Chapter 7: Membrane Structure And Function

Question 1

What is a phospholipid?

Answer 1

A type of lipid (fatty acid/general group) that consists of a hydrophilic head and hydrophobic tail; an amphipathic molecule

Question 2

What percentage of the human body is water?

Answer 2

60%

Question 3

What is a the cell membrane made of?

Answer 3

It is primarily composed of phospholipids, specifically a phospholipid bilayer

Question 4

What does cholesterol do in the cell membrane?

Answer 4

It allows for greater membrane fluidity.

Question 5

What are peripheral proteins?

Answer 5

They are proteins on the edge of the bilayer.

Question 6

What are integral proteins?

Answer 6

They are proteins that go through both sides of the cell membrane; also includes chanel proteins

Question 7

What is selective permeability?

Answer 7

Means that the cell membrane will allow some things to pass through it and not others

Question 8

What will 100% pass through the cell membrane?

Answer 8

Small, nonpolar molecules

O2, CO2, N2

Question 9

What will 50% pass through the cell membrane?

Answer 9

Small, uncharged polar molecules

H2O

Question 10

What will 20% pass through the cell membrane?

Answer 10

Large, uncharged, polar molecules

Glucose, sucrose

Question 11

What will 0% pass through the cell membrane?

Answer 11

Ions

Na+, K+, Cl-

Question 12

What is osmosis?

Answer 12

The process by which molecules of a liquid tend to pass through a semi-permeable membrane from a less concentrated solution to a more concentrated one, this equalizing the concentrations on each side of the membrane

Question 13

What is passive transport?

Answer 13

Passive transport is a type of membrane transport that does not require energy to move substances across the cell membrane; instead of using cellular energy like active transport, it relies on diffusion

Question 14

What is diffusion?

Answer 14

Is the movement of anything of high concentration to a region of lower concentration

Question 15

What is facilitated diffusion (helped diffusion)?

Answer 15

Is the transport of substances across a biological membrane from an area of high concentration to an area of lower concentration with the help of a transport molecule

Question 16

What is active transport?

Answer 16

Is the movement of molecules across a cell membrane from a region of lower concentration to a region of high concentration and requires energy (ATP; because it’s not necessarily a natural process)

Question 17

What is endocytosis?

Answer 17

Is the process of capturing a substance or particle from outside the cell by engulfing it with the cell membrane and brining it into the cell

Question 18

What is exocytosis?

Answer 18

Describes the process of vesicles fusing with the plasma membrane and releasing their content to the outside of the cell (particularly waste)