PACAT Practice Exam - Version 2 Flashcards
Case:
Chlorine, potassium chloride, manganese (II) chloride, and water are to be produced by a graduate student through a reaction between potassium permanganate and hydrochloric acid. As part of their pre-lab checklist, the graduate student balances the chemical equation per the law of conservation of matter.
Question:
What coefficient is assigned to hydrochloric acid?
a. 1
b. 2
c. 4
d. 16
d. 16
Case:
Ubiquitination is a post-translational modification used to regulate many processes: the cell cycle, cell death, protein function, protein degradation by the proteasome. Deubiquitinating enzymes remove ubiquitin from proteins, with implications in the same processes. Some viruses use deubiquitinating enzymes as a way to hijack the host cell.
Question:
What type of small molecule would combat such a virus?
a. Deubiquitinating enzyme activator
b. Deubiquitinating enzyme inhibitor
c. Proteasome activator
d. Proteasome inhibitor
b. Deubiquitinating enzyme inhibitor
Case:
Down syndrome (trisomy 21) is an inherited genetic disorder associated with intellectual disability, characteristic facial appearance, and weak muscle tone (hypotonia) in infancy. It is a chromosomal disorder where affected children carry an extra copy of the 21st chromosome.
Question:
What is the genetic categorization of this disease?
a. Aneuploidy
b. Duplication
c. Euploidy
d. Insertion
a. Aneuploidy
Case:
An epidemic of diarrheal disease caused by toxigenic Vibrio cholera affects a population.
Question:
What pathogen represents the source of disease?
a. Bacteriophage
b. Parasite
c. Prion
d. Virus
a. Bacteriophage
Case:
A graduate student is tasked with making a sodium hydroxide (NaOH) solution.
Question:
What solvent is most appropriate?
a. C3H8O
b. C6H14
c. H2O
d. Pd
c. H2O
Frequency Table
A B C D E F
1 0 1 2 2 0
What word matches this letter frequency table?
a. ADDED
b. BEADED
c. DECADE
d. DEFACED
c. DECADE
Case:
DNA strands are wound around histones to form nucleosomes when forming chromosomes. Post-translational modification of histones affects the chromatin structure. One common post-translational histone modification is histone acetylation, where a positively charged lysine residue on the histone is acetylated and loses its charge.
Question:
How will histone acetylation affect chromatin structure and transcription?
a. Compact chromatin, decrease transcription
b. Compact chromatin, increase transcription
c. Relax chromatin, decrease transcription
d. Relax chromatin, increase transcription
d. Relax chromatin, increase transcription
Pyruvate formed through the glycolytic pathway is transported to the mitochondrial matrix during the second stage of aerobic oxidation.
What is the end product of this oxidation?
a. CO2
b. FADH2
c. NAD+
d. O2
a. CO2
Case:
A gas travels through a porous structure with openings smaller than the mean free path of the particles of the gas.
Question:
The opening must be smaller than what parameter?
a. Diameter of the molecule
b. Distance between collisions
c. Knudsen number
d. Viscosity of the gas
b. Distance between collisions
Case:
Neurofibromatosis type 1 (NF1) is a genetic disease that results in dark spots (cafe-au-lait spots) and tumors on nerves in the skin, brain, and other parts of the body. With each pregnancy, one affected parent (father or mother) will have offspring with a 50% chance of being affected by the disease.
Question:
What can be deduced about the pattern of inheritance for NF1?
a. Autosomal dominant
b. Autosomal recessive
c. X-linked dominant
d. X-linked recessive
a. Autosomal dominant
Case:
The rate of a certain condition in the United States is 2% of adults over age 50. A sample of 200 people from this population is taken.
Question:
What is the mean proportion of the sampling distribution of adults over 50 with this condition?
a. 0.02
b. 0.04
c. 2
d. 4
a. 0.02
A scatter plot shows a data sample of efficiency versus area. Refer to the image.
