell.
 Structure of nucleus consist of
1. Nuclear membrane (double layer, provide protection to nucleus))
2. Nucleolus ( cluster of DNA)
3. Nucleoplasm (karyolymph -fluid of nucleus)
4. Chromatin (compress the DNA into a compact unit )
5. Nuclear pore (transportation)
 Function :
 It contains the genetic information of the cell in the form of deoxyribonucleic acid (DNA) or
chromosomes and thus, controls cell growth and cell division.
 storage of DNA, RNA and ribosome.
 control of the protein and enzyme synthesis.

25. Cell parts and their function
Cell part Key points Function
Cell or plasma
membrane
• phospholipid bilayer
• Fluid mosaic model
• Sandwich model
Protection
Cytoplasm • Cytosol – nucleus Contains cell organelles and protection
Mitochondria • Power house of cell ATP generation
Ribosome • 70 s and 80 s ribosome Site of protein synthesis
Endoplasmic
reticulum (EPR)
• SER and RER Steroid hormone synthesis, protein synthesis
Golgi body • Export house of cell Storage of proteins, food material, lipid, Supply of materials
to all organs
Lysosome(suicid
e bags)
• Contains degenerative enzymes Digestion of food material
Centrosome • Microtubules and centriole Help in cell division by karyokinesis
Nucleus • Control center of cell contains the genetic information (DNA)