Cell Types & Organelles

There are two major cell types. They share a common ancestry — both have a cell membrane, nucleic acids, ribosomes and cytoplasm — but differ in size and organisation.

Eukaryotic organelles

Eukaryotes have membrane-bound organelles that compartmentalise biochemistry:

• Nucleus (holds DNA) and nucleolus (makes ribosomes)
• Mitochondrion — aerobic respiration (ATP)
• Chloroplast — photosynthesis (plants)
• Rough & smooth ER — protein and lipid processing
• Golgi body — packages and ships molecules in vesicles
• Ribosome — protein synthesis
• Lysosome — digestion; vacuole — storage; cytoskeleton — support

Plant, animal and fungal cells differ too: plant and fungal cells have a cell wall (cellulose vs chitin) and large vacuoles; only plants have chloroplasts.