Midterm 1

Question 1

which functional group is acidic

Answer 1

carboxyl

Question 2

which functional group(s) are/is basic

Answer 2

amine

Question 3

which functional group has a nitrogen

Answer 3

amine, amide

Question 4

which functional groups have a sulphur

Answer 4

thiol

sulfhydrl

Question 5

what functional groups have a carbonyl carbon

Answer 5

carboxyl, amide,

Question 6

what functional groups have both carbon and hydroxyl

Answer 6

carboxyl

Question 7

what functional group has a carbonyl carbon and and an amine

Answer 7

amide

Question 8

what functional group has an h-donor but isn’t acidic

Answer 8

hydroxyl, amine, amide

Question 9

what functional groups has an H-bond acceptor

Answer 9

carboxyl

hydroxyl

sulfhydryl

amide

Question 10

why is benzene flat but cyclohexane is kinked

Answer 10

benzene : each C has identical sp2 orbitals that lie at 120 degree angles. all atoms lie in same plane

cyclo: has sp3 orbitals so they have tetrahedral geometry so they don’t lie in same plane (tetrahedral geometry)

Question 11

why is a covalent bond stronger than an H-bond

Answer 11

since covalent bonds result from shared e- while h -bonds e- arent shared so they’re further apart

Question 12

what kind of geometry do sp3 C have

Answer 12

tetrahedral

109 degree

Question 13

what kind of geometry do sp2 C have

Answer 13

trigonal

120

Question 14

what causes a polar molecule

Answer 14

asymmetrical charge distribution due to unequal e- sharing

Question 15

what happens to polarity with the more similar the electronegativity

Answer 15

smaller

Question 16

what are amino acids joined by

Answer 16

peptide bonds (covalent bond)

Question 17

what is the opposite of a aromatic compound

Answer 17

aliphatic

Question 18

what is an isomer

Answer 18

non identical compounds with the same molecular formula

Question 19

what is a constitutional isomer

Answer 19

same formula
different arrangement

Question 20

what is a sterioisomer

Answer 20

same linkage
3d orientation differ

Question 21

what makes a molecule chiral

Answer 21

like -hands (non-superimposable)

NO plane of symmetry

4 DIFFERENT substituents

Question 22

what is an enatiomer

Answer 22

chiral molecules that are mirror images

Question 23

what is a dipole moment

Answer 23

vector sum of magnitude and direction of bond dipoles

Question 24

what are molecules in a cell primarily made of

Answer 24

C,H,O

Question 25

what is dna/rna primarily made of

Answer 25

H C O P

Question 26

what is proteins primarily made of

Answer 26

H C N O S

Question 27

what are lipids mainly made of

Answer 27

H C N O P S

Question 28

are are carbs mainly made of

Answer 28

H C O

Question 29

what does intermolecular mean

Answer 29

between molecules

Question 30

What does intramolecular mean

Answer 30

within a molecule

Question 31

what holds atoms together in a molecule

Answer 31

covalent bonds

Question 32

what are the specialized covalent bonds

Answer 32

phosphodiester - hold phosphates together and nucleotides glycolosidic bond - joins ribose to base in ATP peptide bond- holds amino acids together in a protein disulphide bonds / bridges - covalent bonds between thiol groups

Question 33

what kind of reaction are the most of the ones that stabilize a protein fold

Answer 33

non - covalent

Question 34

what are the kinds of weak chemical reactions

Answer 34

H bonds electrostatic van der Waals hydrophobic interactions

Question 35

what is a van der Waals interactions

Answer 35

all intermolecular focus between electrically neutral molecules

Question 36

what is one of the causes of protein folding

Answer 36

hydrophobic effect

Question 37

why is water a good solvent

Answer 37

its polar

Question 38

what is the distance between h - bonds

Answer 38

2 A

Question 39

what is the difference between covalent bonds

Answer 39

1A

Question 40

what holds DNA in a helical shape

Answer 40

H-bonds

Question 41

what is a dielectric constant (D)

Answer 41

indicates reduction in attraction of 2 opposed charged ions in a solvent relative to in a vacuum (D=1)

Question 42

what is enthalpy

Answer 42

heat energy

Question 43

what is Gibbs free energy

Answer 43

amount of energy from reaction that is available to do useful work

Question 44

what is standard states

Answer 44

T= 25 C P= I atm concentration = 1M for reactants and products r = 8.314 JKm-1 mol-1 for ' ph=7 [Mg 2+] = 1 mM [h2o] = 55.5 M

Question 45

what does pH at midpoint = ``

Answer 45

ph = pKa

Question 46

what does keq =

Answer 46

[products] / [reactants]

Question 47

when is something exergonic

Answer 47

when S<1 (favoured)

Question 48

what is a reaction that another can be coupled with

Answer 48

ATP -> ADP (atp hydrolysis)

Question 49

when do weak acids have highest buffering capacity

Answer 49

when pH = pKa

Question 50

what kind of ka and pka will strong acids have

Answer 50

large ka and small pka

Question 51

At midpoint which is larger concentration of products or reactants

Answer 51

equal

Question 52

what is buffering range

Answer 52

1 above/below pka

Question 53

what are the two enzyme recognition theories

Answer 53

lock and key : substrate is perfect fit for active site induced fit: both substrate and active site change shape to fit conformations close to their transition state

Question 54

what do enzymes do to energy

Answer 54

convert it from one form to another ex: atp hydolysis

Question 55

what direction do enzymes increase reaction rate

Answer 55

both directions