BIOL1300 Chapter 3: 9-25-12 Ch. 3 membrane function.docx
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Question 1
Plasma membranes are selectively permeable. This means that
A. | glucose cannot enter the cell. | |
B. | the plasma membrane allows some substances to enter or leave a cell more easily than others. | |
C. | plasma membranes must be very thick. |
Question 2
Oxygen molecules O2 crosse a plasma membrane by
A. | passive transport | |
B. | osmosis | |
C. | active transport |
Question 3
Facilitated diffusion across a biological membrane requires ________ and moves a substance ________ its concentration gradient.
A. energy and channel proteins; against (up) | ||
B. transport proteins that make channels ; down | ||
C. energy ; down |
Question 4
When two aqueous solutions that differ in solute concentration are placed on either side of a semipermeable membrane and osmosis is allowed to take place, the water will
A. move to the side with lower water concentration | ||
B. | move to the side with higher water concentration | |
C. | move to the side with lower solute concentration |
Question 5
Kinetic energy differs from chemical energy in that
A. | chemical energy is a particular form of kinetic energy. | |
B. | kinetic energy is the energy of a moving object, whereas chemical energy is the potential energy of molecules. | |
C. | kinetic energy is stored energy that has the potential to do work, and chemical energy is the energy of movement. |
Question 6
When a cell uses chemical energy to perform work, it uses the energy released from a(n) ________ reaction to drive a(n) ________ reaction.
A. | exergonic; endergonic | |
B. | endergonic; exergonic | |
C. | spontaneous; exergonic |
Question 7
When an enzyme catalyzes a reaction
A. it raises the activation energy of the reaction. | ||
B. it lowers the activation energy of the reaction. | ||
C. it is used once and discarded. |
Question 8
Which of the following statements regarding enzyme function is false?
A. An enzyme's function depends on its three-dimensional shape. | ||
B. Enzymes are very specific for their substrates. | ||
C. Enzymes are used up when they catalyze a chemical reaction so must be synthesized for each new chemical reaction |
I have this questions for my homework i need help with them look please it is important i need help so please give me the correct answers for each question and also please be clear to understand and aslo be correct it is very important becuase i need them so i really need the right answers. please help me and on Questions 6 and 9 please help me with it hope you can help me with the correct answers please
Question 5
At a constant temperature, if you increase the number of unsaturated fatty acid chains in the phospholipid, the membrane will become......
less fluid |
more fluid |
fluidity will be unchanged |
Question 6
Bacteria in a hot spring at 80 degrees celsius would be expected to have ______________ in their cell membrane
high proportions of saturated phospholipids |
high proportions of unsaturated phospholipids |
an equal ratio of saturated to unsaturated phospholipid |
Question 7
Membrane proteins have an important role in membrane fluidity
True |
False |
Question 8
The HIV virus can't attach to cells that have a mutation in the CCR5 gene and so such individuals are resistant to HIV. What population of people have a higher incidence of the mutant CCR5 gene and why?
europeans because their ancestors survived the bubonic plague |
North Americans because their ancestors survived small pox |
europeans because they have a longer evolutionary past with HIV |
Africans because they have a longer evolutionary past with HIV |
Question 9
Nematode trapping fungi have ______________ molecules called ______________ that recognize specific carbohydrates on the surface of the nematode worms. This is how a fungus can recognize that its prey, the nematode worm, has wriggled into the loop. Write two words on lowercase separated by a space with no other syntax
Question 10
Diffusion requires energy
True |
False |
Question 11
The net direction of molecule movement when molecules diffuse is
down their concentration gradient |
random directions |
Question 12
In osmosis, water molecules from a solution of higher solute concentration cross a semi-permeable membrane into a solution of lower solute concentration?
True |
False |
Question 13
Which best defines osmosis?
In osmosis, water from a solution of lower solute concentration move across a semi-permeable membrane into a solution of higher solute concentration? |
In osmosis, water from a solution of higher solute concentration move across a semi-permeable membrane into a solution of lower solute concentration? |
Question 14
Animal cells placed into a hypotonic solution would most likely?
lyse (burst) |
shrink |
remain unchanged in size |
Question 15
Glucose and amino acids move into cells via carrier proteins, the same protein can move glucose or amino acids
True |
False |
Question 16
ATP powered pumps move substances into and out of cells by diffusion?
True |
False |
Question 17
For every 3 Na ions moved out, 2 K ions are moved into a cell by one cycle of the sodium-potassium pump.
True |
False |
Question 18
Bulk transport of fluid and any of the substances within that fluid is called
pinocytosis |
phagocytosis |
receptor-mediated endocytosis |
exocytosis |
I have this questions for my homework i need help with them look please it is important i need help so please give me the correct answers for each question and also please be clear to understand and aslo be correct it is very important becuase i need them so i really need the right answers. please help me and be correct and clear it is important ok
Question 5
At a constant temperature, if you increase the number of unsaturated fatty acid chains in the phospholipid, the membrane will become......
less fluid |
more fluid |
fluidity will be unchanged |
Question 6
Bacteria in a hot spring at 80 degrees celsius would be expected to have ______________ in their cell membrane
high proportions of saturated phospholipids |
high proportions of unsaturated phospholipids |
an equal ratio of saturated to unsaturated phospholipid |
Question 7
Membrane proteins have an important role in membrane fluidity
True |
False |
Question 8
The HIV virus can't attach to cells that have a mutation in the CCR5 gene and so such individuals are resistant to HIV. What population of people have a higher incidence of the mutant CCR5 gene and why?
europeans because their ancestors survived the bubonic plague |
North Americans because their ancestors survived small pox |
europeans because they have a longer evolutionary past with HIV |
Africans because they have a longer evolutionary past with HIV |
Question 9
Nematode trapping fungi have ______________ molecules called ______________ that recognize specific carbohydrates on the surface of the nematode worms. This is how a fungus can recognize that its prey, the nematode worm, has wriggled into the loop. Write two words on lowercase separated by a space with no other syntax
Question 10
Diffusion requires energy
True |
False |
Question 11
The net direction of molecule movement when molecules diffuse is
down their concentration gradient |
random directions |
Question 12
In osmosis, water molecules from a solution of higher solute concentration cross a semi-permeable membrane into a solution of lower solute concentration?
True |
False |
Question 13
Which best defines osmosis?
In osmosis, water from a solution of lower solute concentration move across a semi-permeable membrane into a solution of higher solute concentration? |
In osmosis, water from a solution of higher solute concentration move across a semi-permeable membrane into a solution of lower solute concentration? |
Question 14
Animal cells placed into a hypotonic solution would most likely?
lyse (burst) |
shrink |
remain unchanged in size |
Question 15
Glucose and amino acids move into cells via carrier proteins, the same protein can move glucose or amino acids
True |
False |
Question 16
ATP powered pumps move substances into and out of cells by diffusion?
True |
False |
Question 17
For every 3 Na ions moved out, 2 K ions are moved into a cell by one cycle of the sodium-potassium pump.
True |
False |
Question 18
Bulk transport of fluid and any of the substances within that fluid is called
pinocytosis |
phagocytosis |
receptor-mediated endocytosis |
exocytosis |