Cellular Transport and the Cell Cycle - PowerPoint PPT Presentation

Loading...

PPT – Cellular Transport and the Cell Cycle PowerPoint presentation | free to download - id: 765b04-OTkwN



Loading


The Adobe Flash plugin is needed to view this content

Get the plugin now

View by Category
About This Presentation
Title:

Cellular Transport and the Cell Cycle

Description:

Cellular Transport and the Cell Cycle Chapter 8 Chapter 8 Sections 8.1 Cellular Transport Osmosis Passive Transport Active Transport 8.2 Cell Growth and Reproduction ... – PowerPoint PPT presentation

Number of Views:47
Avg rating:3.0/5.0
Slides: 36
Provided by: Samue126
Category:

less

Write a Comment
User Comments (0)
Transcript and Presenter's Notes

Title: Cellular Transport and the Cell Cycle


1
Cellular Transport and the Cell Cycle
  • Chapter 8

2
Chapter 8 Sections
  • 8.1 Cellular Transport
  • Osmosis
  • Passive Transport
  • Active Transport
  • 8.2 Cell Growth and Reproduction
  • Cell Size limitations
  • Cell Reproduction
  • Cell Cycle
  • 8.3 Control of the Cell Cycle
  • Normal
  • Cancer

3
Cellular Transport
  • Section 8.1

4
Cellular Transport
  • Substances move into and out of the cell in two
    ways
  • 1.) Passive Transport No energy is used.
  • Diffusion
  • Osmosis
  • Facilitated Diffusion
  • 2.) Active Transport Energy is used.
  • Endocytosis
  • Exocytosis

5
Diffusion
  • Diffusion is the movement of molecules from high
    to low concentrations.
  • Diffusion continues until dynamic equilibrium is
    reached (the same concentration throughout).
  • Osmosis diffusion of water across a cell
    membrane
  • The cell membrane does NOT limit water movement.
    Water crosses the membrane freely.
  • It stops molecules that are dissolved in water
    from entering the cell.

6
Osmosis
  • What determines whether water flows into or out
    of a cell?
  • The amount of dissolved substances inside the
    cell compared to outside the cell.
  • Isotonic Environment
  • Amount of substances outside the cell is the same
    as inside cell.
  • Water flows into and out of the cell at the same
    rate.
  • Hypotonic Environment
  • Amount of substances outside the cell is less
    than inside the cell.
  • Water flows into cell.
  • Hypertonic Environment
  • Amount of substances outside the cell is more
    than inside the cell.
  • Water flows out of cell.

7
Facilitated Diffusion
  • Facilitated diffusion
  • Diffusion of substances into or out of the cell
    with the help of transport proteins.
  • Substances move from high to low concentrations
    during facilitated diffusion.
  • There are two types of transport proteins
  • Channel proteins
  • Carrier Proteins

8
Active Transport
  • Active Transport Movement of substances across
    the cell membrane from areas of lower to higher
    concentration
  • Active transport requires energy!
  • The substances move across the cell membrane
    against the concentration gradient (from low to
    high concentration)
  • This is the opposite of diffusion (passive
    transport)
  • Like facilitated diffusion (a type of passive
    transport),
  • active transport occurs with the help of carrier
    proteins.

9
Channel and Carrier Proteins
10
Transport of Large Substances
  • Sometimes substances are too large to cross the
    cell membrane or move through a transport
    protein.
  • Endocytosis
  • Cell surrounds and takes in material that is too
    large for transport through the membrane
  • Exocytosis
  • Expulsion or secretion of materials
  • The opposite of endocytosis
  • Both endocytosis and exocytosis require energy.
  • Are they types of passive or active transport?

