Biology: Unit 3: Cells Transport
Osmosis is the diffusion of water molecules across a selectively permeable membrane from an area of 1)________ concentration to an area of 2)_______ concentration.
1) higher 2) lower
What color will Lugol's turn if it test positive for starch?
A dark blue-black
What is a good metaphor to explain diffusion?
A good metaphor for this movement of molecules is what happens if you were to open a bottle of perfume in one corner of a room. It would not be long before someone in the opposite corner of the room would smell the perfume. The molecules moved from an area of higher concentration of perfume where the open bottle was to an area of lower concentration of perfume like the opposite corner of the room. Eventually a balance, or equilibrium, is reached. In other words, the concentration of perfume will be approximately equal throughout the room and no net movement of perfume will occur from one area to the other.
Active transport uses energy in the form of _____.
ATP
Which solution needs to be heated in order to be tested?
Benedict's
How does water move into and out of cells?
By osmosis
What are examples of passive transport, or movements across a concentration gradient without the consumption of energy?
Diffusion, Osmosis, and facilitated diffusion
Laura is finished with the glassware portion of the experiment so she feels that it is safe to remove her goggles. Her lab partner Emily, keeps her goggles on until the entire experiment is complete. Which student followed proper lab procedure?
Emily
Diffusion results in what?
Equilibrium
Lizzie and Ruth turned off their burner and allowed their test tubes to sit in a water bath for five minutes. Since five minutes has passed, it is now safe for them to pick up the tubes with their bare hands.
False
Sarah is finished with her bunsen burner for now, but she will need it again later. She decides to leave the burner on until she needs it again. She is following proper lab procedure because she does not plan to leave the burner unattended.
False
Suzzie cut her finger on a chipped beaker. The cut was minor and doesn't really hurt, so it is not necessary to report the injury to the teacher.
False
T/F: Diffusion requires transport molecules.
False
What does Benedict's solution test for?
Glucose
What environment do plant cells tend to do the best in?
Hypotonic environment
What environment do animal cells tend to do the best in?
Isotonic environment
What is the most important feature of a cell's phospholipid membranes?
It is that they are selectively permeable or semipermeable.
How would the cell move something against a concentration gradient?
It starts by using energy.
What happens to a cell that has a rigid cell wall when placed in a hypotonic solution?
It will swell until the cell is turgid.
What will happen to a freshwater fish in the ocean?
It's cells will swell and the fish will die because osmosis will cause the saltwater of the ocean to enter the freshwater fish's body.
What would happen to a freshwater fish in the ocean?
Its cells would shrink and the fish would die
What types of animals need a contractile vacuole?
Organisms that live in a hypotonic environment
__________________ are selectively permeable or semipermeable.
Phospholipid membranes
Distinguish solute from solvent and solution.
Solution - the mixture of a solute and solvent Solute - the substance that is dissolved in the solvent Solvent - the substance that the solute is dissolved in
What does Lugol's solution test for?
Starch
If a saltwater fish is placed in freshwater, its cells will do what?
Take up water
The bell rang before Jessica and Amanda finished cleaning up their experiment. In order to get to their next class on time, they left their used glassware in the the sink. Jessica and Amanda were in violation of proper lab procedures.
True
Which type of transport moves large molecules across the cell membrane using sacs made from the cell membrane itself?
Vesicle Transport
is the energy-requiring process of pumping molecules and ions across membranes "uphill" - against a concentration gradient.
active transport
pumps molecules and ions against a concentration gradient
active transport
The ways through which molecules can pass through phospholipid membranes are what?
active transport, vesicle transport, and passive transport
What color will Benedict's turn if it test positive for sugar?
blue to bright orange or cloudy white
What can help maintain a state of homeostasis inside of cells?
cell membranes
The factors that are responsible for the permeability of cells include all except ___________. molecule size, cell size, polarity, all of the above
cell size
In a hypertonic solution, a cell with a ____________ will lose water too.
