what is life?. a “little” history… theory
TRANSCRIPT
A “little” history…
http://ed.ted.com/lessons/the-wacky-history-of-cell-theory
7 MUST HAVE Characteristics of Living Things:
1. It obtains and uses energy
2. It grows and develops
3. It reproduces
4. It responds to the environment including movement
5. It breathes/respires (exchange of gasses)
6. It produces waste
7. It is made up of cells
Is it made up of cells?
Cells
Eukaryotes(has a nucleus)
UnicellularEx. Protists
MulticellularEx. Plants
and Animals
Prokaryotes(No Nucleus)
Ex. bacteria
Discovering the Cell
Robert Hooke-1655– used a microscope
to study cork; coined the term “cell” b/c they looked like cells in a monastery where monks lived!
Anton van Leeuwenhoek– first person to record looking at
water under a microscope
Matthias Schleiden – 1838
- Observed that plants are composed of cells
Theodor Schwann – 1838
- Observed that animals are composed of cells
Rudolph Virchow – 1859
- Determined that cells come from other cells; cells are not spontaneously generated.
I. Introduction to the Cell
Cell Theory
– All living organisms are made upof one or more cells.
– Cells are the basic unit of structure & function in organisms.
– All cells come from preexisting cells.
Cells are the building blocks of you.
Cells form tissue
Tissue forms organs
Organs form systems
Systems form organisms
Reflection: Why is this important?
It helps us to understand how we are made and how we are similar.
– Most cells contain a variety of membrane- bound ORGANELLES - cell parts that PERFORM SPECIFIC FUNCTIONS FOR THE CELL
Internal Organization
– A Large Organelle near the Center of the Cell is the NUCLEUS. IT CONTAINS THE CELL'S GENETIC INFORMATION (DNA) AND CONTROLS THE ACTIVITIES OF THE CELL.
– DNA – Genetic information
located in chromosomes
“BRAIN” of the cell
Other Organelles
MITOCHONDRIA – this bean-shaped structure is the cell’s energy center. It turns sugars into chemical energy.
“Powerhouse” of the cell
Other Organelles
CYTOPLASM – jelly-like substance that support/protects the organelles
VACUOLE – storage area for water and other substances, plant cells usually have one large central vacuole (animal cells have 2-3 small vacuoles)
CELL MEMBRANE
• Selectively permeable (semi-permeable) ; it regulates what comes into the cell and what leaves the cell
• Provides support and protection
Similar to our skin
Have additional structures• CELL WALL – surrounds the membrane and
provides additional support
• CHLOROPLASTS – contain green pigment called Chlorophyll, used in photosynthesis
• CENTRAL VACUOLE – large water container in the center of the cell
Plant Cells