Ch 6, 7: Membranes

Question 1

Integral proteins

Answer 1

Proteins that are in contact with hydrophilic heads and hydrophobic tails in the membrane
Amino acids penetrate of entirely cross the phospholipid bilayer

Question 2

Peripheral proteins

Answer 2

Proteins found on one side of the membrane

Lack exposed hydrophobic groups

Question 3

Glycolipids

Answer 3

Carbohydrate-bound lipids

Question 4

Desmosomes

Answer 4

Structural support
“Spot welds”
Hold the cells in place and together

Question 5

Tight junctions

Answer 5

Two proteins put together at a junction
Prevents the flow of anything between cells and leakage
Keeps things moving through the cell

Question 6

Gap junctions

Answer 6

Spread action potential (ions), which changes the charge
Facilitates sharing of small substances (ions)
Formed with connexons
Evens out resting potential

Question 7

Connexons

Answer 7

Small membrane proteins

Put together to make a channel between two cells with gap junctions

Question 8

Permeability

Answer 8

How substances move through the protein portion of the membrane

Question 9

Protein channel

Answer 9

Protein on the membrane that permeated to ions
Simple diffusion
Quaternary proteins

Question 10

Osmosis

Answer 10

The diffusion of water across membranes
Passive process
Solute concentration determines water amount

Question 11

Isotonic solution

Answer 11

Same amount of solute compared to the intracellular fluid

Water will not move in out out

Question 12

Hypertonic solution

Answer 12

High solute (low water) compared to the intracellular fluid
Water will move out of the cell
Cell will shrink

Question 13

Hypotonic solution

Answer 13

Low solute (high water) compared to the intracellular fluid
Water will move inside the cell
Can cause the cell to eventually burst

Question 14

Voltage Gated Channels

Answer 14

Change in ionic charge causes the channels to open

Found in excitable cells

Question 15

Stretch Gated Channels

Answer 15

Channels that open only when there is a change in shape of a membrane
Mechanical

Question 16

Phosphorylation Gated Channels

Answer 16

Chemical

Question 17

Ligand Gated Channels

Answer 17

Channel opens the receptor when the ligand binds

Ex. neurotransmitter

Question 18

Mediated transport

Answer 18

Used to transport molecules larger than ions against their gradient
Special proteins are embedded within the membrane
Highly specific and requires a conformational change
Molecule binds to the pore of the transporter

Question 19

Facilitated diffusion

Answer 19

Proceeds from high to low concentration - energetically favorable
Passive transport
Requires a conformational change

Question 20

Passive transport

Answer 20

.

Question 21

Active transport

Answer 21

Requires the expenditure of energy
Ions are moved across the membrane against their concentration
Requires a transport

Question 22

Uniport transporters

Answer 22

Moves a single type of solute

Ex. specific ion channels

Question 23

Symport transporters

Answer 23

Moves two solutes in the same direction

Ex. Na+/Glucose pump

Question 24

Antiport transporters

Answer 24

Moves two solutes in opposite directions

Ex. Na+/K+ pump

Question 25

Primary active transport

Answer 25

Directly requires ATP Pumps - work against concentration gradient Only cations can pass Ex. Na+/K+ pump

Question 26

Secondary active transport

Answer 26

Indirectly requires ATP Facilitated diffusion, made possible by active transport Coupled transporter Ex. Na/Glucose co-transporter

Question 27

Na/Glucose co-transporter

Answer 27

Glucose moves against concentration gradient inside the cell Movement of glucose at the expense of sodium Na+/K+ pump uses ATP to filter out Na+ Symport Found in cells of the digestive system and the nephron kidneys

Question 28

Endocytosis

Answer 28

Brings macromolecules into the cell Plasma membrane invaginates toward the cell interior and engulfed the macromolecule Molecule binds to the membrane, which pinches it off inside the cell Requires a lot of energy

Question 29

Receptor mediated endocytosis

Answer 29

Hormone comes and binds to the membrane Buds off via endocytosis Can have an effect on the nucleus

Question 30

Exocytosis

Answer 30

Materials packages in vesicles and are secreted from the cell Vesicle membrane fuses with the plasma membrane and releases vesicle contents into the surroundings Requires a lot of energy

Question 31

Vesicles

Answer 31

A part of the plasma membrane that has been pinched off inside the cell

Question 32

Phagocytosis

Answer 32

Enzymes in the cell - phagocytes Lysosomes fuse to the vesicle and break down the contents Release waste via exocytosis

Question 33

Adenylyl cyclase (AC)

Answer 33

An effector molecule that converts ATP to cAMP | Activated by alpha subunit on G protein

Question 34

Cyclic AMP (cAMP)

Answer 34

Molecule that activated protein kinase A

Question 35

Protein Kinase A

Answer 35

Enzyme that phosphorylates a particular protein