3.1.4 Membranes: Basic Structure

Question 1

note

Answer 1

• The structure of plasma membranes allows cellular compartmentalization and selective permeability to various substances
• The plasma membrane separates the eukaryotic cell’s contents from the outside. The cytoplasm is defined as all the cell’s contents from the plasma membrane to the nucleus. The cytosol is the liquid of the cytoplasm
• Proteins are also embedded in the bilayer. Because the proteins are charged, they are hydrophilic. The proteins occur throughout the bilayer complex.

Question 2

fluid mosaic model

Answer 2

• a model of membrane structure. According to the model, membranes are composed of a double layer of phospholipids in which proteins are embedded. The layer is somewhat fluid, allowing the movement of proteins within it.

Question 3

phospholipid

Answer 3

• The main structural molecule of the cell membrane is the phospholipid, a lipid consisting of glycerol bonded to two fatty acid “tails” and a phosphate-charged “head

Question 4

phospholipid bilayer

Answer 4

• refers to the arrangement of phospholipids in the cell
  membrane. The phospholipids form a double layer; the hydrophilic heads face outwards and the hydrophobic tails form the center of the layer.

Question 5

Which of the following statements about phospholipids in plasma membrane is not true?

Answer 5

• Phospholipid molecules have three tails

Question 6

Phosphatidylcholine is a __________.

Answer 6

• phospholipid

Question 7

True or false?

Cytosol is another name for cytoplasm.

Answer 7

• false

Question 8

As constituents of the cell membrane, phospholipids

Answer 8

• are have a hydrophobic tail and a hydrophilic head

Question 9

With regard to the fluid mosaic model of cell membranes, which statement is false?

Answer 9

• Embedded proteins are hydrophobic in nature

Question 10

True or false?

The cell membrane is also known as the plasma membrane.

Answer 10

• true