Cell Biology
Explore the building blocks of the human body through interactive diagrams and concept checks.
The Human Cell
Identify key organelles and their functions
Every cell contains specialized structures called organelles that work together to maintain life. Understanding cell structure is the foundation for understanding how diseases affect the body at the cellular level.
Why This Matters for Nursing
When you learn pathophysiology, you'll trace disease mechanisms back to cellular dysfunction. For example, MI (heart attack) starts with ischemia → cellular hypoxia → mitochondrial failure → cell death.
Cell Structure: Click to Identify
Click each point to reveal the organelle name. Can you identify all 12?
Organelle Deep Dive
Explore each organelle
Cell Membrane
The phospholipid bilayer forms a selectively permeable barrier with embedded integral proteins, channel proteins, and cholesterol. It controls ion and molecule transport through passive diffusion, facilitated diffusion, and active transport (Na⁺/K⁺ ATPase). Glycoprotein receptors on the surface mediate cell signaling and immune recognition.
Nucleus
The command center of the cell, enclosed by a double nuclear envelope with nuclear pores that regulate macromolecule transport. Contains chromatin (DNA wound around histone proteins) that condenses into chromosomes during division. The nucleolus inside assembles ribosomal subunits from rRNA.
Mitochondria
The powerhouse of the cell with a double membrane; the inner membrane folds into cristae to maximize surface area for the electron transport chain. Produces ~36 ATP per glucose molecule through oxidative phosphorylation. Contains its own circular mtDNA inherited exclusively from the mother.
Rough Endoplasmic Reticulum
An extensive folded membrane network studded with ribosomes, continuous with the nuclear envelope. Responsible for co-translational protein folding, N-linked glycosylation, and quality control of newly synthesized proteins. Especially prominent in cells with high secretory output like plasma cells and pancreatic acinar cells.
Golgi Apparatus
Stacked flattened membrane cisternae that receive proteins from the ER at the cis face and process them through post-translational modifications including glycosylation, phosphorylation, and sulfation. The trans face sorts and packages proteins into vesicles for secretion, lysosomal targeting, or membrane insertion.
Lysosomes
Membrane-bound vesicles maintaining an acidic interior (pH ~5) filled with over 50 types of acid hydrolase enzymes. They digest materials from autophagy (recycling old organelles), phagocytosis (destroying pathogens), and endocytosis. Essential for cellular housekeeping and programmed cell death.
Organelle Function Matching
Match each organelle to its primary function
Terms
Definitions
Membrane Transport
How substances move in and out of cells
Key Principle
'Water chases salt': water moves toward areas of higher solute concentration through osmosis. This explains why IV normal saline stays in the vasculature while free water distributes across compartments.
Passive Transport
No energy needed. Moves DOWN concentration gradient. Examples: diffusion, osmosis, facilitated diffusion.
Active Transport
Requires ATP energy. Moves AGAINST concentration gradient. Example: Na+/K+ pump (3 Na+ out, 2 K+ in).
Cell Biology Check
1/10Which organelle is primarily responsible for ATP production?
Pre-nursing comprehensive review
1/20Which organelle contains its own DNA and is inherited exclusively from the mother?