Mid 1600s - Robert Hooke
–observed and described cork–first to use the term “cell”
Late 1600s -
Antony van Leeuwenhoek –observed sperm, microorganisms–“Father of Microbiology”
1820s - Robert Brown –
observed and named nucleus
Matthias Schleiden –
All plants are made of cells
Theodor Schwann –
All animals are made of cells
Cells only come from other cells
The cell theory
- 1) All organisms are composed of cells
- 2) Cell is smallest unit having properties of life
- 3) Cells come only from other cells
tell me 5 different thing about the cell
- Smallest unit of life.
- Has potential to survive on its own.
- Is highly organized.
- Senses and responds to environment.
- Has potential to reproduce
what are the Structure of Cells
- All cells contain:
- –Plasma membrane
- –DNA (often in nucleus)
- Two major types of cells:–Prokaryotic–Eukaryotic
what do microscopes help us do
- Allow us to see something that is otherwise too small to see
- Light microscopes
- –Simple or compound
- Electron microscopes
- –Transmission EM or Scanning EM
Limitations of Light Microscopy
- Wavelengths of light are 400-750 nm.
- If a structure is less than one-half of a wavelength long, it will not be visible.
- Light microscopes can resolve objects down to about 200 nm in size.
- Uses streams of accelerated electrons rather than light.
- Electrons are focused by magnets rather than glass lenses.
- Can resolve structures down to 0.5 nm.
what are 4 things about Prokaryotic Cells
- Archaebacteria and Eubacteria
- DNA is circular and not enclosed in nucleus
- Smallest, simplest cells
- Lack organelles
the 4 things to know about Eukaryotic Cells
- Eukaryotic organisms
- -Highly organized
- -DNA in the nucleus
- -Many organelles
7 Animal Cell Features
- Plasma membrane
Functions of Nucleus
- Separates the DNA from cytoplasm
- DNA can be copied before cells divide
Function of Cytomembrane System
- Organelles which
- 1.assemble lipids
- 2.modify proteins
- Products are sorted and shipped
componets of Cytomembrane System
- Endoplasmic reticulum (ER)
- Golgi bodies
- In animal cells, continuous with nuclear membrane
- Extends throughout cytoplasm
- Two regions: rough ER and smooth ER
- Modifies proteins and lipids from ER.
- Packages material for shipment.
- Material arrives and leaves in vesicles
- Powerhouses of the cell
- 1. Site of cellular respiration
- 2. Produce ATP
- Membranes form two distinct compartments ATP-making machinery embedded in inner mitochondrial membrane
Plant Cell Features
- Plasma membrane Nucleus
- Ribosomes Cytoskeleton
- Endoplasmic reticulum Golgi body
- Vesicles Cell wall
- Mitochondria Central vacuole Chloroplast
Specialized Plant Organelles
- Central Vacuole
- Site of photosynthesis
- Convert sunlight energy to ATP
Why Are Cells So Small?
- Surface-to-volume ratio
- The bigger a cell is, the less surface area there is per unit
- volume Above a certain size, material cannot be moved in or out of cell fast enough