1. The Generic Cell The major parts of the cell include Plasma membrane —the outer boundary of the cell Nucleus—contains and protects DNA (genetic information Cytoplasm—contains organelles, water, and dissolved substances Plasma Membrane Cytoplasm Nucleus

2. GENERIC CELL (and its major parts) Plasma membrane Lysosome Golgi apparatus endoplasmic reticulum Nucleus Nucleolus endoplasmic reticulum Ribosomes Mitochondrion Cytoplasm Peroxisome Centriole Cytoskeleton

3. Parts/Components of cell Cell = Plasma Membrane + Cytoplasm + Nucleus Cytosol + organelles

4. Cytoplasm: internal contents of cell Cytoplasm = cytosol + organelles + inclusions --Masses/aggregations of molecules not surrounded by membranes -- specialized structures w/ specific functions -- Division of labor and compartmentalization Where most cellular activity occurs -- Liquidy/syrupy-like -- H 2 O + dissolved molecules & ions

5. Cytoplasm The cytoplasm of the cell consists of all the material surrounded by the PM including: Organelles (including the nucleus): organelles are structures that perform specialized functions for the cell’s operation –some organelles are surrounded by a membrane the processes they perform are isolated from the general cytoplasm and so organelles can perform incompatible processes –other organelles are not surrounded by membranes

6. Organelles: Non-membrane Bound ribosomes Centrioles/centrosomes Cytoskeleton proteosomes Membrane Bound nucleus Endoplasmic Reticulum Golgi Apparatus vessicles lysosomes peroxisomes mitochondria There are two categories of organelles:

7. Cytoskeleton: (microtubules & microfilaments) Cytoskeleton Supports cell and gives it shape Creates cellular movement and shape change Moves or holds in place cellular contents (including chromosomes in mitosis)

8. Ribosomes: assembles/builds proteins (i.e., protein synthesis) free in cytoplasm (free ribosomes) bound (fixed) to endoplasmic reticulum (forming rough ER) Ribosome (The non-purple parts are the protein being made from an RNA molecule).

9. Centrosome/Centrioles: Forms part of the cytoskeleton movement and organization of cytoskeleton during cell division

10. Organelles Surrounded by a lipid bilayer (membrane) Surrounded by a membrane –Phospholipid bilayer with proteins Membrane isolates contents and activity or organelle from cytoplasm Includes: Endoplasmic Reticulum Golgi apparatus Lysosomes Mitochondria Peroxisomes Vessicles

11. Organelle membranes Membrane = phospholipid bilayer + embedded proteins Selectively permeable membrane Separates/isolates the contents or processes of the organelle from the general cytoplasm. Allows interactions and regulation due to membrane receptors, enzymes, anchors, and transporters

12. Endoplasmic Reticulum (ER): interconnected flattened sacs connected to nuclear envelope new membrane is made by the ER Rough ER (rER) has ribosomes on its surface Function: creation of proteins for release or use in membrane Smooth ER (sER) has no ribosomes Function: makes lipids and carbs, detoxifies harmful chemicals sER rER

13. vessicles Sacs/bubble-like Transport (and store) materials within cell and transport materials to and from the PM

14. Golgi Apparatus: A series of flattened sacs Modify, package, distribute proteins and lipids (for internal use or secretion) Create lysosomes

15. lysosomes Created by golgi Contain “digestive” enzymes Destroy/breakdown molecules, foreign matter (pathogens), and organelles purposeful self-destruction of cells,

16. mitochondria Produce ATP through breakdown of O2 and nutrients Nutrients (e.g., glucose) + O 2  CO 2 + H 2 0 + ATP + heat Two membranes (double membrane) Own DNA Semi-autonomous nutrients O2O2 ATP CO 2

17. Peroxisomes: contains enzymes that break down materials (lipids, amino acids and hydrogen peroxide [a metabolic waste]).

