Prokaryotic Cell Structure

Think of a prokaryotic cell as a highly efficient microscopic factory with everything it needs packed into a tiny space. Unlike your cells, prokaryotes don't have their DNA locked away in a nucleus - instead, it floats freely in a region called the nucleoid.

The cell envelope acts like the factory's security system, consisting of multiple protective layers. The plasma membrane controls what enters and exits the cell, whilst the cell wall maintains the cell's shape and prevents it from bursting. Some bacteria have an additional outer membrane and periplasmic space filled with helpful enzymes.

Inside the cell, the cytoplasm serves as the main workspace - a watery soup containing everything needed for life. Ribosomes float here like tiny protein-making machines, translating genetic instructions into useful proteins. Storage granules act as the cell's pantry, storing nutrients like glycogen and lipids for later use.

Many bacteria have special features for survival and movement. Flagella work like propellers to help bacteria swim towards food or away from danger. The protective capsule shields bacteria from your immune system, whilst tough endospores can survive extreme conditions that would kill most other life forms.

Key Point: The chromosome contains most genetic information as one long DNA strand, but plasmids carry extra genes - often including antibiotic resistance - that can be shared between bacteria.