Block 1 Questions Flashcards
Study key terminology from missed questions in Block 1 of MCAT studying
A lactone is a cyclized ______.
Ester (formed by intramolecular transesterification)
A lactam is a cyclized ______.
Amide
What kind of substrate would you use in a reaction to achieve the kinetic enolate product as opposed to the thermodynamic enolate? Under what conditions is the kinetic enolate favored?
Bulky base
Kinetic enolate is favored at low temperatures
Which has more substituted double bonds, thermodynamic or kinetic enolate?
Thermodynamic enolate
Why is the kinetic enolate able to form with a lower activation energy, what does this determine about the product stability?
Lower activation energy but forms a less stable product
Formed quickly because the alpha hydrogens (more acidic) and more easily removed
Sucrose is composed of which 2 sugars? These sugars are joined by which linkage?
Glucose + Fructose
1’1 glycosidic bond
What is the purpose of a Michael addition?
We want to add an enolate nucleophile to an alkene in order to add 2 aldehydes, 2 ketones or an aldehyde to a ketone
What is the rate determining step of an SN1 reaction?
Stability of the carbocation that is formed (most stable if on a tertiary substituted carbon)
In which type of rxn mech (SN1 or SN2) is an inversion of configuration observed? Is the absolute or relative configuration changing?
SN2 - inversion occurs when the carbon is attacked by the nucleophile at the opposite side of the plane Relative config (R/S) CHANGES but the absolute config (L/D) might or might NOT change ****SN1 may have carbon skeleton arrangement but SN2 never rearranges carbon skeleton
Polar protic solvents favor (SN1 or SN2) reactions whereas polar aprotic solvents favor (SN1 or SN2)? Why?
Polar protic = SN1 because they participate in H bonding and can stabilize the carbocation and the nucleophile (we don’t want the nuc to be stabilized in SN2 rxns)
Polar aprotic = SN2 b/c they DONT H bond
Label the following groups with the respective filled PEL subshells in their electron configuration?
a) Alkali + Alkali earth metals
b) Transition Metals
c) Metals/Nonmetals and Halogens
a) s
b) s and d
c) s and p
For a convex lens if the object distance is in between 2f and f would you expect the image to be real/virtual or enlarged/reduced?
Real and enlarged
Violet light is emitted at ____ wavelength and Red light is emitted at ____ wavelength
Violet = 400 nm Red = 700 nm
What are 3 major assumptions of Michaelis Menten Kinetics?
1) initial velocity is measured under steady state conditions
2) Solution pH remains constant at all substrate conc
3) [E] «««««_space;[S]
What is indicated by the kcat?
Tells us how many substrate molecules are converted into product by a single active site per unit time
kcat = vmax/ [E]
If an object is moving in the same direction at the same speed as the detector what is f’ relative to f?
f’ and f are the same and there is NO Doppler effect because the relative velocity is zero
How is resistivity related to conductivity?
Resistivity and conductivity are inversely proportional
What are 3 formulas to express the energy stored in capacitors?
U = (1/2) Q*V U = (1/2) C * V^2 U = (1/2) Q^2/C
If a sound wave moves into a different medium which of the following factors will NOT change?
a) wavelength
b) frequency
c) amplitude
d) wave speed
frequency of the sound wave will not change in the new medium
Which 3 aspects of molecular structure determine whether or not a mol will act as an acid (by releasing H+ in solution)?
1) Strength of the bond holding the H
2) Polarity of the bond
3) Stability of the conjugate base
What is indicated by the half equivalence point of a titration curve?
Is the point where exactly half of the acid has been neutralized by base (conc at which acid = conc of conjugate base)
Log values:
log(1) = 0 log(2) = 0.3 log(3) = 0.48 log(4) = 0.6 log(5) = 0.7 log(6) = 0.78 log(7) = 0.85 log(8) = 0.9 log(9) = 0.95 log (10) = 1
What does it mean to use counterbalancing in an experimental set up?
A method to control for any effect that the order of presenting stimuli might have on the dependent variable
What is a negative symptom in a psychological disorder?
Negative symptoms are defined as the absence of appropriate behaviors and emotion (i.e. emotional flattening in schitzophrenia)
What is negative priming?
Is an implicit memory effect in which prior exposure to a stimulus unfavorably influences the response to the same stimulus
What is priming?
Change in response towards a stimulus due to a subconscious memory effect
What is an unrealistic belief or attitude that is firmly held in the absence of evidence?
Delusion
What are neuroleptic antipsychotics designed to treat?
Treat the positive symptoms (hallucinations, delusions, agitation) of schizophrenia
If a molecule is tagged for ubiquination, which enzyme acts to degrade it?
Proteosome
GAPDH is an enzyme that catalyzes which reversible reaction of glycolysis?
catalyzes the reversible conversion of glyceraldehyde-3-phosphate to 1,3-bisphosphoglycerate.
List at least 5 types of postranslational modifcations of proteins:
- Phosphorylation
- Glycosylation
- cleavage of peptide bonds (propeptide synthesis by removing start Met codon)
- Lipidation
- Acetylation/Deacetylation
- Methylation
What is RT PCR?
Reverse transcription PCR, or RT-PCR, allows the use of RNA as a template. An additional step allows the detection and amplification of RNA. The RNA is reverse transcribed into complementary DNA (cDNA), using reverse transcriptase.
Schwann cells, PNS or CNS?
PNS!
Oligodendrocytes, PNS or CNS?
CNS!
Would you expect a frameshift mutation in the open reading frame to change the N-terminus or C-terminus of the protein?
C-terminus
Microtubules within the cell originate from which cellular structure?
Centrosome
Where in the male reproductive system does sperm become motile?
Epididymis
As people age, would you expect fluid intelligence to remain constant or decline?
Decline
**Crystallized intelligence improves with age
What is correspondance bias?
The tendency to make dispositional attributes when we should make a situational attribution.
