Module 2: Biological Molecules - Inorganic Ions Flashcards
What are inorganic ions.
An ion is an atom or a group of atoms that has an electric charge..
An organic ion contains carbon.
An inorganic ion doesn’t contain carbon.
What is a cation and anion.
A cation is a positively charged ion.
An anion is a negatively charged ion.
How are ions formed?
Ions are formed when an atom transfers its electrons to another atom.
The atom which loses electrons becomes a cation.
The atom which gains the electrons is called an anion.
Give 5 examples of Cations.
Calcium. (Ca 2+)
Sodium. (Na +)
Potassium. (K +)
Hydrogen. (H +)
Ammonium. (NH4 +)
Explain the role of Calcium.
Ca 2+
It is involved in the transmission of nerve impulses and the release of insulin from the pancreas.
Acts as a cofactor (non-protein molecule that supports a biochemical reaction) for many enzymes.
Bone formation requires calcium. Proper bone formation cannot occur without calcium, and bones are the major store site for calcium in the body.
Calcium makes up the middle lamellae in plants. The middle lamella is a layer in plant cells that joins two plant cell walls together. It is made up of calcium and magnesium ions.+
Explain the role of Sodium.
Sodium ions (Na+) are key for co-transport. Sodium helps molecules such as glucose and amino acids cross the cell membrane in order to enter a cell through a process known as co-transport.
It is important for generating nerve impulses, for muscle contraction.
Sodium is crucial for fluid regulation. Movement of water follows the movement of salt (i.e. sodium). When sodium ions leave the cell, so does water, and the volume of extracellular fluid increases. Conversely, when sodium ions reenter into cells, water follows, and the volume of extracellular fluid decreases.
Explain the role of Potassium.
Potassium ions (K+) are important for nerve impulses and fluid balance. Just like sodium, it helps generate nerve impulses. It also plays the same role as sodium in fluid balance, i.e. its movement is tightly controlled by the body to regulate the amount of fluids in intracellular and extracellular compartments.
Potassium helps muscles contract. Potassium is essential for the contraction of muscle fibres, therefore, the levels of potassium can affect how well key muscular organs can function e.g. the heart.
Photosynthesis requires potassium. Potassium is responsible for the opening and closing of the stomata in leaves, thus potassium controls how much CO2 is being taken in by the plant.
It activates essential enzymes needed for photosynthesis in plant cells.
Explain the role of hydrogen.
Hydrogen ions (H+) help control pH in digestion. Hydrogen ions are also important for maintaining the low pH of the gastric juices within the stomach which is important for digestion.
Hydrogen ions also help in respiration. Hydrogen ions play a very important role in ATP synthesis in the mitochondria during cellular respiration.
Explain the role of Ammonium.
Ammonium ions (NH4+) are key ions in plants.
Plants absorb ammonium from the soil, and is able to use the nitrogen from it to synthesise necessary biological molecules such as nucleic acids and amino acids. (protein synthesis)
Give 5 examples of Anions.
Nitrate (NO3 -)
Hydrogencarbonate (HCO3 -)
Chloride (Cl -)
Phosphate (PO4 3-)
Hydroxide (OH -)
Explain the role of Nitrate.
Nitrate ions (NO3-) are an important part of the Nitrogen circle.
Plants absorb nitrate ions from the soil, and is able to use the nitrogen from it to synthesise necessary biological molecules such as nucleic acids and amino acids. (protein synthesis)
Explain the role of Hydrogencarbonate.
Hydrogencarbonate ions (HCO3-) maintain blood pH levels.
Also known as the bicarbonate ion, it works as a buffer in the blood, keeping its pH levels within a narrow range.
Explain the role of Chloride.
Chloride ions (Cl–)
it is involved in the ‘chloride shift’ which keeps the pH level of blood constant when gas exchange occurs.
Responsible for transmitting certain nerve impulses.
Is a cofactor for the digestive enzyme amylase.
Explain the role of Phosphate.
Phosphate ions (PO4 3-) are found in phosphate groups.
Phosphate groups are found in DNA, RNA, and ATP. In ATP the energy is stored in the phosphoanhydride bonds between the three phosphate groups which make up ATP.
Phosphate groups drive phosphorylation (the attachment of a phosphate group to a molecule or an ion.) Phosphate groups can be added to molecules to make them more reactive through phosphorylation.
Phosphate groups are found in phospholipids. The phospholipids are a key component of cell membranes, forming the phospholipid bilayer.
Explain the role of Hydroxide.
Hydroxide ions (OH–) are bases.
When there is a high concentration of hydroxide ions in a solution, it will make the solution alkaline.
