Final Exam Chapter 5 review

Question 1

What is the difference between a leak channel and a gated channel?

Answer 1

Leak channel: They are channels that are always open and allow stuff to go through whenever

Gated channel: Gated channels are closed. SO the ligand has to bind to the channel which will then open the channel

Question 2

What is channel mediated simple diffusion?

Answer 2

ions that go through the membrane channel proteins with no energy (leak channels and aquaporins)

Question 3

Where are these ions super concentrated in (high amounts of) and where are they not so concentrated in (low amounts of) extracellular fluid or intracellular fluid?

Na+
K+
Ca2+
Bicarbonate (HCO3-)

Answer 3

Ka+- Extracellular fluid (HIGH)
Intracellular fluid (LOW)

K+- Extracellular fluid (LOW)
Intracellular fluid (HIGH)

Ca2+- Extracellular fluid (HIGH)
Intracellular fluid (LOW)

Bicarbonate (HCO3-)- Extracellular fluid (HIGH)
Intracellular fluid (LOW)

Question 4

What are the steps of the sodium potassium pump? (Na+ & K+) (5)

Answer 4

1. 3 Na+ from the extracellular fluid moves in the pump and binds to the carrier protein
2. ATPase is activated and hydrolyzes ATP to ADP and an inorganic phosphate which blocks the openings
3. ADp is released causing a shape change that allows 3 Na+ to exit the pump to the outside of the cell
4. 2K+ enters the carrier protein from the outside, which releases an inorganic phosphate
5. The pump returns to its original shape and releases 2K+ to the inside

Question 5

How does the calcium pump work when there are low levels of calcium in the cell vs high calcium levels in the cell? (which is active and passive diffusion)

Answer 5

High calcium levels in the cell: The pump removes calcium against its gradient with the use of ATP energy (active transport)

Low calcium levels in the cell: The pump lets calcium in the cell by its gradient NO ENERGY USED. Does it by diffusion (passive transport

Question 6

Is the calcium pump a symport, antiport or uniport?

Answer 6

Uniport

Question 7

What is the Na+ linked H+ pump? What kind of transport does it use? (active, passive, secondary active transport?

Answer 7

It is where Na+ is moving into the cell by diffusion to create energy to pump out the H+ ions (against its gradient). As Na+ is being pumped in it needs to be pumped out as well. So it is a secondary active transport of H+ ions

Question 8

Is the Na+ linked H+ pump a symport, antiport or uniport?

Answer 8

It is an Antiport

Question 9

How do aquaporins transport water molecules through the membrane?

Answer 9

It breaks the hydrogen bonds between H20 molecules and sends down each individual molecule one by one down the channel

Question 10

Where are GLUT 1, GLUT 2, GLUT 3, and GLUT4 located in the body?

Answer 10

GLUT1: Most cells of the body
GLUT2: Liver, Kidney, Intestines
GLUT3: In the neurons
GLUT4: Adipose tissue and skeletal muscles (cell membranes when stimulated by insulin)

Question 11

Which of the glut receptors can be stimulated to increase in number?

GLUT 1, GLUT 2, GLUT 3, or GLUT 4

Answer 11

GLUT 4

Question 12

Why can GLUT 4 receptors be stimulated to increase in number and why not the other ones?

Answer 12

Because Insulin binds to the GLUT 4 receptor and it increases glucose uptake

Question 13

How does the sodium potassium pump get energy?

Answer 13

ATPase hydrolyzes ATP which is used to energize the pump

Question 14

What is the purpose of ATPase?

Answer 14

To break down ATP to ADP so that the inorganic phosphate can be used to power the sodium potassium pump

Question 15

Is ATPase involved in primary active transport or secondary active transport?

Answer 15

primary active transport

Question 16

What are transport vesicles?

Answer 16

vesicles that move materials, such as proteins and carbohydrates, between organelles or regions of the same organelle within a cell

Question 17

What characteristics do molecules need to have to go through the membrane without channels? (passive transport) (6 things)

Answer 17

1.Need to be lipid soluble (non polar)
2. be small molecules,
3. need to go with the gradient (high to low),
4. the membrane needs to be more permeable (shorter tails and unsaturated),
5. and needs to have a larger membrane surface area (large membrane)
6. The molecule is not water soluble

Question 18

What characteristics do molecules have that require the use of channel proteins to get through the membrane? (active transport) (6 things)

Answer 18

1. They are NOT lipid soluble (polar molecules)
2. They are big molecules
3. Go against the gradient (low to high)
4. The membrane has longer tails and the fatty acids are saturated
5. has a smaller membrane surface area (lets less stuff through)
6. the molecule is water soluble

Question 19

How many mOsms does the intracellular and extracellular fluid need to have to be in homeostasis?

Answer 19

300 mOsms

Question 20

Define carrier proteins (how do they work)

Answer 20

They require that the molecule binds to the carrier protein. Then the carrier protein changes shape to the molecule. Once that is done it sends it in or out of the cell (whichever way it is going)

Question 21

What is the Na+-linked Glucose pump?

Answer 21

It is a secondary active transport that it uses the Na+ when it goes with its gradient into the cell the glucose tags along and uses that energy from the Na+ to get into the cell. BUT the Na+ gets pumped out right after it gets pumped in