Campbell Chapter 7

Question 1

What is an amphipathic molecule

Answer 1

molecule that has both hydrophilic and hydrophobic regions

Question 2

Most membrane proteins and membrane Lipids are _______

Answer 2

Amphipathic

Question 3

How are proteins distributed in the membrane

Answer 3

They form groups of protein that act as long lasting patches

Question 4

What interactions hold a membrane together

Answer 4

Hydrophobic interactions

Question 5

Are membranes Stagnant or Fluid

Answer 5

Fluid

Question 6

What 2 proteins are found in the membrane

Answer 6

integral proteins and peripheral proteins.

Question 7

What are Integral Proteins

Answer 7

proteins that are permanently embedded in the cell membrane.

Question 8

What are Peripheral Proteins

Answer 8

proteins that are attached to the surface of a cell or mitochondrial membrane, but are not embedded in it

Question 9

What are glycolipids

Answer 9

Lipids that have Carbohydrates covalently bonded

Question 10

What is a selective permeability of the membrane

Answer 10

the membrane allows some substances to cross more easily than others.

Question 11

What are transport proteins

Answer 11

Transport Proteins are proteins that span the cell membrane, letting in hydrophilic substances without touching the hydrophobic interior of the membrane

Question 12

What are Aquaporins

Answer 12

Transport Protein that let water molecules into a cell

Question 13

Polar molecules are hydrophobic or hydrophilic

Answer 13

hydrophilic

Question 14

nonpolar molecules are hydrophobic or hydrophilic

Answer 14

hydrophobic

Question 15

What is Diffusion

Answer 15

the movement of particles of any substance so that they spread out into the available space

Question 16

How is diffusion ruled

Answer 16

In the absence of any other forces, a substance will diffuse from where it is more concentrated to where it is less concentrated.

Question 17

Does diffusion need energy

Answer 17

no

Question 18

What is the diffusion of a substance across a biological membrane called

Answer 18

Passive transport

Question 19

What is Osmosis

Answer 19

The diffusion of free water across a selectively permeable membrane, whether artificial or cellular

Question 20

What is Tonicity

Answer 20

ability of a surrounding solution to cause a cell to gain or lose
water

Question 21

If a cell without a cell wall, such as an animal cell, is immersed
in an environment that is isotonic(same tonicity) to the cell what happens

Answer 21

there will be no net movement of water across the plasma membrane

Question 22

What does being hypertonic mean

Answer 22

a solution has a higher concentration of solute and lower concentration of water

Question 23

What does being hypotonic mean

Answer 23

a solution has a lower concentration of solute and higher concentration of water

Question 24

What is Osmoregulation

Answer 24

the control of solute concentrations and
water balance

Question 25

How does a cell wall change the effect of a hypotonic solution on a cell

Answer 25

the cell wall helps maintain the cell’s water balance.

Question 26

As water enters the cell, what happens

Answer 26

Cell Swells

Question 27

What does it mean when a cell is “Turgid”

Answer 27

a cell is swollen and firm due to a high internal water pressure

Question 28

What does it mean when a cell is “Flaccid”

Answer 28

a cell that has lost its rigidity and is soft and limp due to a loss of water

Question 29

What is Plasmolysis in plants

Answer 29

contraction of the protoplast of a plant cell as a result of loss of water from the cell.

Question 30

What is facilitated diffusion

Answer 30

polar molecules and ions blocked by the lipid bilayer of the membrane diffuse passively with the help of transport proteins that span the membrane

Question 31

What are the types of transport proteins in the cell membrane

Answer 31

channel proteins and carrier proteins.

Question 32

What are Channel Proteins transport proteins

Answer 32

provide corridors that allow specific molecules or ions to cross
the membrane

Question 33

What are Carrier transport proteins

Answer 33

proteins that undergo a subtle change in shape that somehow translocates the solute-binding site across the membrane

Question 34

What type of transport is facilitated diffusion

Answer 34

Passive Transport

Question 35

What is Active Transport

Answer 35

pump a solute across a membrane against its gradient
requires work; the cell must expend energy

Question 36

Large molecules, such as proteins and polysaccharides,
generally don’t cross the membrane by diffusion or transport
proteins. Instead what do they do

Answer 36

They leave or enter the membrane packed in vesicles

Question 37

What is Exocytosis

Answer 37

cell secretes certain molecules by the fusion of vesicles
with the plasma membrane