18. Mitochondrial Disorders Mitochondrial myopathies: –Onset between 4-15 years, progressive and leads to death. No cure. drugs seem to be minimally effective. cognitive impariment/dementia Strokes/TIA’s Deafness Acidosis Weaknes Siezures –Leber’s Hereditary Optic Neuropathy Causes blindness –MELAS

19. Lysosomal Storage Disorders A group of 40+ rare inhereted disorders All based on missing or insufficient amounts of an enzyme that should be part of a lysosome Results in molecules accumulating/building up in cell causing disfunction –Tay-Sachs disease –Gaucher’s Disease –Pompe disease/glycogen storage disorder –And many, many more

20. Lysosomal Storage Disorders Tay-Sachs disease –inability to break down a lipid; accumulation leads to paralysis, blindness, and deafness. –Usually appear by age 6 mo death by age 4. Gaucher’s Disease, –inability to breakdown a lipid (glucocerebroside) – accumulates in white blood cells, spleen, liver, kidneys, lungs, brain and bone marrow causing enlargment of spleen and liver, liver malfunction, bone lesions, swelling lymph noteds, anemia, joint swelling, increase succeptablity to infection. some forms can be treated by enzyme replacement. Pompe disease/glycogen storage disorder: –inability to breakdown glycogen in muscle cells. –causes muscle weaknes (myopathy); if present at birth and untreated average age of death is 9 yo due to cardiorespirtory failure (also some nervous system problems)

21. Peroxisome Disorders Adrenoleukodystrophy (ALD) –Peroxisome lacks a membrane proteins that transports a fatty acid (lipid) degrading enzyme into the peroxisome –the lipid accumulates causes nervous system damage and adrenal gland malfunction –early signs are lethargy, dizzyness, and weakness by age 4-10 is most common form –leads to loss of motor function/paralysis, blindness, reflexes such as swallowing and then causes persistent vegatative space followed by death. –no cure by diet can slow progession

22. The nucleus

23. Nucleus : Contains & Protects DNA Double membrane regulates movement of substances into and out of nucleus. Assembles Ribosomal parts

24. Endomembrane System A series of membrane bound organelles that create and accept vessicles. New membrane produced by the ER can make its way to other organelles and the PM Allows membrane composition to be changed, new membrane to be added, and old membrane to be replaced. Consists of: –ER –Golgi Apparatus –Lysosomes –Vessicles –PM

25. ENDOMEMBRANE SYSTEM

26. 26 Protein Flow through the Golgi Apparatus

27. Membrane Flow The flow of membrane between components of the endomembrane system and the PM. How new membrane gets to PM

28. Endomembrane System and Membrane Flow: Proteins and membranes move or “flow” from one organelle to another and too and/or from the PM. This is called membrane flow. Any membrane that is involved with this process is part of the endomembrane system.

29. Endomembrane System and Membrane Flow

30. Organelles the build/synthesize Free Ribosomes sER rER w/ fixed ribosomes mitochondria Golgi apparatus Proteins for use in cytosol (cytoplasm) Proteins for use in a membrane or release from cell Creates peroxisomes Lipids, e.g. phospholipids (and possibly carbs) Alters/modifies products of ER Makes lysosomes ATP & CO2

31. Organelles the break things down lysosomes Peroxisomes Proteosomes mitochondria Waste, ingested macromolecules, & pathogens many proteins, polysaccharides, lipids, nucleic acids 30+ enzymes lipids & toxins/harmful substances Different enzymes than lysosomes Proteins Nutrients & O2

32. Organelles the support/connect and transport Vesicles Cytoskeleton (microtubules, microfilaments, intermediate filaments) Cell shape Cell movement Attachement point for organelles Transport routes Transport within cell. Transport to and from the PM “Delivery packages”

33. Cell Differentiation Our description of cells (above) was of a ‘generic’ cell. Most cells have most of the components discussed Specialized cells have a combination of cell features unique to their function The specialized (differentiated) cells of our body are different in their: 1.Shape 2.Organelle composition 3.The DNA they use and proteins they make

34. Differentiated Cells: Note the shape differences between these cells: Long thin neurons Flat sheet of epithelial cells Tightly packed muscle cells