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Review Lecture MAJEC Unit 1 (PMC).pptx
- 1. CELL STRUCTURE & FUNCTION MAJECUNIT #:1 PMC TOPIC #:4
- 2. • Course contents: 1. Comparisonbetween Prokaryotic and eukaryotic cell 2. Comparison between plants and animal cell 3. Cell wall 4. Fluid mosaic model of plasma membrane 5. Cytoplasm and cell organelles Nucleus Endoplasmic Reticulum Golgi apparatus/Golgi complex/Golgi bodies Lysosome Vacuole Mitochondria Plastids/chloroplast
- 3. INTRODUCTION TO CELL: •Basic structural and functional unit of all living organism. • Smallest unit that can carry out all activities of life. • Building blocks of complex multicellular organisms. TYPES OF CELLS Multicellular Unicellular Eukaryotes (Protozoa) Prokaryotes (Bacteria) Eukaryotes (Animalia) Simple Multicellular Complex Multicellular
- 4. COMPARISON BETWEEN PROKARYOTICAND EUKARYOTIC CELLS Features Prokaryotic Cell Eukaryotic Cell Nucleus Absent Present DNA Submerged in cytoplasm Present in nucleus Type of DNA Circular DNA as nucleoid Linear DNA in nucleus Membrane Bounded Organelles Absent Present Ribosomes Small sized, 70S ribosomes (50S larger sub-unit and 30S smaller sub-unit) Large sized, 80S ribosomes (60S larger sub-unit and 40S smaller sub-unit) Cytoskeleton Absent Present Cell Wall Peptidoglycan/ Murein/ Sacculus Cellulose/ Chitin
- 5. Cell Membrane Sterolsabsent Sterols present Mesosomes Present Absent Cell Division Binary fission Mitosis/ Meiosis Histones Absent Present Composition of Flagella Flagellin Tubulin Cilia Absent Present Pili/fimbria Present Absent Plasmid Present Absent (Yeast have) RNA polymerase Single type 3 types Replication Cytoplasm Nucleus Transcription/Translati on Cytoplasm Cytoplasm Cell division Binary fission Mitosis Replication fork Single Multiple Example Bacterial cell, Cells of blue Plant and Animal cells Features Prokaryotic Cell Eukaryotic Cell
- 6. COMPARE THE STRUCTUREOF TYPICAL ANIMAL AND PLANT CELL Features Animal Cell Plant cell Cell wall × Plastids × Glyoxysomes × Centrosome(Centriol es) × Lysosomes × Flagella × Phagocytosis × Mitotic Apparatus Spindles + Asters Spindles Only Cytokinesis Inwards Outwards Phragmoplast × Cell plate formation × Plastids ×
- 7. COMPARE THE STRUCTUREOF TYPICAL ANIMAL AND PLANT CELL Features Animal Cell Plant cell Plasmodesmata × Mitochondria More in number Fewer in number Vacuoles Small and many Large and single Storage Products Glycogen Starch Cellular Shape Do not have fixed shape Have fixed shape Nucleus Central Peripheral Spindle formation Centrioles Analogous region Mode of nutrition Autotrophic Heterotrophic Effect of hypotonic solution Burst Turgid
- 8. CELL WALL Outermost non-livingcovering Absent in animal cells. Secreted by protoplasm Freely permeable Support Protection of internal components Prevent from osmotic lysis Provide definite shape to cell
- 9. CELL WALL Structure ofPlant Cell Wall: Primary Wall: True wall, Thin, Elastic Pectin and hemicellulose is also deposited in it. All have Middle Lamella In between the primary walls Magnesium and calcium salts and pectin Secondary Wall Thick and rigid, Inelastic Composed of inorganic salts, Silica, Waxes, Lignin, Cutin
- 10. PLASMA MEMBRANE Found inall living prokaryotic and eukaryotic cells. Proteins (60-80%) Chemical Composition: Extrinsic proteins Intrinsic proteins Lipids (20-40%) Sphingolipids Phospholipids Cholesterol Carbohydrates (small quantity) Glycoproteins Glycolipids Transmembrane Proteins/ integral proteins (Hydrophilic/ hydrophobic ) Peripheral Proteins Surface marker/ Cell to cell interaction
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- 13. Role of plasmamembrane: 1. Transport of materials by; i. Passive transport i. Simple diffusion ii. Facilitated diffusion iii. Osmosis ii. Active transport iii. Impulse transmission iv. Endocytosis and exocytosis v. Excrete waste vi. Maintain ionic gradient
- 14. CYTOPLASM • Cytosol Solublepart of cytoplasm, 90% water and 10 % fundamental molecules • Fundamental molecules of life • Cell organelles • True solution Function of Cytoplasm Store house of vital chemicals Site of certain metabolic pathways Glycolysis Translation Fermentation Between nucleus and plasma membrane Composition Colloidal solutions. (non-viscous) or gel (viscous).
