Biology A Unit 3: Lessons 11-14
What happens when a specific substance binds to a carrier protein?
The carrier protein changes shape and moves the substance through the cell membrane.
How are channel and carrier proteins similar? Select all that apply.
Channel and carrier proteins are both specific for select types of particles that they can transport across the membrane. Channel and carrier proteins are both types of facilitated transport.
Study the image. https://cdstools.flipswitch.com/asset/media/1156531 Which membrane component is a channel protein?
B
What is true for both endocytosis and exocytosis?
Both require energy.
How are channel and carrier proteins different? Select all that apply.
Carrier proteins can allow much larger substances to cross the membrane than channel proteins do. Carrier proteins undergo a shape change as they move substances across the membrane, while channel proteins do not. Channel proteins move substances across the membrane at a much faster rate than carrier proteins.
What is true about active transport? Select all that apply.
It is transport against a concentration gradient. It is transport that requires energy.
Lesson 11:
Lesson 11:
Lesson 12:
Lesson 12:
Lesson 13:
Lesson 13:
Which statement describes how molecules move when there is a concentration gradient?
Molecules move from areas of high concentration to areas of low concentration to restore equilibrium.
If a cell is in a hypotonic solution, which statement is true about water movement and the cell?
More water enters the cell than leaves the cell.
What problem with the CFTR protein causes cystic fibrosis?
The CFTR protein cannot pump ions out. This means water cannot move out of the cell. The result is very thick mucus.
Which statement best describes the fluid mosaic model?
The fluid mosaic model shows a cell membrane with a pattern-like structure and flexibility.
Study the image below, which shows how the sodium-potassium pump works. https://cdstools.flipswitch.com/asset/media/1157245 Identify the error in the image.
The pump is powered by an ATP molecule. The ATP molecule should be located in the cytoplasm, not outside the cell, as shown.
Which statements correctly describe how the sodium-potassium pump works? Select all that apply.
The pump transports the two types of ions in different directions. ATP provides the energy to operate the motion of the pump.
What is the function of the cell membrane's selective permeability?
The selectively permeable membrane allows only certain substances to enter or exit the cell.
Which statements accurately describe channel proteins? Select all that apply.
They work like a tunnel that allows certain substances to pass through the membrane. They can transport molecules in either direction, depending on the concentration. They are best suited for the transport of smaller substances like ions.
The sodium-potassium pump is an example of active transport. True or False?
True
True or False? Facilitated transport does not require the cell to use energy because moving molecules from areas of higher concentration to areas of lower concentration is powered by diffusion.
True
If a cell is in an isotonic solution, which statement is true about water movement and the cell?
Water leaves and enters the cell at the same rate.
Study the image. https://cdstools.flipswitch.com/asset/media/1156531 Which membrane component would help ions to travel in and out of a cell?
XXX WRONG XXX C
Study the series of images. https://cdstools.flipswitch.com/asset/media/1156569 What type of transport is illustrated and what does that transport do?
XXX WRONG XXX facilitated diffusion: solutes move from areas of higher concentration to areas of lower concentration with the help of a channel protein exocytosis: sodium ions move to the outside of the cell through a vesicle
Which are examples of active transport proteins? Select all that apply.
a carrier protein that uses ATP the sodium-potassium pump
What exists when there is a concentration difference from one area of a solution to another area?
a gradient
What is a solvent?
a substance that dissolves a solute
What is a solute?
a substance that is dissolved in a solution
What does the CFTR protein transport?
chloride ions
In a solution, solute substances naturally tend to move from areas of higher concentration to areas of lower concentration. What is the name of this process?
diffusion
Read the following scenario: The movement of a large food particle into the cell would provide a source of nutrition. Which transport method would be the most effective in moving this food particle into the cell?
endocytosis
In this process, a vesicle moves large substances, such as cells' waste products or specific products, out of the cell. What process does this describe?
exocytosis
Which type of transport does not require energy but uses carrier proteins to help move substances across the cell membrane?
facilitated transport
What kind of new therapies are scientists working on to treat cystic fibrosis? Select all that apply.
gene therapies to fix the CFTR gene inhalers to deliver CFTR to the cells
Study the image. https://cdstools.flipswitch.com/asset/media/1157307 What type of membrane protein does label A point to?
glycoprotein
What does hydrophilic mean?
having a tendency to interact with water
The tail of a phospholipid avoids interacting with water. What term describes this?
hydrophobic
What does hydrophobic mean?
lacking an affinity for, or attraction to, water
Which are examples of passive transport? Select all that apply.
osmosis diffusion facilitated transport
Which are examples of active transport? Select all that apply.
phagocytosis exocytosis pinocytosis
What molecules are found in the structure of cell membranes? Select all that apply.
phospholipids proteins carbohydrates
Where does the energy used for active transport come from?
the ATP molecule
What is endocytosis?
the energy-using process in which macromolecules are taken into the cell
Phospholipids line up so that their heads point outward, toward water, while their tails point inward. What is this double layer of phospholipids called?
the lipid bilayer
What is the function of channel proteins?
to allow specific ions or molecules to pass freely
What is the function of receptor proteins?
to detect outside conditions and signal the information to the inside of the cell
Why does active transport require energy?
to move substances against their concentration gradient
Which of these are functions of membrane proteins? Select all that apply.
to send signals across the cell membrane to help move molecules across the membrane to serve as identification for the cell
