The document provides an overview of cell structure and function. It discusses: 1. The cell theory proposed by Schleiden and Theodore that cells are the basic unit of life and all cells come from pre-existing cells. 2. The key components of cells including the cytoplasm, nucleus, mitochondria, endoplasmic reticulum, Golgi apparatus, lysosomes, peroxisomes, and cell membrane. 3. The functions of these cellular components such as protein synthesis in the endoplasmic reticulum, energy production in mitochondria, modification and sorting of proteins in the Golgi apparatus, and degradation of molecules in lysosomes.

1. Dr MANJU JHA
Department of Biochemistry
CELL
&
CELLULAR
ORGANIZATION

3. Cell hierarchy:
AA & FA…………
…………….PROTEINS AND COMPLEX LIPIDS
membrane and membrane bound organisms.

4. What is cell?
Simplest integrated form /unit of life

5. Term ‘cell’?
Cell theory?
Cell doctorine: Schleiden & Theodore

6. Cell doctorine:
1. All organisms consists of one or more cells.
2. Cells are smallest unit characteristic of life.
3. All cells arise from pre-existing cells.
4. Cells carry hereditory informations from cells.

7. What are the properties of living cells?
1. Metabolism
2. Growth
3. Reproduction
4. Mutations
5. Response

8. What are integrated/different functions
of cells?
1. Skeletal
2. Integumentry
3. Muscular
4. Digestive
5. Cardiovascular
6. Respiratory
7. Excretory
8. Nervous system
9. Endocrinal
10. Reproduction

9. Components of cells
1. Cytoplasm
2. Nucleus

10. Components of cells
Cytoplasm: contains?
Nucleus: genetic information

11. Mitochondria?
Mutations causes mitochondriopathies:
• Chronic progressive external ophthalmoplegia
• Kearns Sayre Syndrome
• MELAS
• LHON
OTHERS: DM (mitochondrial diabetes)

12. Rough endoplasmic reticulum
PROTEIN SYNTHESIS
Sensor molecule, that monitor amount of unfolded or
improperly folded proteins that accumulate in the cell.
Excessive amount of mutant proteins that are folded
incorrectly may increase.
Accumulation of non-functional proteins in the ER, k/a ER
Stress.
ER stress is associated with Diabetes, Cancer, &
Neurodegenerative disorders

13. SER-
Lipid synthesis
Hydroxylation reactions.
(Cytochrome P450 )
Microsomes-
Marker enzyme
Glucose 6 Phosphatase
Smooth endoplasmic
reticulum

14. Specialized organ where proteins
are processed, modified, and
prepared for export from the
cells. Proteins are received from
ER and passed through layers of
golgi apparatus where
polysachharides are synthesized
and attached to proteins to make
Glycoproteins or to lipids to
make Glycolipids
•Marker enzyme
Galactosyl transferase
Golgi Complex (Dictyosomes)

15. Modification and sorting of proteins.
Glycosylation of Proteins
Major site of new membrane synthesis -
formation of lysosomes and peroxisomes.
Cisternae are of three types – cis, medial and
trans.
Glycoproteins are generally transported from ER
to cis golgi (proximal), medial (intermediate) and
then to trans (distal) golgi. Trans Golgi has
maximum glycoprotein content.

16. Lysosomes:
Hydrolytic enzymes (about 40+)
Proteases, nucleases, glycosidases, lipase, phosphatase,
sulfatase…………….
Marker: Acid phosphatase

17. Peroxisomes:
Single membrane sac containing ENZYMES
• Detoxification of alcohol in liver cells.
• Removal of ammonia from amino acids.
• Participate in degradation of long chain fatty acids.
• Liver peroxisomes contain: catalase, urate oxidase, D-A
A Oxidase
Defects: Adrenoleukodystrophy, Zellweger’s syndrome,
Refsum’s disease

19. • Protective sheath,
• Selective transport of ions and molecules,
• Recognition of various stimuli,
• Contains receptors for bio molecules like hormones,
neurotransmitters etc,
• Cell morphology and movement,
• Compartmentalization,
• Membrane is very active metabolically,
• Contains the ecto-enzymes 5’ nucleotidase (nucleotide
phosphatase) and alkaline phosphatase on the outer
membrane,
• FUNCTIONS OF CELL MEMBRANE

21. Cell Organelles can be Separated by Ultracentrifugation.

23. Subcellular
organelle
Pellet formed at the centrifugal
force of ..
Marker
Nucleus 600–750 x g, 10 minutes DNA
Mitochondria 10,000–15,000 x g,10 minutes Inner membrane
ATP synthase
Lysosome 18,000–25,000 x g, 10 minutes Cathepsin
Golgi complex 35,000–40,000 x g, 30 minutes Galactosyltransferase
Microsomes 75,000–100,000 x g, 100 minutes Glucose-6-phosphatase
Cytoplasm Supernatant Lactate dehydrogenase

24. Organelle Functions
Nucleus DNA replication, transcription
Endoplasmic
reticulum
Biosynthesis of proteins, glycoproteins,
lipoproteins, drug metabolism, ethanol oxidation,
synthesis of cholesterol (partial)
Lysosome Degradation of proteins, carbohydrates, lipids and
nucleotides
Mitochondria Electron transport chain, ATP generation, TCA
cycle, beta oxidation of fatty acids, ketone body
production, urea synthesis (part), heme synthesis
(part), gluconeogenesis (part), pyrimidine
synthesis (part)
Cytosol Protein synthesis, glycolysis, glycogen metabolism, HMP shunt
pathway, transamination, fatty acid synthesis, cholesterol synthesis,
heme synthesis (part), urea synthesis (part), pyrimidine synthesis
(part), purine synthesis
Metabolic functions of subcellular organelles

25. • Plasma membrane:
Fence with gates; gates open when message is received
• Nucleus:
Manager’s office
• ‰
Endoplasmic reticulum:
Conveyor belt of production units
• Golgi apparatus:
Packing units
• ‰
Lysosomes:
Incinerators
• Vacuoles:
Lorries carrying finished products
• ‰
Mitochondria:
Power generating units
Comparison of ell with a factory

26. Thank
you