Cytology is a branch of biology that involves examining cells under a microscope to determine their appearance, how they form and function, and if they are abnormal or malignant.

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1. CYTOLOGY Cell Shape Cell Theory & Its Development Cell Structure & Function Principal Ways that a Substance Traverse the Membrane Cell Cycle & Division

2. Cytology Study of cell structure and function Cytologist Different types of microscope Cell chemistry

3. C. Cell Structure and Function Three M ain Parts 1. cell wall 1.1 Cell membrane 2. cytoplasm 1.2 Organelles 3. nucleus

4. 1 . Cell Walls (Plant Cell) Found in plants, fungi, & many protists Surrounds plasma membrane Primary (1) and secondary (3) wall 60 % is cellulose, other components are hemicellulose, pectins , lignins and proteins

5. Cell wall Characteristics Primary cell wall 25% cellulose Thin Flexible Found at the root and shoot tip Cells that are a ctively growing areas With glycoproteins Undergo mitosis Secondary cell wall 25% lignin Rigid Hard Resist decay Found in mature areas Cells that stops growing Lack glycoproteins Die when reach maturity

6. 1. Cell Walls Suberin (cork cells) Inhibit water loss through bark Useful in making stoppers for wine bottles

7. A. Middle lamella - Layer between cells that contain pectin

8. B . Plasmodesmata Tiny connections that occur between adjacent cells Channels for the movement of materials from one cell to another Nectar glands/oil glands

9. 1.1 Plasma Membrane Differentially permeable membrane Double layer of phospholipids & proteins (fluid mosaic model)

10. Phospholipids Polar Hydrophylic head Hydrophobic tail Interacts with water

11. Functions of Plasma Membrane Increase the ratio of membrane surface to cell volume Movement of molecules Water , Carbon dioxide, Ammonia, Oxygen Translate chemical and environmental signals from outside the cell Signals translated by the plasma membrane change cellular metabolism

12. Membrane junctions - where 2 cells come together tight junction - nothing passes between 2 ) gap junction - ions pass between 3 ) desmosome - protein fibers bind the cells together (Animal cell)

13. 2. Cytoplasm Viscous fluid containing organelles components of cytoplasm Interconnected filaments & fibers Fluid = cytosol Organelles storage substances

14. 2.A. Ribosome Site of protein synthesis 20 nm in diameter Consist of approximately equal amounts of protein and ribosomal RNA ( rRNA ) Produced in the nucleus Exported to the cytosol Polysomes (clusters) Not surrounded by membranes

15. 2.B. Endoplasmic reticulum Extensive network of sheetlike membranes distributed throughout the cytosol Plasmodesmata also contain portions of ER, which form a continuous internal membrane between cells.

16. Two Regions of ER rough (RER) - has ribosomes attached. Ribosomes produce the proteins, RER transports them . b ) smooth (SER) - no ribosomes attached , produces steroids, inactivates toxins, stores Ca ++, transports lipids.

17. Functions of ER Rough ER - major protein synthesis Smooth ER - synthesis of phospholipids and the assembly of new membranes Both ER forms vesicles that break away and fuse with other membranes; its contents are secreted from the cell; cell-wall components, waxes lipids, and mucilages ; other vesicles can fuse with organellar membranes and become part of them

18. 2. C. Dictyosomes (Golgi bodies) Stacks of flattened, membranous vesicles Usually two sided, with one facing the smooth ER and one side facing the plasma membrane Membrane-bound vesicles occur near the edges

19. Functions of Dictyosomes Receive material from the smooth ER Modify the material Sort into separate packets. Sugar linked to proteins converted to glycoproteins produces cell membranes

20. 3.D Microbodies Smallest membrane-bound organelles in the cell Single membrane Spherical in shape 0.5 – 1.5 µm in diameter Associated with membranes of ER, chloroplast and mitochondrion

21. Kinds 1. peroxisome Occur primarily in leaves Enzymes, catalase and oxidase Metabolize hydrogen peroxide (H 2 O 2 ) Oxidize other cellular toxins, ethanol and nitrites 2. glyoxysomes Common in seeds and seedlings Breakdown fatty acid to the synthesis of carbohydrates for respiration and sucrose synthesis

22. Kinds (animal cell) 3. Lysosomes ( lys = split, some = body) – small sacs with hydrolytic enzymes

23. 2.E Mitochondrion Consists of a smooth outer membrane and inner membrane that is folded into tubular or vesicle-shaped (crista/e)

24. 2.E Mitochondrion Enzymes for producing ATP. Contain DNA - can self-replicate

25. 2. F. Vacuole (plant cell) Fusion of vesicles (ER & GA) and small vacuoles Tonoplast (membrane) Turgor pressure Water; enzymes and protein; water souble pigments- red and blue anthocyanin; growth hormones; ions- K and Cl; alkaloids-oxalic acid

26. Vacuole (animal cell) Small in size isolate and remove waste products from the other organelles and the cytoplasm

27. 2.G. Plastids (animal cell) Round or oval organelles that produces pigments Types : chloroplasts (chlorophyll) - photosynthesis; chromoplasts ( carotene,lycopene,anthocyanin ) - color; leucoplasts ( amyloplasts,elaioplasts ) - storage

28. 3. Nucleus Most conspicuous “command center of the cell” 1. Surrounded by two membrane (nuclear envelope) 2. Nuclear pore (except DNA) 3. Nucleoplasm 4. Nucleolus

29. Nucleolus Most cells have 2 or more Directs synthesis of RNA Forms ribosomes dense chromatin in the nucleus, no membrane

30. Nuclear Envelope