Unit 1.2 and 1.3 Flashcards
regulates the flow of materials
into and out of the cell
Plasma membrane
fluid portion and the organelles
cytosol
houses most of the cell’s DNA.
nucleus
passive
ions move from an area of higher concentration to an area of lower concentration until an equilibrium is reached
Diffusion
The rate of diffusion across a plasma
membrane is affected by:
the steepness of the concentration gradient
Temperature
mass of the diffusing substance
surface area available for diffusion
the distance over which diffusion must occur
solute moves down its
concentration gradient across the lipid
bilayer through a membrane channel
Channel-mediated
facilitated diffusion
solute binds to a specific carrier
protein on one side of the
membrane and is released on
the other side after the
carrier undergoes a change in
shape
Carrier-mediated
facilitated diffusion
there is net movement of
water through a selectively
permeable membrane
Osmosis
red blood cells maintain their normal
shape
isotonic
swell and undergo
hemolysis
hypotonic
shrink and undergo
crenation
hypertonic
the method of transporting material that requires energy
Allows movement from a lower concentration to a higher
concentration
Active transport
move two substances
in the same direction
across the membrane
Symporters
move two substances
in opposite directions
Antiporters
detach to move into
Endocytosis
merge to move materials out
Exocytosis
selective uptake of
large molecules and particles
clathrin-mediated
endocytosis
Receptor-mediated
endocytosis
captures the cellular fluid and
dissolved substances
(“pino” means “to drink”)
Bulk-phase endocytosis
(pinocytosis)
no extension
pinocytosis
extends outwards
phagocytosis
vesicles undergo endocytosis
on one side of a cell, move
across the cell, and undergo
exocytosis on the opposite
side
Transcytosis
synthesizing large numbers of diverse proteins.
a gene’s DNA is used as a template for synthesis of a specific protein.
PROTEIN SYNTHESIS
flow of genetic information
suggests that DNA contains the information needed to make all of our proteins, and that RNA is a messenger that carries this information to the ribosomes
The Central Dogma of Life
the information in the DNA of every cell is converted into
small, portable mRNA (messenger RNA)
Newly synthesized pre-mRNA is modified before leaving the nucleus
TRANSCRIPTION
