FLE Missed Flashcards
Which statement is NOT true of PRIONS?
- They can be inherited
- They convert normal proteins into pathogenic proteins
- They can cause pathology in nearly every organ of the body
- They can be acquired through consumption of contaminated food
4
The correct answer is 4 because pathology is only observed in the CNS of the infected person or animal
Although prion infections are usually associated with consumption of contaminated meat, they also can be inherited and encoded in a person’s DNA
Prions convert normal proteins of the brain into pathogenic ones
This conversion is exponential and does take years to decades to complete
Which of the following bacterial populations would have the greatest size after 24 hours?
A) 10 cells with a doubling time of 8 hours
B) 100 cells with a doubling time of 12 hours
C) 1 cell with a doubling time of 2 hour
D) 1000 cells with a doubling time of 24 hours
C
- C is the correct answer since in a 24 hour period it will have 12 doubling times if it doubles every 2 hours*
- Therefore 1 cell will grow exponentially to* 4096 cells
- Answer A will have 4 doubling times in 24 hours. 10 cells will grow to 20, then 40, then 80, and finally 160
- Answer B will only have 2 doubling times in its 24 hour period. 100 cells will double to 200 and then to 400 cells
- Lastly, answer D will only double once in a 24 hour period resulting in 2000 cells.
Which event is an example of bacterial conjugation?
- A) A virus transferring the DNA for a toxin from Shigella dysenteriae to Escherichia coli
- B) The lysing of Escherichia coli cells and the DNA being picked up by Shigella dysenteriae
- C) The passage of RNA from Staphylococcus aureus cells to another strain of Staphylococcus aureus through a pilus
- D) The passage of DNA from Escherichia coli to Shigella dysenteriae through a pilus
D
- D is the correct answer because the definition of bacterial conjugation is the passage of foreign DNA through a pilus*
- pilus =a hairlike appendage found on the surface of many bacteria*
- Answer A describes transduction, which is the movement of foreign DNA from one cell to another via a phage
- Answer B is describing transformation, which is the picking up of naked DNA from the environment
- Answer C is also describing the passage of nucleic acid through a pilus, but only DNA is passed and not RNA
An increase in CHOLESTEROL has what impact on the plasma membrane?
A) increased membrane fluidity
B) increased solute transport across the membrane
C) decreased membrane fluidity
D) decreased solute transport across the membrane
A
- This question is asking you to recall knowledge about the fluid mosaic model (see pic)*
- Cholesterol is an important part of plasma membranes*
- It adds vital fluidity by disrupting the stacking of the lipid tails forming the membrane*
- By disrupting the stacking, the lipids can move more freely, and other molecules, such as trans-membrane proteins, can move about*
- C is incorrect because cholesterol is adding fluidity, not decreasing it
- B and D are incorrect because cholesterol does not impact solute transport across membranes
- However, you can also reach the answer rationally by looking at the figure of cholesterol and imagining how it might look within the lipid bilayer*
- It is very hydrophobic, so it will interact with the lipid tails, but it is also made of multiple planar rings, so it will not stack neatly with the long carbon chains*
- Since it doesn’t fit neatly into the membrane, it will increase movement.*
Based on the data in Figure 2, what is a normal cellular progesterone level?
A) 0.19 ng/ml
B) 0.36 ng/ml
C) 38 ng/ml
D) 0.38 ng
B
- The “normal” cells for this experiment are tested in the first lane, without cAMP or CCCP added*
- From the information given in Experiment 1, you can see that progesterone is labeled P4, which tells you that the chart above the graph has the data about progesterone concentration*
- For lane 1, the progesterone level is 0.3 +/- 0.1 ng/ml, giving you a range of 0.2-0.4 ng/ml*
A is incorrect because 0.19 ng/ml is outside that range
C is incorrect because 38 ng/ml is too large
This might be distracting, however, if you assume that the bar graph is telling you the progesterone concentration, since the bar for lane 1 is at approximately 38
Make sure when looking at a figure that gives multiple types of data that you know which data is coming from where
D is incorrect because 0.38 ng is not a concentration, it is merely a mass
H2O2 vs O2
Bond STRENGTH roughly correlates with bond….?
ORDER!
