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MCAT (Medical College Admission Test) Biological and Biochemical Foundations of Living Systems Syllabus

The Biological and Biochemical Foundations of Living Systems syllabus for MCAT (Medical College Admission Test) in full: 5 chapters, 22 topics and 53 sub-topics, every one listed below, plus 51 Biological and Biochemical Foundations of Living Systems flashcards with answers.

5Chapters

22Topics

53Sub-topics

51Flashcards

Biological and Biochemical Foundations of Living Systems syllabus: all 5 chapters

Expand any chapter to see its topics and sub-topics.

Biomolecules: Structure and Function
4 topics
- Amino Acids and Proteins
  - Classification, side chains, and isoelectric point
  - Primary, secondary, tertiary, and quaternary structure
  - Protein folding, denaturation, and the peptide bond
- Carbohydrates
  - Monosaccharides, stereochemistry, and anomers
  - Glycosidic linkages and polysaccharides
- Lipids
  - Fatty acids, triacylglycerols, and phospholipids
  - Steroids, terpenes, and membrane lipids
- Nucleic Acids
  - Nucleotide structure and base pairing
  - DNA and RNA architecture
Enzymes and Metabolism
5 topics
- Enzyme Function and Regulation
  - Active site, specificity, and catalytic mechanisms
  - Michaelis-Menten and Lineweaver-Burk kinetics
  - Competitive, noncompetitive, and allosteric inhibition
- Carbohydrate Metabolism
  - Glycolysis and gluconeogenesis
  - Citric acid cycle
  - Glycogenesis and glycogenolysis
- Oxidative Phosphorylation
  - Electron transport chain
  - Chemiosmosis and ATP synthase
- Lipid and Amino Acid Metabolism
  - Beta-oxidation and ketone bodies
  - Fatty acid synthesis
  - Transamination and the urea cycle
- Metabolic Integration and Regulation
  - Hormonal control of fed and fasted states
  - Tissue-specific metabolism
Molecular Biology and Genetics
5 topics
- DNA Replication and Repair
  - Replication machinery and fidelity
  - Mutations and DNA repair mechanisms
- Transcription and Translation
  - RNA synthesis and processing
  - The genetic code and ribosomal translation
  - Post-translational modification
- Gene Expression and Regulation
  - Operons in prokaryotes
  - Eukaryotic transcription factors and epigenetics
- Classical and Molecular Genetics
  - Mendelian inheritance and pedigrees
  - Linkage, recombination, and Hardy-Weinberg equilibrium
- Biotechnology Techniques
  - PCR, gel electrophoresis, and cloning
  - DNA sequencing and CRISPR
Cell Biology and Microbiology
3 topics
- Cell Structure and Organelles
  - Plasma membrane and transport mechanisms
  - Nucleus, ER, Golgi, and lysosomes
  - Mitochondria and the cytoskeleton
- The Cell Cycle and Cell Death
  - Mitosis, meiosis, and checkpoints
  - Apoptosis and cancer biology
- Microbiology and Viruses
  - Prokaryotic structure and reproduction
  - Viral life cycles (lytic and lysogenic)
  - Fungi and bacterial genetics
Human Physiology and Organ Systems
5 topics
- Nervous and Endocrine Systems
  - Neuron structure and action potentials
  - Synaptic transmission and reflex arcs
  - Hormonal signaling and feedback loops
- Circulatory, Respiratory, and Immune Systems
  - Heart anatomy and the cardiac cycle
  - Gas exchange and respiratory mechanics
  - Innate and adaptive immunity
- Digestive and Excretory Systems
  - Digestion, absorption, and accessory organs
  - Nephron function and osmoregulation
- Musculoskeletal and Integumentary Systems
  - Muscle contraction and sliding filament theory
  - Bone structure and remodeling
- Reproduction and Development
  - Gametogenesis and fertilization
  - Embryonic development and differentiation

MCAT (Medical College Admission Test) Biological and Biochemical Foundations of Living Systems flashcards — 51 questions with answers

