Lesson 2.2: Cell membrane

Question 1

The cell membrane is composed of ________ containing ______ and ______

Answer 1

• phospholipid bilayer
  -hydrophilic head
  -hydrophobic tail

Question 2

Amphipathic means

Answer 2

• has polar and non polar part

Question 3

What types of molecules cannot and can pass through the cell?

Answer 3

Large molecules: ions and macromolecules need to pass through gated channels

Non polar molecules and lipids can pass through

Question 4

Three functions od the membrane that surrounds the cell

Answer 4

1) Forms a barrier between the cell and outside world

2) Regulates passages of substances in and out of the cell

3) Help maintain homeostasis

Question 5

Components of the hydrophilic head

Answer 5

glycerol and phosphate group

Glycerol: nitrogen binded to 4 Carbons

Phosphate group: double bond with oxygen

Question 6

Component in Macromolecules

Answer 6

Carbo - CHO
Lipids - CHO
Phospholipids = CHOP
Protein = CHON
Nucleic Acid = CHONP

Question 7

Where are the hydrophobic tails attached?

Answer 7

Carbon chain

Question 8

The hydrophobic tails are composed of ________ Carbon

Answer 8

18

Question 9

What is the difference between two hydrophobic tail?

Answer 9

First is linear, consisting of only single bonds, while the second has “kink” because of a double bond bet. C15 and C16.

Question 10

Explain what structure caused the fluidity of cell membrane

Answer 10

-the kink or the double bond makes it semi-aqueous or fluid.

Question 11

Explain the orientation and the interaction of phospholipid bilayer.

Answer 11

mirrored
hydrophilic head intearcts outside with polar substance

hydrophobic tail interacts with nonpolar substances inside

Question 12

_______ proteins are embedded throughout the bilayer. They carry out
1)
2)
3)
4)
5)

Answer 12

Transmembrane
1) Transport proteins
2) Enzymes
3) Recognition proteins aid in cell-to-cell communication
4) Adhesion proteins
5) Receptor proteins

Question 13

________ proteins are attached from the upper surface of the cell membrane.

They are easy to wash out because __________

Answer 13

Peripheral proteins
their attachment to the cell membrane is not that strong

Question 14

Appendages are sometimes ______ and ______ and used for ___________

Answer 14

carbohydrates and sugar
cell-to-cell communication

Question 15

_______ are located near the tail where proteins for ____ are also attached.

Answer 15

Cholesterol
signaling

Question 16

Phospholipid bilayer are made up of
______ and _____ along with _____ and ______

Answer 16

cholesterol, proteins, with sugar molecules and microfilament of the cytoskeleton

Question 17

____ are used for bodybuilding called ______

But in cell membranes they are called ________ and an example is _______

Answer 17

Steroid, anabolic steriods

membrane steroid, cholesterol

Question 18

What is the primary role of cholesterol in the membrane?

Answer 18

keep the membrane at the right level of fluidity

Question 19

In membrane the phospholipids are. (movement) ____________________

The combination of ______ and ______ forms a fluid mosaic

Answer 19

constantly moving and switching places or materials

phospholipids and proteins

Question 20

Three factors that influences the fluidity of the membrane

Answer 20

1. Temperature
2. Cholesterol
3. Saturated and unsaturated fatty acids

Question 21

Temperature

If it is cold the phospholipid are ________________ forming a _______

If it is too hot they ______ and they ______

Answer 21

bound together forming a rigid and not flexible membrane and may break

move apart from each other and they won’t hold a shape.

Question 22

Cholesterol

they are randomly distributed in the ______ part

They help the bilayer to stay fuild in _________ as they ________ together

Answer 22

hydrophobic part
different environmental conditions

hold phospholipid

Question 23

Explain what will happen to phospholipid without cholesterol in cold conditions

Answer 23

-they will clump together making it difficult for the smaller molecules to enter the cell even gases

Question 24

which is a good and bad fatyy acids explain

Answer 24

Good- unsaturated, liquid at room temp

Bad -saturated solid at room temp