1 / 27

Cells

Cells. The 3 Basic Parts of all Cells. Plasma Membrane Controls what enters & exits the cell Cytoplasm Entire contents of cell between P.M. and nucleus Where most metabolic activity occurs Nucleus or Nuclear Area Contains DNA, the genetic material. Phospholipids form a two-layer sheet

venetia-natasha
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. Cells

  2. The 3 Basic Parts of all Cells • Plasma Membrane • Controls what enters & exits the cell • Cytoplasm • Entire contents of cell between P.M. and nucleus • Where most metabolic activity occurs • Nucleus or Nuclear Area • Contains DNA, the genetic material

  3. Phospholipids form a two-layer sheet Called a phospholipid bilayer, with the heads facing outward and the tails facing inward Water Hydrophilicheads Hydrophobictails Water Figure 5.11B

  4. Classes of Cells • Two basic types of cells: • Prokaryotic cells • Eukaryotic cells

  5. Prokaryotic cells are structurally simpler than eukaryotic cells Prokaryotic cell Nucleoidregion Colorized TEM 15,000  Nucleus Eukaryotic cell Organelles Figure 4.3A

  6. Prokaryotic Cell Figure 4.3B Pili Cell wall Plasma membrane Nuclear area Ribosomes Flagella

  7. Eukaryotic cells Animal Cell Fig 4.4A

  8. 1. The nucleus is the cellular control center Containing the cell’s DNA, which directs cellular activities Nucleus Chromatin Two membranesof nuclearenvelope Nucleolus Pore Roughendoplasmicreticulum Figure 4.5 Ribosomes

  9. 2. Smooth endoplasmic reticulum, or smooth ER Synthesizes lipids Processes toxins and drugs in liver cells Stores and releases calcium ions in muscle cells Smooth ER Rough ER Nuclearenvelope Ribosomes Rough ER Smooth ER TEM 45,000 Figure 4.7

  10. 3. Rough endoplasmic reticulum or Rough ER Ribosomes on the surface Produce proteins that are secreted, inserted into membranes, or transported in vesicles to other organelles 4 Ribosome Secretory(glyco-) proteininside trans-port vesicle 1 2 Glycoprotein Polypeptide Rough ER Transport vesiclebuds off 3 Sugar chain Figure 4.8

  11. 4. The Golgi apparatus finishes, sorts, and ships cell products Stacks of membranous sacs receive and modify ER products then ship them to other organelles or the cell surface Figure 4.9 Golgi apparatus “Receiving” side ofGolgi apparatus Golgiapparatus Transportvesiclefrom ER TEM 130,000 New vesicleforming Transportvesicle fromthe Golgi “Shipping” sideof Golgi apparatus

  12. 5. Vesicles: • Membrane-bound “balloons” that transport and store substances in cells

  13. 6. Lysosomes are sacs of enzymes function in digestion within a cell Lysosomes in white blood cells destroy bacteria that have been ingested recycle damaged organelles

  14. Fig 4.13 • The various organelles of the endo-membrane system are inter-connected structurally and functionally

  15. 7. Mitochondria harvest chemical energy from food Mitochondria carry out cellular respiration which uses the chemical energy in food to make ATP for cellular work Mitochondrion Outermembrane Intermembranespace Figure 4.14 Innermembrane TEM 44,880 Cristae Matrix

  16. 8. Cytoskeleton & related structures - a network of protein fibers help organize its structure and activities Fig 4.17 Tubulin subunit Actin subunit Fibrous subunits 25 nm 10 nm 7 nm Microfilament Intermediate filament Microtubule

  17. Microfilaments of actin Enable cells to change shape and move Intermediate filaments Reinforce the cell and anchor certain organelles Microtubules give the cell rigidity And provide anchors for organelles and act as tracks for organelle movement

  18. Cilia and flagella move when microtubules bend Eukaryotic cilia and flagella are locomotor appendages that protrude from certain cells Colorized SEM 4,100 LM 600 Figure 4.18

  19. Tight junctions can bind cells together into leakproof sheets Anchoring junctions link animal cells into strong tissues Gap junctions allow substances to flow from cell to cell Tight junctions Figure 4.18B Anchoring junction Gap junctions Extracellular matrix Space between cells Plasma membranes of adjacent cells

  20. Please do the activities at the following 2 sites: http://learn.genetics.utah.edu/content/begin/cells/insideacell/ http://learn.genetics.utah.edu/content/begin/cells/scale/

  21. Plant Cell –Fig. 4.6b

  22. Plant cells also have: • Vacuole • stores water, solutes, waste • Important for growth and rigidity • Chloroplasts • Site of photosynthesis: conversion of light to ATP which drives formation of sugars • Cell wall • Protects, supports **Plant cells do not have lysosomes

  23. Vacuoles function in the general maintenance of the cell lysosomal and storage functions Nucleus Chloroplast Centralvacuole Colorized TEM 8,700 Figure 4.12

  24. Chloroplasts convert solar energy to chemical energy found in plants and some protists convert solar energy to chemical energy in sugars Chloroplast Stroma Inner and outermembranes TEM 9,750 Granum Intermembranespace Figure 4.15

  25. Plant cells have rigid cell walls made of cellulose Are connected by plasmodesmata - connecting channels Vacuole Plasmodesmata Layers of one plant cell wall Cytoplasm Plasma membrane Walls of two adjacent plant cells Figure 4.22

More Related