review
External air has a higher concentration of oxygen molecules than does the cytoplasm of your lung cells. Where in your lungs will there be a net increase of oxygen due to diffusion?
inside of the lung cell
The movement of molecules from an area of low concentration to an area of high concentration is called:
active transport
Mrs. Crandall placed 2 tablespoons of salt into a glass of water and then placed a selectively- permeable membrane into the glass that divided the glass into left and right halves. The left side is _______ to the right side.
isotonic
Hypotonic
less than, below A hypotonic solution will cause the cell to take in water, and swell
How is facilitated diffusion different than simple diffusion?
Facilitated diffusion occurs through selective transport proteins.
Plasma membranes are selectively permeable. This means that
the plasma membrane allows some substances to enter of leave a cell more easily than others.
Which phrase best describes passive transport?
requires no energy from the cell
f a cell is placed in a hypotonic solution, the cell will _______
swell (get bigger)
The cell membrane contains channels and pumps that help move materials from one side to the other. What are these channels and pumps made of?
proteins
Gases like oxygen and carbon dioxide move passively across cell membranes using
Diffusion
while large molecules like sodium ions move passively using
Facilitated diffusion
In which situation would water enter a cell through osmosis?
The cell is 20% water, and the cell's environment is 80% water.
Both side of a selectively- permeable membrane are equal. The sides are
isotonic
Hypertonic
more, above the water or solution OUTSIDE of the cell is saltier than the INSIDE of the cell. water moves out a cell
What does selectively-permeable mean?
only allows certain materials to pass through
The pressure inside of a cell as a cell pushes itself against the cell wall.
turgor pressure
During active transport molecules tend to move:
up the concentration gradient
Endocytosis
•how materials ENTERthe cell (cell eating/engulfing)
How does osmosis differ from other cell transport processes?
It moves water molecules by diffusion.
Which of the following statements regarding diffusion is false?
It occurs when particles spread from areas where they are less concentrated to areas where they are more concentrated.
In this given scenario, corn syrup is hypertonic to an egg with a dissolved shell. What will happen to the egg when it is place in corn syrup?
It will shrink- get smaller.
Water moves passively across cell membranes using
Osmosis
Which of the following statements tells how facilitated diffusion differs from simple diffusion?
Particles move within channel proteins that pass through cell membranes.
Which of the following is the primary component of the cell membrane?
Phospholipids
An animal cell placed in a hypertonic (salty) solution will
Shrink- get smaller
Ideally, your cells should be in a(n) _______ solution
isotonic
The diffusion of water across a selectively permeable membrane is called
osmosis
What is the term for the diffusion of water across a semipermeable membrane?
osmosis
Diffusion does not require the cell to expend any ATP. Therefore, diffusion is considered a type of
passive transport
What molecule is the cell membrane primarily composed of?
phospholipids
Which of the following statements is true regarding active transport?
The cell must use energy.
If a cell is isotonic in a 80% sucrose solution, how will the movement of water across the cell membrane affect the size of a cell if it is moved from an 80% sucrose solution to a 40% sucrose solution?
The cell will increase in size.
A cell with 1% solute concentration is placed in a beaker with a 5% solute concentration.What will happen to this cell over time?
The cell will lose H2O and shrink.
If you looked at red blood cells under a microscope and saw the blood cells exploded, what would you say happened?
The cells were placed in a hypotonic solution.
In the given scenario what will happen? An egg with a dissolved shell is placed in pure water for 48 hours.
The egg will gain water and swell.
Since cyanide is a poison that limits a cell's ability to manufacture ATP energy, a cell containing cyanide is least likely to carry on the process of:
active transport
Which process would include a net movement of sugar molecules through a membrane from a region of lower concentration to a region of higher concentration?
active transport
During diffusion molecules tend to move:
down the concentration gradient
Which term refers to the condition that exists when no net change in concentration results from diffusion?
equilibrium
The movement of molecules down a concentration gradient [from high to low concentration] through transport proteins in the cell membrane is a type of
facilitated diffusion
A molecule that diffuses down a concentration gradient goes from an area of ____________ concentration into an area of ____________ concentration.
high; low
Phagocytosis
how larger materials ENTERthe cell (cell eating/engulfing)
Exocytosis
how materials EXITthe cell (how the cell uses the bathroom)
Pinocytosis
how small materials ENTERthe cell (cell eating/engulfing
Phospholipid molecules in a membrane are arranged with their ________ on the exterior and their ________ on the interior.
hydrophilic heads ... hydrophobic tails
If a cell containing 5% salt is placed into a glass of water with 20% salt, the water is _______ compared to the cell.
hypertonic
If a solution outside a cell is more concentrated so that the cell loses water to its environment, the external solution is said to be __________ to the cell contents.
hypertonic
has more solute , less water than the cell
hypertonic
In osmosis, water always moves towards the _______ solution, that is, toward the solution with the _____ solute concentration.
hypertonic....greater
has more water, less solute than the cell
hypotonic
What will be the most likely effect of placing a freshwater protozoan in a highly concentrated saltwater solution?
The protozoan will shrink.
Which of the following must be true for diffusion to occur?
There must be areas of different concentrations.
If a cell is placed in a hypotonic solution, which will occur?
Water will move into the cell from the surrounding solution.
A cell has a 95% concentration of water inside its membrane. It is placed in an environmental solution that has an 85% concentration of water. In which direction and by what process will water molecules move across the cell membrane?
Water will move into the cell, along the concentration gradient, by osmosis.