Chem/Phys Flashcards
Does a peptide bond have an amine or an amide group ?
amide
- Does Sn1 or Sn2 create a carbocation?
- Does Sn1 or Sn2 attack tertiary?
- Does Sn1 or Sn2 create a receamic mixture?
- Sn1 always creates a carbocation. Sn2 creates a five bond intermediate.
- Sn1 attacks tertiary because it is able to stabilize the carbocation with its 3 carbons. Sn2 attacks primary and secondary which less steric hinderance and allows the nucleophile to attack from around.
- Sn1 creates a racemic mixture. Sn2 creates, optrically acitve (achiral) and inverted.
In gas-liquid chromatography, what is the mobile and stationary phase? What else can separate the components?
stationary= metal or polar liquid
mobile= inert gas
Size can also separate them if they don’t differ in polarities. The lightest will elute first.
what is a Deuterium?
A heavy proton
Someone has eye to lens distance is 2 cm, and can only see objects closer to 1 m. What is the strength of the person’s lens?
use strength equation: 1/0 + 1/I = S
1/1 m + 1/ (2/100)m = 51 D
what is the index of refraction of the vitreous humor with speed of light of 2.1 x 10^8 m/s?
index of refraction= speed of light/speed in material of interest
3 x 10^8 / 2.1 x 10^8 = 1.4
What is intensity of electromagnetic radiation?
The number of photons (energy) emitted per unit time.
What is the energy of the photon emitted by LED at a frequency of 610 THz?
E= hf = hc/ λ
E= (6.6 x 10^-34 J.s)(610 THz)
E= (6.6 x 10^-34)(610 x 10^12)
E= about 4 x 10^-19
shortcut= just multiply 6.6 x 6 and choose the answer closer
what fraction of a sample decays in 10 min (1/2 life= 2min)
31/32 because question is asking for DECAY.
1/32 of the sample is LEFT.
What is the work generated by an adult that circulates 9 L of blood in 10 min?
what is the assumption of an ideal gas?
individual molecular volume and intermolecular forces are negligable.
What is the function of rods?
To detect detail in dim light . Responsible for night vision.
- Would the recognition site of this molecule be hydrophilic or hydrophobic?
- What is the hybridization of carbon 6 off the ring?
- Hydrophobic bc the molecule is mostly composed of hydrogens and carbons making it largely nonpolar.
- sp2. double bond coutns as one.
Rodopsin is phosphorylated by rhodopsin kinase and then binds to arrestin. What is the source of phoshate?
A. rhodopsin kinase
B. ATP
C. arrestin
B. ATP
rhodopsin kinase is the enzyme that cleaves a phosphate from ATP. ATP is the source.
- What is the mechanism of a kinase ?
- What is the mechanism of a phosporylase?
- What is the mechanism of a phosphotase?
- ATP + kinase —> ADP + Pi + substrate-phosphate
- glucose + phosphorylase + substrate-phosphate —–> glucose-Pi + substrate
- substrate-Pi + phosphotase + H2O —–>
substrate-OH + Pi
What is the funciton fo LipA (lysosomal lipase?
A. ATP hydrolysis
B. Peptide cleavage
C. Hydrolysis of Triglycerides
C. Hydrolysis of Triglycerides.
Answer is in the word itself. LIPASE. no need to interpret graphs.
What is the net charge change when going from RKMYI to GDDCM ?
+2 charge going to -2
net change of -4
- what creates the a-1,4 bond?
- what cleaves the a-1,4 bond?
- what creates the a-1,6 bond?
- what cleaves the a-1,6 bond?
- Glycogen synthase
- Glygogen Phosphorylase
- Branching Enzyme
- Debranching Enzyme
What is the structure of ribose?
The cathode reduction potential (Eo) is 0.339 V and the anode Eo is -0.127 V. Will this reaction occur spantaneously?
Yes, because Ecell = Eocathode - Eoanode
Ecell= 0.339 - (-0.127) = 0.466
A (+) Ecell (emf) = spontaneous reaction bc
ΔG= -nFEcell
Do microscopes work at visible wavelength?
Yes- at 400-750 nm
What will you use to find mechanical work of a spring?
W= (k x2)/2
K can be equal to force
Whic of the the following mixtures, with each component present at a concentration of 0.1 M, has a pH closest to 7?
HClO and NaClO
HNO2 and NaNO2
HNO3 and NaNO3
HClO and NaClO
The question says that the components are in equal concentration thus, according to HH equation when HA= A- pH= pKa
HClO is the molecule with pH closest to 7. (trick 8-1)
What is the best explanation for the fact that a solution of NaNO2 is basic?
NO2- is hydrolyzed with the formation of OH- when it reacts with water.
If something is negatively charged will it be polar or non polar?
It will be polar bc the negative charge can interact with water molecules. eg. SO3-
What could be the structure of R1 and R2, considering that this molecule is a lipid on cell membranes?
A. CH3
B. NH2
C. (CH2O)10CH3
D. (CH2)15CH3
D. (CH2)15CH3
Since this is a lipid, we should realize that the R1 chain should be a long carbon chain. A- Ch3 is too short
Considering the equation below, what will happern to the pH of a soapy solution as a result of this reaction?
A. the pH increases as [H+] increases
B. The pH is not changes since no acid-base reaction occurs.
C. The pH decreases as [Oh-] decreases
D. The effect on pH depends on the identyty of M2+
C. The pH decreases as [Oh-] decreases
Because A and B are wrong. There is an acid base reaction occuring since a weak base is eliminated. D is wrong bc all metals stated in the passage were 2+ charge.
(missed this question bc did not look at correct reaction.)
Soaps can be derived from all of the following except:
A.fatty acids
B.cholesterol
C. triaglycerols
D.phospholipids
B. cholesterols
soaps are structurally different to cholesterol molecules
What happens when the OH on carbon-5 attacks the hydroxyl and when OH on carbon 4 attacks the hydroxyl on glucose?
5= pyranose
4=furanose
What is the equation for Kcat
Kcat= 1/[S]
Vmax= Kcat [E]
Does a catalyst Change the transition state of a reaction?
No. It finds alternate pathways with lower transition states.
