• Share
  • Email
  • Embed
  • Like
  • Save
  • Private Content
(10) the cell theory 9 19

(10) the cell theory 9 19



Slildeshow to help with the Cell Theory Timeline activity

Slildeshow to help with the Cell Theory Timeline activity



Total Views
Views on SlideShare
Embed Views



0 Embeds 0

No embeds



Upload Details

Uploaded via as Microsoft PowerPoint

Usage Rights

© All Rights Reserved

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
Post Comment
Edit your comment

    (10) the cell theory 9 19 (10) the cell theory 9 19 Presentation Transcript

    • The Cell Theory – a timeline
      • Late 1500’s: -first lenses used in Europe
      • -used to determine cloth quality (weave and precision)
      • -combos of lenses gave better view
      • Early 1600’s: Leeuwenhoek uses microscope to study nature
    • Early 1600’s Early 1600’s
      • Leeuwenhoek
      • first to view pond water organisms
      • First to see living microscopic orgs
      • Made careful sketches
    • Robert Hooke ( 1665)
      • Used light microscope to look at thin slices of plant tissues -- cork
      • Looked empty, like monk’s chamber
      • Called tiny chambers “cells”
    • Matthias Schleiden 1838
      • German Botanist (plants)
      • All plants looked at were made of cells, so concluded:
      • “ All plants are made of cells.”
    • Theodore Schwann -- 1839
      • German scientist who studied animals -- zoologist
      • Saw that all animals he studied were cellular so concluded:
      • “ All animals are made of cells.”
    • Rudolf Virchow -- 1855
      • German physician who studied cell reproduction
      • “ Where a cell exists, there must have been a preexisting cell…..”
    • The Cell Theory
      • All living things are composed of cells
      • Cells are the basic units of structure and function in living things
      • New cells are produced from existing cells
    • Prokaryotes vs. Eukaryotes
      • Prokaryotes: * NO NUCLEUS
      • *Small and Simple – few organelles
      • *Have cell membranes and cytoplasm
      • Ex. Bacteria
      • Eukaryotes: *Contain nuclei
      • *Contains organelles that perform specialized functions
      • *Uni-or multicellular
    • Figure 7.4 A prokaryotic cell
    • Basic Cell Structures
      • Cell membrane – thin, flexible barrier around cell
      • Nucleus – large, centralized structure that contains genetic material and controls cellular activities
      • Cytoplasm – material inside membrane (but not inside the nucleus) that supports the internal cell shape and organelles
    • Basic cell parts: cell membrane and cytoplasm
      • Cell membrane –
      • *provides barrier between internal and external environment of cell
      • *is semi-permeable (some things can go in, some cannot; some things can exit, some never can)
      • *made up of phospholipid bilayer with proteins embedded that allow for needed passage of large molecules
      • Major job of cell membrane is to maintain the cell’s environment – establish homeostasis
    • Fluid Mosaic Model
      • Cell membrane and embedded proteins are not locked into position – they flow against one another as the cytoplasm and the external liquid environment dictate (so, is fluid)
      • There are MANY different components of the cell membrane – it is a mosaic of many parts
    • Figure 8.6 The detailed structure of an animal cell’s plasma membrane, in cross section
    • Nucleus
      • Largest organelle
      • Enclosed by nuclear envelope or membrane, which is a double membrane – each of which is a lipid bilayer!!!
      • Nuclear membrane has pores in it
      • Contains inactive DNA – chromatin
      • When gets ready to divide, chromatin condenses into chromosomes
      • Directs protein synthesis by synthesizing mRNA and sending to ribosomes in the cytoplasm
    • Cytoplasm
      • Entire region between the nucleus and the cell membrane
      • The semifluid substance that fills this area is called CYTOSOL , and this is what the organelles are suspended in
    • Cell Wall
      • Found in plant cells (another barrier in ADDITION to the cell membrane)
      • Protects the cell
      • Gives support to cell
