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Physiology
RUSM Semester 1
28
Physiology
Graduate
05/12/2012

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Cards

Term
What type of molecules can cross a bilayer freely?
Definition
non-polar, lipid soluable (water, hormones, O2)
Term
Name 3 types of passive movement across membranes.
Definition
1. simple diffusion
2. pores & channels
3. facilitated diffusion
Term
Name 3 types of active movement across membranes.
Definition
1. Primary active transport
2. Secondary active transport
3. Vesicular transport
Term
What type of transport goes against a concentration gradient?
Definition
Active Transport (primary, secondary)
Term
Why are pores & channels needed if the molecules passing through them are doing so passively with the concentration gradient?
Definition
Because polar molecules cannot cross the lipid bilayer.
Term
What type of membrane transport is always open?
Definition
Pores
Term
What is required for a molecule to pass through a channel?
Definition
Conform with the shape for the channel and a signal for the gate to open received.
Term
What are 3 ways a gate is regulated?
Definition
1. voltage
2. ligand
3. mechanical/stretch
Term
Write out Fick's law of diffusion.
Definition

Jx = PxA (C1-C2)

Jx = Rate of diffusion

Px = Permeability coefficient (cm/sec)

A = Surface area (cm2)

C = concentration (mmol/L OR mg/ml)

 

NOTE: 1 ml = 1 cm3

Term

What happens to rate of diffusion if;

 

1. ↑A 

2. ↑C1 

3. ↑C2 

4. ↑w 

Definition

1. = ↑Jx

2. = ↑Jx

3.=↓Jx

4. = ↓Jx

(w = membrane thickness, lowers Px)

Term
Name 3 types of carrier-mediate transport.
Definition

Facilitated diffusion,

primary active transport,

secondary active transport

Term
Do simple diffusion, pores, & channels have a Vmax?
Definition
NO
Term

Which of the following types of membrane transport directly use ATP?

 

diffusion

pores

channels

facilitated diffusion

primary active transporter

secondary active transporter

Definition
primary active transporter
Term
Give an example of a active primary transport.
Definition
Sodium-Potassium pump
Term
Give an examply of a secondary active transport that is a symporter.
Definition
Sodium-Glucose transporter in kidney.
Term
Give an example of a secondary active trasnport that is an anti-porter.
Definition
Sodium-Calcium exchanger
Term

Which of the following types of membrane transport does not require a direct or indirect energy source to move molecules across a membrane?

 

1.Primary active transport
2.Operation of the Na/K pump
3.Potassium leak channels
4.Secondary active transport
5.Cotransport of glucose and Na+ across the membrane
Definition
3. Potassium leak channels
Term

The rate of diffusion of a particle across a membrane will increase with which of the following changes?

 

1.The area of the membrane decreases
2.The thickness of the membrane increases
3.The size of the particle increases
4.The concentration gradient of the particle increases
5.The permeability coefficient of the particle decreases
Definition
4.The concentration gradient of the particle increases
Term

[image]

Identify #1-5

Definition
  1. Diffusion
  2. Carrier-mediated Transport
  3. Vesicular Transport
  4. Passive movement
  5. Active movement
Term

The movement of glucose through a Na+/glucose cotransporter is an example of what type of membrane transport?

                A.  Primary active transport

                B.  Secondary active transport

                C.  Simple diffusion

                D.  Facilitated diffusion

                E.  Vesicular transport

Definition
B.  Secondary active transport
Term

Which properties are characteristic of ion channels?

                A.  They are made of lipids

                B.  They exist on one side of the plasma   membrane, usually the intracellular side

                C.  They can open and close depending on the presence of any of three types of ‘gates’

                D.  They permit movement of ions against their concentration gradients

                E.  They mediate primary active transport

Definition
C.  They can open and close depending on the presence of any of three types of ‘gates’
Term

The permeability of a solute in a lipid bilayer will be increased by an increase in which of the following?

                A.  Molecular radies of the solute

                B.  Particle coefficient of the solute

                C.  Thickness of the bilayer

                D.  Ionic charge of the molecule

Definition
  B.  Particle coefficient of the solute
Term

In considering diffusion of ions through an ion channel, which driving force(s) must be considered?

                A.  Only the ion concentration gradient

                B.  Only the electrical gradient

                C.  Osmosis alone

                D.  The ion concentration AND electrical gradients

                E.  Osmosis AND the ion concentration gradient

                F.  Osmosis AND the electrical gradient

Definition
D.  The ion concentration AND electrical gradients
Term

Which statement is incorrect?

                A.  Diffusion of a solute through a membrane is considerably quicker than diffusion of the same solute through a water layer of equal       thickness.

                B.  A single ion, such as K+, can diffuse through more than one type of channel.

                C.  Lipid-soluble solutes diffuse more readily through the phospholipid bilayer of a plasma membrane than do water-soluble ones.

                D.  The rate of facilitated diffusion of a solute is limited by the number of transporters in the membrane at any given time.

Definition
A.  Diffusion of a solute through a membrane is considerably quicker than diffusion of the same solute through a water layer of equal thickness.
Term

.  The rate of diffusion of a particle across a membrane will increase if which of the following occurs?

                A.  The area of the membrane decreases

                B.  The thickness of the membrane increases

                C.  The size of the particle increases

                D.  The concentration gradient of the particle decreases

                E.  The lipid solubility of the particle increases

Definition
E.  The lipid solubility of the particle increases
Term

.  In which of the following transport processes is the substance moving down its electrochemical gradient?

                A.  Sodium out of a nerve cell by the Na/K ATPase

                B.  Calcium into the sarcoplasmic reticulum by the Ca2+ ATPase

                C.  Hydrogen into the lumen of the distal nephron by the H+ ATPase pump

                D.  Glucose into adipose tissue through a facilitated diffusion glucose transporter

                E.  Potassium into striated muscle cells by the Na/K ATPase

Definition
D.  Glucose into adipose tissue through a facilitated diffusion glucose transporter
Term

Which of the following characteristics is shared by simple and facilitated diffusion of glucose?

                A.  Occurs down an electrochemical gradient

                B.  Is saturable

                C.  Requires metabolic energy

                D.  Is inhibited by the presence of galactose

                E.  Requires a Na+ gradient

Definition
 A.  Occurs down an electrochemical gradient
Term

Which of the following transport processes is involved if transport from the intestinal lumen into a small intestinal cell is inhibited by abolishing the usual Na+ gradient across the cell membrane?

                A.  Simple diffusion

                B.  Facilitated diffusion

                C.  Primary active transport

                D.  Secondary active cotransport  

Definition
 D.  Secondary active cotransport  
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