1 / 22

Cells

Molecular Biology of the Cell. Chapters 6 & 7. Cells. WSU Cancer Cell. Light Microscopes (LM). Electron Microscopes (EM). Dust Mite. Dust Mite on the head of a pin. Cell Size and Cell Function. Enormous nerve cells of some animals…

kairos
Download Presentation

Cells

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Molecular Biology of the Cell Chapters 6 & 7 Cells WSU Cancer Cell

  2. Light Microscopes (LM) Electron Microscopes (EM)

  3. Dust Mite Dust Mite on the head of a pin

  4. Cell Size and Cell Function Enormous nerve cells of some animals… Neurons in the giraffes' legs may be several meters long. Plant-sized algal cell Caulerpa can grow up to 1 m in length. …..bounded plasma membrane and cell wall …..long and thin, not short and fat, helps Caulerpa in diffusion processes by increasing its surface-to-volume ratio …..vacuoles take up most of the space inside the cell, squeezing the cytoplasm into a thin layer between the vacuole and the cell wall …..the layer of cytoplasm is only five microns thick

  5. Cell Size & Cell Function The typical bird egg contains an enlarged yolk surrounded by a protein-rich accessory fluid called the egg white or albumen. • bird egg cells are large because of need for nutrients for the developing embryo The yolk is the enlarged ovum or egg cell and it undergoes mitosis. Egg-laying (oviparous) birds have large yolks rich in proteins and lipids to sustain the embryo. The developing chick obtains air through minute pores in the calcium carbonate egg shell. Pores in the shell are plugged by collagen, but are still permeable to air. “13 inches” Aepyornis (A pee ORN iss) titan Elephant Bird Egg

  6. Human RBC’s fit through small blood capillaries

  7. Neurons or Nerve Cells

  8. Muscle Cells

  9. Fruit Fly Sperm Cell

  10. Prokaryotic Cell Domains SizeOrganelles E. coli bacterium

  11. Eukaryotic cells Domain Eukarya Complexity and Size Organelles enclosed in internal membrane Organelle specificity = cell function

  12. Plant Cell Animal Cell Central vacuole Chloroplast Cell Wall Flagellum Centriole Lysosome

  13. NucleiNucleoli Pompe’s diseaseglycogen Endocytosis or Phagocytosis Tay-Sachs disease lipid Smooth ERRough ERRibosomes Golgi Apparatus or Golgi Body Vesicles Lysosomes Exocytosis

  14. Most plant cells do NOThave lysosomes Plants cells have a central vacuole that can function as a large lysosome. Contractile vacuoles store food, poison, pigments, water, wastes

  15. Chloroplast Mitochondria

  16. Cytoskeleton Microfilament Intermediate filament Microtubule Cilia Flagella

  17. Cells in their Social Context

  18. ‘CELL JUNCTIONS’ Occur at points of cell to cell and cell to matrix contact in all tissues, and plentiful in epithelia. Occluding Junction… Type of cell junction that seals cells together in an epithelium, forming a barrier through which even small molecules cannot pass; prevents small molecules from leaking Anchoring Junctions… Mechanically attach cells (and their cytoskeletons) to their neighbors or to the extra-cellular matrix. Communicating junctions… Mediate the passage of chemical or electrical signals from one interacting cell to its partner.

  19. Plasmodesmata are lined with plasma membrane common to two connected cells. Tubular structure derived from smooth ER Cytoplasmic channels of plasmodesmata pierce the plant cell wall and connect all cells in a plant together.

  20. Transport proteins are confined to different regions of the plasma membrane in epithelial cells of the small intestine. Transfer nutrients across the epithelium from the gut lumen to the blood Glucose is ACTIVELY transported into the cell by Na+ driven glucose symports at the apical surface, and it DIFFUSES out of the cell by facilitated diffusion mediated by glucose carriers in the basolateral membrane Tight Junctions Tight Junctions confine transport proteins to their appropriate membrane; block the backflow of glucose into the gut lumen.

  21. Symport Glucose symport… concentrate glucose against a very large concentration gradient. Two Na+/one-glucose symporter; a protein that couples transmembrane movement of one glucose molecule to the transport of two Na+ ions Driven by two forces: by the Na+ concentration gradient (the Na+ concentration is l ower inside the cell than in the medium) and by the inside-negative membrane electric potential Sodium ions flow down their concentration gradient while the glucose molecules are pumped up theirs. Later the sodium is pumped back out of the cell by the Na+/K+ ATPase.

  22. Tight Junctions Impermeable barrier to fluid to prevent passage of materials between cells Anchoring Junctions Attaches cells to neighboring cells or to the extracellular matrix Gap Junctions Intercellular channels

More Related