Tour of the Cell Flashcards
3 tenets of cell theory
1) cell are the fundamental units of life
2) all living organisms are composed of cells
3) all cells come from preexisting cells
Magnification
increase size of an object
resolution
clarity of an image
contrast
visible difference in brightness in parts of the sample
LM uses _____ and EM uses
Light beams; magnets + electron beam
Bright field unstained LM
minimal contrast + detail
Bright field stained LM
helps enhance contrast
Phase-contrast LM
more enhancement of light in dark regions
Differential interference contrast LM
gives impression of shadow within the cell
Fluorescence LM
using dyes and light beams to visualize specific cellular material
Deconvolution LM
applied to confocal microscopy to improve contrast + resolution
Confocal
uses fluorescence + focuses emitted light so a single pain of cell can be seen
Scanning electron microscopy SEM
visualize a 3D surface of an object
- cannot be used for living cells
Transmission electron microscopy TEM
beam of electrons is focused on object, if the beam passes through they are detected on a fluorescent screen
Cell Fractionation is
taking cells apart + separating major components from one another
The steps in cell fractionation
1) Aquire tissue sample
2) Homogenization
3) Homogenate
4) Centrifugation
Differential centrifugation is
the ability to study the structure + function of different organelles
Main features of prokaryotic cells
- absence of membrane bound nucleus
- still has DNA present in the form of a nucleotide
- Has cytosol, plasma membrane, ribosomes
- some mechanism for local motion ex- flagella
main features of eukaryotic cells
- DNA is organized differently
- has membrane bound organelles
- uses internal membranes to compartmentalize functions that take place in the cell
- larger
Compartmentalization benefits
- chemical reactions can be partitioned from one another ->
1) chemical reactions will be more efficient
2) able to maintain in higher concentrations
3) groups enzymes to increase efficiency
P + E cell have a ______ that serves as a
plasma membrane; selective barrier
the _____ of a cell is related to…
volume; chemical reactions
Cells whose role is _____ will have adaptations to increase _____
exchange; surface area
The E cell’s genetic instructions are housed in _____ and carried out by
nucleus; ribosomes
The _______ contains chromosomes and is the site for events like
Nucleolus; transcription +replication
The nuclear envelope has a _____ membrane and a ______ membrane
inner; outer
The nuclear envelope has ____ that allow for the _______ of contents in and out of the cell
pores; regulation
Ribosomes job is to ______ and are involved in ____
manufacture proteins; polypeptide synthesis
Ribosomes do not have a
meembrane
The two locations of ribosomes
1) scattered in the cytoplasm
2) bound to membranes
Cytoplasm ribosomes are considered
free ribosomes
Proteins from free ribosomes will _______ in the _______ or be transfered to specific _____
remain; cytoplasm; organelles
Ribosomes consist of a
1) large subunit
2) small subunit
The ribosomes subunits participate in _______ and are stabilized through
polypeptide synthesis; non-covalent bonding
The endomembrane system consists of
1) Nuclear envelope
2) Endoplasmic reticulum
3) Golgi apparatus
4) Lysosomes
5) Vesicles
6) Plasma membrane
7) SECRETION
The components of the endomembrane system are either _____ or connected vis transfer by _____
continuous; vesicles
the ER is continuous with the
nuclear envelope
The smooth er lacks
ribosomes
the smooth er contains _____ involved in the formation or breakdown of _____
enzymes; lipids
Smooth er is a site of
phospholipid production
Smooth er serves a role in ______ + stores ____
detoxification; intracellular calcium
the smooth er benefits from
compartmentalization
the rough er has
ribosomes
The ribosomes in the rough er will generate ____
polypeptides
The interior of he rough er is called
lumen
The lumen is the sit of
protein folding and modification
Proteins can be modified through ______ which is the addition of a ___
glycosilation; carbohydrate
The ration of rough er to smooth er is based on
the function of the cell
The testes have more ______ which means they will have more
lipid synthesis; smooth er
cell that have more ____ scretion will have more
protein; rough er
Golgi are where
proteins are processed, sorted, and shipped
the Golgi has flattened sacks called
cisternae