They have cytoplasm and a cell membrane surrounded by a cell wall.

This lesson looks at the structure of a bacterial cell. A bacterium is built from a cytoplasm and a cell membrane, and that membrane is surrounded by a cell wall. We will look at what each layer does and how to label them in the correct order. Start inside the cell. The cytoplasm holds the cell's chemical reactions and the ribosomes that make proteins. Around it, the cell membrane is partially permeable and controls what enters and leaves the cell. Outside the membrane sits the cell wall, which gives the cell shape and protection. Notice the division of jobs. The cell membrane is partially permeable, so it decides what passes in and out. The wall is not selectively permeable, so it does not control entry. That is why the term partially permeable belongs to the membrane only, never to the wall. Two mistakes are common here. First, saying the cell wall is partially permeable and controls entry. Give that role to the membrane and describe the wall as supportive instead. Second, placing the wall inside the membrane. Draw the wall as the outermost of the two layers. Pause here and think about how you would label a bacterial cell diagram from the outside in. Working outwards from the cytoplasm, first draw the cell membrane. Then draw the wall as a line outside the membrane, and label each layer separately. If the question asks for functions, match each structure to one clear job. Bacterial walls are made of peptidoglycan, a polymer of sugars and amino acids. This differs from the cellulose walls of plant cells, so do not call a bacterial wall cellulose. Some bacteria also have a slime capsule outside the wall. To recap. The cytoplasm holds the chemical reactions and ribosomes. The cell membrane is partially permeable and controls what enters and leaves. The cell wall lies outside the membrane and gives shape and protection, but does not control entry. Bacterial walls are peptidoglycan, and some bacteria have a slime capsule outside the wall.