Cell Theory and What It Actually Predicts About Life
A working tour of cell theory, the prokaryote-eukaryote split, the endosymbiotic origin of mitochondria, and the acellular agents that bend the rules.
8 min read
MCAT subject hub
MCAT Biology Hub
Public biology overview for cell biology, physiology, genetics, and experimental reasoning.
Answer first
Biology questions reward mechanism tracking: what changes, where it changes, and how the passage measures it. Use this page as a public overview. Full lesson flows, quizzes, and account progress stay inside the private app, while these edited guide links give crawlers and students enough context to understand the topic area before signup.
Membrane Transport: How Molecules Actually Cross the Bilayer
A first-principles walkthrough of how the plasma membrane decides what crosses, what gets pumped, and what gets swallowed whole.
9 min read
The Endomembrane System: How Cells Move Proteins from Birth to Destination
How a protein travels from the rough ER through the Golgi to its final destination via vesicle trafficking, glycosylation, and address tags.
9 min read
Mitochondria and Bioenergetics: How Cells Turn Food Into ATP
Mitochondrial structure, the TCA cycle, the electron transport chain, and chemiosmotic ATP synthesis explained as one connected energy pipeline for the MCAT.
8 min read
Cytoskeleton and Motor Proteins: How Cells Hold Their Shape and Haul Cargo
How the three cytoskeletal filaments build cell architecture and how kinesin, dynein, and myosin convert ATP into directed mechanical work.
8 min read
Prokaryote vs Eukaryote: The Contrast That Anchors Cell Biology
A mechanism-first contrast of prokaryotic and eukaryotic cells covering compartmentalization, genome architecture, ribosomes, and the endosymbiotic origin story that ties it all together.
9 min read
How Viruses Hijack Your Cells: Replication Strategies That Matter on Test Day
A mechanism-first walkthrough of how DNA, RNA, and retroviral genomes commandeer host machinery to replicate, with the test-day distinctions students miss.
9 min read
Cell Junctions and the Extracellular Matrix: How Tissues Hold Together
Five junction types and the protein mesh outside the cell — what they do, why test writers love them, and how to keep them straight.
9 min read