Lecture 2/01.15.25

Question 1

Explain the chemical reactions that results in the hGh and muscle tissue growth?

Answer 1

The bonding of this is due to noncovalent bonding. What happens is that the hGh binds to the receptor and transmits the signal. The binding is weak but is responsible for the structure

Question 2

What maintains the linear of nucleotides in DNA?

Answer 2

covalent bonds

Question 3

What maintains the double helix in DNA?

Answer 3

non covalent bonds

Question 4

Are macromolecules maintained by covalent or non covalent bonds?

Answer 4

both

Question 5

What is the strength of noncovalent bonds?

Answer 5

Noncovalent bonds are weak (10-100x weaker) and allows for them to be broken down and reformed again(non-permanent interaction). Many of the 3D structures are maintained by noncovalent bonds and allow for flexibility

Question 6

What are the types of noncovalent bonds based on strength?

Answer 6

1. charge-charge
2. charge-dipole
   3.dipole-dipole
   4.charge-induced dipole
   5.dipole-induced dipole
3. dispersion(van der waals)
4. hydrogen bond

Question 7

What is true about noncovalent bonds?

Answer 7

They are all electrostatic in nature which means that they all depend on the forces that electrical charges exert on one another

Question 8

What is charge-charge interactions?

Answer 8

Often reffered to as ionic bonding or salt bridges(also crystals). It is the simplest bonding.

Question 9

What is an example of charge-charge interactions?

Answer 9

Sodium and chloride bonding

Question 10

What is true about a large dielectric constant?

Answer 10

It allows for ionic bonds to come apart and is weaker

Question 11

What does it mean for a molecule to be polar?

Answer 11

An asymetrical distribution of charge where it sometimes can lead to a dipole moment that is expressed as a micro

Question 12

What molecules have a high micro or dipole moment?

Answer 12

Water because electrons are drawn from the hydrogen atoms toward the oxygen atom

Question 13

What does it for a molecule to become polarizable?

Answer 13

It means for a molecule to have an induced dipole

Question 14

What is an induced dipole interaction?

Answer 14

Interactions of polarizable molecules

Question 15

What is true about molecules with no net charge?

Answer 15

If they are close enough, they can attract each other

Question 16

What is a Van der Waals interaction?

Answer 16

A weak attraction that when two molecules approach each other very closely that starts to have its charge fluctuate.

Question 17

What is hydrogen bonding?

Answer 17

The interaction between a hydrogen atom covalently bonded to another atom and a pair of non bonded electrons on a separate atom(typ. O or N, F)

Question 18

Question 19

What is the hydrogen bond donor?

Answer 19

The atom to which the hydrogen is covalently bonded

Question 20

What is the hydrogen-bond acceptor?

Answer 20

The atom with the non-bonded electron pair

Question 21

What is true about hydrogen bonding?

Answer 21

They have both covalent and noncovalent features because electrons are shared between donors and acceptors

Question 22

What are some properties of water?

Answer 22

It acts like glue because of the hydrogen bonds and is a polar solvent that dissolves ionic compounds quickly.

Question 23

What happens when ionic compounds are dissolved in water?

Answer 23

They form hydration shells where the negative ends of the water dipoles with cations and the positive ends go with anions. This is energetically favorable

Question 24

Why do ionic compounds dissolve in water?

Answer 24

It is due to their dielectric constant that is high that decreases the force between oppositely charged ions that would pull them together

Question 25

What happens when a hydrophobic molecule bonds with water?

Answer 25

Since it is hydrophobic, instead, it will form a cage rather than a shell. This is energetically unfavorable. However, this plays a role in protein folding.

Question 26

What does it mean for a molecule to be amphipathic?

Answer 26

Molecules that are bot hydrophobic and hydrophilic. Where the polar head interacts with the water and the non polar tail hides

Question 27

What happens when you shake or try to dissolve amphipathic molecules?

Answer 27

They can form micelles, spherical structures, or bilayer vesicles

Question 28

What are acids?

Answer 28

Acids are H+, proton donors

Question 29

What are bases?

Answer 29

bases are H+, proton, acceptors

Question 30

What is the equilibrium acid dissociation constant?

Answer 30

It is the Ka which predicts how fast something will dissociate. Where a large Ka means it dissociates quickly

Question 31

What is the physiological pH range?

Answer 31

It is the range that our body normally has which is from 6.5 to 8.0 where a living cell is somewhere from 7.2 to 7.4

Question 32

What does a high pH mean?

Answer 32

lower concentration of H+

Question 33

What does a large Ka mean with a pKa?

Answer 33

Large Ka means small pKa and likely an acid

Question 34

What does the pKa mean?

Answer 34

The pH at which the solution is 50% dissociated

Question 35

What does the Henderson-Hasselbach equation predict?

Answer 35

As the pH increases, more –OH present, an acid will become more dissociated. And, As pH decreases, more H+ present, acids and bases become protonated

Question 36

What is true about charge-charge interactions vs. van der waals interactions?

Answer 36

Charge-charge is much stronger over large distances in comparison to van der waals

Question 37

What is a dipole interaction?

Answer 37

A carrying of no net charge but have asymmetrical distribution of charge, called polar and have a dipole moment that expresses the magnitude of the polarity.

Question 38

What does a strong acid mean?

Answer 38

It loses their hydrogen protons and dissociate more quickly

Question 39

What is the dissociate constant?

Answer 39

pKa

Question 40

What is the formula for force interaction?

Answer 40

F= kq1q2/r2

Question 41

How many molecules can each water molecule make?

Answer 41

4

Question 42

What is the equilibrium dissociation constant?

Answer 42

Ka=H+A-/HA

Question 43

What is the formula for pKa?

Answer 43

-logKa