1. Cellular Transportation And The Cell Cycle
Unit 2 Notes
Cellular Transportation And The Cell Cycle

2. Cell Transportation: 2 main types
1. Passive transport: Does not require energy from the cell
Moves downhill, with the concentration gradient

3. Cellular Transportation Type 2
2. Active Transport: Requires energy to occur.
Moves uphill, against the concentration gradient.

4. Passive Transport (No energy required)
3-Types

5. 1st Type Passive Transport
Simple Diffusion : Movement of any substance from areas of higher to lower concentrations
diffusion animation

6. 2nd Type Passive Transport
Osmosis: Movement of water from areas of higher to lower concentrations

7. 3rd Type Passive Transport
Facilitated diffusion: Movement of substances from higher to lower concentration with help from a protein molecule
Animation: How Facilitated Diffusion Works

8. 2-Types of Active Transport (Energy Required)
1. Exocytosis: The expulsion of particles from the cell.
2. Endocytosis: surrounding and engulfing particles.
Pinocytosis: Cell drinking – the cell takes in liquids.
Phagocytosis: Surrounding and taking in of large particles.

9. Animation: Phagocytosis

10. Solute vs Solvent Solute: The dissolved substance in a liquid.
Solvent: The liquid that the solute is dissolved in: Usually water

11. Types of solutions Isotonic solution
Concentrations of solute are equal in the cell and the solution. (cell=solution)
Water moves back and forth at the same rate.
Water in =Water Out

12. Hyp-O-tonic solution (Hyp-Ohh no I’m swelling-tonic)
HypOtonic: Concentrations of solute are higher in the cell than in the solution (cell-higher, solution-lower)
Water moves into the cell.
The cell swells and can burst.

13. Hypertonic Solution
Concentrations of solute are lower in the cell than in the solution (cell-lower, solution-higher)
Water moves out of the cell.
The cell shrinks.

14. Limits to cell size
A cells size is limited, so organisms grow by cellular division.
The cells of a baby are the same size as the cells of an adult.

15. So… Why Can’t cells just grow larger???

16. Three factors that limit the growth of cells
1. Diffusion across cell surface.
2. Shortage of DNA.
3. Surface to volume ratio.

17. Diffusion
Diffusion is efficient over short distances, but becomes inefficient and slow over large distances.
So…cells that are large have a more difficult time getting nutrients into the cell and waste products out of the cell.

18. DNA
A cell cannot survive without sufficient amounts of DNA to make necessary proteins
Unusually large cells must have multiple nuclei in order to supply needed DNA

19. Surface Area to Volume Ratio
As a cell’s size increases, its volume increases faster than its surface area

20. Cell Reproduction Mitosis: Asexual reproduction (Cell Cycle)
The process by which one cell divides into two cells, both identical to the original parent cell

21. The Dreaded “C” Words! Chromatin Chromosomes Chromatid Centromeres
Centrioles

22. Chromatin
Relaxed DNA.

23. Chromosomes Condensed DNA.
DNA that is preparing to undergo cellular division
Can now be seen with a microscope.

24. Chromatids and Centromeres
Sister Chromatids: Halves of a duplicated parent chromosome.
Centromeres: The structure that joints two sister chromatids.

25. Chromatin and Chromosome

26. Centrioles- Produce the spindle and aid in replication

27. The Cell Cycle
The process of asexual reproduction (mitosis) of the cell
Contains three major parts
1. Interphase 2. Mitosis 3. Cytokinesis

28. The Cell Cycle

29. Part One of the Cell Cycle Interphase
The cell spends the majority of its life in interphase.
A time in which the cell is preparing for division.

30. Interphase 3-Parts G-1: Maturation.
S-Phase: DNA replicates - makes a duplicate copy of itself.
G-2: Organelles replicate and final preparations for division.

31. Mitosis Division of the nucleus 4-phases Prophase Metaphase Anaphase
Telophase
PMAT

32. Parts of Mitosis Prophase
The chromatin condense to form visible chromosomes
The nuclear envelope begins to dissolve
The centrioles divide and begin to migrate to opposite sides of the cell

33. Parts of Mitosis Cont… Metaphase
Centrioles have moved to opposite sides of the cell
The spindle has formed
Chromosomes are lined up in the middle of the cell across the equator

34. Parts of Mitosis Cont… Anaphase
The centromeres split and the spindles pull the sister chromatids apart toward opposite sides of the cell

35. Parts of Mitosis Cont… Telophase
The chromosomes move to opposite sides of the cell.
The nuclear envelope begins to reform around each set of chromosomes at opposite sides of the cell.

36. Cytokinesis Division of the cytoplasm Begins to occur during telophase
Different in plants and animal cells

37. Cytokinesis Cont…
Animal cells: the plasma membrane pinches in to form two separate cells
Plant cells: A rigid cell plate begins to form between the two new cells, dividing them and becoming a cell wall.

39. mitosis animation

40. Control of the Cell Cycle
The cell cycle is controlled by proteins and enzymes
Contact with other cells causes cell to stop dividing.
Cell stop dividing when they lose contact with other cells

41. Cancer Uncontrolled cell growth resulting in tumors
Metastasis: Cells break lose and travel through the circulatory system spreading throughout the body.

42. Causes of Cancer Environmental factors that damage genes.
Ex: Cigarette smoke, UV rays from the sun, air and water pollution, viruses