1.6.4 - inorganic ions Flashcards
what is ion
atom (or group of atoms) that has an electrical charge
positive ion
cation
negative ion
anion
inorganic ion
an ion that does not contain carbon
inorganic ion role
plays an important role in many essential cellular processes
inorganic ions occur in solution in
-cytoplasm and body fluids of organisms
-some occur in high concentrations and others in very low concentrations
-the concentration of certain ions can fluctuate and cell be used in cell signalling and neuronal transmission
-each type of inorganic ion has a specific role, depending on its properties
inorganic ions
-hydrogen H+
-iron Fe2+/Fe3+
-sodium ions Na+
-phosphate ions PO4 3-
-calcium ions Ca2+
what are hydrogen ions
protons
what does concentration of H+ determine
pH
relationship between pH value and H+ ion present
-inverse relationship between value of pH and H+ ion concentration
-the more H+ ions the lower the pH as more acidic
-the fewer H+ ions the higher the pH as more alkaline
how does concentration of pH affect enzyme controlled reactions
-affects the pH
-fluids in the body normally have a pH of approximately 7.4
-the maintenance of this normal pH is essential for many of the metabolic processes that take place within cells
-changes in pH can effect enzyme structure
-for example, abnormal levels of hydrogen ions can interact with side-chains of amino acids and change into secondary and tertiary structures of proteins that make up enzymes
-this can cause denaturation of enzymes
what do the iron ions depend on
oxidation states
what is Iron (II) also known as
ferrous ions (Fe2+)
what is Iron (III) also known as
ferric ions (Fe3+)
use of Iron ions in binding oxygen
-haemoglobin is the large protein in red blood cells that is responsible for transporting oxygen around the body
-haemoglobin is made up of 4 polypeptide chains that each contain one Fe2+
-this Fe2+ is a key component in haemoglobin as it binds to oxygen
-Myoglobin in muscles function in a similar way (is an oxygen binding protein) but only made of one polypeptide chain (containing one Fe2+)
how are Iron ions used in transfer of electrons during respiration and protein synthesis (key to biological generation of energy)
-iron ions are an essential component of cytochromes (that are themsleves a component of electron transport chains)
-cytochrome c contains an iron ion that is essential to its function
-during the electron transport processes, this iron ion switches between the Fe3+ and Fe2+ oxidation states, which allows for electrons to be accepted and donated
what are the two roles of iron ions
-binding to oxyegn –> haemoglobin
-transfer of electrons during respiration and photosynthesis
what is use of sodium ion
Na+ is required to transport glucose and amino acids across cell-surface membranes
how is Na+ used to transport glucose and amino acids across cell-surface membranes
-glucose and amino acid molecules can only enter cells through carrier proteins alongside Na+
-this processes is known as co-transport
-first, Na+ is actively transported out of the epithelial cells that line the villi
-the Na+ concentration inside the epithelial cells is now lower that the Na+ concentration of the lumen of the small intestine
-Na+ now re-enters the cells (moving down the concentration gradient) through co-transport proteins on the surface membrane of the epithelial cells, allowing glucose and amino acids to enter at the same time
Na+ use in nerves
required for the transmission of nerve impulses
what 2 things is the sodium ion used for
-Na+ is required for the transport of glucose and amino acids across cell-surface membranes such as in the small intestine
-Na+ is also required for transmission of nerve impulses
phosphate ions as phosphate groups
-phosphate ions attaches to other molecules to form phosphate groups which are an essential component of DNA, RNA and ATP
-in DNA and RNA the phosphate groups allow individual nucleotides to join up (to form polynucleotides)
phosphate ions use in storing energy
- in ATP, the bods between phosphate groups store energy
-these phosphate groups can be easily attached or detached
-when the bonds between the phosphate groups are broken, they release a large amount of energy, which can be used for cellular process
phosphate ions in cell membranes
-phosphates are also found in phospholipds which are key components of the phospholipd bilayer of cell membranes
