1. Chapter 7 Cell Structure and Function
Section 7.1- Life is Cellular
Section 7.2- Eukaryotic Cell Structure
Section 7.3- Cell Boundaries
Section 7.4- Diversity of Cellular Life

2. Section 7.1- Life is Cellular
Discovery of Cells
Robert Hooke
Used light microscope to look at cork cells
Cells reminded him of monk cubicles
“many little boxes”
Called them CELLS

3. Section 7.1- Life is Cellular
Discovery of Cells
Anton van Leewenhoek
First to observe living cells
Invented simple, tiny microscopes

4. Section 7.1- Life is Cellular
The cell theory states that:
all living things are composed of one or more cells
cells are the basic units of structure and function in an organism
cells come only from the reproduction of existing cells

5. Section 7.1- Life is Cellular
Cellular Basis of Life
All living things
are made of organized parts
obtain energy from their surroundings
perform chemical reactions
change with time
respond to their environment
reproduce.

6. Section 7.1- Life is Cellular
Prokaryotes
Prokaryote cells lack a nucleus and membrane-bound organelles.
Have genetic material not contained in a nucleus

7. Section 7.1- Life is Cellular
Eukaryotes
Eukaryote cells have a nucleus and membrane-bound organelles

8. 7.4- The Diversity of Cellular Life

9. Unicellular Organisms
Single cell organism
Dominate life on Earth

10. Multicellular Organisms
Made up of many cells
MO depend on communication and cooperation among specialized cells
Cell Specialization
Cells develop differently to perform different tasks
A cell’s shape reflects its function.

11. Two Basic Types of Cells
Eukaryote
Has a nucleus
Has organelles
Cytoplasm/cell membrane
Nucleolus
Prokaryote
Lacks a nucleus
Lacks organelles (ribosomes)
Cytoplasm/cell membrane

12. Cellular Organization
In multicellular eukaryotes, cells organize into tissues, organs, organ systems, and finally organisms.

13. Section 7.2- Eukaryotic Cell Structure

14. Basic Parts of a Cell

15. Comparing Cells
There are some differences between plant and animal cells
There are some similarities

16. Nucleus
“The Brain”
DNA, surrounded by nuclear envelope, nucleolus- where ribosomes are made

17. Ribosomes “The Construction Company” Builds proteins
Free floating in the cytoplasm or attached to the ER

18. Endoplasmic Reticulum
“The Highway” (tubes and sacs)
Rough
Produces phospholipids and proteins
Smooth
Produces cholesterols

19. Golgi Apparatus “The Post Office” Receives proteins from ER
Modifies, labels and directs proteins to locations in the cell

20. Lysosomes Specialized organelles
Lysosome- “The Killer or Garbage Truck”
Breaks down molecules
Maintains cell’s health by getting rid of non-functioning parts

21. Vacuole Specialized organelles Vacuole- “The Storage Center”
Stores water, nutrients and waste

22. Mitochondria
“The Power House”
Where ATP is produced

23. Chloroplast Use light energy to make C6H12O6 and O2 Thylakoids
Flattened membranous sacs that contain chlorophyll
Chlorophyll
Pigment that absorbs light and captures light energy for the cell

24. Cytoskeleton “The Infrastructure” Cell support Microtubule
Hold organelles in place
Microfilaments
Cell movement
Intermediate Filaments
Maintain internal shape of cell

25. Section 7.3- Cell Boundaries

26. Cell Membrane
Cell membrane
Border
Phospholipid bilayer

27. Cell Membrane Fluid Mosaic Model Proteins embedded in lipid bilayer
Cell surface markers, pumps, channels, receptors

28. Cell Wall
rigid layer
made of cellulose

29. Passive Transport What does passive mean? What does transport mean?
Movement of substances across a membrane “down” their concentration gradients without using energy

30. Diffusion Net flow from high conc. to low conc.
Driven by kinetic energy (energy of motion)

31. Diffusion Semipermeable Membrane Down Concentration Gradient
Equilibrium
“both sides are equal”
High [ ]
Low [ ]

32. Osmosis Diffusion of water across a membrane
Direction of osmosis into or out of a cell depends on solute concentrations inside and outside the cell
Animation of Osmosis

33. Osmosis- Direction of Osmosis
Isotonic
Hypertonic
Hypotonic
Salt is the solute
A solute is a substance that dissolves in a solvent

34. Facilitated Diffusion
Diffusion that requires the help of carrier proteins
Animation of Facilitated Diffusion

35. Diffusion Through Ion Channels
Ion channels are membrane proteins that allow only specific ions to pass through.
Channels can be “open” or “gated”
If an ion channel is gated, it can be opened by stretching the cell membrane, a voltage, or a chemical

36. Active Transport
Cell Membrane Pumps
Movement in Vesicles

37. Active Transport What does active mean? What does transport mean?
Movement of substances across a membrane “up” their concentration gradients using energy

38. Cell Membrane Pumps ATP
Carrier proteins that move substances from areas of low concentration to areas of high concentration.
Requires energy
What molecule furnishes the energy to power the pump?
ATP

39. Sodium-Potassium Pump
Transports Na+ and K+
3 Na+ out of cell / 2 K+ into cell

40. Animation of Sodium-Potassium Pump
How Na+/K+ pump works:
Animation of Sodium-Potassium Pump

41. Movement in Vesicles
What happens if substances are too large to pass through the cell membrane or carrier protein?
What does the prefix endo- mean?
What does the prefix exo- mean?
What does cyto- mean?
What does –osis mean?

42. Movement in Vesicles Endocytosis
Process by which cells ingest what they need.
Requires energy
Cell membrane folds and pinches off to form a vesicle

43. Endocytosis 2 Types Pinocytosis Phagocytosis
Endocytosis of solutes and fluids
Phagocytosis
Endocytosis of large particles and whole cells
Phagocytes

44. Movement in Vesicles Exocytosis
Process by which cells release unwanted substances.
Requires energy
Vesicles fuse to membrane to let substances out of cell