1 / 37

Organization of the Cell

Organization of the Cell. Cell theory Cells are the basic living units of organization and function All cells come from other cells Work of Schleiden, Schwann, and Virchow contributed to this theory Each cell is a microcosm of life. Biological size and cell diversity.

mbroderick
Download Presentation

Organization of the Cell

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. Organization of the Cell

  2. Cell theory • Cells are the basic living units of organization and function • All cells come from other cells • Work of Schleiden, Schwann, and Virchow contributed to this theory • Each cell is a microcosm of life

  3. Biological size and cell diversity

  4. Cell surface area-to-volume ratio • Plasma membrane must be large enough relative to cell volume to regulate passage of materials • Cell size and shape related to function

  5. Cell surface area-to-volume ratio

  6. Microscopes • Light microscope, referred to as compound microscope, used by most students • Two features determine how clearly an object is viewed • Magnification • Resolution • Light microscope has 500 times more resolution than human eye

  7. Special optical mechanisms for light microscopes • Bright-field microscopy • Phase contrast microscopy • Differential-interference-contrast microscopy • Fluorescence microscope, including confocal fluorescence microscope

  8. Electron microscope • Developed in the 1950s • Allows study of the ultrastructure of cells • 10,000 times more resolution than human eye

  9. Types of electron microscope • Transmission electron microscope • Scanning electron microscope

  10. Comparing light and electron microscopy

  11. Cell fractionation • Used to determine function of organelles • Cells broken apart and the resulting cell extract spun in a centrifuge • Centrifugal force separates extract • Pellet • Supernatant

  12. Cell fractionation

  13. Prokaryotic • Bacteria and archaea • DNA not enclosed in a nucleus • Eukaryotic • All other known organisms • Highly organized membrane-enclosed organelles • Cytoplasm • Nucleoplasm

  14. Functions of cell membranes • Divide cell into compartments, allowing for specialized activities • Interacting membranes form endomembrane system • Vesicles transport materials between compartments

  15. Diagram ofa plant cell

  16. Diagram ofan animal cell

  17. The cell nucleus • Contains DNA • Bounded by • Nuclear envelope • Double membrane perforated with nuclear pores • DNA forms chromatin, which is organized into chromosomes • Nucleolus • RNA synthesis and ribosome assembly

  18. The cellnucleus

  19. Endoplasmic reticulum (ER) • Network of folded internal membranes in the cytosol • Smooth ER • Site of lipid synthesis • Site of detoxifying enzymes • Rough ER • Ribosomes manufacture proteins • Proteins may be moved into the ER lumen

  20. Endoplasmicreticulum (ER)

  21. Golgi complex • Cisternae that process, sort, and modify proteins • In animal cells, Golgi complex also manufactures lysosomes • Glycoproteins transported to the cis face • Golgi modifies carbohydrates and lipids and packages into vesicles

  22. Golgi complex

  23. Lysosomes break down worn-out cell structures, bacteria, and other substances • Peroxisomes • Involved in lipid metabolism and detoxification • Contain enzymes that produce and degrade hydrogen peroxide

  24. Lysosomes

  25. Mitochondria • Sites of aerobic respiration • Organelles enclosed by a double membrane • Place important role in apoptosis • Cristae and matrix contain enzymes for aerobic respiration • Nutrients broken down and energy packaged in ATP • Carbon dioxide and water by-products

  26. Mitochondria

  27. Chloroplasts • Plastids that carry out photosynthesis • Inner membrane of chloroplast encloses the stroma • During photosynthesis, chlorophyll traps light energy • Energy converted to chemical energy in ATP

  28. Chloroplast

  29. Cellular respiration and photosynthesis

  30. Cytoskeleton • Internal framework made of • Microtubules • Microfilaments • Intermediate filaments • Provides structural support • Involved with transport of materials in the cell

  31. TheCytoskeleton

  32. Cilia and flagella • Thin, movable structures that project from cell surface • Function in movement • Microtubles anchored in cell by basal body

  33. Structureof cilia

  34. Glycocalyx, cell coat formed by polysaccarides extending from plasma membrane • Many animal cells also surrounded by an extracellular matrix (ECM) • Most bacteria, fungi, and plant cell walls made of carbohydrates

  35. Extracellular matrix

  36. Plantcell walls

More Related