Lecture 3

Question 1

What is the purpose of cholesterol

Answer 1

provide rigidity to cell membrane
precursor to sex hormones

Question 2

What are the 6 hormones derived from cholesterol

Answer 2

Testosterone
Androstenedione
Estradiol
Progesterone
Cortisol
Aldosterone

Question 3

What is the precursor to testosterone that was abused by baseball players in the past?

Answer 3

Androstenedione

Question 4

Why is aldosterone able to interact with cortisol receptors?

Answer 4

Both are made from cholesterol so their structure is very similar, so they can react with each other’s receptors

Question 5

What is the function of Phosphatidylinositol (PI)

Answer 5

used in smooth muscles to produce inositol triphosphate (IP3), regulates muscle contraction

Question 6

What is the function of Phosphatidylserine (cytosolic)

Answer 6

immune marker

In a healthy cell, serine portion is inside the cell.

if immune system sees serene on the outside it will destroy the cell

Question 7

What enzyme functions to flip serines to proper orientation

Answer 7

flippase

Question 8

What does flippase need to reorient serine?

Answer 8

ATP

if cell is dying and isn’t producing enough ATP the flippase will be unable to flip serines and thus the immune system will sweep in

Question 9

What do combinations of phosphatidyl compounds help produce?

Answer 9

surfactant

Question 10

What is sphingomyelin?

Answer 10

fatty compound use for
constructing myelin for the nervous system

Question 11

What is the function of phosphatidylcholine (PCh)?

Answer 11

body can store choline to later assemble acetylcholine

acetylcholine is super important in cell signaling and signal transduction

Question 12

What mediates destruction of dying cells by the immune system?

Answer 12

energy deficient flippase that is unable to flip serine

Question 13

What are the 4 phosphatidyl- compounds

Answer 13

Phosphatidylinositol (PI)
Phosphatidylserine (cytosolic)
Phosphatidylcholine (PCh)
Phosphatidylethanolamine (PE)

Question 14

What is Arachidonic Acid (AA) a parent compound of?

Answer 14

Prostaglandins
TXA2-thromboxane A2
Leukotrienes
EET &HETE

Question 15

What enzymes convert arachidonic acid to prostaglandins?

Answer 15

COX1 and COX2

Question 16

What enzymes convert arachidonic acid to leukotrienes?

Answer 16

lipoxygenase (LO)

Question 17

What does thromboxane A2 (TXA2) do?

Answer 17

released when blood vessel damaged that signals nearby blood vessels to constrict in effort to reduce bleeding

Question 17

What is a common drug that inhibits COX1 and COX2?

Answer 17

aspirin
NSAIDs

Question 18

What effects do prostaglandins have?

Answer 18

pain signal ramping,
causes inflammation

Question 19

What are differences between COX1 and COX2

Answer 19

COX 1 = wide spread, lots of tissues can produce, used more to create TXA2

COX 2= more inducible, the isoform that gets turned on in response to pain

Question 20

Does naproxen inhibit COX1 or COX2

Answer 20

COX2

Question 21

Are COX1 inhibitors or COX2 inhibitors more effective in treating pain?

Answer 21

COX2

Question 22

What is toxic side effect of COX2 inhibitors?

Answer 22

harmful to kidney and cardiac

inhibits 2ndary effect of COX2 keeps kidney healthy and helps heart heal after ischemia

Question 23

Why do COX inhibitors lead to increased bleeding?

Answer 23

COX is enzyme in prostaglandin pathway of arachidonic acid that also produces TXA2 that helps stop bleeding.
- COX1 (aspirin) = more bleeding

Question 24

LTA4, LTC4, LTD4, LTE4 are examples of what?

Answer 24

leukotrienes

Question 25

What is the function of leukotrienes?

Answer 25

Immune mediated inflammatory response - lung swelling, activates mucous glands

Question 26

What drug is an example of leukotriene synthesis inhibitor?

Answer 26

Singulair - leukotriene receptor antagonist (allergy med) Directly inhibits lipoxygenase → decrease leukotriene production

Question 27

What are the 3 pathways of arachidonic acid?

Answer 27

COX1/2 -> Prostaglandins and TXA2 Lipoxygenase -> leukotrienes HETE/EET -> acute inflammatory disease processes

Question 28

What are the two types of cell membrane proteins?

Answer 28

Enzymes and Receptors (Integral and peripheral)

Question 29

What are the two types of diffusion?

Answer 29

Simple and Facilitated

Question 30

What are similarities and difference between simple and facilitated diffusion?

Answer 30

similar - don't require ATP, movement is dictated by concentration gradient difference- facilitated goes through channel protein, requires a bond and conformational change; simple is crossing without a protein (ex. gases)

Question 31

What is an example of a facilitated diffusion?

Answer 31

GLUT transporter

Question 32

Besides concentration gradient, what gradient also affects diffusion?

Answer 32

electrochemical gradient cell is normally (-) charged when inactive, (+) when active

Question 33

What are are the two types of active transport?

Answer 33

1st and 2nd degree

Question 34

What is an example of 1st degree active transport?

Answer 34

ATPase pump (Na/K pump) CA2+ pumps H+ proton pumps in stomach

Question 35

What is an example of 2nd degree active transport?

