The importance of ions in biology
Ions are important for organisms because they are used in many processes in our body and without
ions, it will lead to the death of an organism.
In co-transport, sodium ions are used to transport glucose and amino acids. Sodium ions in the cell are
actively transported into the blood through the use of ATP and this creates a concentration gradient of
sodium ions. The sodium ions then couple up with glucose or the amino acids and enter the cell through
channel proteins through facilitated diffusion. There is a high concentration of glucose and amino acids
in the cell compared to the blood therefore, glucose/amino acids diffuse out of the cell down their
concentration gradient by facilitated diffusion. This shows the importance of ions because if there were
no sodium ions then less glucose would be available to the respiring cells, and this would lead to the
respiring cells dying due to the starvation of oxygen. So, this can lead to the organism dying as oxygen is
the final electron acceptor in aerobic respiration so there won’t be enough ATP to maintain all the
metabolic reactions in the organism. Also, fewer amino acids would be available to make proteins,
therefore, fewer proteins are made so the cell won’t grow and fewer cells would be prepared, which
would kill the organism.
Calcium ions are needed in muscle contraction. Calcium ions are released from the sarcoplasmic
reticulum and binds to the troponin-tropomyosin complex which alters the shape of the protein and
exposes the binding sites in actin. This shows the importance of ions because if there were no calcium
ions then the binding sites from the actin won’t be exposed therefore, the myosin heads cannot bind to
the binding sites and form a cross bridge, and the myosin heads cannot nod their heads, or perform the
power stroke, to pull the actin and move across the filament to bind with other binding sites. This can
increase the risk of the organism being in danger because they can’t run away from danger, like
predators, as they cannot contract their muscles as the actin binding sites are covered as there aren’t
any calcium ions.
Calcium, sodium and chloride ions are needed in the nervous system. When an incoming impulse in the
presynaptic knob occurs, the calcium ion channels open so calcium ions can diffuse into the presynaptic
knob and fuse with vesicles and stimulate enzymes. The vesicle then fuses with the membrane and the
release of neurotransmitters, such as acetylcholine (Ach), dopamine, GABA, and serotonin. The
neurotransmitter is then released by exocytosis. The neurotransmitter, such as Ach, then binds to
receptors on the sodium ion channels on the postsynaptic neuron, which opens the sodium ion channels
so sodium ions can diffuse into the postsynaptic neuron which depolarizes it and creates an action
potential. GABA can be released which binds to chloride ion channels on the postsynaptic neuron which
the chloride ion channels open, so chloride ions diffuse in and hyperpolarize the postsynaptic neuron, so
an action potential is inhibited. This shows the importance of ions because if there were no calcium ions
then the neurotransmitter won't be released to create an action potential. If there were no sodium ions,
then an action potential on the postsynaptic neuron cannot be generated. This can lead to the organism
Ions are important for organisms because they are used in many processes in our body and without
ions, it will lead to the death of an organism.
In co-transport, sodium ions are used to transport glucose and amino acids. Sodium ions in the cell are
actively transported into the blood through the use of ATP and this creates a concentration gradient of
sodium ions. The sodium ions then couple up with glucose or the amino acids and enter the cell through
channel proteins through facilitated diffusion. There is a high concentration of glucose and amino acids
in the cell compared to the blood therefore, glucose/amino acids diffuse out of the cell down their
concentration gradient by facilitated diffusion. This shows the importance of ions because if there were
no sodium ions then less glucose would be available to the respiring cells, and this would lead to the
respiring cells dying due to the starvation of oxygen. So, this can lead to the organism dying as oxygen is
the final electron acceptor in aerobic respiration so there won’t be enough ATP to maintain all the
metabolic reactions in the organism. Also, fewer amino acids would be available to make proteins,
therefore, fewer proteins are made so the cell won’t grow and fewer cells would be prepared, which
would kill the organism.
Calcium ions are needed in muscle contraction. Calcium ions are released from the sarcoplasmic
reticulum and binds to the troponin-tropomyosin complex which alters the shape of the protein and
exposes the binding sites in actin. This shows the importance of ions because if there were no calcium
ions then the binding sites from the actin won’t be exposed therefore, the myosin heads cannot bind to
the binding sites and form a cross bridge, and the myosin heads cannot nod their heads, or perform the
power stroke, to pull the actin and move across the filament to bind with other binding sites. This can
increase the risk of the organism being in danger because they can’t run away from danger, like
predators, as they cannot contract their muscles as the actin binding sites are covered as there aren’t
any calcium ions.
Calcium, sodium and chloride ions are needed in the nervous system. When an incoming impulse in the
presynaptic knob occurs, the calcium ion channels open so calcium ions can diffuse into the presynaptic
knob and fuse with vesicles and stimulate enzymes. The vesicle then fuses with the membrane and the
release of neurotransmitters, such as acetylcholine (Ach), dopamine, GABA, and serotonin. The
neurotransmitter is then released by exocytosis. The neurotransmitter, such as Ach, then binds to
receptors on the sodium ion channels on the postsynaptic neuron, which opens the sodium ion channels
so sodium ions can diffuse into the postsynaptic neuron which depolarizes it and creates an action
potential. GABA can be released which binds to chloride ion channels on the postsynaptic neuron which
the chloride ion channels open, so chloride ions diffuse in and hyperpolarize the postsynaptic neuron, so
an action potential is inhibited. This shows the importance of ions because if there were no calcium ions
then the neurotransmitter won't be released to create an action potential. If there were no sodium ions,
then an action potential on the postsynaptic neuron cannot be generated. This can lead to the organism
