Cells and Organelles: The Molecular City
Cells Are Organized Systems
Prokaryotes and Eukaryotes
Prokaryotic cells are simpler and do not have a nucleus. Eukaryotic cells, including plant and animal cells, have a nucleus and many membrane-bound organelles.
Key Organelles
The nucleus stores DNA, ribosomes make proteins, mitochondria help produce usable energy, the endoplasmic reticulum helps make and process molecules, and the Golgi apparatus helps modify and ship them.
Membranes Create Order
Compartmentalization lets cells run many different chemical processes at the same time without interfering with one another.
Organelle Roles
Which organelle is the main site of protein synthesis?
Ribosomes read RNA and assemble amino acids into proteins.
Correct answer: Ribosome
What is one major difference between prokaryotic and eukaryotic cells?
This is a defining feature of cell organization.
Correct answer: Eukaryotic cells have a nucleus and membrane-bound organelles, while prokaryotic cells do not.
What is the function of the cell membrane?
The membrane acts as a selective barrier.
Correct answer: Controls movement of substances in and out of the cell