O2 is (+2)
H2O2 is (+1)
Therefore O-O bond in O2 is stronger
“Chelation”=?
“Chelation” describes a particular way that
ions and molecules
bind METAL IONS
Specifically: involves the formation or presence of two or more separate coordinate bonds between a multiple-bonded ligand and a single central atom
WHAT is the primary type of attraction that:
facilitates complimentary base pair matching?
What other kind of attraction can occur if this primary type is present?
H-bonding
is the primary type of attraction that facilitates complimentary base pair matching
Van der Waals attraction will also occur if molecules are hydrogen bound.
What is the synthetic purpose of the thermal decomposition of azobisisobutyronitrile (AIBN) in Step 2a?
- A) two tertiary free radicals for the functionalization of CRGO in Step 2b
- B) radical cations for the nucleophilic attack of CRGO in Step 2b.
- C) a stable diatomic nitrogen molecule.
- D)heat, to increase reaction rate.
A
A correct; tertiary radicals are most easily formed
- B is incorrect; the radicals formed are neutral
- C the byproducts are irrelevant to the further reactions
- D Branched vs. unbranched carbon chains presents no strong advantage to subsequent steps nor to the function of the biosensor.
In which solvent is P4 LEAST soluble?
A) H2O
B) CH3CH2OH
C) CH3COCH3
D) C6H6
A
- P4 is nonpolar; all bond dipole moments “cancel” each other out
- Water should be immediately recognized as the most polar of all solvents in choices A-D, and hydrocarbons as the least polar
- Alcohols are of intermediate polarity
- Answer C is a ketone, which is relatively non-polar, but more polar than benzene, Answer D
Therefore, the most polar, and therefore LEAST likely to dissolve P4 among the choices listed is water, Answer A
What are the most likely sources of human dietary PHOSPHORUS?
A)protein and hydroxyappetite
B)protein and amino bisphosphonate
C)DNA and RNA
D)phosphoric acid and calcium
C
- Nucleic acids are dietary sources of phosphorus due to the presence of the phosphate backbone*
- RNA and DNA are nucleic acids*
- Although “Diets rich in protein and calcium” were mentioned as diets that would likely meet phosphorus requirements, protein and calcium do not themselves contain any phosphorus
- A is incorrect because proteins do not contain phosphorus
- there are no biological amino acids that incorporate protein
What is the EMPIRICAL formula for HYDROXYAPATITE?
Ca5(PO4)3OH
A) Pi electrons of the phenyl ring and the tertiary hydrogen
B) Pi electrons of the cyclohexenyl ring and the methyl group
C) Hydroxyl groups, epoxide oxygen lone pairs, and nitrogen lone pair
D) Only the lone pairs of the epoxide oxygen
C
- For complex formation between a molecule and an antigen binding fragment, or for almost any binding interaction described in biochemistry, the interactions are intermolecular in nature*
- In other words, the process is not breaking and forming new covalent bonds, but causing attractions between molecules to hold them into a binding site*
- Further, hydrogen bonding is the most widely used and strongest of the intermolecular forces
- There are four locations on morphine that can participate in H-bonds:
- the two hydroxyl groups (donors or acceptors)
- the lone pair on the epoxide oxygen (H-bond acceptor only)
- the lone pair on nitrogen (H-bond acceptor only)
In which concentration range would the paper-based lateral-flow test strip be most effective as a quantitative tool for predicting blood morphine levels based on test line intensity?
A) 1.0 – 100 ng/mL
- because the color intensity is highest over this range
B) 1.0 – 100 ng/mL
- because the difference between test and control line intensities is positive and has the greatest magnitude
C) 0.1 – 1.0 ng/mL
- because over this range the control test line color intensity is the most consistent
D) 0.1 – 1.0 ng/mL
- because over this range the intensity vs. morphine concentration plot has the greatest slope
D
- For a test to be a good candidate for quantitative measurements, (as opposed to qualitative test where the goal is to determine “morphine present” or “morphine absent”)
- the observable response must:*
_VARY SUBSTANTIALLY_ and in a CONSISTENT DIRECTION
In the 0.1 to 1.0 ng/mL region:
- the relative color intensity increases from about 1 to 25 in near-linear fashion
- ΔYaverage per ΔX can be estimated to see that this range has a large slope compared to the other regions.
