The Cell Membrane (Unit 3 - Part 1) Flashcards
1 or more cells compose..
all living things (part of the cell theory)
cells are the basic unit of..
structure and function in living things (part of the cell theory)
cells functions are based on..
their size and shape (part of the cell theory)
cell division
a process in which all cells come from other cells (part of the cell theory)
What cell most not have come from a cell?
the very first cell ever to exist (exception to the cell theory)
Viruses are
smaller than cells and maybe even alive (exception to the cells theory)
cell membrane
thin outer covering
a cell membrane..
-defines the boundary of the cell
-regulates the movement of chemicals in and out of the cell
DNA
genetic material that gives organisms directions on how to make and use materials needed for life processes
cytoplasm
region of the cell between the nucleus and the cell membrane
cytoplasm is made mostly of..
water
the cell membrane is made of 2 layers of
mostly lipids and some proteins embedded
regulation
maintains a stable environment for a cell
selectively permeable membrane (SPM)
lets in some materials but not others
semi permeable
things can pass through
receptors
some proteins in a cell membrane that respond to chemical messengers and cause changes in the cell
transporters
some proteins in a cell membrane that act as passageways for certain materials to move through
one function of proteins in the cell membrane is..
communication
communication
helps cells recognize each other
What impacts how a particle can move through a cell membrane?
size
small molecules…
enter cells easily
large molecules…
DON’T enter cells easily
diffusion
when particles move passively from an area of high to an area of low concentration
equilibrium
the concentration of a substance is the same throughout an area or on both sides of a cell membrane
concentration gradient
when the concentration of a substance is different on either side of a membrane
Does passive transport need energy?
no
passive transport
when materials move from high to low concentration across a semipermeable CELL MEMBRANE
Does diffusion need energy?
no
osmosis
the diffusion of water across a membrane and it is essential for life
water always moves from a…
high to low concentration
-when placed in pure water, cells…
-this happens because..
-swell and burst
-too much water goes into the cells
-when placed in salt water, cells…
-this happens because
-shrink and shrivel
-too much water diffuses out of the cell
-plant cells will not/will (choose one) burst like animal cells because they have a..
-not
-cell wall as well as a membrane
-when placed in salt water, ONLY a PLANTS cell…
membrane shrivels but there cell wall does not
active transport
when materials move from low to high concentration across a semipermeable cell membrane, against or up a concentration gradient
Does active transport need energy?
yes
Does active transport allow for large molecules to enter the cell membrane that could not though diffusion?
yes
active transports uses ___ proteins in the cell membrane
transport
active transport allows cells to maintain special…
concentrations
the two types of active transport are..
endocytosis and exocytosis
endocytosis
particles are engulfed into the cell when the cell membrane pinches in resulting in a vesicle (small organelle)
endo=
enters
exocytosis
particles move out of the cell
exo=
exit
