Ch 7 - Cell and Cell Transport

1. INTRODUCTION TO CELLS
Chapter 7 pg.182-207 (Unit 3)
Ms. Zeron

2. 2
HISTORY OF THE CELL
1664 - Robert Hooke:
• made a simple microscope
• Looked at the dead cells of bark.
• He named the “boxed-shaped” structures “cell”

3. HISTORY OF THE CELL
1600s - Leeuwenhoek:
• 1st to view living things
• Pond water & scrapings from his teeth
• Designed his own microscope
3

4. Co-founders of the Cell Theory
1838 –M. Schleiden:
all plants are made of cells
1839 – T. Schwann - all
animals are made of cells
1855 - Rudolph Virchow –
cell comes from other cells.
4

5. CELL THEORY:
Includes the following three principles:
1. All living things are made of one or more
cells.
2. Cells are the basic unit of life
3. Cells come from pre-existing cells.

6. Theory vs. Scientific Law
Theory: an explanation of the
observed phenomenon.
Law: description of an observed
phenomenon.
Similarities: supported by
considerable data and widely accepted
by the scientific community.
Ex.: Kepler's Laws describe (how) the
motions of planets but do not provide an
explanation (why) for their movements.

7. MICROSCOPE TECHNOLOGY

8. Compound Light Microscopes:
Used to see living organisms. Magnifies objects up to
1000x.

9. Transmission Electron Microscope:
• TEMs produce high-resolution, 2-dimensional
images. It allows you to zoom in to see organelles.
• Disadvantage: specimens are dead
• Advantage: magnifies objects up to 500,000x.
Mitochondrion inside a cell
Teacher’s Notes:
TEM are tools used for
medical and biological
research. Most powerful
microscope!

10. Scanning Electron Microscope:
It’s a type of electron microscope that
produces images of a sample by scanning it
with a focused beam of electrons.
Advantage: creates 3D images
Disadvantage: Specimens are dead

11. SEM Images

12. GENERAL INFORMATION ABOUT
CELLS

13. GENERAL CHARACTERISTICS OF ALL
CELLS
A plasma cell membrane
Genetic material (RNA, DNA)
Break bonds to release energy
ATP

14. Organisms may be:
• Unicellular – composed of one cell
• Multicellular- composed of many cells
14

15. In Multicellular Organisms:
15
Cells take on different shapes & functions
through cell differentiation.
Differentiation occurs numerous times
during the development of a multicellular
organism as the organism changes from a
simple zygote to a complex system of
tissues and cell types.

16. How do cells specialize?
• Cells can turn different genes on and off
allowing a cell to change into a different
cell with a specific function (job)

17. Specialized Animal Cells
Muscle cells
17
Red blood cells
Cheek cells

18. Specialized Plant cells
18
Guard Cells
Pollen Xylem cells

19. TWO MAIN TYPES OF
Prokaryotes vs. eukaryotes
CELLS

20. TWO TYPES OF CELLS
PROKARYOTES:
• Lack a nucleus
• Simple & Smaller
• Unicellular
• Circular DNA
• Reproduce by binary
fission
Ex: bacteria
EUKARYOTES:
- Have a nucleus
- Complex
- Single or multi-celled
Ex. Algae, yeast,
plants and animals

21. Main Structures in Prokaryotes:
•Cell wall (or capsule)
•Cell membrane
•Ribosomes
•Circular DNA
called plasmid
21
Teacher’s Note: There are no
mitochondria in prokaryotes

22. Plant vs Animal Cells (eukaryotes)
Structures found in plant cells only:
• Cell wall
• Central vacuole
• Chloroplast
Structures found in animal cells only:
• Centrioles (used in cell division)
• Lysosomes (rare in plants)

23. Examples of Eukaryotes
24
Single celled organism Paramecium
(protista)
Plant cell
Animal cell

24. CELL MEMBRANE
Structure and Function
(Also known as the Fluid Mosaic Model)

25. Integral Protein are
embedded
Peripheral
Protein
Cholesterol for
flexibility
Inside of cell
Carbohydrate
chains for ID
The Fluid Mosaic Model

26. Why do we mean by fluid mosaic
model?
FLUID- phospholipids and proteins can move around freely
within the layer
MOSAIC- the pattern produced by the scattered protein

27. Function of the plasma membrane:
• Involved in cell ID.
• Controls what goes in and out of cell
• Binding site for enzymes.
• Protective barrier
• Anchors cytoskeleton (shape)
• Attach to other cells (tissue)

28. Structure of the plasma membrane
• Made of two layers
• Surrounds outside of all cells
• Made of many phospholipids units
31
Outside of cell
Cell
membrane
Inside of cell
(cytoplasm)
Proteins
Carbohydrate
chains
Protein
channel Lipid bilayer

29. Essential Components:
• PHOSPHOLIPID: Units that make up the lipid
bilayer.
• CHOLESTEROL: Maintains flexibility
• CARBOHYDRATE CHAINS: Involved in cell
recognition
Outside of cell
Inside of cell
(cytoplasm)
Cell
membrane
Proteins
Carbohydrate
chains
Protein
channel Lipid bilayer

30. Proteins in the Cell Membrane
Integral proteins
• help move ions and other
molecules that can’t cross the
membrane.
• They are embedded completely
through the membrane.
• Ex.: carrier proteins & channel
proteins
Peripheral proteins: attached on
the surface (inner or outer). Used
for anchoring & binding site.

