12. RESPIRATION Flashcards Preview

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Flashcards in 12. RESPIRATION Deck (10)
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for what does human needs energy?

Contract muscle
Synthesise proteins
Cell division (to make new cells)
Enable active transport to take place
Allow nerve impulses to be generated
Maintain a constant internal body temperature


How is Respiration Controlled?

Respiration is a series of reactions that are controlled by enzymes.


Define respiration?

Respiration is a chemical process that involves the breakdown of nutrient molecules in order to release the energy stored within the bonds of these molecules


Brief aerobic respiration

Aerobic respiration is defined as the chemical reactions in cells that use oxygen to break down nutrient molecules to release energy.
It is the complete breakdown of glucose to release a relatively large amount of energy for use in cell processes
It is the complete breakdown of glucose

glucose+ oxygen - carbon-dioxide and water
C6H12O6 + 6O2 - 6CO2 + 6H2O


Brief anaerobic respiration.

Anaerobic respiration is defined as the chemical reactions in cells that break down nutrient molecules to release energy without using oxygen
It is the incomplete breakdown of glucose and releases a relatively small amount of energy for use in cell processes
It produces different breakdown products depending on the type of organism


Brief Anaerobic respiration in animals

less energy is released per molecule then aerobic respiration


What causes oxygen debt

lactic acid builds up in muscles and blood during vigorous exercise causing an oxygen debt.


Outline how the oxygen debt is removed.

1. Lactic acid builds up in muscle cells and lowers the pH of the cells - This could denature the enzymes in cells so it needs to be removed
2.Cells excrete lactic acid into the blood. When blood passes through the liver, lactic acid is taken up into liver cells where it is oxidized, producing carbon dioxide and water- AEROVIC RESPIRATION of lactic acid
3. This is the reason we continue to breath heavily and our heart rate remains high even after finishing exercise – we need to transport the lactic acid from our muscles to the liver, and continue getting larger amounts of oxygen into the blood to oxidise the lactic acid
4.This is known as ‘repaying the oxygen debt’


Brief anaerobic respiration in yeast

- used in bread- making and brewing/ beer making
- Glucose -- ETHANOL + CO2
C6H12O6 -- 2C2H5OH + 2 CO2


Comparison of Aerobic and Anaerobic respiration

- oxygen is needed
- glucose breakdown complete
- CO2 and water
- energy released is alot

- oxygen is not needed
- glucose breakdown is incomplete
- in animals- LACTIC ACID
in yeast- ETHANOL and CO2
- energy released is less