1. Microscopy & Fractionation
Light Microscope (LM): Living cells / Dynamic processes.
SEM: 3D / Surface / Topography.
TEM: Internal / Ultrastructure / Cross-sections.
Resolution: Image clarity (Closer distance = Better
resolution).
Cell Fractionation Rule: Heavy/Big pellets First (Low
speed) \rightarrow Light/Small pellets Last (High speed).
Centrifugation Order: Nuclei (Low) \rightarrow
Mitochondria/Chloroplasts (Medium) \rightarrow
Microsomes/ER (High) \rightarrow Ribosomes (Highest).
2. Cell Architecture & Sizes
Universal Features: Plasma Membrane + Cytosol +
Chromosomes + Ribosomes.
Prokaryotes: No Nucleus (Nucleoid) / No organelles / Small
(1-5\,\mu\text{m}).
Eukaryotes: True Nucleus / Membrane-bound organelles /
Large (10-100\,\mu\text{m}).
Cell Size Limit: Volume grows faster than Surface Area (r^3
vs r^2).
Exam Trick: Smaller cells = Higher SA/V ratio = Most
efficient diffusion.
Animal Only: Lysosomes + Centrosomes + Flagella.
Plant Only: Chloroplasts + Cell Wall + Central Vacuole +
Plasmodesmata.
3. Nucleus & Ribosomes
Nuclear Envelope: Double membrane / Pores (Traffic
control).
Nuclear Lamina: Protein filaments / Maintains nuclear
shape (Mechanical support).
Nucleolus: Non-membranous / rRNA Synthesis / Ribosome
assembly.
Free Ribosomes: Cytosol suspended / Makes Internal/Local
proteins (e.g., metabolic enzymes).
Bound Ribosomes: On Rough ER / Makes Secretory
proteins (Export) / Membrane proteins.
4. Endomembrane System
Smooth ER: Lipid synthesis (Steroids/Oils) / Detoxification
(Liver) / Ca^{2+} Storage (Muscle).
Rough ER: Secretory proteins (Glycoproteins) /
Membrane factory / Transport vesicles.
Golgi Apparatus: Shipping & Receiving. Cis face = Receives
from ER / Trans face = Ships out. Modifies carbs / Tags
products.
Light Microscope (LM): Living cells / Dynamic processes.
SEM: 3D / Surface / Topography.
TEM: Internal / Ultrastructure / Cross-sections.
Resolution: Image clarity (Closer distance = Better
resolution).
Cell Fractionation Rule: Heavy/Big pellets First (Low
speed) \rightarrow Light/Small pellets Last (High speed).
Centrifugation Order: Nuclei (Low) \rightarrow
Mitochondria/Chloroplasts (Medium) \rightarrow
Microsomes/ER (High) \rightarrow Ribosomes (Highest).
2. Cell Architecture & Sizes
Universal Features: Plasma Membrane + Cytosol +
Chromosomes + Ribosomes.
Prokaryotes: No Nucleus (Nucleoid) / No organelles / Small
(1-5\,\mu\text{m}).
Eukaryotes: True Nucleus / Membrane-bound organelles /
Large (10-100\,\mu\text{m}).
Cell Size Limit: Volume grows faster than Surface Area (r^3
vs r^2).
Exam Trick: Smaller cells = Higher SA/V ratio = Most
efficient diffusion.
Animal Only: Lysosomes + Centrosomes + Flagella.
Plant Only: Chloroplasts + Cell Wall + Central Vacuole +
Plasmodesmata.
3. Nucleus & Ribosomes
Nuclear Envelope: Double membrane / Pores (Traffic
control).
Nuclear Lamina: Protein filaments / Maintains nuclear
shape (Mechanical support).
Nucleolus: Non-membranous / rRNA Synthesis / Ribosome
assembly.
Free Ribosomes: Cytosol suspended / Makes Internal/Local
proteins (e.g., metabolic enzymes).
Bound Ribosomes: On Rough ER / Makes Secretory
proteins (Export) / Membrane proteins.
4. Endomembrane System
Smooth ER: Lipid synthesis (Steroids/Oils) / Detoxification
(Liver) / Ca^{2+} Storage (Muscle).
Rough ER: Secretory proteins (Glycoproteins) /
Membrane factory / Transport vesicles.
Golgi Apparatus: Shipping & Receiving. Cis face = Receives
from ER / Trans face = Ships out. Modifies carbs / Tags
products.