What distinguishes the structures of the 20 standard amino acids from one another?
Their R-group (side chain), which determines polarity, charge, and chemical behavior. All share a central alpha carbon bonded to an amino group, a carboxyl group, and an H.
Name the only achiral standard amino acid and explain why.
Glycine, because its R-group is a single hydrogen atom, so the alpha carbon has two identical H substituents and is not a stereocenter.
What four levels of protein structure exist, and what stabilizes each?
Primary (peptide bonds), secondary (H-bonds in backbone forming alpha-helices/beta-sheets), tertiary (R-group interactions: disulfide bonds, hydrophobic, ionic, H-bonds), quaternary (interactions between multiple subunits).
What is the isoelectric point (pI) of an amino acid?
The pH at which the molecule carries no net charge (exists as a zwitterion). For a simple amino acid, pI = average of the two relevant pKa values.
What is the general molecular formula of carbohydrates, and how are monosaccharides classified?
(CH2O)n. Classified by number of carbons (triose, pentose, hexose) and by carbonyl type: aldoses (aldehyde) or ketoses (ketone).
Distinguish alpha and beta anomers of a cyclic sugar.
They differ in configuration at the anomeric carbon: in alpha the OH is on the opposite side (axial/trans) from the CH2OH reference; in beta it is on the same side (cis). E.g., alpha-glucose vs beta-glucose.
Compare the glycosidic linkages in starch, glycogen, and cellulose.
Starch and glycogen use alpha-1,4 linkages (with alpha-1,6 branches); cellulose uses beta-1,4 linkages, making it indigestible to humans and structurally rigid.
What functional definition distinguishes lipids from other macromolecules?
Lipids are defined by solubility, not structure: they are hydrophobic/amphipathic molecules soluble in nonpolar solvents but insoluble in water.
What is the difference between saturated and unsaturated fatty acids?
Saturated fatty acids have no C=C double bonds (straight chains, solid at room temp); unsaturated have one or more double bonds (kinks, lower melting point, often liquid).
Describe the structure of a phospholipid and why it forms bilayers.
A glycerol backbone with two hydrophobic fatty acid tails and a hydrophilic phosphate head. This amphipathic nature drives spontaneous bilayer formation in water.
What are the components of a nucleotide?
A five-carbon sugar (ribose or deoxyribose), a nitrogenous base, and one to three phosphate groups.
State Chargaff's rules and the base-pairing scheme of DNA.
In DNA, A pairs with T (2 H-bonds) and G pairs with C (3 H-bonds); thus %A=%T and %G=%C. Purines (A, G) pair with pyrimidines (C, T).
How do the strands of a DNA double helix run relative to one another?
Antiparallel: one strand runs 5' to 3' while the complementary strand runs 3' to 5'.
What is the difference between competitive and noncompetitive enzyme inhibition (effect on Km and Vmax)?
Competitive: inhibitor binds active site; raises apparent Km, Vmax unchanged. Noncompetitive: binds allosteric site; Vmax decreases, Km unchanged.
What does the Michaelis constant (Km) represent?
The substrate concentration at which reaction velocity is half of Vmax. A low Km indicates high enzyme affinity for the substrate.
What is feedback inhibition in metabolic regulation?
The end product of a pathway allosterically inhibits an enzyme earlier in the pathway (often the committed/rate-limiting step), preventing overaccumulation.
What are the net products of glycolysis per glucose molecule?
2 pyruvate, 2 net ATP, and 2 NADH. Glycolysis occurs in the cytoplasm.
What is the rate-limiting enzyme of glycolysis and how is it regulated?
Phosphofructokinase-1 (PFK-1). It is inhibited by ATP and citrate and activated by AMP and fructose-2,6-bisphosphate.
What are the per-turn products of the citric acid (Krebs) cycle?
Per acetyl-CoA: 3 NADH, 1 FADH2, 1 GTP (or ATP), and 2 CO2. It occurs in the mitochondrial matrix.
What is the role of the electron transport chain and the final electron acceptor?
It uses NADH and FADH2 to pump protons across the inner mitochondrial membrane, creating a gradient. Oxygen is the final electron acceptor, forming water.

