The Cell Membrane

Question 1

What is a cell membrane?

Answer 1

-The cell membrane is a biological membrane that separates the interior of all cells from the outside environment which protects the cell from its environment.
Functions
-A biological Barrier keeps the stuff inside the cell and separates it from the stuff outside the cell.
-A selective filter that allows certain molecules to pass through it while preventing other molecules from passing through it.

Question 2

The Cell Membrane’s structure and properties.

Answer 2

• The cell membrane is actually made of Lipids(fat)

- The lipids that make up the cell membrane are found in special molecules called phospholipids.

Question 3

What are phospholipids made up of?

Answer 3

The name Phospholipid tells you that the molecule is made up of a Phosphate Group(“Phospho”) and a Lipid Group(“lipid”).

Question 4

Hydrophilic Heads and Hydrophobic Tales

Answer 4

OEach Phospholipid in the cell membrane is made up of one Hydrophilic phosphate head and two Hydrophobic fatty acid tales.

Question 5

Hydrophilic

Answer 5

“Hydro”=Water
“Philic”=Loving
(Water-Loving)

Question 6

Hydrophilic

Answer 6

“Hydro”=Water
“Phobic”=Fearing
(water-fearing)

Question 7

since each phospholipid is made up of a hydrophilic (polar) phosphate head and two Hydrophobic(non-polar) fatty acid tales they have a tendency to form a…..?

Answer 7

bilayer (bi=two.”layers”= layer)

Question 8

when the fatty acid tales face inwards the phosphate faces____?

Answer 8

outwards

Question 9

when the phosphate is facing outwards fatty acid tales faces___?

Answer 9

inwards

Question 10

what does the phospholipid bilayer contains?

Answer 10

phospholipid subunits and proteins that help the cell membrane function

Question 11

what does cell membrane act more like and why?

Answer 11

liquid more than a solid because the cell membrane is made up of specialized phospholipid and it contains constant motion

Question 12

the embedded molecules are also free to move around the membrane like?

Answer 12

rafts on a lake

Question 13

since there are many other molecules embedded in it (ex: proteins ) it looks like?

Answer 13

a mosaic

Question 14

what are the phospholipid bilayers two major functions

Answer 14

Biological Barrier and a Selective filter

Question 15

what do the biological barriers surround in?(phospholipid bilayer)

Answer 15

organelles inside the cell preventing unwanted chemical reactions from happening
EX. lysosomes contain harsh digestive enzymes that could harm the cell however the phospholipid bilayer surrounding the lysosomes prevents that from happening

Question 16

what does a Biological barrier do (phospholipid bilayer)

Answer 16

the phospholipid bilayer acts as a biological barrier separating the contents of the cell (cytoplasm) from the outside of the cell

Question 17

what else does phospholipid bilayer also act as and why?

Answer 17

selective filter and through the phospholipid bilayer acts as a barrier it also needs to allow molecules to pass through it like water, salt and hormones

Question 18

because it has the ability to

selectively filter for certain molecules it is called?

Answer 18

semi-permeable

Question 19

certain molecules can pass through the membrane freely while others must be transported across the membrane using?

Answer 19

specialized transport proteins found in the membrane

Question 20

the cell membrane must allow some materials to move in and out of it lists a few of these materials

Answer 20

water, salt and hormones

Question 21

cell membranes are composed of a double layer of phospholipid imbedded with protein. the molecules that make up this double layer have a hydrophobic and a hydrophilic end. explain the difference between hydrophobic and hydrophilic

Answer 21

hydrophobic hate water and don’t let it in and hydrophilic love water and let it in.

Question 22

since the cytoplasm and the environment surrounding a cell is most water, which of the two ends are pointed into the middle of the bilayer and away from the water?

Answer 22

hydrophobic

Question 23

the diagram is a model of a cell membrane called the fluid mosaic model. brief;y explain why it is fluid and why it is a mosaic

Answer 23

the cell is made up of specialized phospholipids that make it act like a fluid. the many molecules embedded intimate it look mosair

Question 24

what do the cell membranes prevent materials found in fluids outside of cells from entering

Answer 24

salt, viruses, sugars, proteins, ions, bacteria

Question 25

what does it mean when the cell membrane is semi-permeable

Answer 25

allows small amounts of a substance in but not others