How Cells Work

“How Cells Work”

  • Cells are the basic units of life. Every living organism is composed of one or more cells.

  • Each cell is divided into three main parts: the cell membrane, cytoplasm, and the nucleus.

  • The cell membrane, also known as the plasma membrane, is the outer layer that separates the cell from its surroundings. It controls what substances can enter or leave the cell.

  • The cytoplasm is a gel-like substance inside the membrane that contains all the cell’s organelles. It’s where metabolic reactions occur.

  • The nucleus is the control centre of the cell. It contains the cell’s DNA, which carries instructions for cell growth, function, and reproduction.

  • Cells reproduce through a process called cell division. This involves the separation of the cell into two new cells.

  • Cells can vary in shape and size, but all have the same basic functions. They take in nutrients and oxygen, use them to produce energy, eliminate waste, and reproduce.

  • Cellular respiration is the process by which cells use oxygen to break down glucose and other nutrients to release energy stored in them.

  • Cells communicate with each other through signals. These can be chemicals released by other cells or physical contact.

  • Specialised cells perform specific functions. For example, red blood cells transport oxygen around the body, while nerve cells transmit electrical signals to and from the brain.

  • Cells form tissue, tissue form organs, and organs form systems. Together, this integration supports a living organism’s survival.

  • Cells respond to their environment. They can change their behaviour in response to changes in their immediate surroundings. This capacity to respond to stimuli is known as cellular responsiveness or excitability.

  • Cells have a limited lifespan and undergo a natural process of death known as apoptosis.

  • The study of cells, including their function, structure, and composition, is called cell biology. Knowledge of cell biology is foundational to understanding anatomy and physiology within the health and social care sector.