Inorganic ions Flashcards
what is an ion?
an atom that has an electrical charge
what is an ion with a positive charge known as?
a cation
what is an ion with a negative charge known as?
anion
what is an inorganic ion?
an ion which does not contain carbon
where do inorganic ions play an important role?
in many essential cellular processes
where do inorganic ions occur?
They occur in solution in the cytoplasm and body fluids of organisms
- some occur in high concentrations others in very low concentrations
where can the concentration of certain ions fluctuating be used?
cell signalling
neuronal transmission
inorganic ions in the body
•Hydrogen ions H+
•Iron ions Fe 2+ / Fe 3+
•Sodium ion Na +
•Phosphate ions PO4 3-
•Calcium ions Ca 2+
what are hydrogen ions?
protons
what does the concentration of H+ in a solution determine?
the pH
what is the relationship between the pH value and the hydrogen ion concentration?
inverse relationship
• the more H+ ions present
the lower the pH
( more acidic solution )
• the fewer H+ ions presents
the higher the pH
( more alkaline solution )
what is the concentration of H+ very important for?
enzyme - controlled reactions
which are really affected by pH
fluids in the body normally have pH value of approximately 7.4
the maintenance of this normal pH is essential for many of the metabolic processes that take place within the cells
How can changes in pH affect enzymes?
can enzyme affect enzyme structure
e.g. abnormal levels of hydrogen ions can interact with the side-chains of amino acids and change the secondary and tertiary structures of the proteins that make up enzymes
— causes dénaturation
what are the two versions of iron ions- oxidation states?
• iron (II) ions,
ferrous ions
Fe 2+
• iron (III) ions,
ferric ions
Fe 3+
why are iron ions essential?
they can bind oxygen
transfer of electrons-
during respiration + photosynthesis
where do iron ions bind oxygen?
Haemoglobin- is the large protein in red blood cells
responsible for transporting oxygen around the body
haemoglobin is made up of 4 polypeptide chains for that each contain one Fe 2+
the Fe 2+ is a key component in haemoglobin as it binds to oxygen
myoglobinin muscles functions in a similar way
- it is an oxygen binding protein
made up of one polypeptide chain
-containing one Fe 2+
How are iron ions involved in the transfer of electrons?
-during respiration and photosynthesis
- key to biological generation of energy
iron ions are an essential component of cytochromes
( that are themselves a component of electron transport chains)
cytochrome c contains an iron ion that is essential to its function during the electron transport
during electron transport process
this iron ion switches between the Fe3+ and Fe2* oxidation states,
which allows for electrons to be accepted and donated
what are sodium ions required for the transport of?
glucose and amino acids across cell surface membranes
transmission of nerve impulses
what does the process of co-transport consist of?
glucose and amino acids molecules can only enter cells through carrier proteins alongside Na +
1- Na+ is actively transported out of the epithelial cells that line the villi
the Na+ concentration inside the epithelial cells is now lower than the Na+ concentration in the lumen of the small intestine
2- Na+ now re enters the cells
(moving down the concentration gradient) through co transport on the surface membrane of the epithelial cells,
allowing glucose and amino acids to enter at the same time
what do phosphate ions do?
PO4 3- attaches to other molecules to form phosphate groups
essential component in DNA, RNA, ATP
In DNA+ RNA phosphate groups allow individual nucleotides to join up
to form polynucleotides
In ATP the bonds between phosphate groups store energy
- these phosphate groups can be easily attached or detached
-when the bonds between phosphate groups are broken, they release a large amount of energy, which can be used for cellular processes
found in phospholipids- key components of the phospholipid bilayer of cell membranes
How are calcium ions essential in the movement of organisms?
in synapses, calcium ions regulate the transmission of impulses from neurone to neurone
how do calcium ions stimulate muscle contraction?
-when an impulse reaches a muscle fibre , Ca 2+ is released from the sarcoplasmic reticulum
- this Ca 2+ binds to troponin C, removing the tropomyosin from myosin-binding sites on actin
-this allows actin- myosin cross bridges to form when the muscle fibre contracts
what can Ca 2+ do to protein channels?
it can help regulate protein channels
which affects the permeability of cell membranes
what are many enzymes activated by?
Ca 2+
making these ions key regulators in many biological reactions