- 15. CYTOPLASM Cell Organelles Non-membranous Double membranous Singlemembranous • Ribosomes • Centrioles • Endoplasmic reticulum • Golgi complex • Lysosome • Microbodies • Vacuole • Mitochondria • Chloroplast • Nucleus Cell Organelles Non-membranous
- 16. RIBOSOMES Small granules Eukaryotes (80S) Prokaryotes(70S) • Freely dispersed • Attached to membrane Ribonucleo- proteins particles. Attached during translation by Mg++
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- 18. ENDOPLASMIC RETICULUM Nuclear Membrane SER RER •Ribosomes attached • Proteins synthesis • Sac like • Lipids metabolism • Detoxification • Impulse transmission • Intracellular transport • Tubular form • Cisternae (tubular structure) Ergastoplasm/Nissl's granules All membranous organelles except mitochondria and chloroplast are formed by endoplasmic reticulum.
- 19. GOLGI COMPLEX Golgibody. Golgi apparatus. Golgi complex. Dictyosomes SER Vesicle Forming face/cis- face/outer/convex Maturing face/trans face/inner/concave Golgi Vesicle Golgi complex
- 20. Functions Cell secretion. Modification of molecules e.g., glycoconjugates. Formation of phragmoplast. Formation of primary lysosomes. Formation of acrosome. Pathway and Fate of Processed Vesicles
- 21. LYSOSOMES • All eukaryoticcells except RBCs. • Rich in acid phosphatase and hydrolytic enzymes • Enzymes are synthesized on RER, golgi process Types of lysosomes • Primary lysosome: • Secondary lysosomes • Tertiary lysosomes Functions Intracellular digestion Autophagy (starvation, routine process) Autolysis (a type of cell death is committed,) Sometimes release of extracellular enzymes
- 22. LYSOSOMES Lysosomal Storage Diseases Congenital diseases 20 such diseases have been discovered so far. These diseases are produced by a mutation In glycogenosis type II disease, more glycogen Tay-Sach’s disease Accumulation of lipids in brain cells leads to mental retardation and even death.
- 23. PEROXISOMES AND GLYOXYSOMES Microbodies. Single membranous, vesicular structure. Diameter of 0.5 µm approximately. FEATURES PEROXISOMES GLYOXYSOMES Occurrence Present in all type of eukaryotic cells Present in plants/Germinating seedlings Enzymes Peroxidase, catalase, glycolic acid oxidase Catalase, glycolic acid oxidase, other enzymes Role Detoxification of alcohol Formation and decomposition of H2O2 Involved in photorespiration Lipid metabolism Conversion of stored fatty acids to carbohydrates (Succinate) through glyoxylate cycle
- 24. VACUOLES Large vesiclesoriginate from the endoplasmic reticulum, Golgi complex and cell membrane. Plant cell have; Single Large Central Animal cell have; Many Small Peripheral Tonoplast cover vacuole Food vacuole Contract vacuole Storage of organic and inorganic Turgor pressure
- 25. MITOCHONDRIA Introduction Power house/batteryof the cell Size and number Self-replicating Circular DNA (1% of the total DNA of cell) Ribosomes (70S) Functions aerobic cellular respiration. pyruvic acid oxidation, Krebs cycle, aerobic respiration, and fatty acid metabolism. ADP is regenerated by mitochondria into ATP
- 26. MITOCHONDRIA Structure Under Electron microscope Compoundmicroscope • Rod • Filaments • Vesicles • Double membrane • Outer membrane • Inner membrane • Inner compartment/ matrix • Outer compartment • DNA • Ribosomes • Organic • Salts • Enzymes • Co- enzymes
- 27. PLASTIDS/CHLOROPLASTS Found inplant and algal cells. Proplastids Chromoplast Leucoplast Chloroplast Elaioplast Proteinoplast Amyloplasts Lipids Starch Proteins Classification
- 28. Chloroplast Stroma Granum Thylakoid Outer Membrane Inner Membrane Inter Grana Porins Calvin cycle Lightreaction Circular DNA Ribosomes CO2 fixation Self-replicating Smaller and larger
- 29. NUCLEUS Structure Nuclear envelope Nuclear pore Chromatin Heterochromatin Euchromatin Nucleoli Nuclear Lamina Nucleoplasm Doublemembrane Ribosomal factory Two regions Central fibril area Peripheral granular area
- 30. NUCLEUS Nuclear Pores RNA and ribosome Cytoplasm •Carbohydrates Proteins • Lipids • Signaling Nucleus Number of nuclear pores Undifferentiated cell Egg (30000 pores/nucleus) Differentiated cell Erythrocytes 3-4 pores/nucleus • It is transparent semi-fluid ground substance. • It contains DNA, RNA, proteins, Mg+2 ions, free nucleotides and enzymes (DNA and RNA polymerase).
- 31. NUCLEUS Chromatin & Chromosome: Chemicallychromosomes are composed of DNA and protein/histones. Satellite DNA Secondary constriction Primary constriction / centromere Kinetochore Telomere Nucleolus organizer Sister chromatids Spindles attachment Identical Chromatid/arm
- 32. NUCLEUS Structure Chromatin & Chromosome: Onbasis of centromere 4 types of chromosomes are; Telocentric Acrocentric Sub- metacentric Metacentric
- 33. NUCLEUS Chromosome Number InDifferent Species Species Diploid (2n) Haploid (n) Species Diploid (2n) Haploid (n) Man 46 23 Frog 26 13 Chimpanz ee 48 24 Drosophil a 8 4 Onion 16 8 Potato 48 24 Garden Pea 14 7 Pigeon 80 40 Functions It controls all the metabolic activities of cell. It has all the genetic information in a cell.
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