TPR Test 3

Question 1

what do each of the terms in the equation q=mcΔT mean?

Answer 1

q=heat lost or absorbed by the substance

m=mass of substance

c=specific heat of substance

ΔT= change in temperature for that reaction

**This equation can also be written as q=CΔT, in which C (heat capacity=mc).

Question 2

T/F: the mixture of conjugates (the product) of a strong acid or strong base is pH neutral

Answer 2

true

Question 3

the secondary structure specific to transmembrane domains is

Answer 3

alpha helices

Question 4

What is the configuration of the electrons in the valence shell of a chloride anion?

Answer 4

3s²3p⁶

explanation: since it’s in its anionic form, it has one extra electron which pushes it from 5 to 6 in the p subshells

Question 5

which are tautomers (can pick more than one)

Answer 5

1 and 3

Tautomers are two neutral molecules with the same molecular formula but different connectivity - constitutional isomers, in other words - which can interconvert in a rapid equilibrium.

2 is not one because it is not neutral

Question 6

β-oxidation occurs in the _________and fatty acid biosynthesis occurs in the _________

Answer 6

mitochondrial matrix

cytoplasm.

Question 7

MCAT tip: do not assume racemization unless it’s reference in some manner in the passage

Question 8

HPLC refers to_________

Answer 8

High performance liquid chromatography. It is basically a highly improved form of column chromatography. As with column chromatography, polar compounds in the mixture being passed through the column will stick longer to the polar silica than non-polar compounds will. The non-polar ones will therefore pass more quickly through the column.

Question 9

T/F: Sound waves reach the ear closest to the source of the sound first, and the further ear second. This time gap allows the brain to determine the location of the sound

Answer 9

true

Question 10

______ cm^-1 is the band on IR representative of the presence of oxygen

Answer 10

3200 cm^–1

Question 11

when a neutral polyprotic molecule loses its first hydrogen, how does that affect the dissociation constant for the second hydrogen

Answer 11

After loss of the first proton, the remaining hydrogen is bound to a negatively-charged molecule. Electrostatic attraction between this remaining hydrogen and the negatively-charged molecule would disfavor loss of the second proton, resulting in a smaller K. Therefore, K2 << K1.

Question 12

What is the critical angle, φ_crit of a light ray crossing 2 media

Answer 12

the angle at which the refracted light emerges tangent to the interface (ie angle of refraction φ_B is 90^o)

total internal reflection will occur when the incident angle is greater than the angle of refraction

*This only occurs if the index of refraction of medium 2 (entered into) is less than that of medium 1 (exiting out of).

Question 13

MCAT tip: always assume 1 for the index of refraction of air

Question 14

T/F: Resistivity of a current-carrying component immediately implies dissipation of heat

Answer 14

true

Question 15

Which of the following is/are true regarding the mechanism in Figure 1?

Reaction 1 is a decarboxylation and reaction 2 is a dehydration.

NADP+ is reduced in reaction 1.

NADPH is oxidized in reaction 2.

A. II only

B. III only Your Answer

C. II and III only

D. I, II, and III

Answer 15

C. II and III only

C. Item I is false. In reaction 1, isocitrate loses a CO2, so this is a decarboxylation reaction. However, an oxygen atom is not lost in reaction 2 so it cannot be a dehydration reaction; it is a reduction (choice D is wrong). Item II is true. The carboxyl group of isocitrate will be oxidized when it leaves, to form CO2 and this must be paired with a reduction reaction. The passage says that both reactions 1 and 2 involve the cofactor nicotinamide adenine dinucleotide phosphate (or NADP+/NADPH). In reaction 1 therefore, NADP+ will be reduced to NADPH (choice B is wrong). Item III is true. In reaction 2, a carbonyl group is reduced to an hydroxyl group and this reduction must be paired with an oxidation. NADPH will therefore be used as a cofactor and NADP+ will be formed (choice A is wrong; option C is correct).

Question 16

T.F: oxidation and reduction reactions are always coupled

Answer 16

true

Question 17

T/F: decarboxylation relies on oxidiation

Answer 17

true (because it leaves as CO2)

Question 18

Systolic blood pressure approaches 0 mm Hg when it reaches the:

A. capillaries.

B. arteries.

C. aorta.

D. right atrium.

Answer 18

D. right atrium. Correct Answer

Blood from the systemic circulation at the end of its circuit through the body enters the heart through the right atrium, and at this point its pressure is near 0 mm Hg (choice D is correct). Although blood pressure is relatively low in the capillaries, it is not 0 mm Hg, or it would never circulate all the way back to the heart (choice A is wrong). Blood leaves the heart through the aorta on its way to the systemic circulation and is at its highest pressure at that point (choice C is wrong); from the aorta the blood travels through many arteries, and the pressure in these vessels is still high (choice B is wrong).