Answer 35

sodium-calcium exchanger (NCX) pump- pumps Ca++ out of the cell, moves Na+ into cell SGLT - uses Na to move glucose in the cell

Question 36

What is the ratio of Na and K moved by the ATPase pump?

Answer 36

3 Na+ : 2 K+

Question 37

What is the difference between primary and 2nd degree active transport?

Answer 37

primary directly uses ATP to pump 2nd degree indirectly utilizes energy used by other pumps

Question 38

Which direction does the ATPase pump K?

Answer 38

from outside to inside of the cell (against concentration gradient)

Question 39

Which direction does the ATPase pump Na?

Answer 39

from inside to outside of the cell (against concentration gradient)

Question 40

What is the normal concentration of Na inside the cell (ICF)?

Answer 40

14 10x less inside the cell

Question 41

What is the normal concentration of Na outside of the cell (ECF)?

Answer 41

140 10x higher than inside the cell

Question 42

What is the normal concentration of K+ outside of the cell?

Answer 42

4 30x less than inside the cell

Question 43

What is the normal concentration of K+ inside of the cell?

Answer 43

120 30x higher inside the cell

Question 44

What is the ratio of Ca++ and Na+ moved by the NCX pump?

Answer 44

1 Ca++ : 3 Na+

Question 45

Which direction is Na+ moving with an NCX pump?

Answer 45

from outside to inside of cell (down its concentration gradient)

Question 46

What type of cells have ATPase pumps?

Answer 46

all excitable cells i.e. neuron & muscle

Question 46

Which direction is Ca++ moving with an NCX pump

Answer 46

from inside to outside the cell (against its concentration gradient)

Question 47

What is the importance of ATPase pumps?

Answer 47

central to all action potentials

Question 48

What is the single most energy requiring process in the body?

Answer 48

ATPase pumps (60-70% of cellular energy)

Question 49

What is the function of an SGLT pump?

Answer 49

glucose can couple with Na+ to move glucose into the cell faster when needed. Utilizes Na+ concentration gradient seen in kidney reabsorbing glucose after filtration

Question 50

Is the Glut transporter an example of facilitated diffusion or active transport?

Answer 50

facilitated diffusion does not require energy when glucose binds to transporter conformational change happens and it moves glucose inside and releases

Question 51

Where are Glut-1 transporters located?

Answer 51

RBCs - not insulin dependent

Question 52

Where are Glut-4 transporters located?

Answer 52

In insulin dependent cells (muscle/fat)

Question 53

What factors determine speed of facilitated diffusion?

Answer 53

[] gradient and # of transporters

Question 54

Arachidonic acid and HETE/EETE are ____________ while Leukotrienes and Prostaglandins are ___________

Answer 54

hydrophobic; hydrophilic

Question 55

What kind of diffusion are channel proteins used for?

Answer 55

Simple - no binding/energy

Question 56

How does water cross the cell membrane?

Answer 56

Simple diffusion and aquaporins

Question 57

What are ion channels? What kind of transport do they contribute to?

Answer 57

A transmembrane protein channel that allows a specific ion to diffuse across the membrane down its concentration or electrochemical gradient. Simple diffusion

Question 58

What are the 3 steps for facilitated diffusion?

Answer 58

1- binding to receptor 2- confirmation change to move across cell membrane 3- release from receptor (No energy required)

Question 59

How much of the cholesterol in the body is endogenous vs exogenous?

Answer 59

80% endo, 20% exo

Question 60

How do statins work to reduce cholesterol?

Answer 60

HMG-CoA reductase inhibitor; reduces the amount of endogenous cholesterol made

Question 61

What are the stress hormones made from cholesterol?

Answer 61

cortisol and aldosterone

Question 62

What are the sex hormones made from cholesterol?

Answer 62

Estradiol, progesterone, testosterone, androstenedione

Question 63

What does surfactant do?

Answer 63

Chemical produced in the lungs to maintain the surface tension of the alveoli and keep them from collapsing

Question 64

Cholesterol is...

Answer 64

Rigid, flat (planar), and lipid soluble

Question 65

What is the -OH group on cholesterol for?

Answer 65

Cholesterol inside of cell wall; cell sees -OH group and pulls it out of cell wall if needed -OH group is polar

Question 66

Acetyl-CoA

Answer 66

Byproduct of metabolism; chemical precursor used to make many products (including cholesterol, makes ATP from glucose and oxygen)

Question 67

Where do cortisol and aldosterone come from?

Answer 67

Adrenal glands

Question 68

Schmidt wouldn't be surprised if a future drug targets _________ instead of just leukotriene receptor antagonist

Answer 68

Lipoxygenases (LO)

Question 69

What are the 3 examples of primary active transport?

Answer 69

Na/K ATPase, calcium pumps, proton pumps

Question 70

What transport mechanism is responsible for the bulk of glucose transport to inside cell?

Answer 70

GLUT transporter

Question 71

What transport mechanism is responsible for the bulk of calcium transport ICF → ECF?

Answer 71

NCX transporter

Question 72

In what ways can glucose be transported into the cell?

Answer 72

Facilitated diffusion - GLUT Secondary active transport - SGLT