Cell Biology Exam Two - Passive Transport

Is simple diffusion up or down gradient?

DOWN

Is facilitated diffusion up or down gradient?

DOWN

Is active transport up or down gradient?

UP

Does simple diffusion require energy?

NO

Does facilitated require energy?

NO

Does active transport require energy?

YES

Does simple diffusion require a protein?

NO

Does facilitated diffusion require a protein?

YES

Does active transport require a protein?

YES

What are some things that are transported via simple diffusion?

CO2

O2

H2O

Ethanol

Glycerol

What are some things transported via facilitated diffusion?

Na+

K+

H+

Ca2+

Cl-

What are some things transported via active transport?

ions ended to move against gradient; nutrients

Name a protein that does simple diffusion?

NONE

Name a protein hat does facilitated diffusion?

Channel Proteins

Transporters

Name a protein that does active transport?

Pumps

Transporters

Characteristics of the substance being transported?

polar / nonpolar

size

The Gradient:

chemical gradient

electrical gradient

Down Concentration Gradient

Passive Transport

Passive transport:

simple diffusion

channel-mediated

transporter-mediated

Up concentration Gradient

Active Transport

What type of diffusion is this?

Simple Diffusion

What type of diffusion is this?

Channel-Mediated

What type of direction is simple diffusion?

Bi-directional

What does bidirectional mean?

Substance can go in or around by the same method

What is the speed of simple diffusion?

The greater the gradient, the faster the transport.

What type of direction is facilitated diffusion?

Bi-Directional, but still down gradient

What type of speed is facilitated diffusion?

speed increases when gradient does, but there is an upper limit

What are the two ways that molecules move via facilitated diffusion?

Channel Proteins

Transporters

Ion channels are

selective and gated

Specific channel proteins allow passage of

Na+

K+

H+

Ca2+

Cl-

Most ion channels have _____ that only open in response to specific stimuli

gates

What are the types of gates in ion channels?

Ligand Gated

Voltage Gated (found in neurons)

Mechanically Gated (found in muscles)

Sodium Channel:

Selective,

Na+ is smaller than K+

Potassium Channel:

part of the channel is linked with carbonyl oxygen atoms

displace water to which potassium is bound, and potassium passes through

sodium is too small to interact and remains bound to water

What type of ion channel is this?

Na+ Channel

What type of ion channel is this?

K+ Channel

Glucose transporters move _____ down gradient

glucose

______ is found on your RBCs

GLUT-1

Is there more glucose in the plasma or the RBC and why?

plasma

phosphorylation inside the cell

Some glucose transporters are ______ sensitive

insulin

________ is in adipose tissue, hart, and skeletal muscle, and is insulin sensitive

GLUT-4

______ is on RBCs and is not insulin sensitive

GLUT-1

Glucose transporters GLUT-4 and GLUT-1 are _______ in a lab but not in a cell

bi-directional

________ is found in the liver and at the base of intestinal cells and is bi-directional

GLUT-2

Insulin:

stimulates glucose intake on insulin sensitive cells

causes the utilization of vesicles containing performed glucose trasportesr

raises the blood sugar

Uniport

Symport

Antiport

RBC Anion Exchange Protein

Chloride-bicarbonate exchanger

Chloride-bicarbonate exchanger is an _______

antiporter

For the RBC Anion Exchange Protein if bicarb comes in _____ comes out

chloride

what does bicarb do

buffers the blood (negative charge)

The Chloride-bicarbonate exchanger can ______ direction of transport

switch

Transporter Protein Kinetics:

specificity

can be specific or not

can be stereospecific

follows Michaelis-Menten

Competitive Inhibition

Competitive Inhibition

can transport more than 1 substrate

osmosis =

movement of water

Water will move ______ gradient, solute will move ____ gradient

down

up

Solute can’t move, but _____ can

water

In osmosis water moves by

simple diffusion

or

facilitated diffusion

________ allows water molecules to cross the membrane rapidly

aquaporins

Aquaporins are _____ to ions; only water moves

impermeable

Where are aquaporins found?

kidneys

lungs

how are aquaporins arranged

in clusters

______ like hypertonic

no cells

Animal cells prefer _______

isotonic

Plant / Fungi cells prefer _______

hypotonic

Contractile vacuoles can act as

siphons

What helps cells not to explode from too much water

cell walls

when ions leave, _____ follows

water

True or False. The major difference between simple and facilitated diffusion is that facilitated diffusion requires energy.

False

True or False. Different glucose transporters are needed in different parts of the body.

True

True or False. Facilitated diffusion using a transport protein requires binding of the molecule being transported.

True

True or False. Facilitated diffusion using a transport protein is specific for the molecule being transported.

True

True or False. Facilitated diffusion using a transport protein. The energy for transport is generated by the gradient of the substance being transported.

True

True or False. Facilitated diffusion using a transport protein. The energy for transport is generated by the molecular bonds of the substance being transported.

False

True or False. Facilitated diffusion using a transport protein. Transport of the substance is the result of a conformational change.

True