Respiration Flashcards
What energy does respiration release and from what?
Respiration releases energy for cells from glucose. This can be aerobic respiration, which needs oxygen, or anaerobic respiration, which does not.
What is aerobic respiration?
Respiration is a series of reactions in which energy is released from glucose. Aerobic respiration is the form of respiration which uses oxygen.
What is the equation for aerobic respiration?
Glucose + oxygen → carbon dioxide + water (+ energy)
Energy is shown in brackets because it is not a substance.Notice that:
-Glucose and oxygen are used up.
-Carbon dioxide and water are produced as waste products.
Where does most aerobic reactions happen?
Aerobic respiration occurs inside mitochondria, tiny objects inside the cytoplasm of the cell. The reactions are controlled by enzymes.
How is the energy released from respiration used?
Energy released during respiration is used by the organism in several ways. It may be used to build up larger molecules from smaller ones. For example:
- Plants make amino acids from sugars, nitrates and other nutrients
- These amino acids are then built up into larger molecules - proteins
How does the energy released from respiration, help animals?
Energy is used by animals to enable the muscles to contract so that the animals can move. Mammals and birds keep their body temperature steady. Energy from respiration is used to do this when their surroundings are colder than they are.
How do muscles respire?
During exercise, the muscle cells respire more than they do at rest. This means that:
-Oxygen and glucose must be delivered to them more quickly.
-Waste carbon dioxide must be removed more quickly.
This is achieved by increasing the heart rate, rate of breathing and the depth of breathing.
What happens when muscles don’t get enough oxygen during exercise?
Not enough oxygen may reach the muscles during exercise. When this happens, they use anaerobic respiration to obtain energy.
What does anaerobic respiration involve?
Anaerobic respiration involves the incomplete breakdown of glucose. It releases around 5% of the energy released by aerobic respiration, per molecule of glucose.
What is the waste product of respiration? And what is the equation?
The waste product is lactic acid rather than carbon dioxide and water:
glucose → lactic acid (+ little energy)
How does anaerobic respiration effect our muscles?
Muscles become fatigued (tired) during long periods of vigorous activity. This means that they stop contracting efficiently. One cause of this is the build-up of lactic acid in the muscles from anaerobic respiration. The lactic acid is removed from the muscles by blood flowing through them.
Which respiration releases more energy? And why?
Much less energy is released during anaerobic respiration than during aerobic respiration. This is because the breakdown of glucose is incomplete.
