Biological membranes

Question 1

This type of protein passes all the way through the membrane. They are often channels or receptors

Answer 1

Transmembrane proteins

Question 2

This type of protein is found only on the outside or inside of the membrane

Answer 2

Embedded

Question 3

This type of protein is bound to the outer (peripheral) membrane through electrostatic interactions. It is most often attached to lipid rafts or transmembrane proteins

Answer 3

Peripheral

Question 4

This type of junction allows for direct cell-to-cell communication. It’s formed from connexins, which create like pores that essentially act as channels between the two cells

Answer 4

Gap junctions (connexons)

Question 5

This type of junction prevent solutes from leaking into the intercellular space. They act as a physical link and form a single layer of tissue that adhere tight enough that things cannot leak out of the cells. Examples include the blood/brain barrier

Answer 5

Tight junctions

Question 6

These form when cells need to communicate with on another through proximity. Example include gap and tight

Answer 6

Cell-to-cell junctions

Question 7

Phospholipids are found in ___ concentration within the membrane while sphingolipids are found in ___ concentration

Answer 7

High

Low

Question 8

Phospholipids have an easier time moving ____ through the membrane than ____

Answer 8

Laterally

Vertically

Question 9

Found on the membrane, these act as attachment points for other molecules. They may have peripheral proteins attached to them as well

Answer 9

Lipid rafts

Question 10

This type of endocytosis involves fluids and dissolved particles

Answer 10

Pinocytosis

Question 11

This type of endocytosis involves large solids like bacteria

Answer 11

Phagocytosis

Question 12

A cell is ____ if water moves into the cell because the intracellular solute concentration is higher inside than outside

Answer 12

Hypotonic

(the cell swells to form an ‘O’ like hypOtonic)

Question 13

A cell is ____ if water moves out of the cell because the intracellular solute concentration is higher outside than inside

Answer 13

Hypertonic (Cell shrivels)

Question 14

A cell is ____ if [solute] is the same inside and out, so water moves back and forth freely

Answer 14

Isotonic

Question 15

This is the type of pressure that has to be applied from the solution side to prevent an influx of water. Occurs between a solution and pure water that are connected by a semipermeable membrane

Answer 15

Osmotic pressure

Question 16

This factor tells you the number of particles a compound dissolves into when it’s in solution

Answer 16

Van’t Hoff factor

Question 17

This type of diffusion involves particles moving across the membrane without the help of channels or carriers. These particles are normally small, and they also go down their concentration gradient

Answer 17

Simple diffusion

Question 18

This type of diffusion occurs when large or impermeable particles (like those that are very polar) are unable to cross the membrane by themselves. They must rely on channels or carriers, but don’t require energy to cross the membrane

Answer 18

Facilitated diffusion

Question 19

How do channels work to allow particles into and out of the cell?

Answer 19

They can be open or closed, but when they’re open, particles are simply allowed to pass through them and flow to the other side

Question 20

How do carriers work to allow particles into and out of the cell?

Answer 20

Carriers are only open from one side of the membrane at a time. When the particle binds, the carrier spins and releases the particle on the other side

Question 21

These type of channels allow the cell to maintain resting membrane potential

Answer 21

Leak channels, like Na+/K+ ATPase

Question 22

Na+/K+ ATPase maintains ___ [Na+] and ___ [K+] intracellularly

Answer 22

Low sodium

High potassium

Question 23

The _____ mitochondrial membrane is very permeable and has large pores while the ___ membrane has restricted permeability and cristae

Answer 23

Outer

Inner