Structure of plasma membrane

Question 1

Identify parts of plasma membrane

Answer 1

1. Phospholipid bilayer
2. Types of proteins
3. Carbohydrates
4. Cholesterol
5. Carbohydrate chain
6. Protein Channel

Question 2

Phospholipid

Answer 2

• A main molecule of which membranes are
  composed
• They have a phosphate
  head and two fatty acid tails

Question 3

Phospholipid bilayer

Answer 3

• A double
  a layer of amphiphilic molecules
• Forms the primary component of membranes

Question 4

Phosphate head

Answer 4

The hydrophilic
subunit of a phospholipid

Question 5

Fatty acid tail

Answer 5

The hydrophobic
lipid subunit of a phospholipid

Question 6

Polar:

Answer 6

• Molecule with
  both a positive end and negative end.
• These tend to be hydrophilic

Question 7

Polar Substances:

Answer 7

• Attracted to
• Dissolve in

Question 8

Nonpolar:

Answer 8

• Molecule without a clearly positive or negative end.
• These tend to
  be hydrophobic

Question 9

Amphipathic: the phospholipid bilayer is?

Answer 9

Molecules with both:

• Hydrophilic and hydrophobic components

Phospholipid bilayer:
- an ex. of this
- Stable

Question 10

Amphipathic is also known as:

Answer 10

Amphiphilic

Question 11

Phospholipid Bilayer - Polar VS non-polar

Answer 11

Polar:

Question 12

Phosphate head

Answer 12

The phosphate head is:
* made of a glycerol and phosphate group
* negatively charged, making it hydrophilic (‘water-loving’) and polar.

Question 13

Two Fatty acid tails

Answer 13

The two fatty acid tails are:
* made of long chains of carbon and hydrogen
* uncharged, hydrophobic (‘water-fearing’), and nonpolar.

Question 14

Hydrophilic

Answer 14

• (‘water-loving’)
• Attracted to water

Question 15

Hydrophobic

Answer 15

• (‘water-fearing’)
• Repels water

Question 16

Amphipathic makes the plasma membrane:

Answer 16

More stable due to polar and non-polar parts of the membrane

Question 17

Nonpolar molecules are:
attracted to and dissolve in
nonpolar substances

Answer 17

Non-polar substances:

1. Attracted to
2. Dissolve in

Question 18

Non-polar molecules do not:

Answer 18

Interact with polar molecules

Question 19

The phosphate head is:

Answer 19

The phosphate head is:
* made of a glycerol and phosphate group
* negatively charged, making it hydrophilic (‘water-loving’) and polar.

Question 20

The two fatty acid tails are:

Answer 20

The two fatty acid tails are:
* made of long chains of carbon and hydrogen
* uncharged, hydrophobic (‘water-fearing’), and nonpolar.

Question 21

Water is a polar or non-polar substance?

Answer 21

• Polar

Question 22

Why the phospholipid bilayer comment on its structural features relative position and why?

Answer 22

Phosphate head:

(to reinforce the notion) because of its hydrophilic nature; it is attracted to water

Two fatty acid tails:

• form the middle portion of the bilayer because it is hydrophobic; not attracted to water

Question 23

Phosphate head/ two fatty acid tails which one is oriented towards, the aqueous intra- and
extracellular environments.

Answer 23

Phosphate head

Question 24

Different types of proteins:

Answer 24

1. Integral protein – proteins that
   are a permanent part of the
   membrane
2. Transmembrane protein – integral
   proteins that span the entire bilayer
3. Peripheral protein – are
   temporarily attached to the
   plasma membrane

Question 25

Carbohydrates: what they are and where in relation to the structure of the plasma membrane

Answer 25

What they are:

• Biomacromolecule made from
  monosaccharide monomers
  consisting of carbon, hydrogen,
  and oxygen. Also known as
  saccharides or sugars

Where:
- Usually in chains that extend
outside the cell

• Rooted in the
  membrane to lipids (glycolipids)
  or proteins (glycoproteins)

Question 26

Cholesterol: in what cells

Answer 26

• A lipid steroid that embeds itself
  between the fatty acid tails of
  the phospholipid bilayer in animal
  cells

Question 27

Protein:

Answer 27

Biomacromolecule made of amino
acid monomers folded into a 3D shape

Question 28

Consisting of:

Answer 28

1. Carbon,
2. Hydrogen
3. Oxygen
4. Nitrogen
5. Sometimes sulphur

Question 29

Consisting of: carbohydrates