- If a sample is analyzed and the line intensity registers a relative color intensity of 15, what is the approximate molarity of morphine in the sample?*
- The molecular formula of morphine is C17H19NO3*
- HINT: MW=285 g*
A) 2.4 × 10–12 M
B)2.5 × 10–9 M
C) 2.4 × 10–6 M
D) 1.1 × 10–9 M
B
- In Figure 4, a relative color intensity of 15 corresponds to a morphine concentration of 0.7 ng/mL*
- If one round 285 grams to 3 x 102 grams, the calculation becomes:
(7 x 10-1 ng/mL)
X (1 g/ 109 ng)
X (1 mol/3 x 102 g)
X (1 x 103 mL/L)
= 2.33 × 10–9 M
See picture
∆G’ = ∆G°’ + RTln [Products]/[Reactants]
=0.4 + (8.31)(310)(ln[0.01])
A PEPTIDE BOND differs from
most OTHER chemical bonds in that it features….?
What does this feature PREVENT?
RESONANCE between the C-O and C-N bonds
PREVENTING
FREE
ROTATION!!!
When a SPRINTER is running:
What is the SOURCE of the work done to accelerate Sprinter?
The GROUND is doing work on the SPRINTER
By definition, the force doing work on an object must be a force ON the object
- The GROUND is exerting a force ⇒ runner*
- Runner’s LEGS are exerting a force ⇒ ground*
A certain medical device converts the KE of high-velocity metal beads into HEAT energy
If 100% conversion efficiency were possible:
What MAXIMUM theoretical heat energy can be produced by a single chromium bead with:
- a VOLUME of 1.0 x 10-4 cm3
- a VELOCITY of 2.0 x 104 m/s?
(Density of Cr = 7,140 kg/m3)
1.4 x 102 J
Begin with the formula KE = 1/2mv2
- Density = mass/volume
- so mass = density*volume
- Substituting mass into the first equation we get:
KE = (0.5)(density)(volume)(velocity)2
However!!
- Volume is given in cm3
- and must be converted to m3
Using dimensional analysis:
1x10-4 cm3 x (1m/100cm)3
= 1.0 x 10-10 m3
Now one can simply solve:
=½(7.1 x 103 kg/m3)(1.0 x 10-10 m3)(2.0 x 104m/s)2
This simplifies to:
= (3.5 x 103)(1 x 10-10)(4.0 x 108)
- = (3.5 x 10-7)(4.0 x 108)
- = 14 x 101
- = 1.4 x 102 Joules
- = 14 x 101
For an acid-base equilibrium at
CONSTANT TEMPERATURE:
which of the values listed is CONSTANT?
A) pH
B) Concentration of the conjugate base
C) Concentration of the weak acid
D) pKa
D
pKa is the ONLY constant among the answers
The acid-base equilibrium constant, Ka, is a constant for a GIVEN REACTION at a GIVEN TEMPERATURE
…Therefore the negative log of that constant would ALSO be a constant!
The pH of the solution is dependent on the concentration of acid and base in the equilibrium
- making Answer A incorrect
The concentration of both the acid and the conjugate base can VARY depending on the reaction
- making both Answer B and C incorrect
Titrating aqueous AMMONIA with HCl
would produce a titration curve that looks like WHAT?
- Hydrochloric acid is a STRONG acid,*
- while ammonia is a WEAK base*
Because the titration starts out with
just the weak base present:
we need a plot that starts out basic, but not strongly basic
In the synthesis of tri-substituted oxazolidines the ACETYLENE acts as a:
A) Bronsted acid
B) Bronsted base
C) Lewis acid
D) Lewis base
C
The acetylenes contain an electron-deficient pi-systems making the double bond ELECTROPHILIC and susceptible to nucleophilic attack
“During normal growth, SOS pathway genes are repressed by LexA, which binds to the SOS box in the operator on either the coding strand or the template strand of the gene”
Q: The nucleotide sequence of the SOS box is most likely:
A) GAACGTTC
B) TATAAA
C) TAGTTGAT
D) GCGCCC
A
- In the passage, it was stated that LexA can bind to either the coding strand or the template strand of the SOS box
This tells you that the SOS box must be a PALINDROME!
