A-Level Biology Cells Revision Notes

• 1Cells can be prokaryotic or eukaryotic, with eukaryotic cells containing membrane-bound organelles.
• 2The plasma membrane regulates the movement of substances in and out of the cell.
• 3Mitochondria are the powerhouse of the cell, producing ATP through cellular respiration.
• 4Ribosomes are responsible for protein synthesis, either free-floating in the cytoplasm or attached to the endoplasmic reticulum.
• 5The cell cycle includes stages of growth, DNA replication, and division (mitosis or meiosis).

Cells are tiny units that make up all living things. They have different parts that help them do important jobs, like making energy and proteins. Some cells are simple, like bacteria, while others, like plant and animal cells, are more complex with many parts. Understanding cells helps us learn how life works.