Parts of a Cell

This describes the parts and functions of a cell.

1. Parts of The Cell

2. Basic Parts of the Cell Three Major Parts of the Cell: Plasma Membrane Cytoplasm Nucleus

3. Cytoplasm

4. Cell Membrane

5. Siomai-like Structure : Double l ayer of p hospholipid m olecules Proteins are embedded in it . Two Kinds of Protein: I ntegral and Peripheral Proteins Phosphate Head: Polar and Hydrophilic Lipid Tail : Nonpolar and Hydrophobic Cell Membrane

6. Cell Membrane Structure: Fluid mosaic m odel “Fluid” – configuration of the phospholipid molecules “Mosaic” – presence of proteins Lipid and other molecules move about in the membrane. The plasma membrane is not smooth.

7. Cell Membrane Functions: Selectively permeable Protects the cell Separates the cell from its environment Gives shape to the cell “Plasma” – living Paramecium – pellicle

8. First structural part to be observed Structure: Spherical in shape and located at the center of the cell It has three parts: Nucleoplasm Nucleolus Nuclear Envelope / Nuclear M embrane Nucleus

9. The Parts of the Nucleus 1. Nucleoplasm - protein-rich protoplasm where nucleolus and chromatins are suspended - Chromatins become chromosomes when the cell is dividing . 2. Nucleolus - Darker area, for synthesis and storage of RNA 3. Nuclear M embrane / Nuclear Envelope - Double membrane separating the nucleus from cytoplasm - Prokaryotic Cell and E ukaryotic Cell - Not a solid barrier (has nuclear pores)

10. Types of Cells Prokaryotes - cells with no distinct nucleus Ex. Bacteria Eukaryotes - cells with distinct nucleus Ex. Animal C ell

11. Control C enter of the C ell Contains most of the cell’s genetic material (DNA) Nucleus

12. The Protoplasm Two Types: Cytoplasm – protoplasm lying around the nucleus Karyoplasm / Nucleoplasm – protoplasm lying inside the nucleus * The structure enclosed within the cell membrane and outside the nucleus is the cytoplasm.

13. Cytosol Structures Cytoplasm

14. Material between the cell membrane and the nucleus Appears : Clear Viscous Colloidal Found in are different structures: Endomembrane S ystem Organelles Supramolecular C omplex Cytoplasm

15. Endomembrane System (Internal Membrane S ystem) Endoplasmic Reticulum (ER) Structure: Network of membranes; tiny canals formed by two parallel membranes T wo distinct regions: 1. Rough ER 2. Smooth ER

16. Endoplasmic R eticulum (ER) Rough ER A ppears rough because of the presence of ribosomes Many types of specialized cells secrete proteins produced by the RER (Ex: White Blood Cell in a human). Proteins destined for secretion are synthesized by ribosomes attached to RER (Ex: Glycoproteins).

17. Endoplasmic Reticulum (ER) 2. Smooth ER Its enzymes synthesize fats, phospholipids, steroids, and other lipids. Carbohydrate Metabolism – done by SER in the liver Its enzymes detoxify drugs and other poisons.

18. Endoplasmic Reticulum (ER) Serves as a channel for products produced in the cell

19. Internal Membrane S ystem Golgi Apparatus Discovered by Camilo Golgi (nerve cell of an owl) Flattened membranous sac

20. Golgi Apparatus Functions: W orks together with the ER. Serves as the Package Counter of the Cell After processing and packaging of substances in the golgi a pparatus, a clean up is needed. Cleaning is done by the l ysosome .

21. Various structures like miniature organs that perform specific functions Organelles

22. Organelles Lysosomes Not commonly found in plant cells Membrane-bound organelles Contain hydrolytic enzymes These enzymes hydrolyze the cell when the lysosomial membrane is damaged. What does hydrolytic enzyme do? Breakdown of macromolecules (proteins, lipids, carbohydrates) Destroys bacteria and other microorganisms Destroys old cells (Programmed cell destruction) “Suicide Bag of Cell ”

23. Organelles Mitochondrion May be single or few in some cells, but most often a cell has hundreds or thousands of mitochondria. Structure: R od-shaped organelles Size ranges from being small to bigger sauge -like structure. Has 2 membranes: Outer membrane – smooth and separates mitochondria from the cytoplasm Inner membrane – with an enfolding called Cristae (where important reactions in the mitochondria take place)

24. Organelles Mitochondria Generates energy ( Power House of the Cell)

25. Organelles Cytoskeleton Network of fibers floating through the cytoplasm Functions: a. Gives mechanical support to the cell b. Transport for some proteins and organelles c. Associated with motility

26. Organelles Cytoskeleton Has 3 components: Microtubules – for movement (Ex: Cilia and F lagella) contain Tubulin Microfilament – for muscle contraction contains Actin Intermediate Filaments – reinforce the shape of the cell

27. Organelles 4. Vacuoles Mostly found in plant cells Fluid-filled sacs surrounded by a membrane Mature plant cells have a single large vacuole. Plant Stem – c ell sap

28. Organelles 5. Plastids F ound in most plant cells C ontain color pigments Two Kinds : C hromoplast – c olored p lastids Ex: Chloroplast – contains chlorophyll L eucoplast – colorless plastids; for storage of food substances

29. Supramolecular Complex Ribosomes T iny dot-like structures scattered throughout the cytoplasm S ite where proteins are assembled “Protein Factories of the Cell”

30. Cell Wall Functions: Protects the cell from mechanical injury Gives rigidity to plant cell Cell wall is porous. Composed mainly of c ellulose Also contains l ignin