- Remember that DNA sequence palindromes read the same 5’-3’ on BOTH sides
In answer A, 5’- GAACGTTC- 3’
the compliment strand is 3’ –CTTGCAAG- 5’
…which is IDENTICAL when read 5’-3’
- Suppose a person holds a mass m in their hand*
- with their elbow bent and their forearm*
- in a neutral horizontal position*
- If both muscle groups are flexed simultaneously, the system will be in equilibrium when the triceps muscle group exerts a force equal to:*
A) exactly 80m
B) one-half the force exerted by the biceps muscle group.
C) twice the force exerted by the biceps muscle group.
D) less than twice the force exerted by the biceps muscle group
D
When a person holds a mass steady with a bent elbow, the forearm is PREVENTED from moving either up or down
The MASS also acts DOWN on the forearm
at a lever arm of 40cm
The forearm itself has mass!
which can be assumed to act downward at approximately the center of the forearm
Therefore the bicep must counteract:
- the torque due to the weight of the mass
- torque due to the weight of the forearm itself
- whatever force/torque the tricep is exerting
- Therefore, when in equilibrium the tricep must be exerting LESS than twice the force of the bicep—
due to the co-directional torque resulting from mass m
What aspect of the BF3 molecule
makes it a Lewis acid?
In the Lewis structure of BF3:
Boron only has access to 6 electrons
…instead of the 8 necessary to make a (desired!) OCTET
Therefore it is a Lewis Acid
VERY WILLING TO ACCEPT ELECTRONS
from an electron pair donor (Lewis Base)
At physiological conditions, the autoionization constant of water (Kw) is slightly above 1 x 10-14
If TEMPERATURE is increased by a factor of FOUR
and PRESSURE is INCREASED to 25 MPa:
Kw is INCREASED by a factor of 100
Q: How does the pH of water at this elevated temperature and pressure differ from pH under physiological conditions?
IT DECREASES BY ONE pH UNIT
At room temp:Kw = 1 x 10-14
This value increases by a factor of 100
- which would be 100 x 10–14*
- or 1 x 10–12*
At the conditions stated in the problem:
-
[H+][OH –] = 1 x 10–12
- AND [H+] = 10–6 M
From this we see that pH = 6
(pH has decreased by one pH unit)
Do Newton’s Laws also apply to SPRINGS?
YES!
Many dynamometers employ a spring to provide resistance as grip strength is assessed
- Q: If the dynamometer measures a force of 500 N after the spring is compressed 4 cm, how much potential spring energy is stored in the system?*
- A) 10 J*
B) 20 J
C) 100 J
D) 200 J
A
First deduce the spring constant, k
Hooke’s law: F = kx
- k = F/x
- = 500N/0.04m
- = 12500 N/m
- = 500N/0.04m
Then use the formula PEspring = ½ kx2
PEspring = ½ (12500) (0.04)2 = 10 J
When a repair sequence is first joined to the undamaged portion of the DNA during homologous recombination:
The JUNCTION points
between damaged and undamaged DNA
form a temporary four-stranded moiety known as a…?
Holliday Junction
a Holliday junction is a branched nucleic acid structure where four double-stranded domains are joined together. Holliday junctions are an intermediate in genetic recombination
Pt2+, NH3 Cl–
Lewis ACID or Lewis BASE?
Pt2+ is a Lewis acid
NH3 and Cl– are Lewis bases
A study reports that the majority of patient falls in which the patient strikes a hard ground surface with a velocity less than or equal to 5.0 m/s do NOT result in serious fractures or other injuries
Q: Ignoring air resistance, falls from which height are UNLIKELY to cause injury?
A) 0.5 m
B) 1.25 m
C) 2.5 m
D) 5.0 m
B
- One can use v = √2gh to solve this problem, OR
You can simply intuit that if a Vfinal of only 5m/s is attained, the person could only have been in free fall for:
-
HALF A SECOND!
- **Because one **FULL** second of free fall changes velocity from **0 ⇒ 10 m/s
∴ traveling at an AVERAGE velocity of 2.5 m/s for 0.5 seconds gives a fall distance of 1.25 m, or Answer B
γ-Hydroxybutanoic acid (GHB) is commonly known as the “date rape” drug
HO-CH2CH2CH2-COOH
GHB metabolism involves TWO oxidations
- First by an alcohol dehydrogenase
- Then by an aldehyde dehydrogenase
Q: If one equivalent of each enzyme is available, the FINAL structure of the metabolite will be…?