Show the other 31 Biological and Biochemical Foundations of Living Systems flashcards

How does ATP synthase produce ATP (chemiosmosis)?
Protons flow down their electrochemical gradient through ATP synthase from the intermembrane space into the matrix; this flow drives phosphorylation of ADP to ATP.
Approximately how many ATP are produced from complete oxidation of one glucose, and from each NADH and FADH2?
About 30-32 ATP total. Each NADH yields about 2.5 ATP and each FADH2 about 1.5 ATP via oxidative phosphorylation.
What is beta-oxidation and what does it produce per cycle?
The mitochondrial breakdown of fatty acids that cleaves two carbons at a time, yielding 1 acetyl-CoA, 1 NADH, and 1 FADH2 per cycle.
What are ketone bodies and when are they produced?
Acetoacetate, beta-hydroxybutyrate, and acetone, produced by the liver from acetyl-CoA during prolonged fasting/starvation or low-carbohydrate states as alternative fuel.
What is the fate of the amino group during amino acid catabolism?
It is removed by transamination/deamination, forming ammonia, which is converted to urea via the urea cycle in the liver for excretion.
Which hormones oppose each other in blood glucose regulation, and what does each do?
Insulin lowers blood glucose (promotes uptake, glycogenesis); glucagon raises it (promotes glycogenolysis and gluconeogenesis). Both are made in the pancreas.
What is the difference between the absorptive (fed) and postabsorptive (fasting) metabolic states?
Fed state: insulin dominates, storing glucose as glycogen/fat. Fasting state: glucagon dominates, mobilizing glycogen, fat, and gluconeogenesis to maintain blood glucose.
Why is DNA replication described as semiconservative?
Each daughter double helix contains one original (parental) strand and one newly synthesized strand.
What is the function of DNA polymerase, primase, helicase, and ligase in replication?
Helicase unwinds the helix; primase lays RNA primers; DNA polymerase adds nucleotides 5' to 3'; ligase joins Okazaki fragments on the lagging strand.
What is the difference between the leading and lagging strands?
The leading strand is synthesized continuously toward the replication fork; the lagging strand is synthesized discontinuously in Okazaki fragments away from the fork.
Name two DNA repair mechanisms and what they correct.
Mismatch repair fixes replication errors missed by proofreading; nucleotide excision repair removes bulky lesions like thymine dimers; base excision repair removes single damaged bases.
What are the three stages of transcription?
Initiation (RNA polymerase binds the promoter), elongation (RNA synthesized 5' to 3' from the template strand), and termination (RNA released).
What three modifications convert eukaryotic pre-mRNA to mature mRNA?
Addition of a 5' guanine cap, addition of a 3' poly-A tail, and splicing out of introns (keeping exons).
What is the role of tRNA and the codon-anticodon relationship in translation?
tRNA carries a specific amino acid and has an anticodon that base-pairs with the complementary mRNA codon, ensuring the correct amino acid is added.
What are the start and stop codons of translation?
Start codon: AUG (codes for methionine). Stop codons: UAA, UAG, UGA (signal termination, code for no amino acid).
How do the lac and trp operons differ in regulatory logic?
The lac operon is inducible (turned ON by lactose/allolactose, a catabolic pathway); the trp operon is repressible (turned OFF when tryptophan is abundant, an anabolic pathway).
How do eukaryotes regulate gene expression through chromatin and epigenetics?
Histone acetylation loosens chromatin and activates transcription; DNA methylation and histone deacetylation condense chromatin and silence genes.
State Mendel's laws of segregation and independent assortment.
Segregation: the two alleles for a trait separate during gamete formation. Independent assortment: alleles of different genes assort independently (for unlinked genes).
What is the difference between incomplete dominance and codominance?
