Chapter 6: Cells and their Structures Flashcards
Define Magnification:
Ratio between the size of an image produced by a microscope and it’s actual size
What are the 3 characteristics of the Cell Theory?
- all organisms are composed of one or more cells
- cells are the smallest units of life
- new cells come only from pre-existing cells by cell division
Define Resolution:
Ability to observe two adjacent objects as distinct from one another
Define Contrast
How different one structure looks from another (enhanced by dyes)
Name the two electron microscope types:
- Transmission Electron Microscope
2. Scanning Electron Microscope
TEM
- beam of electrons transmitted through sample
- thin slices stained with heavy metals
- some electrons scatter while others pass through to form an image
SEM
- sample coated with heavy metal
- beam scans surface to make a 3D image
What are the two categories of cell structure?
- Prokaryotes
2. Eukaryotes
Prokaryotic Cells
- Simple cell structure
- Lack a membrane-enclosed nucleus
- Single circular DNA chromosome
Name the two categories of Prokaryotes:
Bacteria (abundant)
Archaea (extreme environments)
Bacterial Cells:
Plasma Membrane: barrier
Cytoplasm:
Contained inside plasma membrane
Nucleiod:
Region where genetic material is found
Ribosomes:
Protein synthesis
Located outside the plasma membrane:
Cell Wall:
Support and protection
Glycocalyx:
- Traps water
- Protection
Capsule:
Hard shell (carb) may help evade iune system
Appendages:
Fimbrea (attachment)
Flagella (locomotion)
Pilli (conjugation)
Eukaryotic Cells:
DNA HOUSED IN THE NUCLEUS
MEMBRANE BOUND ORGANELLES
Cytosol:
Outside cell organelles
Cytoplasm:
Everything in the plasma membrane
The sum of all chemical reactions by cells is the?
Metabolism
Catabolism:
- Breakdown of a molecule
- Releases Energy
- Spontaneous
Anabolism:
- Synthesis of a molecule
- Requires Energy
- Not Spontaneous