MCAT Section Bank Concepts Flashcards

Chemistry and Physics Concepts

• Induced Fit Model: Active site changes shape to better bind substrate.
• Photon Energy: Proportional to radiation frequency.
• Transferase Enzymes: Function to transfer functional groups between molecules.
• Tm (Melting Temperature): Temperature where half of proteins in solution denatured.
• Kcat (Turnover Number): Rate-limiting step under saturating substrate conditions; lower y-intercept indicates higher Kcat.
• Km (Michaelis Constant): Substrate concentration at which reaction rate is half of Vmax.

Hydrogen Bonding in Nucleotides

• Adenine: One hydrogen bond donor and one acceptor.
• Thymine: One hydrogen bond donor and one acceptor.
• Guanine: Two hydrogen bond donors and one acceptor.
• Cytosine: One hydrogen bond donor and two acceptors.

Biochemical Properties and Reactions

• High pI: Contributed by basic residues.
• Reducing Sugar Requirement: Must have a hemiacetal end.
• pH Effects: High pH leads to deprotonation; low pH leads to protonation.
• Cysteine Presence: Indicates covalent disulfide bonds in dimers.
• Protein Unfolding Curve: Sigmoidal shape due to cooperative processes.

Enzyme Kinetics

• Catalytic Efficiency: Calculated as Kcat/Km; low Kcat and high Km decrease efficiency.
• Uncompetitive Inhibitors: More effective at high substrate concentration; lower both Km and Vmax.
• Lineweaver-Burk Plot Slope: Km/Vmax.
• Competitive Inhibitors: Do not affect Vmax; solely increase Km.

Structural Biology

• Transmembrane Helices: Comprised of stretches of hydrophobic amino acids.
• Dimerization: Interaction of two receptor proteins to form functional complexes.
• Phosphodiester Bonds: Link adjacent nucleotides in DNA, not involved in tertiary structure stabilization.

Protein Separation Techniques

• Isoelectric Focusing and Ion Exchange Chromatography: Separate proteins based on charge.
• SDS-PAGE: Separates proteins based on mass.
• Affinity Chromatography: Separates proteins based on ligand interactions.

Metabolism and Enzyme Functions

• Glucose-6-Phosphatase: Active in both gluconeogenesis and glycogenolysis.
• Glycogen Phosphorylase: Catalyzes the rate-limiting step of glycogen breakdown.
• Glycerol: Acts as a gluconeogenesis precursor.
• Phosphogluconate: Involved in pentose phosphate pathway, not gluconeogenesis.

Molecular Biology Techniques

• cDNA Cloning Tools: Utilizes DNA polymerase, DNA ligase, and reverse transcriptase; RNA polymerase is not used.
• Deamidation Reaction: Releases ammonia (NH3).
• Hill Coefficient: Measures cooperativity; values greater than 1 indicate positive cooperativity.

Psychology and Sociology Concepts

• Hypothalamus: Maintains homeostasis but does not influence learning and attention.
• Cocaine: Acts as a stimulant; mirrors stress response affecting glucose metabolism.
• Monozygotic Twins: Identical twins from a single zygote splitting into two embryos.
• Social Epidemiology: Examines the impact of social and cultural factors on disease patterns.

Behavioral Theories and Models

• Looking-Glass Self: Self-image shaped by perceived views of others.
• Demographic Transition Theory: Describes the decrease in birth and death rates.
• General Adaptation Syndrome (GAS): Stress response with three phases: alarm, resistance, exhaustion.
• Signal Detection Theory: Relies on stimulus strength and psychological factors.

Neurology and Cognition

• fMRI: Measures brain activity through blood flow changes.
• Fluid Intelligence: The ability to solve problems and think on one’s feet.
• Effect of Severed Corpus Callosum: Individuals can name objects presented to the right side due to left hemisphere processing.

Social Structures

• Vertical Mobility: Movement between social positions of different ranks.
• McDonaldization: Describes the spread of efficiency and dehumanization in modern society.