SFP: Basic Concepts of Cell Biology Flashcards
what are the two main examples of prokaryotes?
- archaebacteria: bacteria found in extreme environments
- eubacteria: most species of bacteria
what are big examples of eukaryotes?
protists, fungi, plants, and animals
what is the structural difference in chromosomes between prokaryotes and eukaryotes?
pro have single circular chromosomes, and eukaryotes have multiple linear chromosomes
what is the general composition of a cell membrane
it is a phospholipid bilayer with polar head groups facing outward and hydrophobic fatty acid tails facing inward. throughout the membrane there are peripheral and transmembrane proteins
what determines a cell membranes functional properties?
the composition of proteins and lipids within it, which differs
what kind of components are found in cytosol?
ions, carbohydrates, nucleotides, amino acids, proteins, etc.
what is the basic function of the plasma membrane
it encloses the cell and separates the cytoplasm from the extracellular space. it also allows the cell to interact with the environment and response to stimuli
what are major components of the nucleus
DNA, nucleolus, nuclear envelope
what is the matrix in terms of organelles?
the internal compartment of the membranous organelle
name some non-membranous organelles
free ribosomes, centrioles, cilia/flagella
what are the components of the cytoskeleton?
microfilaments (actin, myosin), intermediate filaments, and microtubules
what is resolving power?
the smallest distance between two object that allows them to be seen as separate objects
why is resolving power important in microscopy?
it allows us to obtain a sharp and detailed image; we can magnify as much as we’d luck, but without ample resolving power we won’t have a good image
describe light microscopy
cells/tissues are fixed, sectioned, and stained. a beam of light is focused on and passes through the specimen, where it is collected by the objective lense.
describe transmission electron microscopy
TEM uses an electron beam to resolve cells. the specimen needs to be fixed with gluteraldehyde and osmium tetroxide, dehydrated in OH, embedded in epoxy resin and cut thin, and stained with heavy metal salts
describe scanning electron microscopy
SEM uses an electron beam and electromagnetic lense similar to TEM. the specimen is coated in heavy metal, and the beam is scanned along the surface of the specimen. the metal surface emits secondary electrons that are collected by a detector and the signal amplifies. this results in cool 3-D images with high contour
describe fluoresence microscopy
a fluorescent dye is used that absorbs light at one wavelength and emits light at another. the dye becomes excited by an excitation filter. a dichronic mirror deflects excitation light, and the fluorescent light passes through
describe immunohistochemistry
uses a labeled antibody to detect specific antigens. usually the antibody has a fluorescent compound or electron dense gold particles
what is direct immunohistrochemistry
the label used has an antibody that binds directly to a specific antigen. this isnt used as often
what is indirect immunohistochemsitry
there is a primary antibody that is not labeled and binds to a specific antigen in cells, there is also a secondary antibody that is labeled and binds to an epitope in the primary antibody
what are the benefits of indirect immunohistochemistry
there is an amplified signal due to multiple secondaries binding to the primary. additionally, the same secondary can be used with many primary antibodies.
