Cell Organelles Flashcards
What do all cells have?
DNA (genetic material)
cytoplasm
plasma membrane
ribosomes
Cell Theory
- All organisms are made of cells
- The cell is the simplest collection of matter that can be alive
3.All cells are related by their descent from earlier cells
4.Cells can differ substantially from one another but share common features
Cell Size
can be large or small
light microscope (LM)
visible light is passed through a specimen and then through glass lenses
Magnification
the ratio of an object’s image
size to its real size
Resolution
the measure of the clarity of the image, or the minimum distance of two distinguishable points
Contrast
visible differences in brightness between parts of the sample
Why do we not use light microscopes to study organelles?
The resolution of standard light microscopy is too low to study organelles, the membrane-enclosed structures in eukaryotic cells
What are the two types of electron microscopes?
Scanning Electron Microscopes
Transmission Electron Microscopes
NOTE: they are all black and white images
Scanning electron microscopes (SEMs)
focus a beam of electrons onto the surface of a specimen, providing images that look 3-D
Transmission electron microscopes (TEMs)
focus a beam of electrons through a specimen
- used mainly to study the internal structure of cells
Prokaryotic Cells
- Bacteria and Archea
- no nucleus
- DNA is in a region
- Cytoplasm with cell membrane
- No membrane-bound organelles
Eukaryotic Cells
- organelles with nucleus
- Protists, fungi, animals, and plants
Nucleioid
region in which DNA is left in prokaryotic cell
Nuclear Lamina
composed of proteins and maintains the shape of the nucleus