Chemistry; Biochemistry

Question 1

The formation of a hydrogen bond requires what?

Answer 1

Both a hydrogen bond donor (a molecule with a hydrogen bonded to a highly electronegative atom such as oxygen or nitrogen) and a hydrogen bond acceptor (an electronegative atom with an available lone pair of electrons).

Question 2

Formula for pH of a solution

Answer 2

-log [H+]

Ex: 0.01 M = 10 to the negative 2 = pH is 2

Question 3

A carbonyl group (C=0) compared to an alkane or alkene in structure and boiling point

Answer 3

More polar & higher boiling point

Question 4

An ebulliator or a boiling chip introduces small air bubbles into a system. What does this prevent?

Answer 4

The air bubbles break the surface tension of the liquid being heated & prevent superheating & bumping

Question 5

When isolating liquids via vacuum fractional distillation where does the separation occur?

Answer 5

In the fractionating column as the two liquids vaporize & condense, with the lower-building liquid distilling first. If the fractionating column is shortened, the liquids will vaporize & condense fewer times (i.e. There will be fewer theoretical plates) & the degree of separation will worsen. Heating the distillation flask (i.e. Increasing the temp) at a slower rate will allow both liquids more time in the fractionating column (increase the number of theoretical plates, allowing liquid & vapor to equilibrate) & likely improve the degree of separation of the two compounds

Question 6

Chiral carbon

Answer 6

Has 4 different substituents

Question 7

The boiling point of a liquid is the temperature at which the vapor pressure of the liquid equals . . .

Answer 7

Surface pressure. The normal boiling point is measured at 1 ATM pressure. The vapor pressure of a liquid increases with increasing temperature. Hence, the boiling point of a liquid decreases as the pressure on the surface of the liquid is decreased

Question 8

Carbonate reacts with water to produce

Answer 8

OH-

Question 9

HCl reacts with CO3 2- to form

Answer 9

CO2 (g)

Question 10

Electrons in the lower energy d orbitals absorb what in order to move to the high energy d orbitals

Answer 10

Visible light

Question 11

Inductive effect

Answer 11

Transmission of charge through a chain of atoms in a molecule, resulting in a permanent dipole in a bond

Question 12

Which is more soluble in water, polar or non-polar

Answer 12

Polar

Question 13

Polarity arises from

Answer 13

The pull of electrons by an electronegative atom

Question 14

Red litmus paper will turn what color in a base

Answer 14

Blue

Question 15

How are multipotent stem cells different in their capabilities than pluripotent stem cells?

Answer 15

Multipotent stem cells can become several different types of cells from a single primary germ layer, while pluripotent stem cells can become any of the three primary germ layers.

Question 16

MHC I

Answer 16

Found on all uncleared cells, including antigen presenting cells. Presents peptide fragments to cytotoxic T cells via the CD8 receptor

Question 17

Behavioralism

Answer 17

Assumes all mental wants are determined by external physical events

Question 18

Photon energy must be larger than what in order to break a bond

Answer 18

Bond energy. Photon energy is directly proportional to radiation frequency

Question 19

Focal length

Answer 19

Insert picture from inside advanced website editor

Question 20

A tertiary alcohol is likely to undergo which type of substitution

Answer 20

SN1 b/c tertiary produces the most stable carbocations and consequently will most easily lose a water molecule upon protonation of the hydroxyl group in acidic media

Question 21

Transferase

Answer 21

Class of kinase that catalyze the transfer phosphate groups from ATP to target proteins. The ATP-dependent phosphorylation of a protein target is catalyze by transferases

Question 22

Conjugation

Answer 22

Extensive delocalization of electrons

Question 23

Km

Answer 23

The concentration of substrate at which the kinetics experiment reaches half the maximum velocity

Question 24

Kcat/Km

Answer 24

A measure of catalytic efficiency

Question 25

Albumin

Answer 25

A protein that mobilizes proteins & lipids in serum. Added to an experiment to maintain homogeneity & prevent the enzyme from adhering to walls & other substances

Question 26

Amino acid good for replacing b/c has minimal impact on the overall structure of an enzyme

Answer 26

Alanine - possesses a small hydrophobic side chain (methyl group) but participates in alpha helical & beta sheets extensively. Using to to replace reduces the interaction of the side chain with other active site components

Question 27

The bond that links monosaccharides together in an oligosaccharide

Answer 27

Glycoside bond

Question 28

Secondary structure of a protein is maintained primarily by what type of bonds

Answer 28

Hydrogen

Question 29

Tertiary & quaternary bonds are both maintained by what?

Answer 29

Intermolecular forces & disulfide bridges

Question 30

Humans are unable to digest cellulose due to the large number of what?

Answer 30

Beta (1,4) glycosidic linkages. These can't be cleaved by human amylase & pass through the GI tract undigested

Question 31

Dehydration synthesis commonly create polymers from what?

Answer 31

Macromolecules

Question 32

Products of the pentose phosphate pathway

Answer 32

NADPH, glycolytic intermediates, & ribose-5-phosphate

Question 33

The conversion of glucose-6-phosphate is converted to ribulose-5-phosphate is what type of reaction (other than decarboxylation)?

Answer 33

Oxidation. When glucose-6-phosphate is converted to ribulose-5-phosphate, NADP+ is converted to NADPH. The conversion of NADP+ to NADPH is a reduction reaction. As NADP+ accepts electrons, glucose-6-phosphate is oxidized

Question 34

Purpose of the pentose phosphate pathway

Answer 34

Replenishes NADPH, which is used by the cell in bio synthetic pathways such as fatty acid synthesis -> more active in adipose tissue than in muscle tissue

Question 35

Proteolytic cleavage is what kind of reaction?

Answer 35

Hydrolysis

Question 36

When a catalyst is added to a chemical reaction, the energy of the activated complex will what?

Answer 36

Decrease & the rate of reaction will increase. The catalyst lowers the activation energy of a reaction (the energy of the activated complex), causing an increase in the reaction rate

Question 37

Number of moles =

Answer 37

mass (g)/ molecular weight

Question 38

K is equal to

Answer 38

Products/reactants

Question 39

If very high hydrogen pressures (reactants) must be employed to get appreciable concentration of products, then K is likely to be

Answer 39

Much less than 1

Question 40

Reactions that lead to the release of gas from a solid have what kind of delta S?

Answer 40

Positive. Positive valises of delta S lead to negative values of delta G at high temperatures. Delta H is a value defined at standard state and doesn't change at high or low temps

Question 41

Delta G =

Answer 41

Delta H - TdeltaS

Question 42

When a system is at equilibrium delta Grxn =

Answer 42

0. Since delta Grxn = delta Hrxn - T delta Srxn