DO NOW- write in complete sentences

Document Sample
DO NOW- write in complete sentences Powered By Docstoc
					   DO NOW- write in complete sentences
• 1. What is the evidence that led to
  the Cell theory?
  2. What are the 3 statements of the
  Cell Theory?
  3. What is surface to volume ratio?
• 4. Why are smaller cells better than
  large ones?
• 5. What are the basic parts of a cell?
      2 Basic Types of Cell Types
• PROKARYOTE                 • EUKARYOTE

  – No nucleus                 – Nucleus present
  – No membrane- bound         – Membrane-bound
    organelles.                  organelles.
  – DNA is floating in the     – Larger than prokaryotes
    cytoplasm                  – Ex. WBC, sperm, skin
  – Ex.Bacteria                  cell, most cells
     Features and the Functions
• 1. CELL WALL: protects and maintains shape
  of the cell.
  – Composed of carb-protein complex called
    PEPTIDOGLYCAN.
  – Some bacteria have extra layer of polysaccharide
    that helps it stick to things. Ex. Bacteria sticking to
    teeth, skin and food.
  2. The CELL MEMBRANE is just inside the cell
    wall.
  – It controls the movement of materials in and out
    of cells.
• Prokaryotic cells reproduce by binary fission
  and the cell membrane plays a role in this.

• There are no compartments in bacterial cells
  so all cellular processes take place in the
  cytoplasm.
• 3. PILI : Hair-like structures that are used for
  attachment. Main function is to join bacterial
  cells together for the transfer DNA from one
  cell to another.

• 4. FLAGELLA: longer than pili. Used for cell
  motility (movement).
• 5. RIBOSOMES: in all prokaryotic cells.
  Function to site of protein synthesis.

  – Gives electron microscope pictures a granular
    appearance.
  –
• 6. NUCLEOID REGION: area within the
  bacterial cell that contains the circular threads
  of DNA.
•EUKARYOTIC CELL
Cheek Cell
Cheek Cell
Onion Cell
Onion Cell
   Cell Organelles and Functions
• 1. Plasma Membrane: also called the Cell
  Membrane.
Functions:
  – Allows only certain molecules to enter or
    leave the cell.
  – It separates internal reactions from outside
    ones.
  – Also allows cell to excrete waste from the
    cell.
• Made of PHOSPHOLIPIDS. Phospholipids
  have a polar end and a nonpolar end.
                2. NUCLEUS:
• Most functions of the cell are controlled by
  the nucleus.

• Functions: “Brain” of the cell.

• It houses and protects the cell’s genetic
  information.
• When the cell is not dividing, the DNA exists in
  long strands. While the cell is dividing, it coils
  up to form CHROMOSOMES.

• The nucleus is the site where DNA is
  transcribed into RNA.
• Nucleolus: dense part of the nucleus.

• Site where DNA is concentrated.
 • Nuclear Envelope: double layer that covers
    the nucleus. Also made of 2 phospholipid
                     bilayers.

• Nuclear Pores: holes in the nuclear envelope
  that allow passageways for RNA and other
  things entering and leaving the nucleus.
• 3. CYTOPLASM: area within the plasma
  membrane excluding the nucleus.
• 4. MITOCHONDRION: tiny, double-membrane
  organelles that transfer ENERGY from organic
  molecules to ATP.

• ATP powers most of the cell’s chemical
  reactions.

• Function: Powerhouse of the cell.
• Active cells have many mitochondrion. Ex.
  Muscle cells.

• Inner folds: CRISTAE. Cristae contain proteins
  that carry out energy-harvesting chemical
  reactions.
• 5. RIBOSOMES: small, spherical organelles.

• Function: make proteins.

• Don’t have a membrane.
• Assembly begins in the nucleolus and is
  completed in the cytoplasm.
• Consists of a large and small subunit.
Ribosomes
Let’s Review