The importance of the control of movement in cells and organisms
Movement in cells is important to establish and maintain concentration gradients.
Concentration gradients allow different types of diffusion to occur, such as active transport
and facilitated diffusion. This is important so that ions can be transported in and out of cells
to carry out their functions. An example of the importance of concentration gradients in
cells is the sodium potassium pump. This is a pump that can be found in the membrane of
cells such as neuronal cells that encourage active transport to occur. In this example, three
sodium ions are pumped out for every two potassiums going in. This allows a charge to be
maintained in the neuron, allowing an action potential to occur for a nerve impulse to be
transported.
Control in movement of cells is also very important in neurons to allow nerve impulses to be
carried. Nerve impulses can only be carried out if an action potential has occurred, where
the excitation of the neuron causes messages to be transported between the nervous
systems. This is an important process as it means that urgent messages can be transported
to the brain and the central nervous system can cause a response. Without these responses,
we would not be able to feel necessary feelings such as pain, and our brain would not be
able to respond to these feelings.
Sometimes the control of movement of a cell contributes to how well it can carry out its
functions. Two examples of this are the specialisations of sperm cells and bacterial cells.
Sperm cells are specialised to have a tail that improves their streamline. This means that
their travel towards the egg is more efficient, increasing their chances of survival. Bacterial
cells are specialised to have a flagellum. This is a hairlike structure that can aid the bacterial
cell in its movement throughout an organism. This allows chemotaxis, which is when a cell
moves towards a chemical stimulus. This means that the bacterial cell can carry out its
functions in the organism.
It is important for plants and animals to be able to move positions or directions in response
to a stimulus. An example of plant movement is phototropism. Phototropism is growth in
response to the direction of light. Shoots of plants are positively phototropic- they grow
towards the light. Roots of plants are negatively phototropic- they grow away from the light.
This is very beneficial for plants as the shoots are able to get the maximum amount of
sunlight possible for photosynthesis, and the further into the ground the roots go the more
water and nutrition they are able to pull from the soil. Another example of plant movement
is the action of auxin. Auxin is a chemical in plants that moves away from the light. This
causes the cells to elongate and the plant to bend, allowing the plant to be more exposed to
the light.
An example of animal movement is tactic response. This is when the stimulus is positively or
negatively directional. An example of the action is when woodlice move away from the light,
towards dark areas. This is beneficial because they can be hidden from predators in these
areas. This is important as it is extremely beneficial to their survival. Another example is
kinetic response. This happens when the stimulus is non-directional (e.g. humidity) . This
action can occur again in woodlouse, where they favour damp areas over dry areas, and so
Movement in cells is important to establish and maintain concentration gradients.
Concentration gradients allow different types of diffusion to occur, such as active transport
and facilitated diffusion. This is important so that ions can be transported in and out of cells
to carry out their functions. An example of the importance of concentration gradients in
cells is the sodium potassium pump. This is a pump that can be found in the membrane of
cells such as neuronal cells that encourage active transport to occur. In this example, three
sodium ions are pumped out for every two potassiums going in. This allows a charge to be
maintained in the neuron, allowing an action potential to occur for a nerve impulse to be
transported.
Control in movement of cells is also very important in neurons to allow nerve impulses to be
carried. Nerve impulses can only be carried out if an action potential has occurred, where
the excitation of the neuron causes messages to be transported between the nervous
systems. This is an important process as it means that urgent messages can be transported
to the brain and the central nervous system can cause a response. Without these responses,
we would not be able to feel necessary feelings such as pain, and our brain would not be
able to respond to these feelings.
Sometimes the control of movement of a cell contributes to how well it can carry out its
functions. Two examples of this are the specialisations of sperm cells and bacterial cells.
Sperm cells are specialised to have a tail that improves their streamline. This means that
their travel towards the egg is more efficient, increasing their chances of survival. Bacterial
cells are specialised to have a flagellum. This is a hairlike structure that can aid the bacterial
cell in its movement throughout an organism. This allows chemotaxis, which is when a cell
moves towards a chemical stimulus. This means that the bacterial cell can carry out its
functions in the organism.
It is important for plants and animals to be able to move positions or directions in response
to a stimulus. An example of plant movement is phototropism. Phototropism is growth in
response to the direction of light. Shoots of plants are positively phototropic- they grow
towards the light. Roots of plants are negatively phototropic- they grow away from the light.
This is very beneficial for plants as the shoots are able to get the maximum amount of
sunlight possible for photosynthesis, and the further into the ground the roots go the more
water and nutrition they are able to pull from the soil. Another example of plant movement
is the action of auxin. Auxin is a chemical in plants that moves away from the light. This
causes the cells to elongate and the plant to bend, allowing the plant to be more exposed to
the light.
An example of animal movement is tactic response. This is when the stimulus is positively or
negatively directional. An example of the action is when woodlice move away from the light,
towards dark areas. This is beneficial because they can be hidden from predators in these
areas. This is important as it is extremely beneficial to their survival. Another example is
kinetic response. This happens when the stimulus is non-directional (e.g. humidity) . This
action can occur again in woodlouse, where they favour damp areas over dry areas, and so
