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Cells Inside and Out.

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Presentation on theme: "Cells Inside and Out."— Presentation transcript:

1 Cells Inside and Out

2 Cell Theory English scientist Robert Hooke used a crude microscope to look at a slice of cork. He saw little boxes that reminded him of the small rooms that monks lived in – Cells

3 Cell Theory Later the observations of scientists Schleiden, Schwann and Virchow led to what we call the Cell Theory: All living things are composed of one or more cells Cells are the basic units of structure and function in organisms All cells arise from existing cells

4 Size Chart Atom Molecule Organelle Cell Tissue Organ Organ System Organism Population Community Ecosystem

5 Cell Size Having many small cells is more efficient than having a few large cells Small cells have larger surface to volume ratios than large ones So, substance exchange is faster in small cells than in large.

6 Surface to Volume Ratio Example
Surface area Equation on a cube L2 X 6 Volume Equation of a cube L2 X H

7 Magnification Light microscope Magnification Resolution
Visible light passes through object A Lens magnifies the image Magnification Making an image seem larger than what it is Resolution What measures the clarity of an object What limits a particular type of scope

8 Magnification Electron Microscope 100,000 X magnification power
Scanning Electron Microscope (SEM)‏ Allows for better resolutions on the surface of an object Shows object in 3D Good for observing living organisms

9 Magnification Electron Microscopes
Transmission Electron Microscope (TEM)‏ Observer to sees through cells allows the observer to see specimen's internal structure

10 Features Common to All Cells
Cell Membrane All cells share this outer boundary This membrane encloses and separates the interior of the cell – the cytoplasm The cell membrane also regulates what enters and leaves the cell

11 Features Common to All Cells
Cytoplasm (Cyto= cell, -plasm= formative material)‏ Everything between plasma membrane and nucleus or nucleoid region. Cytoskeleton (Cyto= cell, -skeleton= structural framework)‏ Structure made of microfibers & microtubules within the cytoplasm that suspends the cells structures Most cells have ribosomes Cellular Structures on which proteins are made

12 Prokaryotes Bacteria Cells Evolved before eukaryotic cells
Have no nucleus Evolved before eukaryotic cells Structures Common to Prokaryotes Nucleoid region- where the chromosome is ribosomes- protein synthesis Cell membrane- “gate keeper” Cell wall (different than plants)‏- support Some have capsules outside wall- resistance to antibiotics Pili- exchange of genetic info Flagella- movement

13 Prokaryotes

14 Eukaryotes Plant and Animal Cells
Cells are more complex than prokaryotic cells Much like Prokaryotes Eukaryotic Cells have a cell wall (plants/protists/fungi)‏ have a plasma membrane have Cytoplasm have ribosomes But within their cytoplasm eukaryotes have Organelles Cytosol - fluid in cytoplasm

15 Major Organelles to know
Cytoskeleton- support & protection Cell membrane- “gate keeper” controls what enters or leaves the cell Nucleus- holds the chromosomes, directs cell Endoplasmic Reticulum- transport & protein formation Golgi Apparatus- packages things Lysosomes- hold digestive enzymes, “suicide sac” Vesicles- storage Mitochondria- “Power house” respiration, ATP energy Cell Wall- support, protection Chloroplasts- photosynthesis, make glucose Central Vacuole- storage, especially of water Ribosomes- protein making

16 Cytoskeleton Provides interior framework to support cell
Made of network of protein fibers tied to the plasma membrane.

17 Cytoskeleton There are three kinds of cytoskeleton fibers
Microfilaments (or Actin Fibers)‏ Made of protein actin Works in the shape and movement of a cell Microtubules Tiny tubules made up tubulin protein Highway for transportation of info. from nucleus to parts of the cell Intermediate Fibers Rope-like fibers where enzymes and ribosomes anchor in the cell

18 Cell Membrane Phospholipid bilayer - barrier separating inside of cell (cytoplasm) from outside Selectively permeable (penetrable) - controls what enters & leaves cell

19 Proteins Embedded in the Plasma Membrane
** Proteins are macromolecules made of amino acids Some proteins embed in the plasma membrane Enzymes Transport Proteins Receptor Proteins Must have both polar & non polar ends to embed in the membrane

20 Nucleus Nucleus and mitochondria contain genes Nucleus consists of:
Envelope Double membrane Pores let messages in and out Chromatin DNA Protein Nucleolus Produces rRNA rRNA with proteins makes up ribosomes

21 Nucleus

22 Endoplasmic Reticulum (endo = Inside, plasm = formed material)‏
Major system of internal membranes- move proteins and other stuff through cell Is a lipid bilayer with embedded proteins Makes steroids, lipids Detoxifies chemicals

23 Endoplasmic Reticulum (ER)‏
Rough ER Has ribosomes embedded so looks “rough” Processes proteins Smooth ER No ribosomes embedded so looks “smooth” Makes lipids and breaks down toxic chemicals

24 Golgi Apparatus/Lysosomes
Flattened pancake like membrane-bound sacs- the packaging distribution center of the cell

25 Lysosomes/Vesicles Lysosomes (lyso-breaking, -some=body)‏ Vesicles
Small spherical organelles- hold digestive enzymes Work with Golgi to produce, package and distribute protiens Vesicles Small bubble-like membrane bound sacs carry material from ER to Golgi and out of cell Some will become lysosomes

26 Here’s the Protein Flow

27 Mitochondria Harvests energy from organic compound (sugars) to make ATP ATP: energy “Money” in the cells Cellular respiration Most eukaryote cells contain mitochondria Double membrane Big bag stuffed in smaller bag Folds of inner bag = cristae Space inside inner bag called matrix Holds enzymes and DNA This DNA ONLY inherited from mom

28 Mitochondria

29 Organelles Common to Plants
Plants contain all of the organelles now mentioned plus more Organelles Only in Plants (not animals) Cell Wall Chloroplast Central Vacuole

30 Cell Wall Surrounds the cell membrane
Made of proteins and carbohydrates Cellulose - polysaccharide(poly=many, saccharide=sugars) cellulose can NOT be digested by all us, but some can. Supports and Maintains the shape of a cell Protects from damage

31 Chloroplasts Plant cells contain mitochondria to produce the energy “bucks” (ATP), AND they contain chloroplasts to make the glucose the mitochondria “burns” to make the ATP Chloroplasts use light energy to convert carbon dioxide and water into sugar, oxygen and energy (ATP)‏ Also found in algae and some protozoans. Chloroplasts have two membranes have enzymes & DNA

32 Chloroplasts

33 Central Vacuole Largest organelle in a plant cell
Contains ions (charged atoms), nutrients (macromolecules), and wastes When full, makes cell rigid which enables the plant to stand upright.

34 Plant Cell

35 The Endosymbiotic Hypothesis
Evolution of the Eukaryotic cell – (with mitochondria and chloroplasts) Theory: one large prokaryotic cell ingested another which became mitochondria and/or chloroplast in the now eukaryotic cell.

36 Evidence Both are similar to bacteria in size and shape Both have a double membrane Outer from being taken into cell Inner from original bacterial cell Contain DNA in loop like bacteria Contain ribosomes - make proteins RNA in ribosomes like bacterial cells

37 The Endosymbiotic Theory

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