Unit 2: Cell Transport (Bozeman Video 16)

Question 1

What is active transport and how is it different from passive transport?

Answer 1

Active transport requires energy (ATP) for the movement of molecules

passive transport does not require energy

Question 2

What is diffusion? Describe an example in living systems.

Answer 2

molecules moving around randomly and then filling in a space without requiring energy

(1) get oxygen inside body and push out CO2

Question 3

osmosis

Answer 3

diffusion of water across a semipermeable membrane

Question 4

hypertonic solution

Answer 4

Has higher solute concentration than the cell

= water flows into a cell when it’s placed in a hypertonic solution

Question 5

hypotonic solution

Answer 5

Has lower solute concentration than the cell

=water will flow out of the cell if placed in a hypotonic solution

Question 6

isotonic solution

Answer 6

same concentration of solute in the solution as in the cell

= no movement of water in or out

Question 7

What is the difference between diffusion and facilitated diffusion?

Answer 7

Facilitated diffusion requires a protein, but it’s still passive transport

Question 8

move against gradient

Answer 8

moving from low concentration to high concentration. Requires energy

Question 9

the sodium-potassium pump

Answer 9

Moves sodium outside the cell and potassium inside the cell. Both moving from low to high concentration; therefore, ATP needs to be used

Question 10

moving along gradient

Answer 10

moving from a region of higher concentration to a region of lower concentration.

Question 11

How does diffusion explain inhalation?

Answer 11

you breathe in air that eventually goes all the way down to the alveoli, which are small sacks of really thin cells. Diffusion happens across that gradient. You have a lot of oxygen when you breathe in in the alveoli, and that’s going to flow into the capillary
beds and from there to the blood and cells in the body

Question 12

How does diffusion relate to exhalation?

Answer 12

we have a lot of carbon dioxide in our capillary beds and that’s going to flow back into the alveoli. And so that requires no energy, eventually being pushed out from high concentration to low concentration outside our body

Question 13

Describe the significance of osmosis with respect to red blood cells in different concentrations of water

Answer 13

• If solute concentrations are equal, there are normal blood cells (Isotonic)
• If solute concentrations are high on the outside of the cell, the blood cells shrivel up (hypertonic)
• If solute concentrations are low on the outside of the cell, the blood cells swell and blow up (hypotonic)

Question 14

Describe how glucose enters the cell

Answer 14

Glucose connects with GLUT while moving randomly. GLUT changes shape and forces glucose in or out the membrane.

Question 15

Co-transport

Answer 15

Simultaneous transport of 2 substances across a membrane. One usually helps the other substance go from low –> high concentration.

Sodium (Na) flows in other direction and takes glucose molecule with it.

Question 16

What is the ATP: Na: K ratio in the sodium potassium pump?

Answer 16

1:3:2

(1 ATP, 3 Sodium, 2 Potassium)

Question 17

Valinomycin, a substance which transports K+ ions across lipid bilayers and down their concentration gradient, kills cells. Which of the following is the cause of cell death?

Answer 17

Dissipating the K+ ion concentration gradient results in uncontrolled ATP hydrolysis.

Question 18

endocytosis (active transport)

Answer 18

cells move large groups of particles inside.

Phagocyte (white blood cell that eats other cells) folds membrane trapping bacteria and forms a phagosome. –> Phagosome contains all bad pathogens, moves into the cell and combines with lysosome to create a phagolysosome. –> Antibodies are produced when the phagosome reaches the nucleus.

Question 19

Exocytosis (active transport)

Answer 19

Moving waste/ molecules out of the cell or in opposite direction

Example: Nerve cell sending actin potential across synapse