Chapter 12: Health And Medicine Notes

Question 1

How is a system at equilibrium? What occurs are equilibrium?

Answer 1

If [AB], [A], [B] are constant over time, system is at equilibrium
-At eq, rate of forward reaction = rate of reverse reaction
-At eq, [AB] is rarely = to [A] = [B]

Question 2

What is the formula for reversible & no reversible reactions for Keq?

Answer 2

For A + B <-> AB
- Keq = [AB] / [A] x [B]
[ ] = M = moles/L

Question 3

What do essentially non-reversible reactions possibly look like?

Answer 3

H+ (10 ^-7 M) + OH- (10 ^ -7 M) = H2O (55 M)
-Reverse reaction does work, but it is more limited

Question 4

What do reversible reactions look like?

Answer 4

AB —> A +B
-some reactions are reversible, especially those that involved non-covalent interactions in biological systems (water to hydrogen & oxygen)

Question 5

How can you tell if an acid is a strong acid?

Answer 5

Strong acids dissociate completely: AH —> A- + H+
- once dissociated, it will not go back to acid from proton and conjugate base
- Examples: HF —> H+ + F-, HCl —> H+ - Cl-

Question 6

How can you tell if an acid is weak?

Answer 6

Some acids do not dissociate completely. Instead they only dissociate partially, such that there are constant amounts of protons, conjugate acid, and undissociated acid: AH <-> A- + H+
- If you see Ka, its a weak acid (strong acids dissociate completely, Ka would be infinity)

Question 7

What is the equation for weak acids of Ka/Keq?

Answer 7

[A-][H+] / [AH]
-weak acids are most acids within our body

Question 8

How do you determine the pH of a strong acid that dissociates completely? Ex: 5mM

Answer 8

The pH can be determined through -log [H+]
To determine the pH of 5.5 mM: -log (5 x 10^-3) = 2.3

Question 9

How can you determine the pH of weak acids that only partially dissociate?

Answer 9

Overtime, there are constant amounts of protons and undissociated acids
- simplification: [H+] &laquo_space;[AH]
-Use I.C.E.: Initial, Change, Equilibrium

Question 10

How do we determine the pKa of weak acids?

Answer 10

AH <-> A- + H+
-At 1/2 equivalence form: [AH] = [A-] –> pH = pKa= -log (Ka)

Question 11

What is [A-] known as?

Answer 11

Known as an effective bugger, meaning it will not change a lot if a base or acid is added
-pH change is minimal

Question 12

What occurs at 1/2 equivalence point? Equivalence point?

Answer 12

1/2: Undissociated acids and conjugate bases are equal
-Equivalence: acid is completely neutralized

Question 13

What is [RH], [H], and [R]?

Answer 13

-RH: complex/bound receptor
-H: free hormone
R- free receptor

Question 14

How do you calculate the concentration of free (unbound receptor [R]?

Answer 14

[R] = [RH] / Keq x [H]?

Question 15

How do you calculate the total concentration of the receptor?

Answer 15

[R] (total) = [R] (free) +[RH]

Question 16

How do you calculate the free bound receptors?

Answer 16

2[H]/ [R] total

Question 17

What is the fraction of a hormone that is bound to a receptor?

Answer 17

[RH] / [RH] + [H] total

Question 18

What happens when binding occurs?

Answer 18

Affinity increases by 10- fold (10x)
-Receptors & hormones stay the same, but Keq increases

Question 19

How do receptor blockers work? What is one of the most important measurements of a drug binding to a target?

Answer 19

-Molecules that are designed to bind a specific receptor should resemble the hormone that naturally binds that receptor
-Affinity

Question 20

What are pharmacophores?

Answer 20

The set of characteristics that determines the binding of drug to receptor
-portions of a molecule that interact with the cellular target

Question 21

What is competitive inhibition? What is an example?

