Cell Organelles: Structure and Function
Ever wondered what makes up a living cell? Cells contain specialized parts called organelles that each have unique jobs. Prokaryotic cells (like bacteria) are simpler, while eukaryotic cells (like human, animal, and plant cells) contain more complex organelles.
The cell wall provides rigid structural support outside the cell membrane. Plant cells have walls made of cellulose, while fungi use chitin. Inside this protective layer sits the cell membrane, a semi-permeable boundary made of phospholipids that controls what enters and exits the cell.
The cytoplasm includes everything inside the cell except the nucleus. It contains cytosol thefluidwithdissolvedionsandwater−solublemolecules and various organelles. The cytoskeleton, made of protein fibers, provides internal structure and support.
Fun Fact: If you stretched out all the membranes from one human cell's organelles, they would extend about 30 times the cell's diameter—that's a lot of organization packed into a tiny space!
In eukaryotic cells, the nucleus houses genetic information DNA/RNA and is surrounded by a nuclear envelope made of lipids. Inside the nucleus, the nucleolus works on ribosome synthesis. Ribosomes themselves—found floating freely or attached to the rough endoplasmic reticulum—are protein-making factories.
The endoplasmic reticulum comes in two varieties: rough (processes proteins) and smooth (handles lipids). The Golgi apparatus works like a shipping department, packaging materials into vesicles that transport them throughout the cell. Lysosomes contain digestive enzymes that break down molecules and can even self-destruct when needed, earning them the nickname "suicide organelles."