USJ Medical Sciences Concours - Medicine, Dental Medicine & Pharmacy flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Na+/K+ ATPase

An active transport pump that moves three sodium ions out and two potassium ions into the cell per ATP hydrolyzed, maintaining resting membrane potential and cell volume.

Mendelian 9:3:3:1 ratio

The expected phenotype ratio from a dihybrid cross of two heterozygotes when genes assort independently and show complete dominance; deviations suggest linkage or epistasis.

Negative feedback loop

A homeostatic mechanism in which a change in a controlled variable triggers a response that opposes the change, restoring the variable toward its set point; examples include thermoregulation and blood glucose control.

Cardiac output

The volume of blood pumped by one ventricle per minute, equal to heart rate multiplied by stroke volume; typical resting value is about five liters per minute.

Oxygen-hemoglobin dissociation curve

A sigmoidal plot of hemoglobin oxygen saturation versus partial pressure of oxygen; rightward shifts from increased CO2, H+, temperature, or 2,3-BPG reduce affinity and enhance tissue oxygen unloading.

Cellular respiration ATP yield

Complete oxidation of one glucose molecule yields about 30 to 32 ATP in eukaryotes via glycolysis, pyruvate oxidation, the citric acid cycle, and oxidative phosphorylation.

Mole concept

One mole contains 6.022×10^23 representative particles and has a mass in grams equal to the molar mass; it links particle counts to measurable laboratory quantities.

Le Chatelier's principle

When a system at equilibrium is disturbed by changes in concentration, pressure, or temperature, the equilibrium shifts in the direction that partially counteracts the disturbance.

Michaelis-Menten equation

v = Vmax[S]/(Km + [S]) describes enzyme kinetics; Km is the substrate concentration at half-maximal velocity and reflects enzyme-substrate affinity.

Carboxylic acid functional group

A carbonyl carbon bonded to a hydroxyl group (–COOH); it is acidic, forms esters with alcohols, and gives amides with amines.

Gibbs free energy

ΔG = ΔH − TΔS; a negative ΔG indicates a spontaneous process at constant temperature and pressure, while zero means equilibrium.

Poiseuille's law

Flow through a cylindrical tube is proportional to the fourth power of radius and the pressure gradient, and inversely proportional to length and fluid viscosity.

Bernoulli's equation

For steady, incompressible, nonviscous flow, P + ½ρv² + ρgh is constant along a streamline; higher fluid speed corresponds to lower pressure.

Ohm's law

Current through a conductor equals voltage divided by resistance (I = V/R); it applies to ohmic materials at constant temperature.

Wave equation

For a wave, speed equals frequency multiplied by wavelength (v = fλ); frequency is set by the source, while speed depends on the medium.

Doppler effect

The observed frequency increases when source and observer approach and decreases when they separate; the shift depends on relative velocity and wave speed.

Thin lens equation

1/f = 1/do + 1/di relates focal length, object distance, and image distance; positive di indicates a real image on the opposite side.

Conditional probability

P(A|B) = P(A∩B)/P(B); it gives the probability of event A given that event B has occurred and requires P(B) > 0.

Bayes' theorem

P(A|B) = P(B|A)P(A)/P(B); it updates a prior probability using the likelihood of observed evidence and the total probability of that evidence.

Binomial distribution

Models the number of successes in n independent trials with constant success probability p; mean is np and variance is np(1−p).

Normal distribution 68-95-99.7

In a normal distribution, about 68% of values lie within one standard deviation of the mean, 95% within two, and 99.7% within three.

Sensitivity and specificity

Sensitivity is true positives divided by all diseased; specificity is true negatives divided by all non-diseased; both are properties of the test.

Positive control

A group expected to produce a known positive result, confirming that the assay or procedure can detect the effect when it is truly present.

Confounding variable

An unmeasured factor associated with both the exposure and the outcome that can create or distort an observed association if not controlled.

Dimensional analysis

A method that multiplies by conversion factors written as fractions equal to one, canceling units to yield the desired unit and catch errors.

Correlation versus causation

Correlation measures association between variables; causation requires evidence such as temporal order, dose-response, and control of confounding, often from randomized experiments.

Diagnostic likelihood ratio

Positive likelihood ratio equals sensitivity divided by (1 − specificity); values above 10 substantially increase the post-test probability of disease.

Main idea identification

The central claim or purpose of a passage, usually stated in the introduction or conclusion and supported by most paragraphs rather than by a single detail.

Inference in reading

A conclusion logically implied but not explicitly stated; valid inferences must be supported by textual evidence and cannot rely on outside assumptions.

Hedging language

Words such as may, suggest, likely, or appear that signal tentativeness; they distinguish cautious scientific claims from established facts.

Reference word resolution

Identifying what pronouns such as it, they, or this point back to by checking number, gender, and nearby nouns, often the preceding sentence's subject.

Cause-effect signpost

Connectors such as because, therefore, due to, and consequently that signal causal relationships; distinguishing them from contrast markers prevents misreading arguments.