Bio 2 exam 2 part 2

Question 1

Permeation by diffusion

Answer 1

small non-polar molecules
small molecules without charge

Question 2

impermeable

Answer 2

large polar molecules
ions
charge polar molecules

Question 3

Tonicity

Answer 3

is the relative concentration of solutes dissolved in solution which determine the direction and extent of diffusion

Question 4

Hypertonic solution

Answer 4

Solute concentration is greater than that inside the cell; cell loses water

Question 5

Isotonic solution

Answer 5

Solute concentration is the same as that inside the cell; no net water movement across the plasma membrane

Question 6

Hypotonic solution

Answer 6

Solute concentration is less than that inside the cell; cell gains water

Question 7

Organisms that are not protected by an external cell wall need to

Answer 7

regulate the influx of water into the cell

Question 8

All cells have voltages across their plasma membranes

Answer 8

caused by the difference in charge between the inside and outside of the cell

Question 9

Two combined forces, collectively called the electrochemical gradient

Answer 9

• a chemical force (the ion’s concentration gradient)
• an electrical force (the effect of the membrane potential on the ion’s movement)

Question 10

Ion transporters (or ion pumps)

Answer 10

are transmembrane proteins that move ions across a plasma membrane against their concentration gradient.

Question 11

Proton Pumps are essential transport proteins that fuel other carriers

Question 12

A proton pump is responsible for generating gastric acid in your stomach

Question 13

Cystic fibrosis

Answer 13

• caused by a mutation in the gene for the protein called CFTR
  -required to regulate the components of sweat, digestive juices, and mucus by moving chloride ions

Question 13

Bulk Transport

Answer 13

requires energy and a large involvement of the membrane

Endocytosis- the process by which substances are engulfed into the cell. capturing a substance or particle from outside the cell by engulfing it with the cell membrane
Exocytosis- the process by which substances are released from the cell.

Question 14

Exocytosis allows the cell to secrete a wide variety of materials from the cell into the external environment

Answer 14

• Animal cells secrete hormones, digestive enzymes, and other proteins
• Plant and fungus cells secrete enzymes and cell wall components

Question 15

Surface Protein

Answer 15

souable proteins that are outside of the bilayer . usually polar aminoacids . anchored into the plasma membrane

Question 16

Transmembranes

Answer 16

embedded throughout the whole membrane. Non polar amino acids are on the outside and polar amino acids are on the inside

Question 17

How do organisms change the biochemistry of their plasma membrane?

Answer 17

• Increasing membrane proteins
• Increasing the number of unsaturated fats
• Increasing cholesterol

Question 18

How does the membrane maintain cell shape?

Answer 18

binds to the cytoskeleton and the ECM tomaintain shape

Question 19

What is cholesterol and what is its importance in the plasma membrane?

Answer 19

Cholesterol is a lipid/ steroid and it is inside the plasmamembarne. Gives cell rigidity

Question 20

Proton pumps

Answer 20

pumps H+ ions to make a source for potential energy within the cell

Question 21

Ion Pumps

Answer 21

transmembrane proteins that moves ions across a membrane against the concentration gradient , active transport

Question 22

Histamines

Answer 22

triggers an immune response when released