1. Chapter 3
Cell Structure & Function
Picture by Molecular Expressions Picture by Cell II: Cellular Organization
http://micro.magnet.fsu.edu/cells/animalcell.html http://ridge.icu.ac.jp/biobk/BioBookCELL2.html

2. 3.1: Microscopes & Cells
 Objectives
 1. Define the cell theory
 2. Identify the magnification powers of
different types of microscopes
 3. Observe how the compound microscope
changes an image

3. Early Microscopes
 Anton von Leeuwenhoek
 (1600s / Dutch) Picture by Answers.com
http://www.answers.com/topic/anton-van-leeuwenhoek
 Used glass lenses to create instrument that
magnified images of very small objects
 Light rays bend to make larger image
 Earliest light microscope
Picture by Mr. Cantor’s Biology Blog
http://cantorsbiologyblog.blogspot.com/2012/01/second-semester-begins-with-cells.html

4. Discovery of Cells
 Leeuwenhoek used microscope to look at
drops of pond water
 Filled with tiny living things
 Called them “animalcules”
Picture by Lens On Leeuwenhoek
http://lensonleeuwenhoek.net/lenses.htm

5. Robert Hooke
 English physicist
 Used microscope to observe Picture by History of the Microscope
http://www.history-of-the-microscope.org/robert-hooke-m
 Flowers
 Insects
 Spider webs
 Slices of cork Picture by Dare To Unravel
http://daretounravel.blogspot.com/2011/01/mi
 Concluded
 Wood parts of plants had rectangular chambers
 Called them cells

6. Theodor Schwann
 1839, German Biologist
Picture by Biographical Outlines
http://www.merke.ch/biografien/biologen_en/schwann.php
 Found some animal tissues resemble
cellular tissue of plants
 Eventually concluded
 Animals are made up of cells
Picture by Biographical Outlines
http://www.merke.ch/biografien/biologen_en/schwann.php

7. The Cell Theory
 Robert Brown (Scottish Biologist)
 Found object in center of cell (nucleus)
Picture by Wikipedia
http://en.wikipedia.org/wiki/Robert_Brown_(botanist)
 Matthias Schleiden (German Biologist)
 Suggested nucleus plays role in cell
reproduction
Picture by Biographical Outlines
http://www.merke.ch/biografien/biologen_en/schleiden.php

8. The Cell Theory
 Rudolf Virchow
 1855 German Physician
Picture by Wikipedia
http://en.wikipedia.org/wiki/Rudolf_Virchow
 Proposed that animal and plant cells are
produced only by the division of cells that
already exist
Picture by The Encyclopedia of Science
http://www.daviddarling.info/encyclopedia/P/plant_cell.html

9. The Cell Theory
 1. All living things are composed of cells
 2. Cells are the smallest working units of
living things
 3. All cells come from preexisting cells
Picture by Mrs. Olsen’s 5th Grade Class Page
http://www.ruediger.leon.k12.fl.us/olsonmd/Class%20Pictures/Forms/DispForm.aspx?ID=2&RootFolder=%2Folsonmd%2FClass%20Pictures%2Fclip%20art

10. Modern Microscopes
 1) Compound Light Microscope
 Contains more than 1 lens
 Magnifies up to 1000 times
 Parts of Microscope Handout
Picture by Wikipedia
http://wiki.district87.org/index.php/Compound_Light_Microscopes

11. Modern Microscopes
 2. Electron Microscope
 Uses magnets to focus beam of electrons to
examine sample
 Magnifies 1000 times more than light
microscope
Picture by Ego TV
http://egotvonline.com/2012/03/13/25-everyday-objects-under-an-electron-microscope/
Picture by UK Electron Microscope Facility
http://www.engr.uky.edu/~bjhinds/facil/emf

12. Types of Electron Microscopes
 Transmission Electron Microscope (TEM)
 Sends electrons through sample
 Puts image on fluorescent screen
 Scanning Electron Microscope (SEM)
 Electron scans sample’s surface
 Puts image on TV screen
Picture by Electron Microscope
http://egotvonline.com/2012/03/13/25-everyday-objects-under-an-electron-microscope/

13. Electron Microscope Limitations
 Sample must be in vacuum
 Be nonliving
 Samples for TEM need to be thin slices
 SEM doesn’t show internal structure
Picture by Electron Microscope
http://egotvonline.com/2012/03/13/25-everyday-objects-under-an-electron-microscope/

14. Scanning Probe Microscope
 Trace surface of sample with tiny tip
(probe)
 Very tiny objects like atoms and molecules
Picture by Principles of Scanning Probe Microscopy
http://www.physics.leidenuniv.nl/sections/cm/ip/group/Principle_of_SPM.htm

15. 3.2: Cell Boundaries
 Objectives
 1. Discuss the roles of the cell membrane and
cell wall
 2. Describe passive transport and active
transport

