Mixed Deck — All PCAT Topics Flashcards

Which of the following best describes the colligative property of boiling point elevation?

Answer: It depends only on the number of solute particles in solution

Boiling point elevation is a colligative property, meaning it depends on the number (not the identity) of dissolved solute particles per kilogram of solvent.

Resistance to beta-lactam antibiotics via production of beta-lactamase enzymes can be overcome by administering:

Answer: Clavulanic acid

Clavulanic acid is a beta-lactamase inhibitor that irreversibly binds and inactivates beta-lactamase, protecting co-administered beta-lactam antibiotics.

Which of the following organisms does not have mitochondria?

Answer: bacteria

Bacteria are prokaryotic organisms, meaning they lack membrane-bound organelles, including mitochondria. Instead of mitochondria, bacteria perform cellular respiration using enzymes embedded in their cell membrane. Amoeba, fungi, and protozoans are all eukaryotic organisms and therefore possess mitochondria for energy production.

Which of the following is equivalent to (x²y³)⁴ / (x³y²)?

Answer: x⁵y¹⁰

(x²y³)⁴ = x⁸y¹²; dividing by x³y² gives x⁵y¹⁰.

What is the net ATP yield from complete aerobic oxidation of one glucose molecule (using the malate-aspartate shuttle)?

Answer: 30-32 ATP

Modern estimates calculate approximately 30-32 ATP net from aerobic glucose oxidation, accounting for the actual P/O ratios of NADH (~2.5 ATP) and FADH2 (~1.5 ATP) rather than the older theoretical values.

During meiosis II, which event separates sister chromatids?

Answer: Anaphase II

During Anaphase II, cohesins break down and sister chromatids are pulled to opposite poles of the cell.

Hemoglobin has the strongest bonds with which of the following?

Answer: carbon monoxide

Hemoglobin has an affinity for carbon monoxide (CO) that is approximately 200-250 times greater than its affinity for oxygen. When CO is present, it preferentially binds to hemoglobin, forming carboxyhemoglobin and effectively preventing oxygen transport to tissues. This strong, stable binding is why carbon monoxide is highly toxic.

What is the role of telomerase in cancer cells?

Answer: It adds telomeric sequences to chromosome ends, enabling indefinite replication

Cancer cells overexpress telomerase, which lengthens telomeres after each division, preventing replicative senescence and allowing unlimited proliferation.

A PCAT reading passage contains this sentence: 'The intervention was efficacious in the subgroup analysis, though the primary endpoint was not met.' What is the most accurate interpretation?

Answer: The overall study did not achieve its main goal, but a specific smaller group showed a positive effect

Missing the primary endpoint means the overall study hypothesis was not confirmed; a positive subgroup finding is hypothesis-generating but does not constitute proof of overall efficacy.

Which cellular structure selectively controls the passage of substances into and out of the cell?

Answer: Plasma membrane

The plasma membrane is a selectively permeable phospholipid bilayer with embedded proteins that regulate what enters and exits the cell.

Which of the following functional groups is correctly identified?

Answer: R-CO-NH2 = primary amide

R-CO-NH2 is a primary amide because the nitrogen bears no additional carbon substituents.

In professional documentation for PCAT, what is the best practice for organizing information?

Answer: Logical structure with clear headings and progression

Logical structure with clear headings helps readers find information quickly and follow the progression of ideas effectively.

Which type of cell junction allows direct communication between adjacent cells via cytoplasmic channels?

Answer: Gap junctions

Gap junctions consist of connexin protein channels (connexons) that allow ions and small molecules to pass directly between neighboring cells.

A passage argues that 'increased medication adherence leads to better patient outcomes.' Which type of evidence would most strongly support this argument?

Answer: A randomized controlled trial showing statistically significant outcome improvements in a high-adherence group versus a low-adherence group

A randomized controlled trial with a statistically significant result provides the highest level of clinical evidence to establish a causal link between adherence and outcomes.

What is the hybridization of the carbon atom in CO2?

Answer: sp

Carbon in CO2 forms two double bonds with no lone pairs, resulting in sp hybridization and a linear molecular geometry.

Which quantum number describes the orientation of an orbital in space?

Answer: Magnetic quantum number (ml)

The magnetic quantum number (ml) specifies the orientation of an orbital in three-dimensional space relative to the other orbitals in the same subshell.

Which neurotransmitter is released at the neuromuscular junction to initiate skeletal muscle contraction?

Answer: Acetylcholine

Acetylcholine released from motor neurons binds nicotinic receptors on the motor end plate, triggering an end-plate potential that leads to muscle contraction.

The oxygen-hemoglobin dissociation curve shifts to the RIGHT in which condition?

Answer: Elevated 2,3-bisphosphoglycerate (2,3-BPG)

Increased 2,3-BPG (produced in exercising muscle) stabilizes deoxyhemoglobin, reducing O₂ affinity and promoting O₂ delivery to tissues.

Which bond links nucleotides together in a DNA strand?

Answer: 3',5'-phosphodiester bond

Adjacent nucleotides in a DNA strand are connected by phosphodiester bonds formed between the 3'-hydroxyl of one sugar and the 5'-phosphate of the next.

A passage argues that 'generic drugs are bioequivalent to brand-name drugs.' Which claim, if true, would most weaken this argument?

Answer: Studies show that certain generic formulations produce significantly different peak plasma concentrations compared to their brand-name counterparts

Bioequivalence requires similar pharmacokinetic parameters including peak plasma concentration (Cmax); significant differences in Cmax would directly undermine the bioequivalence claim.