11
Classwork Due Today!
  • Section Assessment page 200 (1-4) Q A

12
Section 8.2 Cell Growth and Reproduction
13
Cell Size Limitations
  • Why are cells so small?
  • Cell size is limited by 3 things
  • Diffusion Limits cell size
  • It would be very difficult to get things into and
    out of the cell because diffusion is slow and
    inefficient over large areas
  • DNA Limits cell size
  • It would take too long to construct the of
    proteins necessary to support a large cell
    because there is a limit to how quickly DNA can
    be copied and read
  • Surface area to volume ratio limits cell size
  • Volume increases faster than surface area
  • (it gets bigger inside than it does outside)
  • It would require more nutrients, and have to get
    rid of more wastes, but through a smaller surface
    area (cell membrane)

14
Cell Division
  • All cells come from other cells.
  • (Schleiden and Schwann - Cell Theory)

15
Cells divide to maintain their sizes
  • Cells cannot become too large, so they divide to
    form more cells.they reproduce.
  • When organisms grow, new cells are made.
  • When cells are damaged or die, they are replaced
    by new cells.
  • The process of cell reproduction is called cell
    division.

16
Chromosomes
  • Chromosomes can only be seen just before a cell
    divides and they disappear after it divides.
  • Chromosomes are tightly wound DNA molecules.
  • (They normally exist as chromatin)
  • Chromosomes (DNA) are copied during cell division
    and are passed on from one generation of cells to
    the next.

17
The Cell Cycle
  • There are two primary parts of the cell cycle.
  • The first part is called interphase.
  • Cells spend most of their lifetime in this phase.
  • The second part is called mitosis.
  • Mitosis is a very short compared to interphase.

18
The Cell Cycle
  • G1
  • S
  • G2
  • PROPHASE
  • METAPHASE
  • ANAPHASE
  • TELOPHASE
  • CYTOKENISIS

INTERPHASE MITOSIS
19
(No Transcript)
20
The Cell Cycle
Plant Cell
  • Interphase is divided into three parts.
  • G1 Rapid Growth. Protein production is
    high. Chromosome not visible.
  • S DNA copied.
  • G2 Organelles produced.
  • Then the cell goes into mitosis (cell division)

Animal Cell
21
  • Steps of mitosis
  • 1- Prophase Chromosomes form

22
Prophase
  • Chromatin coils up and becomes the visible
    chromosomes.
  • Chromosomes consist of two halves (which are
    copies of one another) called sister chromatids.
  • A structure called a centromere holds the sister
    chromatids together.
  • The nucleus of the cell disappears.
  • Centrioles migrate to opposite poles
    (they help pull the
    chromatids apart when the cell divides).
  • Spindle fibers made of microtubules form between
    centrioles (help pull sisters apart too).

23
2- Metaphase Chromosomes line up
24
Metaphase
  • Chromosomes become attached to spindle fibers at
    centromeres.
  • Chromosomes are pulled to middle of cell
    (equator) by spindle fibers. They all line up.
  • Each sister chromatid is attached to its own
    spindle fiber which is connected to the opposite
    pole of the cell.

25
3- Anaphase Chromosomes begin to be pulled
apart by spindle fibers.
26
4- Telophase Sister chromatids reach
opposite ends of the cell
27
Telophase
  • Telophase is the reverse of Prophase.
  • The cells nucleus reforms.
  • Chromosomes unwind into Chromatin.
  • Spindle breaks down.
  • A new nuclear envelope is formed around each set
    of chromosomes.

28
5- Cytokenisis Cell
splits into two cells. The plasma membrane is
pinched into two parts to form the new cells.
29
The Cell Cycle
  • G1
  • S
  • G2
  • PROPHASE
  • METAPHASE
  • ANAPHASE
  • TELOPHASE
  • CYTOKENISIS

INTERPHASE MITOSIS
30
(No Transcript)
31
Section 8.3 Control of the Cell Cycle
32
Control of the Cell Cycle
  • Proteins called Cyclins and enzymes that attach
    to the cyclins control the timing of the cell
    cycle.
  • They are in charge of the cell cycle.
  • Sometimes there is a failure in protein and
    enzyme production and cancer results.
  • Cancer is uncontrolled cell division.
  • There are many different possible causes of
    cancer including environmental factors and viral
    infections.

33
Cancer
  • Cancerous cells form masses of tissue called
    tumors.
  • Tumors deprive normal cells of nutrients.
  • Cancer can affect any tissue in the body.
  • 2nd leading cause of death in US.

34
Cancer Prevention
  • Diets low in fat and high in fiber content.
  • Vitamins and minerals may also prevent cancer.
  • Daily exercise and control of environmental
    conditions.

35
Classwork Due Today!
  • Ch. 8 Worksheets
About PowerShow.com