16. Cell Membrane
 Outer boundary that separates and
protects cell from its surroundings
 Must allow certain substances to come in
 Must allow waste to exit
 Descried as selectively permeable
 “The bouncer” or “Main gate”
Picture by The Biology Corner
http://www.biologycorner.com/bio1/cell.html

17. Lipid Bilayer
 Cell membrane is made up of lipid molecules
 Known as phospholipids
 Polar end = head (attract water)
 Nonpolar end = tail (repel water)
Picture by TutorVista.com
http://www.tutorvista.com/biology/membrane-lipid-bilayer

18. Lipid Bilayer
 Line up in double-layer pattern
 Known as lipid bilayer
 Lipid Bilayer
 Provides cell membrane with tough flexible
barrier
 Protects cells
Picture by TutorVista.com
http://www.tutorvista.com/biology/membrane-lipid-bilayer

19. Other Cell Membrane Components
 Most cell membranes have
proteins in lipid bilayer
 Have carbohydrates
attached
 Protein purpose
 Move material across cell
membrane
Picture by Cell Membrane Wiki
 Protect membrane http://torresbioclan.pbworks.com/w/page/22377072/cell%20m
 Carbohydrates act as “ID”
cards

20. Cell Wall
 Porous membrane located outside cell membrane
 Found in plant cells, algae, and bacteria
 NOT found in animal cells
 Supports and protects cells
 Allow substance to pass in and out
 Made of:
 Carbohydrates called cellulose
 Give plants their strength
 Proteins
Picture by Molecular Expressions
http://micro.magnet.fsu.edu/cells/plantcell.html

21. Passive Transport
 Process of moving substances in and out
of a cell
 Does NOT use energy
Picture by Cell Organization & Functions
http://www.williamsclass.com/SeventhScienceWork/CellsOrganization.htm

22. Diffusion
 Process by which substances spread
through a liquid or gas
 Move from region of high concentration to area
of low concentration
 Example: food coloring in water
 In cells…
 Liquids and small lipids diffuse directly across
cell membrane
Picture by Biology Corner
http://www.biologycorner.com/bio1/diffusion.html

23. Facilitated Diffusion
 Cell membrane also contains protein channels
 Allows larger substance to pass through
 Facilitated Diffusion
 Diffusion that occurs with the aided help of a protein
channel
 Each protein channel is specified for a certain substance
Picture by Our Virtual Classroom
http://ccaoscience.wordpress.com/notes/transport-protein/

24. Osmosis
 The diffusion of water through a
selectively permeable membrane
 Water diffuses from areas of high
concentration to areas of low
concentration
Picture by Free Drinking Water
http://www.freedrinkingwater.com/resource-a-complete-resource-guide-to-osmosis.htm

25. Osmotic Pressure
 When water moves by osmosis, it
produces pressure
 Enough to destroy cell
 Three ways to control:
 1) cell wall
 2) pump out water
 3) bathe cells in blood Picture by Non Ideal Solutions
http://www.chem.ufl.edu/~itl/4411/colligative/lec_i.html

26. Osmotic Pressure
 Cell Wall
 Strong tough wall prevents
cell from expanding
 Counter acts osmotic pressure
 Pump Out
 Cells use contractile vacuole
to pump out water
Picture by Non Ideal Solutions
http://www.chem.ufl.edu/~itl/4411/colligative/lec_i.html

27. Osmotic Pressure
 Bathe Cells in Blood
 Mostly in large animals
 Blood cells have same concentration of
dissolved substances
 Help absorb excess water
Picture by A Sweet Life
http://asweetlife.org/a-sweet-life-staff/articles/interview-dr-zachary-bloomgarden-on-the-hba1c-assay/8020/

28. Active Transport
 Movement of a substance against a
concentration difference
 Requires A LOT of energy
 Transports:
 Large molecules
 Food
 Whole cells
Picture by G11-BioA -2011
http://g11-bioa-2011-12.wikispaces.com/(d)+Active+transport

29. 3.3: Inside The Cell
 Objectives
 1. Describe the composition and function of
the nucleus
 2. List and describe the organelles of the
cytoplasm
 3. Interpret the changes observed when a
paramecium takes in food

30. Nucleus
 Large, dense structure contained in cells
 Known as control center
 “Main office of factory”
Picture by Plant Cell
http://library.thinkquest.org/06aug/01942/plcells/nuclues.htm

31. Nucleus
 Organisms can be classified into 2 categories
 1. Eukaryotes
 Organisms cells HAVE nuclei
 Include unicellular and multicellular
 2. Prokaryotes
 Organisms that do NOT contain nuclei
 Small single celled organisms
Picture by Bacterial/Prokaryotic Phylogeny
http://www.bacterialphylogeny.info/eukaryotes.html

32. Role of Nucleus
 Contains nearly all of cell’s DNA
 Has instructions to make proteins / molecules
 Form material called chromatin
 Spreads through nucleus
 When cell divides
 Chromatin condense into chromosomes
 Acts as “blueprint of factory”
Picture by Animal Port
http://www.animalport.com/animal-cells.html