γ-Hydroxybutyric acid has the structure:
HO-CH2CH2CH2-COOH
Alcohol dehydrogenase oxidizes the alcohol to give:
⇒ HOOC-CH2CH2-CHO ⇒
Aldehyde dehydrogenase oxidizes the aldehyde to give:
HOOC-CH2CH2-COOH
One of the major accomplishments of the SENSORIMOTOR stage is the acquisition of…..?
Object Permanence
During the PREOPERATIONAL stage, children acquire _________and engage in _____ ____
Acquire LANGUAGE
Engage in PRETEND PLAY
During the CONCRETE OPERATIONAL stage, children acquire both _______ and _________
CONSERVATION and REASONING
During DIASTOLE, the heart is not _______ ;
all chambers are ________
During diastole, the heart is NOT CONTRACTING;
all chambers are RELAXED
(FILLING WITH BLOOD)
If something is “FEMINIZED,”
that just means that…..?
Use Poverty as an example
If something is “feminized,”
that just means that
MORE women are doing it
(in this case, more women are living in poverty means poverty is eing “feminized”)
Deuterium has an extra ______ compared to the 1H proton, and thus a larger at WHAT?
As a result, how does D2O compare to H2O?
Deuterium has an extra neutron compared to the 1H proton,
and thus a larger atomic mass
As a result, deuterium oxide must have a different molecular weight than water
Phosphorylation is a common mechanism for doing WHAT to an enzyme?
Phosphorylation is a common mechanism for
activating or inactivating an enzyme
What is the most likely explanation for how PHOSPHORYLATION influences
activation or inactivation?
The CHARGE on the phosphate:
creates a repulsive interaction, resulting in a conformational change in the enzyme
A pro-inflammatory cytokine cannot work ANTAGONISTICALLYagainst
another pro-inflammatory cytokine BECAUSE?
Becuase they will both
stimulate inflammation
Why can’t an anti-inflammatory
cytokine work SYNERGISTICALLY
with a pro-inflammatory cytokine?
Because one decreases (anti)
and
one increases (pro) inflammation
Can Pro-inflammatory cytokines can work together (synergistically)?
YES!
but that would only increase inflammation further
ANTI-inflammatory cytokines are often UPregulated in the presence of increased WHAT?
Why is this?
In the presence of PRO-inflammatory
cytokine production
because antagonists control the amount of inflammation produced
During prolonged strenuous exercise, _____ produced by anaerobic glycolysis is transported to the ______, where it is converted to _____ and eventually metabolized
- This metabolism involves the conversion of _____ to _____ in the LIVER and metabolism of ______ in the MUSCLE
During prolonged strenuous exercise, lactate produced by anaerobic glycolysis is transported to the liver
where it is converted to glucose and eventually metabolized. This process involves the conversion of:
lactate to glucose in the liver and metabolism of glucose in the muscle.
The anomeric position of a sugar is an “______ _____”
The anomeric position of a sugar is an invertible epimer
The mechanism of β-galactosidase is known to be a double displacement hydrolysis
Given this information, what is the most likely stereochemical outcome for the anomeric position of β-galactosidase?
retained
A displacement reaction generally inverts stereochemical configuration, such as in an SN2 reaction.
A double displacement hydrolysis would involve two sequential inversions of configuration
which would lead to an overall retention of configuration
- Some accelerometers use springs rather than electrical current to measure acceleration
- In a device designed to measure left-right acceleration only, a spring, free-floating seismic mass, and transducer are arranged as shown below
_If the net acceleration of the seismic mass is to the RIGHT,_
_how do the forces of the spring and the transducer on the seismic mass compare?_
- The force of the spring on the seismic mass is larger than the force of the transducer on the seismic mass
- The force of the transducer on the seismic mass is larger than the force of the spring on the seismic mass.
- The forces of the spring and the transducer on the seismic mass are equal according to Newton’s Third Law
- The forces of the spring and the transducer on the seismic mass are equal according to Newton’s First Law.
