Lecture 1 8/23/23

Question 1

What are the five main physiologic categories of protein function?

Answer 1

-catalysis of reactions
-reaction coupling
-membrane transport
-cell structure/support
-molecular signaling

Question 2

What are the effects of proteins as catalyzers?

Answer 2

-speeds up reaction time
-does not change net products or energy change

Question 3

How do proteins function in reaction coupling?

Answer 3

facilitating the pairing of rxns so the energy from one can supply the other

Question 4

Which rxn within the body is a big example fo rxn coupling?

Answer 4

ATP hydrolysis (addition of water to produce ADP and Pi)

Question 5

How are proteins involved in signaling?

Answer 5

-membrane proteins that accept signals
-aid in signal transduction

Question 6

What is an allosteric protein?

Answer 6

a protein that changes shape when another molecule binds to it

Question 7

Why are allosteric proteins important?

Answer 7

the change that occurs when the molecule binds alters the activity and/or properties of the protein

Question 8

How does ligand binding affect allosteric proteins?

Answer 8

the binding of a ligand can open or close binding sites, providing/reducing signaling abilities

Question 9

How does phosphorylation play a role in allosteric changes?

Answer 9

phosphorylation can lead to changes in protein shape, allowing for the attachment/disattachment of various molecules to channel proteins

Question 10

How does voltage play a role in allosteric changes?

Answer 10

voltage can lead to the opening or closing of channels, preventing or encouraging the movement of molecules

Question 11

What molecules are able to pass through the pure lipid bi-layer?

Answer 11

-small polar molecules, like water and urea
-non-polar, fat-soluble molecules

Question 12

What molecules are not able to pass through the pure lipid bi-layer?

Answer 12

-ions
-large polar molecules

Question 13

How do chemical forces impact molecular movement?

Answer 13

molecules want to move from areas of high concentration to areas of low concentration

Question 14

How do electrical forces impact molecular movement?

Answer 14

molecules want to move from areas of similar charge to areas of opposite charge

Question 15

How do chemical and electrical forces both impact molecular movement?

Answer 15

the combined force of chemical and electrical forces will determine the way in which molecules move

Question 16

What is diffusion/passive transport?

Answer 16

spontaneous movement of particles from areas of high electrochemical concentration to areas of low concentration

Question 17

What is osmosis?

Answer 17

the movement of water from areas of high water conc. to low conc. (water follows solute)

Question 18

What is water pressure?

Answer 18

-water pressure required to bring system to equilibrium
-balance of pressure and concentration

Question 19

What is oncotic pressure?

Answer 19

osmotic pressure resulting from dissolved proteins

Question 20

How does protein impact water movement?

Answer 20

-proteins will pull water into blood vessels
-low albumin (protein) in the vessels means water will likely leave the vessels

Question 21

How does hydrostatic pressure impact a blood vessel?

Answer 21

-closest to the heart, higher hydrostatic pressure will push water out (filtration)
-furthest from the heart, lower hydrostatic pressure + greater protein conc. will draw water in (reabsorption)

Question 22

How can both the heart or albumin levels cause a fluid filled abdominal cavity?

Answer 22

-heart: inc. water pressure due to heart failure
-albumin: low levels lead to low oncotic pressure and water leaving vessels

Question 23

What is active transport?

Answer 23

the utilization of energy/work to move molecules against their electrochemical gradient

Question 24

What is the main example of active transport?

Answer 24

sodium-potassium pump

Question 25

What is secondary active transport?

Answer 25

-couples the movement of one molecule with its gradient to the movement of another molecule against its gradient
-molecule moving with its gradient can bring in other molecules

Question 26

What is facilitated diffusion?

Answer 26

-use of protein carriers to move ions and larger molecules from high to low conc.

Question 27

What are the potential methods of facilitated diffusion?

Answer 27

-ungated channels
-carriers
-ligand-gated channels
-voltage-gated channels

Question 28

What is the function of aquaporins?

Answer 28

to move water at a much faster rate than osmosis

Question 29

What is transcellular/epithelial transport?

Answer 29

movement of particles across a membrane through the engulfment of said particles by the membrane