Plants & Mineral Ions (Edexcel IGCSE Biology)

Mineral Ions

Spec point — 2.22 · understand that plants require mineral ions for growth, and that magnesium ions are needed for chlorophyll and nitrate ions are needed for amino acids

• Photosynthesis provides a source of carbohydrates, but plants contain and require many other types of biological molecule; such as proteins, lipids and nucleic acids (DNA)
• As plants do not eat, they need to make these substances themselves
• Carbohydrates contain the elements carbon, hydrogen and oxygen but proteins, for example, contain nitrogen as well (and certain amino acids contain other elements too)
• Two fundamental mineral ions required by plants are nitrate and magnesium, without a source of these elements, plants cannot photosynthesise or grow properly
• Plants obtain these elements in the form of mineral ions actively absorbed from the soil by root hair cells
• ‘Mineral’ is a term used to describe any naturally occurring inorganic substance

Mineral ion function and deficiencies in plants table

The effect of mineral deficiencies on plants