The force of the spring on the seismic mass is LARGER than the force of the transducer on the seismic mass
TDLR: Since accel (caused by spring) of mass is greater than the acceleration caused by transducer, the force of the spring must ALSO be greater (“O.S.D.”)
For this problem you must consider the forces acting on the seismic mass
There are only two forces:
- the force from the spring which is pushing it to the right
- the force from the transducer which is pushing it to the left
- Because the stem says specifically that the device is accelerating to the right,*
- the system is NOT in equilibrium*
∴ The Fnet must ALSO be to the RIGHT
This means that Fspring > Ftransducer
A new bacteria is discovered that utilizes a novel nucleotide, designated as H.
H has replaced guanine in the bacteria’s genome and base pairs with cytosine.
This bacteria is highly successful at evading the host’s immune defenses because:
A) The bacteria’s genome will not be recognized by antibodies because the host is unfamiliar with the H nucleotide
B) Due to the dramatic change in genome structure, the bacteria produces new proteins which are undetectable to the innate immune system
C) Restriction endonucleases that target non-self DNA molecules and degrade them have very specific cleavage sites, and the H substitution disrupts this functionality
D) The new nucleotide alters the surface proteins of the bacteria to mimic host cell proteins, enabling the bacteria to utilize cell surface receptors and enter the cell undetected
C
- The newly discovered bacteria has a genome that uses ATCH instead of ATCG, but no other changes are listed
- H basepairs with C, so you can assume that it behaves in most respects just like G does
- C is correct because one way that organisms fight invaders is through restriction endonucleases
- that recognize DNA sequences in genomes that are “non-self.”
- These endonucleases have very specific restriction sites
- (because it would be very dangerous to have endonucleases without specific sites, since they could cleave any DNA)
If an endonuclease recognizes CATATG, it will NOT recognize CATATH
- Even though this sequence is still a palindrome (when double stranded), the endonuclease will “read” H differently than G and will not cleave that DNA
- Then the bacteria can continue replicating within that cell, and the infection can spread
A typical blood bicarbonate concentration is 26 mM
What must the carbonic acid concentration be to achieve a pH of 7.0
if the Ka for carbonic acid at physiological temperature is 9.94 ×10–7?
Use Henderson-Hasselbalch equation:
pH = pKa + log( [HCO3] / [H2CO3] )
First, convert the Ka given to pKa
Just round the Ka up to 10
pKa = -logKa
pKa = -log(10 x 10-7)
- = -log(1 x 10-6) = 6
- 7.0 = 6.0 + log(26mM/x)
1.0 = log(26mM/x)
or 26mM/x = 1 x 101
or 26mM/x = 10
x = 26mM/10**, therefore **x = 2.6
What does the term “ANHYDRASE” imply wrt what’s happening in the reaction?
“anhydrase” implies
removal of water
Compare PRIMARY and SECONDARY
REINFORCERS
Primary reinforcers
- Act to reinforce a behavior WITHOUT previous conditioning
Secondary reinforcers
- Only take on their reinforcing value as a function of their association with a primary reinforcer
In contrast to globular proteins, some cytosolic proteins (BETTER KNOWN AS…?)
have significant flexibility due to unfolded domains and the lack of a tightly ordered internal core
A protein with which characteristics will exhibit the greatest flexibility in dilute solution?
- A) High net charge and low hydrophobicity
- B) High net charge and high hydrophobicity
- C) Low net charge and low hydrophobicity
- D) Low net charge and high hydrophobicity
A
high net charge density and a low hydrophobicity
- The cytosolic proteins referenced in the stem are called Intrinsically Disordered Proteins (IDPs)
- Intrinsically disordered proteins, which have a high degree of flexibility, are characterized by a high net charge density and a low hydrophobicity.
These characteristics prevent formation of a hydrophobic core
stabilizing the protein
How is release of Parathyroid Hormone (PTH) regulated by POSITIVE feedback?
IT ISN’T!!!!!!!
It’s regulated by SIMPLE FEEDBACK INHIBITION (by Ca2+ lvls in the blood!)
POSITIVE feedback would imply that increased
PTH levels would cause a decrease in release of PTH, but…..
If a face stimulus were presented in the right visual field, which area of the brain would be responsible for processing that information?
