Unit 5 P4, M1, D1 The role of energy
P4
The conservation and transformation of energy
The first law of thermodynamics, also referred to as the conservation of energy states; Energy can be
transformed but cannot be created or destroyed. The first part of the law refers to transformation of
energy from one form to another. The second form is of no use or cannot be measured.
Heat, sound and light
Energy can exist in several forms with chemical energy being most common. Energy is the chemical
bond uniting atoms and molecules together. When a new bond is made between two atoms, in
order to form, energy is required. This is usually in the form of heat, although light and electrical
energy can be used. When a bond is broken, atoms are released as well as the energy in the bond.
Heat, light, sound, electrical and nuclear energy are other forms of energy.
Energy metabolism
Energy is required to circulate blood, lymph and tissue fluid throughout the body. Energy is
necessary for breathing and the intake of oxygen, producing new cells for continuing growth and
repair, transmitting nerve impulses to allow response to changes in the environment, and to
construct a variety of complex molecules such as enzymes and hormones from simple molecules
produced after the digestion of food.
Anabolism and catabolism
Some chemical reactions include breaking down molecules and releasing energy, these are known as
catabolic reactions for example; the oxidisation of glucose in the cells is a catabolic reaction. The
opposing process is the construction of complex molecules from simple substances and using energy
which are anabolic reactions.
Activities involved in supplying energy to the cells of the body
Activities involved in supplying energy include the cardiovascular, respiratory and digestive systems.
The digestive system is responsible for the intake of food and water, using enzymes and separating
complex molecules into elementary soluble materials, capable of travelling to adjoining capillaries of
the cardiovascular system. The cardiovascular system then transports these elementary materials to
the liver and body cells through the blood stream, directed by the pumping of the heart. During this
time the respiratory system continuously refreshes the oxygen in the lungs and removes waste
products such as carbon dioxide through the breathing process. Diffused oxygen then travels
through the alveolar walls, into the bloodstream transported to the cells. This means the body cells
have a constant supply of raw materials such as glucose so that the catabolic process can begin. This
initially begins in the cytoplasm and is completed in the mitochondria. The released energy is
captured as chemical energy in adenosine triphosphate (ATP).
M2
The cardiovascular system
The heart
Structure
The adult heart is the size of a closed fist. It is located in the thoracic cavity in-between the
lungs, protected by the rib cage. The heart is enveloped by a strong membrane called the
pericardium, containing a thin film of fluid preventing friction. The heart is a double pump
mechanism, with each side consisting of a muscular upper chamber called the atrium and
lower chamber called the ventricle. The right side pumps deoxygenated blood from the
blood to the veins for oxygenation. The left side of the heart pumps oxygenated blood from
the lungs to the body. Both sides are completely disconnected by a septum. The blood
travels twice through the heart in any one cycle and is often referred to as ‘double
P4
The conservation and transformation of energy
The first law of thermodynamics, also referred to as the conservation of energy states; Energy can be
transformed but cannot be created or destroyed. The first part of the law refers to transformation of
energy from one form to another. The second form is of no use or cannot be measured.
Heat, sound and light
Energy can exist in several forms with chemical energy being most common. Energy is the chemical
bond uniting atoms and molecules together. When a new bond is made between two atoms, in
order to form, energy is required. This is usually in the form of heat, although light and electrical
energy can be used. When a bond is broken, atoms are released as well as the energy in the bond.
Heat, light, sound, electrical and nuclear energy are other forms of energy.
Energy metabolism
Energy is required to circulate blood, lymph and tissue fluid throughout the body. Energy is
necessary for breathing and the intake of oxygen, producing new cells for continuing growth and
repair, transmitting nerve impulses to allow response to changes in the environment, and to
construct a variety of complex molecules such as enzymes and hormones from simple molecules
produced after the digestion of food.
Anabolism and catabolism
Some chemical reactions include breaking down molecules and releasing energy, these are known as
catabolic reactions for example; the oxidisation of glucose in the cells is a catabolic reaction. The
opposing process is the construction of complex molecules from simple substances and using energy
which are anabolic reactions.
Activities involved in supplying energy to the cells of the body
Activities involved in supplying energy include the cardiovascular, respiratory and digestive systems.
The digestive system is responsible for the intake of food and water, using enzymes and separating
complex molecules into elementary soluble materials, capable of travelling to adjoining capillaries of
the cardiovascular system. The cardiovascular system then transports these elementary materials to
the liver and body cells through the blood stream, directed by the pumping of the heart. During this
time the respiratory system continuously refreshes the oxygen in the lungs and removes waste
products such as carbon dioxide through the breathing process. Diffused oxygen then travels
through the alveolar walls, into the bloodstream transported to the cells. This means the body cells
have a constant supply of raw materials such as glucose so that the catabolic process can begin. This
initially begins in the cytoplasm and is completed in the mitochondria. The released energy is
captured as chemical energy in adenosine triphosphate (ATP).
M2
The cardiovascular system
The heart
Structure
The adult heart is the size of a closed fist. It is located in the thoracic cavity in-between the
lungs, protected by the rib cage. The heart is enveloped by a strong membrane called the
pericardium, containing a thin film of fluid preventing friction. The heart is a double pump
mechanism, with each side consisting of a muscular upper chamber called the atrium and
lower chamber called the ventricle. The right side pumps deoxygenated blood from the
blood to the veins for oxygenation. The left side of the heart pumps oxygenated blood from
the lungs to the body. Both sides are completely disconnected by a septum. The blood
travels twice through the heart in any one cycle and is often referred to as ‘double
