Membrane transport mechanism Flashcards
1) What is (are) the main difference(s) between passive transport and active transport?
- Passive transport does not require any cellular proteins; active transport requires cellular proteins.
- Active transport requires cellular energy for substances to cross the cell membrane; passive transport does not.
- Active transport works against gravity (for example, upwards from the roots of a tree); passive transport works with gravity
- Passive transport occurs primarily in single-cell organisms; active transport occurs primarily in multi-cellular organisms.
Active transport requires cellular energy for substances to cross the cell membrane; passive transport does not.
2) Which example(s) of cell tranposrt does not require chemcial energy?
- neither A nor B
- potato slice is placed in water and water molecules from inside the potato move into the surrouning water.
- both A and B
- Drops of blue food coloring are placed in water and spread throughout the water, turning it blue.
Correct answer: both A and B
Endocytosis is an example of what type of transport?
- passive transport
- active transport
- osmosis
- facilitated diffusion
active transport–
All of the following are types of passive transport except endocytosis diffusion facilitated diffusion osmosis
endocytosis
What is the role of ATP in the process of active transport?
- It lengthens the fatty acid chains in the membrane.
- It weakens the membrane, allowing molecules to pass through more easily.
- It provides the energy to transport the cell in its environment.
- It provides the energy that cells need to move molecules against a concentration gradient.
It provides the energy that cells need to move molecules against a concentration gradient.
Facilitated diffusion allows certain kinds of compounds that are normally blocked by the cell membrane to cross the cell membrane. All of the following are examples of compounds that move by facilitated diffusion except glucose water potassium sodium
water
Exocytosis is an example of what type of transport? facilitated diffusion osmosis active transport passive transport
active transport
Which of the following is an example of osmosis?
- Intesintal cells use osmosis to absorb nutrients from food.
- The human body uses osmosis to move antibodies out of cells.
- A single-celled organism uses osmosis to take in food particles.
- A plant’s roots use osmosis to absorb water from the soil.
A plant’s roots use osmosis to absorb water from the soil.
9) How do substances move into or out of the cell through endocytosis?
- Substances are engulfed by a cell’s plasma membrane and brought into the cell in a vesicle.
- Substances are engulfed by a cell’s plasma membrane to form a channel into the cell.
- Substances are engulfed by a vesicle, which crosses the cell membrane.
- Substances cross the cell membrane through protein channels.
Substances are engulfed by a cell’s plasma membrane and brought into the cell in a vesicle.
10) What kind of material is transported through osmosis?
- oxygen
- blood
- water
- nitrogen-fixing bacteria
water
In facilitated diffusion, what are the special channels that help substances cross the cell membrane made of?
- proteins
- nucleic acids
- water molecules
- carbon bonds
proteins
Which statement is true regarding active transport?
Substances can only move across the cell membrane if they are water soluble.
Substances can only move into cells, not out of cells.
Substances do not require additional energy to move in and out of cells.
Substances can move from areas of low concentration to areas of high concentration.
Substances can move from areas of low concentration to areas of high concentration
How does particle size affect a molecule’s transport across a cell membrane?
It is easier for large molecules to diffuse across the cell membrane.
Particle size does not affect a molecule’s transport speed across the cell membrane.
Particle size is less important than particle shape for calculating transport speed.
It is easier for small molecules to diffuse across the cell membrane.
It is easier for small molecules to diffuse across the cell membrane.
What causes the diffusion process to stop?
The concentration of materials outside the cell becomes greater than the concentration of materials inside the cell.
The concentration of materials inside the cell becomes greater than the concentration of materials outside of the cell.
The concentration of materials inside and outside the cell becomes equal.
The concentration of materials cannot be changed because ATP is no longer available.
The concentration of materials outside the cell becomes greater than the concentration of materials inside the cell.
Suppose that you stayed in the bathtub too long, causing your hands and feet to look wrinkled. What kind of passive cell transport causes this effect?
diffusion
exocytosis
facilitated diffusion
osmosis
osmosis
Which best describes the role of endocytosis in cell transport?
Endocytosis moves substances into the cell.
Endocytosis moves substances out of the cell.
Endocytosis moves substances into or out of the cell, down a concentration gradient.
Endocytosis moves substances into or out of the cell, against their concentration gradient.
Endocytosis moves substances into the cell
In general, in what direction does a diffusing substance move?
it depends on the substance being diffused
down its concentration gradient
in the opposite direction than it would normally move
up its concentration gradient
down its concentration gradient
Which best describes the role of exocytosis in cell transport?
Exocytosis moves substances out of the cell.
Exocytosis moves substances into or out of the cell, against their concentration gradient.
Exocytosis moves substances into or out of the cell, down a concentration gradient.
Exocytosis moves substances into the cell.
Exocytosis moves substances out of the cell.
Correct order of simple diffusion
a) gases > small uncharged particles > water > large uncharged polar molecules > charged particles > charged large polar molecules
b) gases > small uncharged particles > water >charged particles> large uncharged polar molecules charged particles > charged large polar molecules
c) gases > small uncharged particles > charged particles > large uncharged polar molecules > charged particleswater > charged large polar molecules
d) gases > small uncharged particles > large uncharged polar molecules > waterl > charged particles > charged large polar molecules
•gases > small uncharged particles > water > large uncharged polar molecules > charged particles > charged large polar molecules
W/c of the following will cause an increase in diffusion rate?
a) increase concentration gradient
b) increase viscosity
c) decrease temperature
d) both a and b
a
W/c of the following is indirectly proportional to diffusion rate? (choose as many as possible)
a) concentration gradient
b) area of diffusion
c) temperature
d) viscosity
e) radius of particles
radius & viscosity
True or False: Simple diffusion can be carrier mediated and channel mediated
f
I.Carrier - Mediated bind substances on one side of the membrane & release them to the opposite side
II. Channel - Mediated transmembrane proteins which act as water-filled pores with gates
A) i. is T
B) II. is F
c) both is t
d) neither is t
c
open or close due to binding of a chemical
a) Mechanical Gating
b) Voltage - gated Gating
c) Ligand Gating
LG
