Chapter 7: Cell Membrane 09/19/2024

Question 1

What is selective permeability?

Answer 1

When the plasma membrane allows some substances to cross more easily than others

Question 2

What does it mean for a phospholipid to be amphipatic?

Answer 2

It means to contain hydrophobic and hydrophilic regions

Question 3

What is the fluid mosaic model?

Answer 3

When a membrane has fluid structure with different various proteins

Question 4

Can phospholipids move?

Answer 4

Only within the plasma membrane in the bilayer. Most of the lipids and proteins drift but cannot flop.

Question 5

What are peripheral proteins?

Answer 5

Proteins that are bound to the surface of the membrane

Question 6

What are integral proteins?

Answer 6

Proteins that penetrate the hydrophobic core

Question 7

What are glycolipids/glycoproteins?

Answer 7

Molecules that help cell-to-cell recognition

Question 8

What is the behavior of hydrophobic molecules in the membrane?

Answer 8

Hydrophobic and non polar molecules dissolve in the lipid bilayer and pass through the membrane (ex: gases)

Question 9

What is the behavior of hydrophilic molecules in the membrane?

Answer 9

Hydrophilic molecules and polar molecules do not pass the membrane easily (ex: H2O, macromolecules, anything with charges)

Question 10

What are transport proteins?

Answer 10

Proteins that allow hydrophilic substances to pass

Question 11

What are aquaporins/channel proteins?

Answer 11

Proteins that allow and facilitate the passage of water

Question 12

What is diffusion?

Answer 12

The tendency for a molecule to spread out evenly in a given space. Movement from high to low.

Question 13

What is osmosis?

Answer 13

The diffusion of water across a selectively permeable membrane. An example of high-to low and is passive transport

Question 14

What is tonicity?

Answer 14

The ability for a surrounding solution to cause a cell to gain or lose water

Question 15

What is an isotonic solution?

Answer 15

When the solute concentration is the same as the inside of the cell and there is no water movement in the plasma membrane

Question 16

What is a hypertonic solution?

Answer 16

When the solute concentration is greater than the inside of the cell and has more on the outside and the cell loses water

Question 17

What is a hypotonic solution?

Answer 17

When the solute concentrations is less than what is inside the cell. More concentration on the inside and the cell gains water

Question 18

What is osmoregulation?

Answer 18

When the control of the solute concentration and water balance is necessary for the adaptation for life in such environments

Question 19

What is a flaccid cell?

Answer 19

When a plant cell and its surroundings are isotonic and no movement in the cell

Question 20

What is turgid plant cell?

Answer 20

When a plant cell is hypotonic and swells up

Question 21

What is active transport?

Answer 21

Where there is energy required and flows from low ->high(against the concentration gradient)

Question 22

What is passive transport?

Answer 22

When there is no energy required and flows from high to ->low(concentration gradient)

Question 23

What is facilitated diffusion?

Answer 23

The transport of molecules through the use of assisted channels

Question 24

Are heads hydrophobic or hydrophilic?

Answer 24

Hydrophilic

Question 25

Is there more movement in saturated or unsaturated fat?

Answer 25

There is more movement in unsaturated fat because it takes up more space. There is little movement in saturated fat because they are packed in a small space.

Question 26

What can allow more space and fluidity in fats?

Answer 26

At low temperatures, cholesterol can allow more fluidity. At high, it will make it more rigid and less movement

Question 27

Is the head polar or non-polar?

Answer 27

Polar. The inside is nonpolar

Question 28

Can hydrocarbons cross through?

Answer 28

Yes. They are nonpolar.

Question 29

What is the concentration gradient?

Answer 29

The movement of going high to low

Question 30

What is against the concentration gradient?

Answer 30

The movement of going low to high

Question 31

What are examples of passive transport?

Answer 31

Diffusion, osmosis, and facilitated difussion