1. Chapter 11 The Cell: Basic Unit of Life

2. Why do we study cells?

3. Cell Theory All organisms are made up of cells
The cell is the basic living unit of organization for all organisms
All cells come from pre-existing cells

4. Activities of life
Most everything you think of a whole organism needing to do, must be done at the cellular level…
reproduction
growth & development
energy utilization
response to the environment
homeostasis

5. Cell Maintenance Every cell wants to maintain homeostasis
Homeostasis- “same state”- it is the condition in which a cell’s (or organism’s) environment remains stable/constant for that particular organism
pH, temperature, water concentration, light, etc

6. Organelles
All cells contain smaller parts that have particular jobs to help the cell exist These smaller parts are called organelles “little organs”

7. Organelles Cell Wall- present only in plant cells
Serves as a protective barrier and to aid in the plant’s structure (support)

8. Organelles Cell membrane
Exchange organelle
Cell membrane functions as selective barrier
allows passage of O2, nutrients & wastes

9. Organelles Cell Membrane is made up of a lipid bilayer
The heads are hydrophilic- “water loving”
Located on both the inside and outside of cell
The tails are hydrophobic- “water fearing”

10. Cell Membrane
The selectively permeable cell membrane allows the transport of some materials into and out of the cell
2 types of transport
Active Transport- this requires the cell to use its own energy to move materials into and out of the cell. This usually occurs with larger particles.

11. Cell Membrane
Passive Transport- this type of cellular transportation does not require the cell to use its own energy to move materials into or out of the cell.
Diffusion- the movement of particles from an area of higher concentration to an area of lower concentration
*OSMOSIS- diffusion through a semi-permeable membrane- the semi-permeable membrane is the cell membrane

12. Organelles
Cytoplasm: jelly-like fluid inside the cell; surround organelles and aiding in transporting substances through cell

13. Organelles Mitochondria: the cell’s “power plant”
They create all of the energy for the cell
Animal cells and plant cells have many

14. Organelles
Endoplasmic Reticulum (ER)- It surrounds the nucleus and connects it to the cell membrane through the cytoplasm.
It is the passageways through the cell.
2 types
Smooth ER- passageways
Rough ER passageways with ribosomes attached to the outside

15. Organelles
Ribosomes- responsible for making proteins, they put proteins together
Proteins- are needed by the cell to make DNA, and acts as enzymes to regulate cellular reactions

16. Organelles
Golgi Apparatus- take the proteins made by the ribosomes and pack them up and carry the proteins where they are needed
FedEX, UPS, Postal Service (USPS)

17. Organelles Vacuoles- storage center
stores food, water and other nutrients the cell may need to be released as required by the cell
Some vacuoles store waste products, some store water
Animal cells have several vacuoles (each storing different materials, specialized)
Plant cells have one large vacuole (storing mostly water; remember choloroplasts store food and plant cells do not have much waste)

18. Organelles Lysosome- digestive system of the cell.
Breaks down foreign substances and disposes of the waste
Breaks down by products of cellular substances that the cell no longer needs and either recycles it to be used again or disposes as waste
Break down bacteria and viruses to keep the cell healthy
Kill bacteria and viruses

19. Organelles Chloroplasts- only present in plant cells
Responsible for making food for the plant in the form of sugar
Photosynthesis- uses water
and carbon dioxide with
sunlight to make sugar and
oxygen
Chloroplasts contain
chlorophyll- green pigment
that stores sunlight energy
(solar panels)

20. Organelles Movement Organelles Cilia- small hair-like organelles
responsible for aiding the cell
in moving
Usually many
Flagella- long whip-like organelles responsible for aiding cell in movement
Usually 1, maybe 2

21. Organelles Nucleus- the “brain of the cell”
Controls the activities of the cell
Contain chromosomes which are composed of DNA and other molecules
DNA is the genetic material that gives an organism its characteristics

22. Plant Vs Animal Cells