1 / 49

The Cell

The Cell. Overview: The Importance of Cells All organisms are made of cells. The cell is the simplest collection of matter that can live (grow, metabolize, reproduce, make adjustments). RELT. 50 µm. Light Microscopes are used to view cells like this one. Differences in Cells. 1. Size:

lorant
Download Presentation

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. The Cell

  2. Overview: The Importance of Cells • All organisms are made of cells. • The cell is the simplest collection of matter that can live (grow, metabolize, reproduce, make adjustments).

  3. RELT 50 µm Light Microscopes are used to view cells like this one

  4. Differences in Cells 1. Size: --smallest @ 0.25μm Mycoplasma hominis --largest @ 0.75 mm Thiomargarita namibiensis 162,000X

  5. The “sulfur pearl of Namibia”

  6. Siphonous green algae (1m long) Chaos chaos (1-5 mm)

  7. A human egg cell = 100 µm Vs. human sperm cell = 5 µm

  8. 2. Number --unicellular (Bacteria, Protists like ameba & algae) --multicellular (Plants, Animals, Fungi, & some Protists)

  9. 3. Kind/type A. Prokaryote means “before kernal” OR B. Eukaryote means “true kernal”

  10. Which one has a nucleus inside?

  11. 4. Plants vs. Animals (lab)

  12. Pili: used to attach to other cells Nucleoid: region where the cell’s DNA is located (NOT In a membrane) Ribosomes: organelles that synthesize proteins Cell membrane: Encloses the cytoplasm Cell wall: rigid structure outside the plasma membrane One circularchromosome 0.5 µm (a) A typical rod-shaped bacterium (b) A thin section through the bacterium Bacillus coagulans (TEM) Flagella: used for locomotion See p. 472 Figure 6.6 A, B

  13. Parts of the Cell • 3 main locations 1. Cell (plasma) membrane +/- cell wall 2. Nucleus (or nucleoid) 3. Cytoplasm (insides of the cell)

  14. Outside of cell (a) Inside of cell 0.1 µm TEM of a plasma membrane. Phospholipids Proteins (b) Structure of the plasma membrane 1. The cell membrane (next topic) • Functions as a selective barrier by allowing movement of nutrients & waste in & out Carbohydrate side chain

  15. 2. The Nucleus: Genetic Library of the Cell • The nucleus contains most of the genetic info <3.2 billion vs. 5 million (or 0.1%) nucleotide base pairs (A-T or C-G) in human cells vs. E. coli> • The nuclear envelope w/ pores encloses the nucleus, separating its contents (nucleolus, chromatin) from the cytoplasm

  16. How are these cells different from the previous slide? • Nucleoid region in a ___ karyote

  17. 3. CYTOPLASMIC ORGANELLES (“tiny organs”) A. Ribosomes=not membrane-bound • Are particles made of ribosomal RNA & protein. • All cells (pro and eukaryote) must have! • The smallest and most numerous organelle.

  18. Weighing in at around 150,000 atoms, the ribosome is the engine of life itself, a delightfully intricate cellular gizmo that executes the last piece of the central dogma of biology: information is transferred from DNA to RNA to protein. The ribosome transforms mRNA into the proteins that brick-by-biological-brick build bacteria, birds, & biochemists. from HHMI

  19. Free ribosomes Bound ribosomes TEM > Large subunit Diagram of a ribosome Small subunit 0.5 µm Ribosomes: found in all cells because…. they act as protein factories (sites of protein synthesis). RER

  20. B. Endoplasmic Reticulum: Biosynthetic Factory • ER is continuous w/ nuclear envelope • Two kinds: • 1. Smooth ER (SER) that lacks ribosomes • 2. Rough ER (RER) w/ ribosomes

  21. Smooth ER Nuclear envelope Rough ER ER lumen Ribosomes Transport vesicle 200 µm Smooth ER Rough ER

  22. The functions of Smooth ER include --synthesizing lipids (testes/ovaries) --detoxifying poisons (liver cells)

  23. SER in the liver

  24. Functions of Rough ER • The RER • Has bound ribosomes so it … • Produces proteins, which are then distributed by transport vesicles to other parts of the cell like …

  25. C. The Golgi Apparatus: Receiving, Packaging, Shipping Center • Receives the transport vesicles produced by the RER • Looks like stack of flattened empty pancakes • Function =modifies the products of RER

  26. 1 Nuclear envelope is connected to RER, which is continuous with SER Nucleus Nuclear envelop Rough ER 2 Transport vesicles “blip” off of ER carrying contents to GA Smooth ER cis Golgi Plasma membrane trans Golgi Transport vesicle carries proteins to cellmembrane for secretion Relationship betw. organelles of inner membrane system Golgi modifies molecules Lysosome containing enzymes

  27. 1. Code travels from nucleus to RER • 2. Ribosomes use code to make raw protein which then travels quickly thru ER • 3. Goes to Golgi where it is modified • 4. Transported to Cell membrane for secretion

  28. D. Vacuoles • membrane-bound sacks in the cytoplasm = storage containers • In plant cells (larger), they hold water & starch. • In animal cells, they are like little ziploc baggies; storage containers for food, H2O & waste.

  29. Central vacuole Nucleus Cell wall Chloroplast 5 µm Central Vacuoles • Are found in plant cells to hold reserves of starch and water Figure 6.15

  30. What organism would have lots of these?

  31. Nucleus 1 µm Lysosome Hydrolytic enzymes digest food particles into… Food vacuole fuses with lysosome Lysosome w/ hydrolytic enzymes Digestive enzymes Cell membrane Food vacuole E. Lysosomes: Digestive Compartments Membrane-bound sacs w/ hydrolytic enzymes + acid used to digest all kinds of macro-molecules. Ex: amylase, pepsin

  32. Mitochondrion Intermembrane space Outer membrane Ribosomes Inner membrane Mitochondrial DNA 100 µm Energy Converting Organelles F. Mitochondria are enclosed by two membranes (a smooth outer & an inner folded membrane) Figure 6.17

  33. Mitochondria • Function: “burn” glucose to produce energy in the form of ATP • Have their own ribosomes and DNA! What does that mean?

  34. The Mitochondrion Mr. W has many of us guys in his running muscle cells!

  35. G. Plastids • Found in plants and algae • Contain pigments so they can photosynthesize • 2 kinds

  36. Chloroplast Ribosomes Chloroplast DNA Inner &outer membranes 1 µm Chloroplasts: Capture Light Energy • Contain chlorophyll (“more like… borophyll”)

  37. Chloroplasts • Have two membranes • Use light to convert CO2 & H2O into glucose • Possess their own ribosomes & DNA!

  38. Chromoplasts contain other pigments • Autumn leaves anyone?

  39. Microtubule Microfilaments 0.25 µm Non-membrane bound organelles H. Cytoskeleton=network of fibers extending throughout the cytoplasm that supports + organizes structures and activities in the cell

  40. 10 µm Figure 6.1

  41. Centrosome Microtubule Centrioles 0.25 µm Microtubules I. Centrioles • Only in animal cells • Used for dividing the nucleus (mitosis)

  42. J. Cilia and Flagella • Are locomotor appendages of some cells (protein extensions from the cell used for movement)

  43. A Cross-Section of a Cilium

  44. 5 µm The Cell: A Living Unit Greater Than the Sum of Its Parts Cells rely on the integration of structures & organelles to function. Here a white blood cell needs what cell parts to recognize, ingest, and destroy the bacteria?

More Related