When the area decreases, does the efficiency generally increase or decrease?
a. Cannot be determined
b. Decrease
c. Increase
d. Stays the same
b. Decrease
Case:
The structure of the fungal cell wall is simple and based on substances other than ones found in animals and plants, which aids production of antifungal medications that are not toxic to mammals.
Question:
Which cell wall component is useful for this targeting?
a. Chitin
b. D-amino acids
c. Peptidoglycan
d. Protomers
a. Chitin
The overall process of transcription is similar in prokaryotes and eukaryotes, but there are fundamental differences.
Which characteristic of transcription is unique to eukaryotes?
a. Lack of post-transcriptional modification
b. Presence of 3 types of RNA polymerase
c. Simple initiation machinery
d. Transcription and translation as a continuous process
b. Presence of 3 types of RNA polymerase
Case:
A state of hypokalemia is increasing the ionic concentration gradient of a cardiac myocyte.
Question:
What additional factor favors potassium efflux under these conditions?
a. Depolarization
b. Insulation
c. Permeability
d. Resistance
c. Permeability
T4 lysozyme is an enzyme that cleaves peptidoglycan in bacterial cell walls. Its activity is pH-dependent, with highest activity when Asp20 is deprotonated and Glu11 is protonated.
If Asp20 has a pKa of 3.6 and Glu11 has a pKa of 5.4, at what pH would you expect the enzyme to be most active?
a. 2.5
b. 4.5
c. 5.5
d. 7.5
b. 4.5
Case:
When a depolarization threshold is reached, a neuron channel for sodium opens, allowing an influx of sodium to enter the cell.
Question:
What is the most direct effector of this phenomenon?
a. Current
b. Induction
c. Potential
d. Resistance
c. Potential
Case:
Programmed DNA double-strand breaks are occurring during meiosis.
Question:
What characteristic will be most heavily influenced?
a. Chromatin strength
b. DNA replication
c. Genetic diversity
d. Reduction division
c. Genetic diversity
Case:
A graduate student is tasked with mixing two containers of gas. The first is 20 L of H2 at 0.8 atm, and the second is 15 L of O2 at 1 atm. Both containers are at standard temperature. Both gases are to be added to a container with a volume of 10 L.
Question:
Once mixed, what is the partial pressure of H2?
a. .8 atm
b. 1.33 atm
c. 1.59 atm
d. 1.8 atm
c. 1.59 atm
The rate of diffusion of a solute across a semipermeable membrane can be affected by several factors.
What factor affects the kinetic energy level of the solute molecules, increasing or decreasing the rate of diffusion?
a. Concentration gradient
b. Mass of molecules
c. Surface area
d. Temperature
d. Temperature
A team of psychologists assesses the effectiveness of two interventions on reducing alcohol consumption: 12-step programs and cognitive behavioral therapy. The psychologists randomly assign 200 patients addicted to alcohol to attend 12-step groups and 200 to attend cognitive behavioral therapy.
What term best describes the type of study the psychologists conducted?
a. Case study
b. Experiment
c. Observational study
d. Survey
b. Experiment
Case:
One organism performs the processes of transcription and translation simultaneously. A second organism undergoes post-transcriptional transformation to protect newly synthesized RNA from the nucleus to the ribosome.
Question:
Where does transcription occur in the first organism?
a. Cytoplasm
b. Golgi apparatus
c. Lysosome
d. Nucleus
a. Cytoplasm
Case:
A patient presents with flank pain and hematuria. On CT scan, the patient is found to have an obstructing renal calculus.
Question:
Where is the stone most likely lodged?
a. Crossing common iliac arteries
b. Crossing external iliac arteries
c. Crossing psoas muscle
d. Crossing renal arteries
a. Crossing common iliac arteries
Case:
Operant conditioning uses positive and negative reinforcement and punishment to modify behavior.
Question:
What is an example of negative reinforcement?
a. A child is placed in timeout for misbehaving.
b. An adolescent is given extra chores after missing curfew.
c. An alarm sounds in a car until the seatbelts are fastened.
d. An employee earns a bonus for performance at work.
c. An alarm sounds in a car until the seatbelts are fastened.