Question 19

oocytes transform from diploid to haploid at what stage?

Answer 19

All eggs are arrested at an early stage (prophase I) of the first meiotic division as a primary oocyte until puberty, at which point one egg per month (ovulation) completes meiosis 1 and becomes a haploid cell. It is then arrest in meiosis II until it is fertilized, at which point it completes meiosis

Question 20

the joining of homologous chromosomes during meiosis I so that crossing over can occur is accomplished by

Answer 20

synapsis

Question 21

_______________occurs when a lysogenic virus excises from the genome and takes a portion of the genome with it.

Answer 21

Transduction

Question 22

speciation is

Answer 22

the formation of new and distinct species in the course of evolution. The Hardy-Weinberg equation does not apply

Question 23

T/F: Fetal and maternal blood mix via the placenta

Answer 23

FALSE: They do not mix, so the only way substances can cross the placental barrier is if they are lipid soluble or if they are actively transported

Question 24

given: you have a 15-mer oligonucleotide with 5’-GACTGCGGTTTTAAC-3’
question: is it double stranded?

Answer 24

Yes, the fact that it’s double stranded is given by the word oligonucleotide which is a short segement of DNA or RNA. Just because only one strand is represented doesn’t contradict this since you can infer the sequence of the other strand from it.

Question 25

T/F: random coil state occurs with denaturation

Answer 25

true

Question 26

In order to have a lower melting temperature, an DNA segment must contain fewer?/more? GC nucleotides

Answer 26

fewer

This is because GC base pairing involves three hydrogen bonds while AT only involves two. Therefore the only way to lower the MP is by having fewer hydrogen bonds.

Question 27

A semipermeable membrane separates an aqueous solution of 0.003 M NaCl from an aqueous solution of 0.0025 M BaF₂ With this apparatus, one would observe that water crosses the membrane:

A. from the BaF₂ solution to dilute the NaCl solution.

B. from the NaCl solution to dilute the BaF₂ solution.

C. from the BaF₂ solution to concentrate the NaCl solution.

D. from the NaCl solution to concentrate the BaF₂ solution.

Answer 27

B:

Osmotic pressure is a colligative property, which means it depends only on the concentration of solute particles, and not their identity. Therefore, a 0.003 M solution of NaCl will have an effective molality of 0.006 M (since NaCl is composed of two ions) and a 0.0025 M solution of BaF2 will have an effective molality of 0.0075 M (since BaF2 is composed of three ions). Osmotic pressure will drive movement of water from the lower concentration solution (NaCl) to the higher concentration solution (BaF2). Note that this movement of water acts to dilute the BaF2 solution.

Question 28

an intercalating agent does what?

Answer 28

inserts itself between base pairs in DNA

Question 29

What is RT-PCR and what is it used for?

Answer 29

Reverse Transcriptase PCR - uses reverse transcriptase to make cDNA from mRNA. The cDNA can then amplified, and then tested for. This is the only method listed that can be used to test for the presence of mRNA and determine if transcription of a gene is occurring or not

Question 30

Buffered solutions are commonly made with

Answer 30

weak acids and their conjugate bases.

Question 31

Question 47

The amphoteric character of amino acids best explains their ability to:

A. form dipolar ions.

B. form peptide bonds.

C. contribute directly to a protein’s secondary structure.

D. dissolve in nonpolar solvents.

Answer 31

QUESTION EXPLANATION

A. The amphoteric character of amino acids describes their ability to do two things: accept a proton or donate a proton. In other words, amino acids can act as either an acid or a base. When the amino portion of an amino acid deprotonates its own carboxylic acid, a dipolar ion (or zwitterion) forms. This is a direct result of the amphoteric character of the amino acid.

Question 32

what happens immediately following fertilization of an ovum?

Answer 32

Question 33

proteins destined for secretion from the cell are made most likely made in the

Answer 33

Rough ER

Question 34

sequence of events in infection by baceriophage

Answer 34

Production of viral DNA polymerase, replication of viral genome, assembly of infectious virus, translation of viral lysozyme

*bacteriophage doesn’t carry its own polymerase

Question 35

The definition of transformation in genetics is

Answer 35

the process in which naked DNA, not a virus, is taken into a cell and changes the genetic characteristics of that cell.

Question 36

Habituation is a type of _________learning

Answer 36

non-associative learning.