cell wall
When placed in a hypertonic solution, a cell without a _____________________ will lose water to the environment, shrivel, and probably die.
cell wall
At the end of a diffusion process, what is eliminated?
concentration gradient
The difference in the concentration of molecules in two areas
concentration gradient
active transport pumps molecules and ions against a ___________
concentration gradient
a type of vacuole that removes excess water from a cell
contractile vacuole
The process of molecules moving from higher concentration to lower concentration
diffusion
how most materials move into and out of a cell
diffusion
the movement of a molecule from an area of high concentration of the molecule to an area with a lower concentration
diffusion
Larger molecules such as starch can also be actively transported across the cell membrane by processes called _______________ and ____________.
endocytosis and exocytosis
What is the end result of diffusion?
equilibrium
does not require energy and carries molecules or ions down a concentration gradient
facilitated diffusion
What does turgid mean?
firm
What is an example of a hypotonic environment?
freshwater
Active transport processes help maintain what?
homeostasis
Which characteristic of life does a selectively permeable membrane help maintain?
homeostasis
an organism's ability to keep a constant internal environment.
homeostasis
is a dynamic equilibrium rather than an unchanging state
homeostasis
refers to the balance, or equilibrium, within the cell or a body
homeostasis
The adjusting of systems within a cell
homeostatic regulation
Molecules that can easily cross the membrane
hydrophobic
The solution with the lower solute concentration is ________.
hypertonic
When a cell gets smaller, is it hypotonic or hypertonic?
hypertonic
higher concentration of water inside of the cell so water will come out of the cell into the solution
hypertonic
A 2% NaCl solution is ___________ compared to a 10% NaCl solution.
hypotonic
Cells placed in a ___________ solution will take in water across their membrane until both the external solution and the cytosol are isotonic.
hypotonic
The solution with the higher solute concentration is ___________.
hypotonic
When a cell gets bigger, is it hypotonic or hypertonic?
hypotonic
water is in a higher concentration outside of the cell therefore moving into the cell
hypotonic
Solutions of equal solute concentration are __________.
isotonic
equal concentration on both sides
isotonic
A fish that lives in salt water will have somewhat salty water inside itself. Put it in the freshwater, and the freshwater will, through __________, enter the fish, causing its cells to swell, and the fish will die.
osmosis
the diffusion of water
osmosis
the diffusion of water molecules across a selectively permeable membrane from an area of higher concentration to an area of lower concentration
osmosis
the main cause of support in many plants
osmotic pressure
If a cell is in a hypertonic solution, the solution has a lower water concentration than the cell cytosol, and water moves (into or out of?) of the cell until both solutions are isotonic.
out of
A way in which small molecules or ions move across the cell membrane without input of energy by the cell
passive transport
Movement of substances across a plasma membrane without using energy
passive transport
Osmosis is what type of transport?
passive transport
What type of transport is osmosis?
passive transport
the movement of substances across a plasma membrane that does not require energy
passive transport
The plasma membrane pulls away from the cell wall as it shrivels
plasmolysis
The cell membrane allows only some substances to pass through it, so it is known as a ___________.`
semipermeable
Diffusion can occur in what?
solids, liquids and gases
Anything dissolved into water
solute
the substance that is dissolved in the solvent
solute
the mixture of a solute and solvent
solution
Always water
solvent
the substance that the solute is dissolved in
solvent
In an isotonic solution, cells _________________.
stay the same
What do all cells need in order to fuel their daily life?
sugars and oxygen
The active transport of small molecules or ions across a cell membrane is generally carried out by _______________________ that are found in the membrane.
transport proteins
Cells with a cell wall will swell when placed in a hypotonic solution, but once the cell is _______, the tough cell wall prevents any more water from entering the cell.
turgid
Which of the following is NOT a type of passive transport? facilitated diffusion, diffusion, osmosis, vesicle transport
vesicle transport
What do cells need in order to remain healthy?
water
What does a membrane that is selectively permeable have control over?
what molecules or ions can enter or leave the cell