      • Made of polysaccharide called cellulose
      • Is very porous and allows molecules to pass through, but is NOT SELECTIVELY PERMEABLE
    • Organelles
      • Control:
        • *Nucleus (plant and animal)
      • Assembly, Transport, and Storage:
        • *Endoplasmic reticulum (plant and animal)
        • *Ribosomes (plant and animal)
        • *Golgi apparatus (plant and animal)
        • *Vacuoles (plant and animal)
        • *Lysosomes (plant and animal)
      • Energy transformations:
      • *Chloroplasts (plant only)
      • *mitochondria (plant and animal)
    • Endoplasmic reticulum – “highway system”
      • EXTENSIVE – accounts for more than half the total membrane system in eukaryotic cells
      • Name means “little net within the cytoplasm”
      • Smooth and rough e.r. are actually connected, not distinct, separate sections
      • Job is to transport materials quickly from one place to another in cell
    • Figure 7.11 Endoplasmic reticulum (ER)
    • Smooth e.r.
      • Functions in synthesis of lipids, metabolism of carbs, detoxification of drugs and poisons
      • *Lipids – oils, phospholipids, steroids
      • (sex hormones and adrenal hormones)
      • *Liver cells – glycogen; gets converted to glucose phosphate which cannot leave cell, so e.r. makes enzyme that converts this to glucose
      • *Detox – liver; adds hydroxyl groups to drugs, makes them soluble and able to be flushed out of body
    • Rough e.r.
      • Makes secretory proteins
      • (ex. Insulin made by pancreatic cells)
      • Most are glycoproteins (proteins covalently bound to carbs)
      • Rough e.r. is also a membrane factory – grows by adding proteins and phospholipids; parts can be taken from here and added to other membrane systems using the vesicles for transport
    • Ribosomes “protein factories”
      • Sites of protein synthesis
      • Are made of rRNA and protein
      • Cells with high rates of protein synthesis have MANY ribosomes (human pancreas cell has MILLIONS of ribosomes)
      • Are “free” ribosomes in cytosol that make proteins for the cell that they are INSIDE of
      • Ribosomes that are attached to endoplasmic reticulum (bound) are making proteins for packaging and export OUTSIDE OF CELL
    • Figure 7.10 Ribosomes
    • Golgi apparatus “Gift wrapper/UPS system”
      • Finishes, sorts, ships cell products
      • Golgi will modify products as needed – gives more variety by removing some monomers and substituting others
    • Figure 7.12 The Golgi apparatus
    • Vacuoles “Bank Vaults” or “trash cans”
      • Sites of storage in cells
      • *good things stored – water, minerals,
      • food etc.
      • *bad things stored – broken down cell parts, waste
    • Lysosomes “suicide bags”
      • Membrane-bounded sac of hydrolytic enzymes
      • Different lysosomes break down each of the major classes of macromolecules – proteins, polysaccharides, fats, nucleic acids
      • Work best at pH of 5
      • Used in autophagy – recycle the cell’s own organic material for use
    • Mitochondria and Chloroplasts “powerhouses”
      • Mitochondria – carry on cellular respiration – sites of energy production in cell (glucose broken down to produce ATP)
      • Chloroplasts – carry on photosynthesis
      • – sites where sunlight, CO2 and water are converted into glucose
    • Figure 7.17 The mitochondrion, site of cellular respiration
    • Figure 7.18 The chloroplast, site of photosynthesis
    • Cytoskeleton “hay in mud makes bricks”
      • Network of fibers extending into cytoplasm of cell
      • Provides structural support, and aids in cell motility and cell regulation
      • Made up of microtubules (thickest), microtubules (thinnest), and intermediate filaments
    • Cilia and Flagella “hairs and tails”
      • Cilia are short projections from cell body – hair-like
      • flagella are much longer – whip-like
      • Movement may not be for entire organism; may be part of a larger unit – ex. Cilia lining windpipe propel foreign substances out…
    • Organelles do not work alone…
      • Cell is a dynamic interaction of ALL of its parts – literally, the basic unit of life….