1. http://images. search. yahoo

2. Cell Analogy is due today!!!!!!!!!!!!!!!!!!!!

3. Check the Website Answer Key’s for: Organic Molecules Guided Notes
Don’t forget about the study guide

4. Reflect and Connect pg 303 #1-3
1. Draw a series of sketches to illustrate important stages of the cell cycle and mitosis. Your drawing should include:
Include a starting cell with genetic material represented by two pairs of chromosomes
Include a nucleus with the appropriate chromosomes in each of the cells
Indicate with a flowchart or sketches the genetic material is duplicated (DNA synthesis)
Show the cells formed as a result
Cell wall
Chromosome pairs
Nucleus

5. Reflect and Connect pg 303 #1-3
DNA Replication
Parent Cell
daughter Cell

6. Reflect and Connect pg 303 #1-3
2. Why is it important that DNA (chromosomes) duplicates before mitosis?
3. Describe why cell division is an important process for all organisms?
All cells within an organism contain the same genetic information. The genetic materials must duplicate for both of the daughter cells to contain the same genetic information as the parent cell
Cell division is important for:
replicating old worn out cells
is needed for the growth of plants and animals and
Is needed to produce specialized cells for plants/animals

7. Define Diffusion
The movement of molecules from a area in which they are highly concentrated to a area in which they are less concentrated.

8. Example of Diffusion.

9. Concentration Gradient
The concentrations of molecules at various points separate high concentrations from low create a boundary called a concentration gradient.
High Concentration
Low Concentration
There is a concentration gradient because of the differences in concentration
Concentration Gradient

10. Down or Up Gradient? Down a concentration gradient
HIGH concentrated to LOW concentrated
Happens automatically without any energy added
Sound familiar? (Diffusion)
Up a concentration gradient
LOW to HIGH concentration
Requires energy

11. Diffusion and Cells
Diffusion: nutrients and materials through the cell

12. The diffusion of water across a selectively permeable membrane.
Define Osmosis
The diffusion of water across a selectively permeable membrane.

13. Osmosis in Cells
Affects the size and shape of cells, by the amount of water/solutes across the membrane.
Gain/loss "pressure" like miniature balloons.
Solute: dissolved substance: a substance dissolved in another substance
Hypertonic: kids are hyper kick them out
Hypotonic: “hypo” prefix means under
Isotonic: “iso” prefix means equal

14. Osmosis in Cells
Hypertonic concentration of solutes is greater outside the cell than inside
Hypotonic: Concentration of solutes is greater inside the cell than outside
Isotonic: Concentration is equal

15. Define Selectively Permeable Membrane
A membrane that allows only certain materials to cross it
Materials pass through pores in the membrane

16. Why Are Osmosis & Diffusion Important?
All living things have certain requirements they must satisfy in order to remain alive
exchanging gases (usually CO2 and O2)
taking in water, minerals, and food,
eliminating wastes.
These tasks happen at the cellular level.
Molecules move through the cell membrane by diffusion

17. Active versus Passive Transport
Are biological processes that move oxygen, water, and nutrients into cells and remove waste products.

18. Active versus Passive Transport

19. Active versus Passive Transport
Moves molecules from areas of HIGH concentration to areas of LOW concentration; so it DOES NOT require energy.
Diffusion
Osmosis
Facilitated Diffusion
Active transport:
Requires ENERGY because it is the movement of molecules from areas of LOW concentration to areas of HIGH concentration.
Uses Protein synthesis to aid

20. Active versus Passive Transport
Glucose
Cannot move easily because it is large. But can pass through with Passive Transport with the facilitated diffusion
Water
Can move easily because it is small. Uses Osmosis, which is Passive Transport
Oxygen
Can move easily because it is small and moves through diffusion (Passive Transport)
Sodium
Use Active Transport, requiring Energy to move against the concentration gradient as well as with it

21. Cell Cycle

22. Why must cells divide in order to grow? Why is this so important?
to reach maximum efficiency for molecular transport, and maintain the functions of the cell.
limits to how large a cell can become, so when those limits are reached the cells divide.
replace old cells that are worn down or damaged
differentiation in multicellular organisms to become different in appearance and function
Cells are composed of atoms, and carbon atoms are essential in cells.
Carbon is essentail to life

23. Mitosis
Is the precise distribution of DNA to daughter cells
IPMAT

24. Differentiation Differentiation:
new cells specialize and become different in appearance and function from their parent cells.
become specialized according to a genetically determined plan
Occurs as a result of a combination of signals that cause different cells to activate different portions of their genetic information
Differences in how cells look & behave reflect differences in how they use the genetic information they have

25. Mitosis: Interphase Interphase: Long and active cycle
DNA and chromosomes are duplicated in the nucleus
Mitochondria are made in the cytoplasm
Cell grows

26. Mitosis: Prophase Prophase: Chromosomes coil & shorten.
Each Chromosome appears as a double structure joined at the centromere
Centrioles move to opposite ends of the cell (except in plants, there are no centrioles, but these events still occur as described here)

27. Mitosis: Metaphase Metaphase: Doubled chromosomes line up
Cytoplasmic fibers are now attached to each doubled chromosome at the centromere

28. Mitosis: Anaphase Anaphase: Doubled chromosomes separate
New chromosomes are pushed and pulled to the opposite ends of the cell by the cytoplasmic fibers

29. Mitosis: Telophase Telophase:
Chromosomes approach the ends and group together
New nuclear membrane
Cytoplasm divides
New cell membrane forms (cell wall laid between new cells in plants)
The new cells enter interphase

30. How is the DNA of a parent cell and daughter cell related in mitosis?
There is absolutely no difference in DNA between the parent cell and daughter cell in mitosis. During mitosis, the DNA is copied exactly and transferred, so the DNA is exactly the same in both cells.