1 / 47

Cell Structure

Cell Structure. Chapter 6 IB Biology. Prokaryotes vs. Eukaryotes. Prokaryotes :. Prokaryotes have no nucleus or membrane bound organelles Most have a cell wall Many have flagella Very primitive Origin: 3.5 BYA. Ex- Bacteria. Eukaryotic Cells. “Eu” = true “Karyo” = kernal (nucleus)

lee
Download Presentation

Cell Structure

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. Cell Structure Chapter 6 IB Biology

  2. Prokaryotes vs. Eukaryotes Prokaryotes: • Prokaryotes have no nucleus or membrane bound organelles • Most have a cell wall • Many have flagella • Very primitive • Origin: 3.5 BYA Ex- Bacteria

  3. Eukaryotic Cells • “Eu” = true “Karyo” = kernal (nucleus) • “YOU are a Eukaryote” • Have a nucleus • Have membrane-bound organelles. • First appeared in fossil records 1.5 bya • All members of the following kingdoms have this type of cell: Protocista, Fungi, Plantae, Animalia.

  4. Prokaryotes/Eukaryotes** Note: s = subunits

  5. Prokaryotic Cell Bacterium:

  6. Prokaryotic Cells Escherichia coli

  7. What do all cells have in common? • Cell membrane • Cytoplasm/cytosol • Genetic material • Ribosomes

  8. Cell Membrane • A selectively permeable phospholipid bilayer that forms a barrier between the cell and its environment

  9. Cytoplasm/cytosol • Liquid substance that all chemical reactions of life take place in • Has dissolved ions, macromolecules

  10. Genetic Material- Chromosomes • DNA is found as either organized chromosomes (eukaryotes) or single, loosely packed chromosome (prokaryotes)

  11. Ribosomes • Two-piece protein-based organelle that makes proteins in both major types of cell • Varies structurally in prokaryotes (70S)and eukaryotes (80S).

  12. Generalized Animal Cell

  13. Generalized Plant Cell

  14. Differences between cells Plants Lack: 1. Lysosomes 2. Centrioles 3. Flagella or Cilia Animals Lack: 1. Chloroplasts 2. Vacuoles 3. Cell Walls 4. Plasmodesmata

  15. Eukaryotic Cell Organelles: Nucleus • Contains cell’s genetic material in form of chromosomes • Controls most of cell activities • Site of transcription (1st step in protein synthesis) • Has a double-membrane

  16. Eukaryotic Cell Organelles: Nucleolus • Smaller, dark body inside nucleus • Responsible for ribosome synthesis

  17. Eukaryotic Cell Organelles: ER • ER =Endoplasmic reticulum • Part of endomembrane system • Smooth ER: no ribosomes, synthesizes lipids, detoxifies substances • Rough ER: studded with ribosomes, transports proteins inside cell

  18. Transport vesiclebuds off 4 Ribosome Secretory(glyco-) proteininside transportvesicle Sugarchain 3 Glycoprotein 1 2 ROUGH ER Polypeptide Rough ER makes membrane and proteins • The rough ER manufactures membranes • Ribosomes on its surface produce proteins

  19. Eukaryotic Cell Organelles: Golgi Apparatus (not body) • Part of endomembrane system • The Golgi apparatus consists of stacks of membranous sacs • These receive and modify ER products, then send them on to other organelles or to the cell membrane • Packages and exports cell chemicals such as proteins, carbohydrates and lipids

  20. Eukaryotic Cell Organelles: Mitochondria • Converts glucose into ATP during cell respiration • Is thought to have been primitive prokaryote because: • Has own genome (mtDNA) • Directs own division • Highly folded inner membrane • Found in cells that are motile and contractible • Has a double membrane, with inner membrane called the cristae.

