The Cell B Flashcards
where is the nucleolus located
in the nucleus, no membrane separates the nucleolus from the rest of the nucleus
what is the function of the nucleolus
production and assembly of ribosome components
does the nucleolus have a membrane
no it’s seen as a dark spot in the nucleus
what is the function of ribosomes
protein synthesis
what is the location of ribosomes
-free-floating in the cytoplasm (makes protein that cell will use)
-attached to rER (makes proteins that can be stored and when released)
what are the three components of the cytoskeleton
-microtubules
-microfilaments
-intermediate filaments
what is the function of the cytoskeleton
form and internal framework to support and give shape to cells
what do the protein rods allow the cytoskeleton to do
can extend or contract, allows cells to change shape, very dynamic (can quickly be dismantled on one part of the cell and reassemble in a new location)
what is the structure of microtubules
hollow, thickest
what is the function of the microtubules
-support cell (give it rigidity)
-transport (in cell, cilia and flagella, transport chromosomes during cell division)
what is vesicle transport
microtubules act as “railroad tracks” involved in movement of organelles in cell
what are centrosomes
-non membranous organelles
-made up of a pair of centrioles (at right angles to each other)
-made up of microtubules
what are the functions of centrosomes
-microtubule-organizing centre
-move chromosomes during cell division
—used to line up DNA
what are two structures used for movement
flagella and cilia
what is the structure of flagella
few and long (made up of microtubules)
what is the structure of cilia
short and numerous (made up of microtubules)
– line respiratory track, line fallopian tube
what is the function of intermediate filaments
maintenance of cell shape (stabilize cell shape)
–no movement
what is the structure of intermediate filaments
-larger than microfilaments but smaller than microtubules
-each type is constructed from different protein subunits
-they don’t bind ATP or serve as tracks for transport
what is the structure of microfillaments
strings of actin (2 chains)
what are the functions of microfillaments
-maintenance of cell shape (stabilize)
-movement of cell (muscle cell contraction)
what are all cytoskeleton components made up of
proteins
what are the 4 functions of extracellular matrix
-holds cells together
-help regulate cell behaviour
-cell signalling
-cell receptors
what is the structure of extracellular matrix
a gel-like substance made of carbs and fibrous proteins
what is another eukaryotic cell
protists (contractile vacuole)
what is the function of the centractile vacuole
exports excess water collected from inside the cell to maintain cytoplasmic concentration of chemicals
what is another eukaryotic cell
plant cells
what is a plant cell
generally similar to animal cells but with some important differences
what do plant cells possess
cell wall (with plasmodesmata)
central vacuole (storage)
chloroplasts
what do plant cells lack
centrioles
what does the cell wall contain to make plants stand up
cellulose
what is the function of the cell wall
supports cells and ultimately the plant
–rigidity to hold plant upright
–helps prevent water loss
what is the plasmodesmata
pores in the cell wall
(similar to gap junctions in animal cells which directly connect to the cytoplasm of two cells)
what is the function of the plasmodesmata
pores permit movement of fluids between cells so water and small solutes can pass freely from cell to cell
what are the functions of the central vacuole
-supports cell and ultimately the plant
-helps maintain turgor
-site of storage various products and of waste
what is turgor
organelles being pushed towards the membrane
more robust cell due to vacuole being filled with water
what kind of compounds does the central vacuole store
proteins, inorganic ions, pigments, defensive compounds that defend the plant against herbivores
why does the central vacuole dispose of metabolic wastes
it would endanger the cell if they accumulated in cytoplasm
what is the function of chloroplasts
site of photosynthesis (traps light energy for)
where are chloroplasts found
found in green parts of the plant, contains pigment
(leaves, large # found in each cell)
what does the mitochodria convert food into
into ATP
what does the chloroplast convert solar energy into
food (chemical energy)
what do all eukaryotes have
mitochondria, not chloroplast
how is cell specialization determined
by which genes are activated
which percent of genes are used in a cell
20
how does the mitochondria make ATP
requires O2, waste product produced CO2
how does the chloroplast make glucose
uses CO2 and solar energy
what can double membrane bound organelles that contain their own DNA and proteins do
made by their own set of ribosomes and can self replicate
what is the differential gene expression
every cell within an organism has the same genetic composition, except gametes (egg and sperm cells)
true or false: some genes are turned on (active) while others are turned on
true, genes turned on in a WBC will not be the same as the on genes in a nerve cell
what happens by expressing different subsets of genes
2 cells can contain different of gene products (proteins)
All cells have the same genes but…
but each cell only expresses the genes that it requires
but wont express other tissue specific genes
are virus alive and why or why not
no they’re not alive
not cells
don’t have seven properties of life
what do viruses consist of
dna or rna
proteins
what does it mean to be an obligate intracellular parasite
need to go into a cell to reproduce and carry out metabolic activities
can viruses make their own proteins
no they don’t have ribosomes
can viruses reproduce or carry out metabolic activities outside a host cell
no
why are viruses host specific
they have specific receptors where they bind
what are examples of host specific viruses
measles: skin cells
HIV: immune cells (white blood cells)
when a virus binds to a receptor what does it do
enters the cell or injects its nucleic acid into it
if the virus goes into the cell what does it do
takes over the cell’s machinery using viral genes to start making other viruses
what happens when the virus enters or injects its nucleic acid in to the cell
the protein coat is released and the viral nucleic acid will replicate
once the viral nucleic acid and protein coat are made what happens
virus is assembled and released
what happens to the host cell when the viruses are done replicating
it gets killed which releases the virus to go infect more cells
how do antibiotics work
work against living things, no viruses only bacteria
