Chapter 7

Question 1

Amphipathic

Answer 1

One side is hydrophilic while the other is hydrophobic

Question 2

Hydrophobic interaction

Answer 2

Weak chemical interaction caused when hydrophobic molecules form together to exclude water

Question 3

Which fatty acids make phospholipids more fluid

Answer 3

Unsaturated carbontails

Question 4

Which fatty acids make membrane more viscous

Answer 4

Saturated fats

Question 5

Function of cholesterol in the membrane

Answer 5

Acts as a fluid buffer, and lowers temperature required to solidify membranes

Question 6

Integral proteins

Answer 6

Transmembrane protein with hydrophobic and hydrophilic regions

Question 7

Transmembrane proteins

Answer 7

Type of integral protein that goes through membrane

Question 8

Peripheral protein

Answer 8

Protein loosely bound to the surface of a membrane or part of an integral protein

Question 9

What holds membrane proteins in animal cells

Answer 9

Cytoskeletons on the cytoplasm side

Question 10

Functions of plasma membrane proteins

Answer 10

Transport, enzymatic activity, cell-cell recognition, attachment to cytoskeleton & ECM

Question 11

Glycolipids

Answer 11

Lipids with one or more covalently attached carb

Question 12

Which substances struggle getting past the membrane

Answer 12

Polar molecules and ions

Question 13

Transport protein

Answer 13

Transmembrane protein that helps substances cross membranes

Question 14

Diffusion

Answer 14

Random thermal motion of molecules

Question 15

What does diffusion do

Answer 15

A net movement of a substance from higher concentration to lower concentration

Question 16

What happens if diffusion goes on for long enough

Answer 16

Dynamic equilibrium

Question 17

Concentration gradient

Answer 17

Region which the density of a substance increases or decreased

Question 18

Passive transport

Answer 18

Diffusion of a substance across membrane without using energy

Question 19

Osmosis

Answer 19

Diffusion of free water across a selective barrier

Question 20

Isotonic

Answer 20

A solution that causes no net movement of water into or out of cells

Question 21

Tonicity

Answer 21

The ability of a solution surrounding a cell to cause it to lose or gain water

Question 22

Hypertonic

Answer 22

Solution that causes the cell to lose water

Question 23

Hypotonic

Answer 23

Solution that causes a cell to take up water

Question 24

Osmoregulation

Answer 24

Regulation of solute concentration and water balance by a cell or organism

Question 25

Plasmolyze

Answer 25

Cytoplasm shrivels and membrane pulls away from cell wall (Occurs in walled cells)

Question 26

Facilitated diffusion

Answer 26

Passage of substance down electrochemical gradient with help of transmembrane transport protein

Question 27

Active transport

Answer 27

Movement of substances across a cell membrane against its concentration/electrochemical gradient

Question 28

Membrane potential

Answer 28

Difference in electrical charge across a membrane due to unequal distribution of ions

Question 29

Electrochemical gradient

Answer 29

Diffusion gradient of ions which is affected by chemical and electromagnetic forces

Question 30

Electrogenic pump

Answer 30

Active transport protein that generates voltage across a membrane while pumping ions

Question 31

Cotransport

Answer 31

Coupling of the downwards diffusion of a substance with upwards transport of another substance against its concentration gradient

Question 32

How do macromolecules get into or out of cells

Answer 32

Vesicles

Question 33

Exocytosis

Answer 33

secretion of biological molecules by fusing vesicles with the membrane

Question 34

Endocytosis

Answer 34

Cellular uptake of molecules by forming vesicles from plasma membrane

Question 35

Receptor mediated endocytosis

Answer 35

Movement of molecules into a cell by specific molecules into the cell in bulk