Respiration Flashcards
Respiration
the process by which energy is released from food by all living cells
Breathing
Breathing refers to the movements in animals that bring oxygen to a gaseous exchange surface and remove carbon dioxide from the surface.
Aerobic Respiration
- Aerobic respiration occurs in most cells. It uses oxygen and takes place in the mitochondria.
- Aerobic respiration always produces carbon dioxide, water and about 38 ATP molecules per molecule of glucose.
Anaerobic Respiration
- Anaerobic respiration takes place without oxygen in the cytoplasm of some cells.
- The products of anaerobic respiration vary, but at least one is always organic, and it produces considerably less energy per molecule of glucose than aerobic respiration.
ATP
adenosine triphosphate molecules are energy carrying molecules which store and transport energy in living cells
they are formed by combining some of the energy released with an adp molecule and a phosphate group present in the cell
energy-currency of cells
Advantages of the storage and transport of ATP
- energy can be released rapidly,
- exactly the right amount of energy can be released when needed (which prevents waste)
- energy can be released exactly where it is needed in the cell.
Why does anaerobic respiration release less energy per molecule of glucose than aerobic respiration?
Anaerobic respiration releases less energy because the glucose is only partially broken down and the organic products still contain some energy, whereas the glucose is completely broken down in aerobic respiration and the products do not contain any energy.
Strenuous Exercise
During the strenuous exercise, the oxygen supply to the athlete’s muscle cells eventually became too low for the demands of aerobic respiration, so his cells began to respire anaerobically and produce lactic acid. The lactic acid
built up in his muscle cells and began to harm them and eventually stopped them from contracting, which caused
him to collapse. The athlete had to rest before exercising again so that his muscle cells could get rid of the lactic acid by respiring it aerobically.
Gaseous exchange
the process by which oxygen diffuses into an organism, and carbon dioxide diffuses out of an
organism, through a gaseous exchange/respiratory surface.
WHY is Breathing and gaseous exchange are essential to organisms that respire aerobically:
- To ensure they have a continual supply of oxygen to meet the demands of aerobic respiration.*
- To ensure that the carbon dioxide produced in respiration is continually removed so that it does not build up and poison cells.
Identify FOUR characteristics that gaseous exchange surfaces have in common.
- They have a large surface area so that large quantities of gases can be exchanged.
- They are very thin so that gases can diffuse through them rapidly.
- They are moist so that gases can dissolve before they diffuse through the surface.
- they have a rich blood supply to quickly transport gases between the surface and the body cells.
gaseous exchange surface in a human.
The walls of the alveoli in the lungs.
HOW is air is drawn into the lungs in a human. Movements of Intercostal muscles and diaphragm
The external intercostal muscles between the ribs contract
and the internal intercostal muscles relax, causing the ribs
and sternum to move upwards and outwards. At the same
time the diaphragm muscles contract, causing the diaphragm
to move downwards or flatten. These movements cause
the volume inside the thorax and lungs to increase and the
pressure to decrease, which draws air into the lungs.
How air reaches the alveoli
As the air is drawn in during inhalation, it is warmed in the nasal passages, and cleaned and moistened by mucus lining the nasal passages and trachea. The mucus is moved to the throat by cilia (microscopic hairs) lining the nasal passages and trachea, and is swallowed. The air passes through the bronchi and bronchioles and enters the alveoli where gaseous exchange occurs between the air and the blood in the capillaries.
Reasons to not smoke
- Smoking cigarettes can lead to nicotine addiction.
- Smoking cigarettes reduces the oxygen-carrying capacity
of the blood. - Smoking cigarettes can cause a persistent cough to
develop. - Smoking cigarettes can lead to the development of
chronic bronchitis. - Smoking cigarettes can cause emphysema.
- Smoking cigarettes can cause cancer of the mouth, throat,
oesophagus and lungs.