Question 37

Generalization (responding with the conditioned response to stimuli other than the conditioned stimulus) and discrimination (responding with the conditioned response to only the conditioned stimulus) are both aspects of what type of learning

Answer 37

classical conditioning

Question 38

Pieget’s stages

Answer 38

Question 39

The ultimate attribution error occurs when

Answer 39

negative behavior by a member of an out-group is attributed by an in-group member to the out-group member’s characteristics (e.g., genetics, intelligence, personality, childhood background), while positive behavior by a member of an out-group is rationalized or explained away (e.g., good luck, special circumstances, etc.)

*related to fundamental attribution error but relates to in groups and out groups

Question 40

T/F: interactionists are concerned with the role of symbols in society

Answer 40

true

Question 41

education is a form of which type of capital

Answer 41

cultural

Question 42

Paul Ekman’s basic emotions

Answer 42

Paul Ekman found 6 main universal emotions which can be identified by everyone
around the world – happiness, sadness, fear, disgust, anger and surprise. They are based on the facial expressions that are universal even in babies

Question 43

Working memory is part of information processing theory. It is the process whereby

Answer 43

an individual holds and manipulates information in his or her mind before that information is encoded into long-term memory,

Question 44

Bottom-up processing is a type of information processing that

Answer 44

uses incoming data from the environment to form a perception. When individuals encounter novel stimuli they are forced to engage in bottom-up processing and construct their perception of the stimuli from bits of raw sensory information

Question 45

lateral geniculate nucleus in the thalamus is involved

Answer 45

with the visual processing pathway of the brain. It is the primary relay center for visual information

Question 46

Schizotypal personality disorder is characterized by

Answer 46

odd or eccentric behavior and acute discomfort in interpersonal relationships, to the point that people with this disorder rarely have social ties outside of immediate family members. Schizotypal individuals also frequently have notable cognitive or perceptual disturbances (but not delusions)

Question 47

T/F: Students who are paid to advocate a given position are more likely to support that position when asked about their opinions if the incentive received was minimal, as they are more likely to attribute their opinion change to internal reasons rather than to an external circumstance (i.e., the compensation)

Answer 47

true

Question 48

schizotypal vs schizoid personality disorder

Answer 48

The main difference between schizotypal and schizoid personality disorder is that schizoid does not have any paranoid ideation or suspiciousness.

Question 49

T/F: Self-schemata can be activated even when one is unconscious

Answer 49

FALSE: self-schemata are cognitive structures, which implies that one must be conscious in order to access them

Question 50

T/F: Baroreceptors detect changes in blood pressure, and are not involved in proprioception

Answer 50

true

Question 51

Which of the following infant reflexes in most closely associated with learning to balance and walk?

A. Moro reflex

B. Babinski reflex

C. Stepping reflex

D. Rooting reflex

Answer 51

C. The stepping or walking reflex involves a baby putting one foot in front of the other when their soles touch a flat surface; this reflex goes away around 8 weeks of age and resurfaces several months later when the baby is actually learning to walk (choice C is correct). The Moro reflex, also known as the startle reflex, is present from birth to about 4 or 5 months of age, and involves the infant spreading arms out then retracting them and usually crying in response to being startled (choice A is wrong). The Babinski reflex, which is normal in infants and disappears by 12-24 months, involves the fanning out of toes and dorsiflexion of the big toe in response to stroking the sole of the foot. The Babinski reflex, if present in an adult, can signify disease in the spinal cord or brain. This reflex is not associated with balance and learning to walk (choice B is wrong). The rooting reflex, present from birth to about 4 months of age, involves an infant turning it’s head and rooting with it’s mouth in response to a touch to the cheek or lips (choice D is wrong).

Question 52

Solomon Asch is famous for which study

Answer 52

Solomon Asch conducted the famous line study and others like it in order to study the effects of conformity. Asch presented subjects with pictures of three lines of varying lengths and asked them to match one of the lines to a line that he had on a separate card. Although one choice was clearly correct, when confederates in the room selected a patently incorrect choice the subjects often followed suit. Asch argued that this behavior was due to the pressure to conform

Question 53

PV=nRT

what do each of these terms mean and what relationships can we draw?

mnemonic: ideal gases are inert

Answer 53

P=pressure

V=volume

n=number of moles

R: gas constant

T: temperature

The number of collisions is directly proportional to pressure.

Question 54

“calculated pressure” or “calculated volume” in refrence to gases is referring to

Answer 54

what the ideal gas law would predict

Question 55

Increased intermolecular attractions cause the ratio PV/(RT) to decline because individual molecules

Answer 55

lose kinetic energy to potential energy and strike the side of the container with less force.

Question 56

at high pressure, values of PV/RT lower than ideal (that is, less than 1) are due predominantly to ______1_______.

values of PV/RT greater than ideal (that is, greater than 1) are due predominantly to ___2______.

Answer 56

1: intermolecular attractions;
2: molecular volume