CH4
Describe Cell theory
Cell theory is the underlying principle of biology that states that cells are the basic units of life, all living organisms are made of cells, and all cells come from pre-existing cells
Describe Magnification, resolution, refractive index, and contrast as they relate to microscopy.
Magnification -> the process of enlarging an object in appearance
Contrast -> the ability to distinguish the specimen from the background
Refractive index -> the bending of light
Resolution -> the ability to distinguish 2 adjacent structures as separate; the higher the resolution the clearer it is
Compare and contrast bright field and electron microscopy
Both magnify specimens.
Bright-field: lower magnification and resolution, bends visible light to provide magnification, and can view living cells
Electron: has a higher magnification and resolution, uses beams of electrons that show fine detail, and usually requires a dead/non-living organism
List the four components common to all cells
1.) plasma membrane that encloses the cell and separates its interior from the environment
2.) cytoplasm made of cytosol in which other components of the cell are found
3.) DNA, the genetic material of the cell
4.) Ribosomes make proteins
List the basic characteristics of a prokaryotic cell
no nucleus or other membrane-bound components
Most have cell walls made of peptidoglycan
similar to earliest cells
Found in domains bacteria and archaea
Describe the surface-to-volume ratio of a cell
As cells get bigger, volume increases faster than surface area.
Explain its importance to proper cellular function
This is important because a high surface-to-volume ratio allows materials to move in and out of the cell more efficiently
Describe the basic functions of the following
Plasma Membrane - responsible for moving materials in and out of the cell
Cytoplasm- supports the cell's components and is where many important cell reactions occur.
Nucleus - holds DNA
Nuclear envelope - regulates what goes in and out of the nucleus (form of protection)
nucleolus- where we make ribosomal RNAs
Free ribosomes - make proteins inside the cell
Mitochondria - regenerate ATP, energy production
Peroxisomes - break down fat so we can use it for energy or get rid of toxins
Lysosomes - "recycling center", breaks down materials we no longer need back to monomer units so we can reuse them
Rough ER - makes protiens that work on the outside of the cell or are part of other organelles
Smooth ER- makes lipids and breaks down toxins
Golgi apparatus- modifies proteins and lipids and distributes them to where they need to go
Cytoskeleton - helps maintain the shape of the cell
Microfilaments- help the cell change shape and move
Microtubules- help the movement of materials within a cell
Intermediate filaments - holds organelles in position
Cilia - moves materials through digestive system (shorter & numerous)
flagella - move materials through digestive system (longer & few)
plasmodesmata - channels between touching plant cells that allow them to communicate and exchange materials.
tight junctions - create watertight cells that prevent materials from leaking
desmosomes - protein structures that hold cells tightly together, helping keep tissues and organs intact.
centrosome - separates DNA during cell division
cell wall - provides structure to the plasma membrane
chloroplast - makes sugar
central vacuole - stores water
extracellular matrix - network of proteins and other materials outside cells that supports, holds, and organizes cells together.
Describe the similarities and list the differences between plant and animal cells
Both have microtubule-organizing centers
Animal cells have a centrosome and lysosomes, which plant cells do not
Plant cells have cell walls, chloroplasts, and a large central vacuole, which animal cells do not
Describe the two major differences between eukaryotic cells and prokaryotic cells
Eukaryotic cells have a nucleus, membrane bound organelles
Prokaryotic cells don't have a nucleus and don't have membrane-bound organelles