TOPIC 1-Inorganic ions Flashcards
Does an atom have an overall charge?
-No
-The number of protons is the same as the number of electrons
When are atoms most stable?
How is this achieved?
-When their outer shells are full
-By either gaining or losing electrons from the outer orbital so it is full
How are ions formed?
When an atom gains or loses an electron
What is an isotope?
When atoms of an element have different numbers of neutrons
What is an ion?
An atom/ a group of atoms that has an electrical charge
What are some uses of isotopes in biology?
-Dating fossils-concentration of ions
-Evidence for semi-conservative DNA replication
-Gas bubbles in ice to determine the atmosphere
-C14 to trace the movement of carbon within a plant
What are complex ions?
They contain more than one atom
Give 2 examples of complex ions.
-Nitrate NO3-
-Phosphate PO4 3-
What are phosphates linked to in other areas of the specification?
-Phospholipids
-DNA structure
-ATP
What is the role of Iron ions in haemoglobin?
-Haemoglobin is a large protein that carries oxygen around the body in red blood cells
-It is made up of 4 different polypeptide chains, each with an iron ion in the centre
-FE2+
-The FE2+ binds to the oxygen in haemoglobin
-When oxygen is bound The FE2+ ion temporarily becomes an FE3+ ion until oxygen is released
Where do inorganic ions occur?
-In solution in the cytoplasm and bodily fluids of organisms
-Some in high concentrations and others in very low concentrations (Depending on their role)
Why does each type of ion have a specific function?
-Depends on its properties
What is an ion with a positive charge called?
-A cation
Give 2 examples of cations
-NA+, a sodium ion that has a charge of +1
-CA 2+, a calcium ion that has a charge of 2+
What is an ion called that has a negative charge?
-An anion
Give 2 examples of anions
-CL-, a chlorine ion has a charge of 1-
-PO4 3-, this is a phosphate ion that has a charge of 3-
What is an inorganic ion?
-One that doesn’t contain carbon (although there are a few exceptions
What is the role of hydrogen ions?
-pH is calculated based on the concentration of hydrogen ions, H+ in the environment
-The more H+ present, the lower the pH ( and the more acidic the environment)
-Enzyme-controlled reactions are all affected by pH
What is the role of sodium ions?
-Glucose and amino acids need help when crossing the plasma membrane
-A molecule of glucose or amino acid can be transported into a cell across the cell surface membrane
-Alongside sodium ions Na+ (co-transport)
What is the role of phosphate ions?
-When a phosphate ion is attached to another molecule
is known as a phosphate group
-DNA, RNA and ATP all contain phosphate groups
-It’s the bonds between phosphate groups that store energy in ATP
-The phosphate groups in DNA and RNA allow nucleotides to join up to form polynucleotides