  21. MITOCHONDRION Outer membrane Inner membrane Cristae Matrix

  22. Eukaryotic Cell Organelles: Chloroplast • Found in plant cells and some protists • Contains chlorophyll • Responsible for converting carbon dioxide and water into glucose during photosynthesis

  23. Eukaryotic Cell Organelles: The Cytoskeleton -Fibrous proteins (actin & tubulin) -Roles: Support, cell motility, biochemical regulation, organelle movement -Microtubules: •thickest (25 nm) •tubulin protein (hollow rods) •maintains shape, support, transport, chromosome separation -Microfilaments: •thinnest ( 7 nm) •actin protein filaments; •motility, cell division, shape -Intermediate filaments: • middle diameter (8-12 nm) •keratin; •shape, nucleus anchorage

  24. The Cytoskeleton Tubulinsubunit Actin subunit Fibrous subunits 25 nm 7 nm 10 nm MICROFILAMENT INTERMEDIATEFILAMENT MICROTUBULE Figure 4.17B

  25. Basic jobs of each Microtubules Microfilaments Intermediate -give the cell rigidity -made of actin -reinforce the cell -provide anchors for -enable cells to change -anchor certain organelles organelles shape and move -act as tracks for organelle movement

  26. Eukaryotic Cell Organelles: Lysosome • Vesicle that comes off of Golgi body containing hydrolytic digestive enzymes • Responsible for digestion of old, worn out cell parts and cells • Also digests nutrients **Found extensively in Macrophages (WBC’s)

  27. Eukaryotic Cell Organelles: Centriole • Found only in animal cells • Composed of microtubules in triplet arrangement • Organizes microtubules that attach to chromosomes during cell division

  28. Eukaryotic Cell Organelles: Vacuole • Small ones in animal cells • Large ones found in plant cells, stores water to maintain turgor pressure • Can accumulate wastes, pigments in plant cells

  29. Eukaryotic Cell Organelles: Peroxisomes • Single membrane • Oxidative organelle ***strips e-’s (H’s) from substances • Produce hydrogen peroxide (H2O2) in cells • Metabolism of fatty acids; detoxification of alcohol (liver) • Hydrogen peroxide then converted to water

  30. Eukaryotic Cell Organelles: Cell Wall • Found only in plants • Made of cellulose • Non-living • Has small pores called plasmodesmata, which allows materials in and out.

  31. Eukaryotic Cell Organelles: Cilia/Flagella • Cilia: short hairlike projections used in cellular movement • Flagella: whiplike projection used in cellular movement • Structure in prokaryotes is slightly different

  32. ECM: Extracellular Matrix** • Extracellular matrix (ECM) composed of (located on outside of cell): -Proteins & Carbodydrate -Specifically: -glycoproteins -glycolipids -integrins -fibronectins -collagen (50% of all protein in the body)

  33. Extracellular Matrix (ECM) - Pg. 118-120 Animal cells secrete or produce: Glycoproteins: •proteins covalently bonded to carbohydrate Collagen (50% of protein in human body •embedded in proteoglycan (another glycoprotein-95% carbohydrate) Fibronectins bind to receptor proteins in plasma membrane called integrins (cell communication?) Functions: support, adhesion, movement**

  34. ECM’s in Plants** Cell Walls are an ECM. -maintain shape -prevents excessive water uptake, and -holds the plant up against the force of gravity.

  35. Samples of Various Types of Cells

  36. Nucleus Contractilevacuoles • These pump out excess water • Protists may have contractile vacuoles Figure 4.13B

  37. Cell, stained for mitochondria, actin, and nucleus Figure 4.1x

  38. Prokaryotic cells, Bacillus polymyxa Figure 4.4x1

  39. Prokaryotic cell, E. coli Figure 4.4x2

  40. Pili on a prokaryotic cell Figure 4.4x3

  41. Prokaryotic flagella Figure 4.4x4

  42. Prokaryotic and eukaryotic cells compared Figure 4.4x5

  43. Paramecium, an animal cell Figure 4.5Ax

  44. Plant cells Figure 4.5Bx1

  45. Chloroplasts in plant cells Figure 4.5Bx2

  46. Nuclei (yellow) and actin (red) Figure 4.6x

  47. Red Blood Cells

More Related