Compounds of the Cell

What is a cell made up of?

A cell contains only a few different elements and minerals, but each of these elements and minerals are important to the cell’s structure. 


A5.1 Four Elements of Cells

Cells also have many other elements present in tiny amounts. These elements, called trace elements, are important to cells’ health. Some of the most important trace elements needed by cells are magnesium, zinc, manganese, and iron.
All cells are made up of four elements: carbon, hydrogen, oxygen, and nitrogen. These elements are found naturally all over Earth: as part of our air, land, and water. This means single-celled organisms and multicellular organisms can live all over Earth as well.

The elements carbon, hydrogen, oxygen, and nitrogen are used to make up four types of compounds used in cells:

  • Lipids—fats and oils: They are made of all four of the elements
  • Carbohydrates—sugars, starches, and cellulose: They are made of carbon, hydrogen, and oxygen.
  • Proteins—muscle fibre: They are made of all four of the elements.
  • Nucleic acids—DNA and other genetic material: They are made up of all four of the elements.
Water is one of the most important compounds used by cells. Most other compounds are dissolved in water, both inside and outside of the cell. Water provides the environment for the functions of the cell to occur. It is made of oxygen and hydrogen.

A5.2 Cholesterol is a lipid, important to the structure of the cell membrane

  Practice Questions

Complete the following practice questions to check your understanding of the concept you just learned. Make sure you write complete answers to the practice questions in your notes. After you have checked your answers, make corrections to your responses (where necessary) to study from.

  1. What is the solvent that provides the environment for all biological reactions inside and outside the cell?
  1. What are the four types of organic compounds used in cells? Give examples of each. What do you think each is used for?
Lipids—fats and oils. They are used for energy storage in the organism. We will study how these are used in the cell membrane in the next lesson.
Carbohydrates—sugars and starches. They are used as energy in the organism. They can also be used as energy storage, depending on the type of organism.
Proteins—muscle fibre. They are used for most jobs in the cell. Movement, digestion, energy creation, production of other materials, and so on.
Nucleic acids—DNA and genetic material. They are used to create the organisms DNA and DNA type molecules used in the production of proteins.

  Problem Solving Activity

What do the trace elements do for cells?


Background Information:

We have learned small amounts of certain elements are needed for a cell’s health, but why exactly are they needed?

Research each of the four trace elements mentioned in the course content and try to determine what each is used for by the cell. Please click the analysis tab to complete the analysis questions.
What are the four trace elements used for by the cell?
  • Magnesium: The energy molecule a cell uses (ATP) must be bound to magnesium to be active. Without magnesium, the cell would have no energy to complete the life functions.
  • Zinc: There is still lots of research going into why this element is important. Some places being researched are protein synthesis, cell communication, gene expression, and cell growth and death.
  • Manganese: This element is essential for normal cell growth and development. It is used in many cellular reactions to help them happen quicker. In humans, too much or too little manganese often leads to problems with the brain and nervous system.
  • Iron: In humans, this element is used in blood cells as part of the system that carries oxygen and carbon dioxide around the body. In cells, it is used to move oxygen used in cellular respiration to the mitochondria. It is also used in protein synthesis.