3.3 Cell Membrane

Question 1

The double-layer of phospholipids that forms a boundary between a cell and the surrounding environment and controls the passage of materials into and out of a cell. is known as?

Answer 1

Cell Membrane

Question 2

A molecule that forms a double-layered cell membrane, consists of glycerol, a phosphate group, and two fatty acids is?

Answer 2

Phospholipid

Question 3

A model that describes the arrangement and movement of the molecules that make up a cell membrane is?

Answer 3

Fluid Mosaic Model

Question 4

What is condition or quality of allowing some, but not all, materials to cross a barrier or membrane known as?

Answer 4

Selective Permeability

Question 5

Protein that detects a signal molecule and performs an action in response is?

Answer 5

A Receptor

Question 6

A cell membrane consist of double layer of phospholipids inter spread with a variety of other what?

Answer 6

Molecules

Question 7

What are the three basic parts of a phospholipid molecule?

Answer 7

• Charged phosphate group
• Glycerol
• Two fatty acid chains

Question 8

Charged phosphate group, glycerol, and two fatty acid chains are the basic parts of what?

Answer 8

A Phospholipid Molecule

Question 9

Which part(s) of the phospholipid are charged or polar?

Answer 9

Phosphate group and glycerol

Question 10

Which part(s) of the phospolipid are nonpolar?

Answer 10

Fatty acid chains/tail

Question 11

What strengthens the cell membrane?

Answer 11

Cholesterol

Question 12

What helps materials cross the membrane and are also part of the cytoskeleton?

Answer 12

Phospholipid

Question 13

What helps identify cell types?

Answer 13

Carbohydrates

Question 14

True or False:
A membrane is fluid, because the phospholipids in each layer can move from side to side, in and out of the cell, by sliding past each other, and by spinning in circles.

Answer 14

False

Question 15

True or False:

A selectively permeable membrane allows all molecules to cross.

Answer 15

False

Question 16

A ————– detects a signal molecule and carries out an action in response.

Answer 16

Receptor

Question 17

A ligand is a molecule that acts as a —————- when it binds to a —————-.

Answer 17

Signal, Receptor

Question 18

A ligand that …………….. cross the cell membrane can bind to an intracellular receptor.

Answer 18

CAN Cross

Question 19

A ligand that cannot cross the cell membrane can send a message to a cell by ……………….. a membrane receptor, which then changes shape.

Answer 19

Binding To

Question 20

What means that the cell membrane allows some, but not all, molecules to cross?

Answer 20

Selective Permeability

Question 21

The fluid mosaic model describes the arrangement of what, that can make up a cell membrane? The model include both the fluidity of the membrane and the variety of molecules that make up the membrane.

Answer 21

Molecules

Question 22

True or False:

The polar head of the phospholipid forms hydrogen bonds with water molecules.

Answer 22

True

Question 23

True or False:

Nonpolar tails are attracted to each other and are repelled by water.

Answer 23

True

Question 24

The cell membrane is made up of two phospholipid layers embedded with other materials known as? (3)

Answer 24

• Proteins
• Carbohydrates
• Cholesterol

Question 25

True or False: | The cholesterol is not located between the two fatty acid chains.

Answer 25

False

Question 26

The cholesterol is located between where?

Answer 26

Two Fatty Acid Chains

Question 27

True or False: | The cell membrane is flexible and non rigid.

Answer 27

True

Question 28

Can proteins embedded in the membrane flip vertically?

Answer 28

No

Question 29

What regulates what moves into and out of the cell?

Answer 29

Cell Membrane

Question 30

The cell membrane has the property of selective permeability, which it means it allows what?

Answer 30

Some but not all materials to cross

Question 31

True or False: Selective permeability enables a cell to maintain homeostasis in spite of unpredictable changing conditions outside of the cell.

Answer 31

True

Question 32

A cell needs to maintain certain conditions to carry out its functions, it must control the what? Of certain molecules and ions.

Answer 32

Import and Export

Question 33

True or False: How a particular molecule crosses the membrane depends on the molecules size, polarity, and concentration inside the versus outside the cell.

Answer 33

True

Question 34

Small nonpolar molecules easily pass through the cell membrane, small polar molecules are transported via what?

Answer 34

Proteins and large molecules are moved in vesicles

Question 35

What is a protein that detects a signal molecule and performs an action in response?

Answer 35

Receptor

Question 36

What two major rectors are present in your cells?

Answer 36

Interacellular and Membrane

Question 37

Interacellular means what?

Answer 37

Within or Inside a Cell

Question 38

True or False: | A molecule that cant cross the membrane may bind to a phospholipid in the cell membrane?

Answer 38

False | -A molecule binds to a receptor in the cell membrane

Question 39

Why is it critical that when a molecule and receptor combine that it changes shape?

Answer 39

Because it affects how a receptor interacts with other molecules

Question 40

When a receptor changes shape does that only happen on the outside of the cell?

Answer 40

No, it changes shape on the inside as well