1. Cells
And
Cellular Transport

3. Where does the name “cell” come from?
“Cells” were named by Englishman Robert Hooke in 1665.
He observed that cork wood looked like monk’s cells in a monastery.

4. The Cell Theory The cell is the basic unit of structure and function.
All organisms are made of one or more cells.
All cells come from pre-existing cells.

5. Exceptions to the Cell Theory
Viruses!! They have DNA and/or RNA inside a protein shell. They are capable of reproduction inside another living cell, but not on their own.
Mitochondria and chloroplasts have their own DNA and can reproduce inside a cell.
Obviously….the first cell.
This is the human Herpes Virus!

6. Levels of Organization…Continued
Organs
Organ Systems
Organism

7. Types of Cells Prokaryotic Cells Eukaryotic Cells
The first and most primitive cells
Lack a nucleus and other membrane bound organelles (mitochondria, etc)
Bacteria are the ONLY prokaryotes
Eukaryotic Cells
Most organisms have eukaryotic cells (ex: all plant and animal cells!)
All genetic material is contained in a nucleus
Have many membrane bound organelles

8. 1.
13.
12. 2.
11. 3. 4.
10. 5. 9. 6. 8. 7.

9. 14. 1.
13.
Lysosome 2. 3. 4.
12. 5.
11. 6.
10. 7. 9. 8.

10. Cell Organelle Functions
Cell Membrane: provides a barrier between the cell and the environment.
Vacuole: stores water, minerals and sometimes food.
Lysosome: a sac of digestive juices (acts like a stomach).
Mitochondria: where cellular respiration takes place, our energy comes from here!
Golgi Bodies: “packages” cell material, wraps a membrane around protiens and materials made in the cells.

11. Cell Organelle Functions
Centrioles: (ONLY in animal cells) help the cell undergo cellular division, or mitosis.
Cytoplasm: jelly like material that fills in the extra space in a cell, also where most of our chemical rxns occur.
Ribosomes: site of protein production.
Endoplasmic Reticulum (ER): Transports materials around the cell.
Nuclear Membrane: separates the nucleus from the rest of the cell.

12. Cell Organelle Functions
Nucleolus: dense part of a nucleus, where RNA is made.
Nucleus: stores DNA, controls most cellular activities.
Cell Wall: rigid structure around the outside of plant cells to give them structure and support.
Chloroplast: site of photosynthesis, makes sugar molecules using sunlight, water and carbon dioxide.

13. The Lipid Bi-Layer, Fluid Mosaic Model,
The Cell Membrane
A barrier that separates a cell from its surroundings.
Also called:
The Lipid Bi-Layer, Fluid Mosaic Model,
And
The Plasma Membrane
Cell membranes are “semi-permeable” because they allow some molecules to pass through, while others cannot.

14. Components of the Cell Membrane
MOVIE

15. Just the lipids!

16. Membrane Facts!
The lipid bilayer consists of two (bi) layers of phospholipids.
The ____________ heads point to the outside and the ____________ tails point to the inside of the membrane.
hydrophilic
hydrophobic
Various _________ molecules are embedded in the membrane as well
proteins

17. Cell Membrane Cross Section
This is one of many kinds on proteins embedded in the membrane.
This is the Lipid Bilayer. Why does this name fit?

18. Membrane Proteins
Marker Proteins: They are like a “name tag” for the cell.

19. Membrane Proteins Continued…
Channel Proteins: These proteins reach through the membrane to both sides. It allows specific molecules to pass from one side of the membrane to the other.
Transport Proteins: Proteins that physically move molecules across the membrane. There are a variety of types!
YouTube - Cell membrane animation

20. Cellular Transport

21. Cellular Transport
Passive Transport does NOT require cellular energy (ATP)
Moves molecules from high to low concentration
Active Transport DOES require ATP

22. Diffusion
The movement of molecules from an area of HIGH concentration to an area of LOW concentration.
The direction of diffusion is called the concentration gradient.
This is a form of passive transport.
_________ molecules CANNOT diffuse, regardless of concentration gradient!
LARGE

23. What types of molecules can NOT diffuse??
Even though all molecules seem small to us, they do vary in size a lot!
Large molecules can NOT cross the cell membrane!
Large molecules must rely on active transport.

24. Cellular Transport
Passive Transport does NOT require cellular energy (ATP)
Moves molecules from high to low concentration
Examples:
Diffusion
Active Transport DOES require ATP

25. Water always moves from low to high SOLUTE concentration.
Osmosis
Osmosis is a special name for the diffusion of ________ across a semi-permeable membrane.
Because this requires NO ATP, it is called _____________.
WATER
Water always moves from low to high SOLUTE concentration.
This is osmosis!
Passive transport

26. If a cell is placed in a solution with a LOWER concentration of solute, it will _________ (water will _________ the cell)
If a cell is placed in a solution with a HIGHER concentration of solute, it will _________ (water will _________ the cell)
swell
enter
shrivel
leave

27. Cellular Transport
Passive Transport does NOT require cellular engery (ATP)
Moves molecules from high to low concentration
Examples:
Diffusion
Osmosis
Active Transport DOES require ATP

28. Phagocytosis
This is “cell eating”. A cell engulfs (or wraps itself around) a food particle thus creating a food vacuole.
This is a type of ACTIVE TRANSPORT!
Clip

29. Cellular Transport
Passive Transport does NOT require cellular engery (ATP)
Moves molecules from high to low concentration
Examples:
Diffusion
Osmosis
Active Transport DOES require ATP
Examples:
Phagocytosis

30. Pinocytosis
This is “cell drinking”. The cell membrane pinches inward (like a pin poking a hole) and creates a vacuole of dissolved particles.
This is a type of ACTIVE TRANSPORT!
Clip

31. Cellular Transport
Passive Transport does NOT require cellular engery (ATP)
Moves molecules from high to low concentration
Examples:
Diffusion
Osmosis
Active Transport DOES require ATP
Examples:
Phagocytosis
Pinocytosis

32. Membrane Proteins Using Cellular Energy: The proteins we learned about in the membrane sometimes require energy!

33. Cellular Transport
Passive Transport does NOT require cellular energy (ATP)
Examples:
Diffusion
Facilitated Diffusion
Osmosis
Active Transport DOES require ATP
Examples:
Phagocytosis
Pinocytosis
Use of membrane proteins (ex: transport proteins)

34. Moving Molecules Against the Concentration Gradient
                                     
                                     
Moving Molecules Against the Concentration Gradient
The sodium ions are more highly concentrated on the inside of the cell.
With the help of ATP, the sodium ions are still pumped back into the cell (against the concentration gradient).

35. Cellular Transport
Passive Transport does NOT require cellular energy ATP)
Examples:
Diffusion
Facilitated Diffusion
Osmosis
Active Transport DOES require ATP
Examples:
Phagocytosis
Pinocytosis
Use of membrane proteins (carrier proteins, etc)
Moving molecules from low to high concentration