The document provides an overview of cell structure and function, beginning with the history of cell discovery using microscopes. It describes the various organelles found inside cells, such as the nucleus that contains DNA, mitochondria that produce energy, and ribosomes that synthesize proteins. The roles of the cell membrane, cell wall, and various transport mechanisms involved in moving materials into and out of cells are also explained.

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