33. Structures In The Nucleus
 Nucleolus
 Small dense region inside nucleus
 Where ribosomes are made
Picture by Molecular Expressions
http://micro.magnet.fsu.edu/cells/nucleus/nucleolus.html
 Nuclear Envelope
 Membrane that surrounds the nucleus
 Has pores to transport materials in and out

34. Cytoplasm
 Fluid outside nucleus held in by cell
membrane
 Holds all other cell organelles
 These are small structures that perform specialized
functions in the cell
 Allows for movement
 Known as the “factory floor”
Picture by Daylilies
http://www.daylilies.org/ahs_dictionary/cytoplasm.html

35. Ribosomes
 Tiny particles made of RNA and protein
 Site for protein synthesis
 Gets instructions from nucleus
 Known as “the workers”
Picture by Cellupedia
http://library.thinkquest.org/C004535/eukaryotic_cells.html

36. Endoplasmic Reticulum (ER)
 Processing and transporting of proteins
and other macromolecules
 Network of membranes
 2 types
 1. Smooth ER… NO ribosomes attached to surface
 2. Rough ER… ribosomes attached to surface
 Act as the subway
Picture by Molecular Expressions
http://micro.magnet.fsu.edu/cells/endoplasmicreticulum/endoplasmicreticulum.html

37. Golgi Apparatus
 Act as packaging center
 Modify and add components to proteins
 Attach carbohydrates or lipids
Picture by Molecular Expressions
http://micro.magnet.fsu.edu/cells/golgi/golgiapparatus.html

38. Lysosomes
 Sac-like membrane that gets rid of waste
 Filled with chemicals and enzymes
 Can also break down and gets rid of
damaged organelles
 Known as the “garbage man”
Picture by Molecular Expressions
http://publications.nigms.nih.gov/insidethecell/images/ch1_lysosome.jpg

39. Cytoskeleton
 Act as a supporting framework for cell
 Found in eukaryotic cells
 Components
 Microtubules
 Mircofillaments
Picture by Cellupedia
http://library.thinkquest.org/C004535/cytoskeleton.html
 These are hollow tubes of protein that provide
framework to support cell

40. Vacuoles
 Sac-like structure used for storage
 Animals
 Store proteins, fats, and carbohydrates
 Plants
 Store water and dissolved salts
 Provide support
 Known as “the warehouse”
Picture by Molecular Expressions
http://micro.magnet.fsu.edu/cells/plants/vacuole.html

41. Mitochondria
 Produces energy from a chemical fuel
 Organic molecules like glucose or other sugars
 Found in eukaryotic cells
 Plants and animals
 Contain own DNA
Picture by Molecular Expressions
http://micro.magnet.fsu.edu/cells/mitochondria/mitochondria.html
 Known as “powerhouse of cell”

42. Chloroplasts
 Organelle that produces energy from
sunlight
 Found in plants ONLY and some algae
 Aids in the process of photosynthesis
 Green due to chlorophyll pigment
 Also contains own DNA
Picture by eTeaching Program
https://www.etap.org/demo/grade7_science/instruction2tutor.html

43. 3.4: The Origin of the Eukaryotic Cell
 Objectives
 1. Define the endosymbiont hypothesis

44. Eukaryotic vs. Prokaryotic
 Eukaryotes  Prokaryotes
 Nuclues  Have NONE of these
 Mitochondria
 Chloroplasts
 Other organelles  WHY???
Picture by BioCoach Activity
http://www.phschool.com/science/biology_place/biocoach/cells/common.html

45. The Work of Lynn Margulis
 Focused on mitochondria and chloroplasts
 Used on DNA to make compounds
 Both surrounded by two membranes
 Both reproduced separately from rest of cell
 Mitochondria from mitochondria
 Chloroplasts from chloroplasts
 Why did this happen???
Picture by The Alien Next Door Blog
http://sfgirl-thealiennextdoor.blogspot.com/2010/06/celebrating-womanhood-i-am-woman-i-am.html

46. The Endosymbiont Hypothesis
 Billions of years
ago…
 Eukaryotic cells arose
as a combination of
different prokaryotic
cells
 Cells consumed other
cells but still each
survived
Picture by Molecular Expressions
http://www.tokresource.org/tok_classes/biobiobio/biomenu/options_folder/D1_life_origins/index.htm

47. Margulis’s Model
 Stated mitochondria and chloroplasts had
ancestors that were free-living organisms
 Were consumed by larger cells
 Became organelles in larger cells
Picture by The Endosymbiotic Hypothesis
http://endosymbiotichypothesis.wordpress.com/

48. Further Evidence
 Chloroplast DNA
 Similar to DNA in prokaryotic cells
 In Mitochondria & Chloroplasts
 Contain own ribosomes to make own proteins
 Ribosomes similar to prokaryotic ribosomes
Picture by Molecular Expressions
http://micro.magnet.fsu.edu/cells/mitochondria/mitochondria.html