Answer 21

When a substrate molecule is prevented from binding to the active site of an enzyme by a molecule that is very similar in structure to the substrate
-Naloxone is a competitive inhibitor of oxycodone & morphine

Question 22

What is important to know about Naloxone & & fentanyl?

Answer 22

-Naloxone competes for binding to their opioid receptors
-Fentanyl is potent opioid, but it does not bind with the same affinity to the same morphine-binding receptors

Question 23

How do morphine & Narcan work against each other in competitive inhibition?

Answer 23

Morphine comes in and out of receptors
-once morphine comes out before coming back in, narcan binds with the receptor

Question 24

What is an antagonist?

Answer 24

A chemical substance that binds to and blocks the activation of certain receptors on cells, preventing a biological response.

Question 25

What is an agonist?

Answer 25

A chemical substance that binds to and activates certain receptors on cells, causing a biological response.

Question 26

What are some common functional groups?

Answer 26

Ester, aldehyide, amine, carboxylic acid, alcohol

Question 27

What is important to know about identifying chiral carbons in molecules?

Answer 27

-Can’t have 2 identical groups
-has to have 4 bonds

Question 28

What are enzymes?

Answer 28

Proteins and/or nucleic acids that act as biochemical catalysts, influencing (mostly accelerating) the rates of chemical reactions

Question 29

How does aspirin work?

Answer 29

It works by inhibiting the cyclooxygenase enzymes COX1 & COX2.
-The enzymes participate in the prostaglandin synthesis pathway, which are responsible for fever, swelling, etc.

Question 30

What are functional groups in organic chemistry?

Answer 30

Groups of atoms that are connected to carbon-containing molecules
-each functional group have a set of characteristic properties

Question 31

What important to know about chiral isomers?

Answer 31

They have the same chemical formula, but they differ in the arrangement of atoms around at least one atom (a chiral center)

Question 32

What do biological systems do to chiral molecules?

Answer 32

They often discriminate chiral molecules, preferring one enantiomer over another

Question 33

What is the most abundant and much maligned steroid?

Answer 33

Cholesterol
-made of 4 non-planar rings and C3 hydroxyl group

Question 34

What do glucocorticoids affect?

Answer 34

Many biological functions: inflammatory responses, mental stress management & metabolism of carbohydrates, proteins, & lipid metabolism (cortisol)

Question 35

What do aldosterone’s & mineralcorticoids do?

Answer 35

Regulate salt balance including excretion of salts by the kidneys.

Question 36

What do androgens and estrogens do and what are some examples?

Answer 36

Regulates sexual development and function
-testosterone, B (beta)-estradiol (estrogen), & progesterone

Question 37

What is vitamin D and what does it do?

Answer 37

A cholesterol derivative
-it regulate calcium absorption from food
-formed by exposure to sun light (triggers a non-enzymatic conversion of cholesterol derivative into vitamin D precursors)

Question 38

What occurs in the absence of vitamin D?

Answer 38

Calcium cannot be absorbed efficiently from the diet
-Rickets: bone malformation and/or softness & tooth brittleness

Question 39

What occurs with an excessive amount of vitamin D?

Answer 39

Causes high serum calcium levels: leads to kidney stones and or failure & calcification of soft tissue

Question 40

What are anabolic steroids? What are some side effects?

Answer 40

Synthetic steroidal hormones used to stimulate muscle and bone growth
-Side effects: mood swings, increased risks for strokes, heart attacks, liver-related issues, etc.

Question 41

What is important to know about herbal supplements & the FDA?

Answer 41

Herbal & dietary supplements are loosely regulated by the FDA.
-current policy is that herbal supplements are sage unless the government shows otherwise

Question 42

How do you calculate the concentration of total hormones?

Answer 42

[RH] + [H]

Question 43

WHAT DO YOU CALCULATE TE CONCENTRATION OF BOUND RECEPTOR?

Answer 43

Bound R / total R
-[RH]/ [R] + [RH]