MDCAT Prep · Biology · Quick Reference

Lesson 5 — Cell Biology Cheat Sheet

Biology

In one line: Mitochondria make ATP, ribosomes make protein, lysosomal enzyme deficiencies cause storage diseases, and tonicity decides whether a cell swells or shrinks.

Key Ideas

1Mitochondria. Double membrane, cristae, own DNA, Krebs cycle + oxidative phosphorylation.

2Ribosomes. 80S (40S+60S) in eukaryotes; 70S (30S+50S) in prokaryotes.

3Lysosomal diseases. Tay-Sachs = hexosaminidase A deficiency; Gaucher = glucocerebrosidase deficiency.

4Fluid mosaic model. Phospholipid bilayer + integral/peripheral proteins + glycoproteins for recognition.

5Osmosis. Hypotonic → swell/lysis; hypertonic → shrink/plasmolysis.

Quick Pairs

Eukaryotic ribosome

80S = 40S + 60S

Prokaryotic ribosome

70S = 30S + 50S

Tay-Sachs disease

↓ Hexosaminidase A

Gaucher disease

↓ Glucocerebrosidase

Hypotonic = water IN = swell/lysis Hypertonic = water OUT = shrink/plasmolysis