Cell Physiology - Theoretical Questions Flashcards Preview

GBA Physiology > Cell Physiology - Theoretical Questions > Flashcards

Flashcards in Cell Physiology - Theoretical Questions Deck (163)
Loading flashcards...
1

1,1) What are the two factors determining the net movement of water across the body compartments?

Hydrostatic Pressure - from Heart pump force + gravity
Osmotic Pressure - from solute but mostly plasma proteins (Oncotic)

2

1,1) Ion concentration difference is kept by?
What kind of transport?

Na+/K+ ATPase (3 Na out and 2 K In)
Primary Active Transport

3

1,1) What is the name of the process which uses the Sodium concentration gradient to increase the cells amount of other nutrients?

Secondary active transport
With Co-transports like SGLT for Na+Glucose (or Amino Acids Co-transporters)

4

1,1) How is plasma concentration of ions different from general ECF ion concentration?
Why?

Plasma is slightly more positive, containing more - Cations.
Due to higher Protein content(-) attracts more positive ions, Gibs Donham Equilibrium

5

1,1) What are the examples of transcellular fluids?

Ocular, Synovial, CSF, Pleural, Peritoneal Fluids

6

1,1)Effect of Liver disease on body fluid distribution? (Among many others.. from Oral exam)

No Production of Albumin, Oncotic Pressure decreases, Less fluid gets reabsorbed back to capillaries, Edema in the Limbs.

7

1,1) What is the Reflection coefficient?
Possible values and their meaning?

Reflection Coefficient (Sigma) - describes how easily the ion can pass through the membrane (Ranges from 0 to 1)
1 - Impermeable (Albumin) = Not Diffusible.
0 - Permeable (Urea) = Diffusible

8

1,1) would we calculate the amount volume of a body compartment using a solute? The general formula and application. (from oral exam)

CV=CV (=Moles)
After the fluid was obtained (blood/urine/csf..) using lab specific technics concentration and volume measurements - indirect indication of body compartment volume.

9

1,1) What solute do we use to measure Blood plasma volume? Why?

Evans blue
It is bound to Plasma proteins therefore it will not penetrate the endothelial layer and go to the Interstitial fluid compartment or ICF.

10

1,1) What solute do we use to measure ECF volume? Why?

Inulin. It is a small carbohydrate molecule that can travel to Interstitial fluid and back (from plasma), Secreted in urine. No transporter to get to ICF.

11

1,1) How should we measure Interstitial fluid volume?

ECF - Blood plasma = Interstitial Fluid.

12

1,1) How should we measure ICF volume?

Total Body water - ECF = ICF.

13

1,1) What solute do we use to measure TBW volume? Why?

TBW - Total body water is measured by Deuterium, an Isotope of Hydrogen - "Heavy water" formes.
This is a substance that goes through all the body compartments.

14

1,2) Membrane Structure - General Features:

According to Fluid Mosaic Model : Primarily phospholipid Bilayer, also cholesterol, proteins and Glycoproteins.

15

1,2) Give examples for substances that the phospholipid membrane is permeable to:

Non-Polar/Hydrophobic Substances:
Oxygen, Carbon Dioxide, Fatty Acids, Steroids

16

1,2) Give examples for substances that the phospholipid membrane is Impermeable to:

Polar/Hydrophilic Substances:
Ions, Glucose, Amino Acids

17

1,2) Give examples for Amphipathic phospholipids:

Most abundant are Lecithin and Sphingomyelin

18

1,2) Give an example for membrane lipid that participates in signaling process ? what is the mechanism? What is the result?

Gq activated PLC cleaves Phosphatidylinositol Bisphosphate to form the Signaling molecule IP3.
DAG is also released. General Ca+ and PKC activation.

19

1,2) What is the job of cholesterol in the phospholipid membrane?

Responsible for Membrane fluidity and Adaptations to different temperatures.
Creates lipid rafts, Separates the phospholipids from one another in specific areas.

20

1,1) Gibbs-Donnan Ratio:

Plasma concentration relative to Interstitial fluid concentration.
Expressed for specific Ions

21

1,2) What are the Integral Proteins?
What are their jobs?

Integral Protein - Embedded into the Membrane.
Some are Transmembrane -Connecting ICM to ECM, Cross it several times,

22

1,2) What are the Integral Proteins?
What are their jobs?

Integral Protein - Embedded into the Membrane by Hydrophobic Interactions.
Some are Transmembrane -Connecting ICM to ECM, Cross it several times, Examples are Ion channels, Na/K ATPase, GPCRS.

23

1,2) What are the Peripheral Membrane Proteins?
What are their jobs?

Peripheral Membrane Proteins - Attached to ECM or ICM side by Electrostatic interactions with Integral Proteins. Ankyrin is an Example.

24

1,2) What are the Glycoproteins?
What are their jobs?

Glycoproteins - Carbohydrates chains attached to the surface and continuous with Integral membrane proteins. Examples are MHC units that function in Immunity and cell cell interactions.

25

1,2) Simple diffusion:

Passive; Concentration gradient dependent solute movement. Not mediated by a carrier. Doesn't require any metabolic energy.
According to Fick's 1st law: J=-DxAx C/X.

26

1,2) Facilitated Diffusion :

Passive; Concentration gradient dependent solute movement. Mediated by a carrier. Doesn't require any metabolic energy. Like GLUT4 or Aquaporins.

27

1,2) Primary Active Transport :

Active; Movement of solute against the Concentration gradient. Mediated by a carrier. Uses Direct metabolic energy in the form of ATP.Like ATPases - Na/K, H/K...

28

1,2) Cotransport:

Cotransport - Secondary Active transport; Uses the Na+ Concentration gradient as a indirect source of energy to move the solute INSIDE the cell. Like SGLT.

29

1,2) Countertransport:

Countertransport - Secondary Active transport; Uses the Na+ Concentration gradient as an indirect source of energy to move the solute OUTSIDE the cell. Like Na+/H+ exchanger.

30

1,2) Vesicular Transport: Give examples.

Endocytosis example - Clathrin coated Cholesterol uptake or Phagocytosis in Macrophages.
Exocytosis - Could be Constitutive or Regulated: For example Insulin secretion in beta cells is regulated by calcium signal.