Chapter 8 Test
a plasma membrane is made up of a(n) ______________________.
phospholipid bilayer
Turgor Pressure
water pressure within a cell
Define isotonic solution
a solution that has the same concentration of the same solute as another solution
The cellular process in which materials are moved across a membrane from an area of low concentration to an area of high concentration is called
active transport
define exocytosis
active transport process by which materials are secreted or expelled from a cell
What is the main function of a selectively permeable cell membrane?
controls what comes in and out of the cell
Jim is in a crowd of people at the mall looking for his girlfriend Tammy, who was supposed to meet him for dinner. Jim realizes Tammy is across the room as he catches a whiff of her overpowering perfume, 'Paris #6'. Which process explains why Jim is able to smell the perfume?
diffusion
describe osmosis
diffusion of water across a selectively permeable membrane
White blood cells engulf bacteria through what process.
endocytosis
Name 2 other types of active transport and explain why they are considered active transport
endocytosis and exocytosis : the both require energy
Define active transport
energy expending process by which cells transport materials across the plasma membrane against the concentration gradient (low to high)
Define dynamic equilibrium
equal concentration or equally distributed in a space
The cell is taking in substances through membrane proteins, without any energy expenditure of its own. The substances naturally follow their concentration gradient. However, they must go through the protein channels, because they are too large to squeeze through the cell membrane. This process is called
facilitated diffusion
Insulin is a hormone produced by the pancreas and helps to regulate the concentration of __________ in the blood.
glucose
Water moves out of a cell if the cell is places in a(n) _______________ solution.
hypertonic
Water moves into a cell placed in a(n) _______________ solution.
hypotonic
If cells are placed in a hypertonic sugar solution, water will __________________.
leave the cell
Freshwater plants die in sea water because their cells _____________________________.
lose water
If it is not watered, a tulip plant wilts because it ___________________________.
loses water pressure
If a cell is placed in salt water, water leaves the cell by _____________.
osmosis
3 types of passive transport
osmosis, diffusion, facilitated diffusion
Substances like oxygen pass through the cell without the use of energy and move from an area of high concentration to an area of low concentration. This process is called
passive transport
define facilitated diffusion
passive transport of materials across a plasma membrane by transport proteins embedded in the plasma membrane
The structure most responsible for maintaining cell homeostasis is the ___________________________.
plasma membrane
a cell's inside would be the same as its outside, were it not for the ____________________________.
plasma membrane
what are two characteristics of a molecule can easily pass through the selectively permeable membrane of an animal cell?
size and charge
What might be a result of a disease that causes a thickened plasma membrane? (think in terms of diffusion across this membrane)
substances are going to move through the cell less because it is harder for them to pass through
define concentration gradient
the difference in concentration of a substance across a space
define diffusion
the net movement of particles from an area of higher concentration to an area of lower concentration
Define hypertonic solution
the solution with HIGHER concentration of SOLUTE and LOWER concentrations of WATER water diffusion will cause the membrane to shrivel bc the water has to leave (low to high)
define hypotonic solution
the solution with the LOWER concentration of SOLUTE and HIGHER concentrations of WATER water diffusionin in to the membrane will cause the membrane to swell (low to high)
