3A

Question 1

plasma membrane

Answer 1

the phospholipid bilayer and embedded proteins which separate the intracellular environment from the extracellular environment. Also known as cell membrane

Question 2

intracellular

Answer 2

inside a cell

Question 3

extracellular

Answer 3

outside a cell

Question 4

selective permeability

Answer 4

a property of cell membranes that ensures only specific substances pass across them. Also known as semipermeable

Question 5

phospholipid

Answer 5

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

Question 6

phospholipid bilayer

Answer 6

a double layer of amphiphilic molecules that forms the primary component of cell membranes

Question 7

phosphate head

Answer 7

the hydrophilic subunit of a phospholipid

Question 8

fatty acid tail

Answer 8

the hydrophobic lipid subunit of a phospholipid

Question 9

hydrophilic

Answer 9

having a tendency to be attracted to and dissolve in water

Question 10

polar

Answer 10

describes a molecule with both a positive end and negative end. These tend to be hydrophilic

Question 11

hydrophobic

Answer 11

having a tendency to repel and be insoluble in water

Question 12

nonpolar

Answer 12

describes a molecule without a clearly positive or negative end. These tend to be hydrophobic

Question 13

amphipathic

Answer 13

describes molecules with both hydrophilic and hydrophobic components. Also known as amphiphilic

Question 14

protein

Answer 14

a class of biomacromolecule made of amino acid monomers folded into a 3D shape, consisting of carbon, hydrogen, oxygen, nitrogen, and sometimes sulphur

Question 15

carbohydrate

Answer 15

a class of biomacromolecules made from monosaccharide monomers consisting of carbon, hydrogen, and oxygen. Also known as saccharides or sugars

Question 16

cholesterol

Answer 16

a steroid-alcohol that regulates fluidity in plasma membranes

Question 16

integral protein

Answer 16

a protein that is permanently secured to the plasma membrane

Question 16

transmembrane protein

Answer 16

an integral protein that spans the entire plasma membrane

Question 17

peripheral protein

Answer 17

a protein that is temporarily attached to the plasma membrane

Question 18

cytoskeleton

Answer 18

the microscopic web of protein filaments in the cytoplasm. It provides structure and support and transports products around the cell

Question 19

glycolipid

Answer 19

a phospholipid bound to a carbohydrate

Question 20

glycoprotein

Answer 20

a protein bound to a carbohydrate

Question 21

fluid mosaic model

Answer 21

the theory of how the plasma membrane is structured

Question 22

saturated

Answer 22

a fatty acid chain with only single bonds between carbon atoms

Question 23

unsaturated

Answer 23

a fatty acid chain with at least one double or triple bond between carbon atoms