Final answer:
When sticking a microscopic pin into the center of a bacterium, you would pass through the capsule, cell wall, cell membrane, cytoplasm, ribosomes, and finally the nucleoid where the DNA resides.
Step-by-step explanation:
If you were to stick a microscopic pin into the center of a bacterium, the order of the structures you would encounter from the outside in would typically be as follows:
- Capsule (if present) - some bacteria have a protective layer called a capsule outside of the cell wall.
- Cell wall - a rigid structure that gives the bacterium its shape and protects the cell membrane.
- Cell membrane - a lipid bilayer that controls the movement of substances in and out of the cell.
- Cytoplasm - a jelly-like substance within the cell that contains all the cell's internal structures (organelles).
- Ribosomes - small structures where protein synthesis occurs.
- Nucleoid - the region where the bacterium's DNA is located, since they do not have a nucleus.
The overall structure of a bacterium is fairly simple compared to eukaryotic cells, as they do not have membrane-bound organelles.