Incomplete dominance: heterozygote shows a blended intermediate phenotype (red x white = pink). Codominance: both alleles are fully and simultaneously expressed (AB blood type).
How is recombination frequency used to map genes?
Recombination frequency between two loci is proportional to the distance between them; 1% recombination = 1 map unit (centimorgan). Linked genes recombine less frequently.
What does PCR do and what are its three temperature steps?
PCR amplifies a specific DNA sequence. Steps: denaturation (~95C, separates strands), annealing (~55C, primers bind), and extension (~72C, Taq polymerase synthesizes DNA).
What is the principle of gel electrophoresis?
DNA/RNA/protein fragments are separated by size and charge in a gel under an electric field; negatively charged nucleic acids migrate toward the positive electrode, smaller fragments moving faster.
Compare Southern, Northern, and Western blots.
Southern detects DNA, Northern detects RNA, Western detects protein (using antibodies).
List three structures found in eukaryotic but not prokaryotic cells.
Membrane-bound nucleus, mitochondria, and other membrane-bound organelles (e.g., ER, Golgi, lysosomes).
What are the functions of the rough ER, smooth ER, and Golgi apparatus?
Rough ER synthesizes/folds proteins (has ribosomes); smooth ER synthesizes lipids and detoxifies; Golgi modifies, sorts, and packages proteins for secretion.
What are the phases of the cell cycle and the key checkpoints?
G1, S (DNA synthesis), G2 (collectively interphase), and M (mitosis). Checkpoints: G1/S (restriction point), G2/M, and the spindle (metaphase) checkpoint.
What is apoptosis and how does it differ from necrosis?
Apoptosis is programmed, controlled cell death (cell shrinks, no inflammation) executed by caspases. Necrosis is uncontrolled death from injury, causing cell swelling and inflammation.
Compare lytic and lysogenic viral life cycles.
Lytic: virus replicates immediately and lyses the host cell. Lysogenic: viral DNA integrates into the host genome as a provirus/prophage and replicates passively until induced into the lytic cycle.
How does an action potential propagate along a neuron?
Depolarization opens voltage-gated Na+ channels (influx), then K+ channels open (efflux) to repolarize; the wave travels down the axon, jumping between nodes of Ranvier in myelinated neurons (saltatory conduction).
What is the difference between the systemic and pulmonary circulation, and which side of the heart drives each?
Pulmonary circulation (right heart) sends deoxygenated blood to the lungs; systemic circulation (left heart) sends oxygenated blood to the body.
Trace the path of a nephron's filtrate and the main function of each segment.
Glomerulus (filtration) to proximal tubule (bulk reabsorption) to loop of Henle (concentration gradient) to distal tubule (regulated Na+/K+) to collecting duct (water reabsorption via ADH).

MCAT (Medical College Admission Test) Biological and Biochemical Foundations of Living Systems FAQ

What is in the MCAT (Medical College Admission Test) Biological and Biochemical Foundations of Living Systems syllabus?

MCAT (Medical College Admission Test) Biological and Biochemical Foundations of Living Systems is split into 5 chapters: Biomolecules: Structure and Function, Enzymes and Metabolism, Molecular Biology and Genetics, Cell Biology and Microbiology and Human Physiology and Organ Systems. Together they contain 22 topics and 53 sub-topics.

How many chapters are in MCAT (Medical College Admission Test) Biological and Biochemical Foundations of Living Systems?

5 chapters, containing 22 topics and 53 sub-topics. The largest chapter is Enzymes and Metabolism, with 5 topics.

Are there flashcards for MCAT (Medical College Admission Test) Biological and Biochemical Foundations of Living Systems?

Yes — a 51-card Biological and Biochemical Foundations of Living Systems deck, printed in full in the flashcards section of this page and available in the Examius app with spaced repetition. The free plan covers one exam of your choice, including its flashcards; Examius Pro, a one-time purchase, unlocks every other exam and deck.