Cell Structure Fundamentals
Your cells are basically tiny, organised cities with each component having a specific job. The plasma membrane acts like a selective bouncer, controlling what gets in and out of the cell whilst containing essential lipids and proteins.
Think of the cytoskeleton as the cell's internal scaffolding system. It's made up of three main types of fibres: microfilaments (made of actin) help with movement and contraction during cell division, microtubules (formed from tubulin) determine cell shape and act as motorways for organelle transport, and intermediate fibres provide structural strength.
The nucleus is your cell's control centre, surrounded by a double membrane called the nuclear envelope with pores for transport. Inside, the nucleolus assembles ribosomes, whilst the nucleus stores all your genetic information - essentially your cell's instruction manual.
Quick Tip: Remember that ribosomes come in two sizes - 70s in prokaryotes and 80s in eukaryotes. They're your protein-making factories, working either freely in the cytoplasm or attached to the rough endoplasmic reticulum (RER).