31. Glycoproteins:
• Proteins with attached carbohydrate
tails that act as markers for cell
recognition/identification.
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32. 35
PHOSPHOLIPIDS:
• Can move sideways to allow small molecules to
squeeze through the lipid bilayer.
Made of:
• Head: water loving (hydrophilic)
• Tail: water fearing, points inward (nonpolar)

33. Phospholipid: The unit that makes up
the cell membrane

34. “SELECTIVE PERMEABILITY”

35. TYPES OF
TRANSPORTS
Section 4 pages 201-207

36. Types of Passive Transports
Moves molecules from a higher to lower
concentrations without the use of energy.
1. Diffusion: Moves tiny molecules such as oxygen
2. Osmosis: Moves water molecules. Will make
cells lose or gain water.
3. Facilitated Diffusion: Moves ions and other
molecules with the help of a transport protein (aka
channel protein)

37. Example of Diffusion

38. Three types of passive transports
DIFFUSION
(ex. oxygen)
FACILITATED DIFFUSION
(ex. glucose)
OSMOSIS
(water)

39. Active Transport:
• Uses a carrier protein that change shapes.
• Requires energy.
Other active transports used for larger
molecules include:
• Endocytosis (moves substances in)
• Exocytosis (moves substances out)

40. Other types of Active Transports:
 Endocytosis: allows for large particles to enter the cell.
 Exocytosis: allows for substances and toxic to exit the cell.

41. Active Transport
PASSIVE
TRANSPORT
(no energy required)

42. Passive vs. Active Transport
PASSIVE
TRANSPORT:
“going down the
concentration
gradient”
ACTIVE TRANSPORT:
“Going against the
concentration
gradient”

43. Types of Solutions:
• Hypotonic: water rushes into the cell.
Makes plant cells firm up but animal cells
burst. Ideal condition for plant cells.
• Isotonic: equal amount of water goes in
and out of cell. Ideal for animal cells.
• Hypertonic: water leaves the cell. Makes
cells shrivel.

44. Effects of Hypotonic Solution on Plant Cells
Shrinks Soft Firm up
*ideal*
Teacher’s Notes: Hypotonic solutions are ideal for plant cells, but will
make an animal cell burst due to osmotic pressure on its cell
membrane

45. Effects of Osmosis on Animal Cells:
Teacher’s Note: Isotonic solution is ideal
for animal cells.

46. END OF NOTES

47. REVIEW: Solutions

48. Concentration Gradient
(HIGH) (LOW)
(LOW) (HIGH)

49. Summary of transport
52
Transport Description Energy?
Diffusion Tiny molecules squeeze thru cell
membrane Ex: Oxygen
No
Osmosis The diffusion of water No
Facilitated
Diffusion
An integral protein (channel
protein) is used to transport
molecules across.
No
Active
Transport
A carrier protein changes its
shape as it lets in molecules.
YES!!
(ATP)

50. PARTS OF AN
EUKARYOTIC CELL
ORGANELLES – ch7 pg.190-200

51. 2. mitochondria
10.
chloroplast
3. Cell membrane
1. Nucleus
5. FREE RIBOSOMES
6. CENTRAL VACUOLE
8.CELL WALL
3. Lysosome
9.Golgi 4. Rough & Smooth ER

52. Function of organelles
• Nucleus – control center,
• Cell membrane – barrier where
transports take place
•Ribosomes – builds proteins.
•ER – helps assembles and transports
proteins
• Golgi – packs and exports proteins.

53. Functions of Organelles
• Lysosome – breaks down parts, contains enzymes
• Cell Wall – rigid, for support
• Central Vacuole – for storage
• Chloroplast – makes food for the plant (solar panel),
holds green pigment.
• Mitochondria – makes ATP (energy) from food
• Cytoplasm – holds organelles, where chemical reactions
take place

54. ANIMAL CELL (eukaryote)
57
Nucleolus
Nucleus
Nuclear envelope
Ribosome (attached)
Ribosome (free)
Cell Membrane
Rough
endoplasmic
reticulum
Golgi apparatus
Mitochondrion
Smooth
endoplasmic
reticulum
Centrioles
chromatin

55. Animal Cell (eukaryote)

56. Plant Cell (eukaryote)
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57. Plant Cell (eukaryote)

58. ADDITIONAL
INFORMATION

59. Organization
Levels OF LIFE
62
Atoms to Organisms

60. 63
Nonliving Levels
ATOMS MOLECULES ORGANELLES

61. 64
Living Levels
CELLS – life starts here TISSUES – Similar cells working
together

62. More Living Levels
ORGANS
ORGAN
SYSTEMS ORGANISM
Different tissues
working together
Different organs
working together
Complete
multicellular
individual

63. ANY QUESTIONS??