Left geniculate nucleus
…of the THALAMUS
Mechanisms in younger children compensate for the lower diffusion capacity shown in Figure 1
Which of the following is a physiological trait that declines with age and is likely to compensate for decreased diffusion capacity in children?
- Density of HgB
- Density of capillaries/kg tissue
- Resting HR
- RBC count
RESTING HEART RATE
The resting heart rate of newborns is 100-160 beats per minute and the average heart rate declines through adolescence
The increase in heart rate would cause blood to flow in and out of the lungs at a faster pace
…thus increasing the opportunity for diffusion of blood gases
Based on Figure 1, in the myocytes of wild-type mice treated with H2O2, administration of the drug carbachol will have what impact on cellular NO levels?
- NO levels will increase
- NO levels will decrease
- NO levels will remain constant
- NO will no longer be produced by eNOS
NO levels will INCREASE
Using Figure 1, it can be determined that in wild type mice carbachol significantly upregulates cGMP levels over basal levels
In the passage we learn that cGMP is an agonist for the activation of MEK 1/2 so therefore carbachol will increase the activation of MEK1/2
The passage also states that following H2O2 treatment the addition of an MEK1/2 agonist results in a significant increase in NO
Therefore the addition of carbachol will cause an increase in NO production.
A man with type A blood and a woman with type B blood have one child who has type B blood, and one child who has type A blood
If the couple has a third child, what is the probability he or she will have type O blood?
25%
The man is type B and the woman is type A
Since they have a child with type B blood, this means the child received the B allele from the man and must have received the O allele from the woman
Recall that O is recessive
So, the woman’s genotype must be AO
The same reasoning from the type A child tells us that the man’s genotype must be BO
When an AO x BO mating occurs, the Punnett square below is used to predict the proportion of each type of progeny
Hence, the probability of obtaining an O child is 25 %
What does a sarcomere that would produce the greatest tension upon contraction look like?
Muscles generate the greatest tension when they are at “optimal” length
The sarcomere shown illustrates the optimal length:
ALL of the myosin heads can form cross bridges, and
the thin filaments can slide the MAXIMAL amount
Which graph depicts the relationship between sarcomere length and distance from the center of a skeletal muscle?
(Length=y axis, distance=x axis)
The model predicts that
sarcomeres will be:
-
SHORTER toward the TENDONS
- …which are located at both ends of the muscle
- and LARGER farther away from the tendons
Why is the amine group on S142 unable to form a hydrogen bond with the amine group on the 5-fluoruracil?
Both functional groups have a partial positive charge
What impact would a Q217 to N217 mutation have on the activity of UPP?
- Binding to 5-fluorouracil would strengthen, increasing UPP activity
- Binding to 5-fluorouracil would weaken, increasing UPP activity
- Binding to 5-fluorouracil would strengthen, decreasing UPP activity
- Binding to 5-fluorouracil would weaken, decreasing UPP activity
Binding to 5-fluorouracil would WEAKEN,
INCREASING UPP activity
the binding to 5-fluorouracil will be weaker since the hydrogen bonding distance will be longer after the mutation
For the hypothetical reaction shown below, with stoichiometric coefficients X, Y and Z, the rate data shown in the table suggest that the reaction order with respect to nitrogen gas is?
FIRST ORDER
The first thing to do for this question is to attempt to balance the equation.
Then one can look at the rate data in the table.
As the table shows, doubling the concentration of the nitrogen gas doubles the rate of the reaction
This is only consistent with a reaction that is
first order in nitrogen
Describe a DISSOCIATIVE FUGUE
Dissociative fugue is a rare disorder
An individual with dissociative fugue suddenly and unexpectedly takes physical leave of his or her surroundings
and sets off on a journey of some kind
An individual in a fugue state is unaware of or confused about his identity,
and in some cases will assume a new identity (although this is the exception)
Which psychological diagnosis would be associated with a person reporting that they had no memory of who they were or where they came from?
Dissociative fugue
is associated with a temporary loss of memory for personal identity
What is the ARCUATE FASCICULUS?
The arcuate fasciculus connects:
BROCA’S AREA (MOTOR aspects of speech) to WERNICKE’S AREA (language comprehension)
