B8.2 - Respiration Flashcards
Respiration happens in
every living cell
What is cellular respiration
the releasing of energy from chemical bonds in food molecules such as glucose.
State the uses of energy in the human body
To produce the contraction of muscle cells
To produce new chemical bonds during the synthesis of new proteins
Produce new chemicals needed for cell division and growth
Active transport of molecules across cell membranes
Produce movement of nerve impulses along nerve cells
Maintenance of constant core body temperature
Respiration that uses oxygen to release energy from glucose in chemical reactions in cells is called
aerobic respiration
symbol and word equation of aerobic respiration
Glucose + oxygen ==> carbon dioxide + water
C6H12O6 + 602 ==> 6CO2 + 6H2O
Why do organisms anaerobically respire
when not enough oxygen is available for aerobic respiration to be carried out fast enough to deliver all the energy that is needed
What is anaerobic respiration
the process of releasing energy from glucose molecules but without oxygen
Organisms like yeast and some bacteria will
respire anaerobically in preference to aerobic even when oxygen is present
word and symbol equation for anaerobic respiration in yeast
glucose ==> ethanol + carbon dioxide
C6H12O6 ==> 2C2H5OH + 2CO2
Process is fermentation
word and symbol equation for anaerobic respiration in muscles during vigorous exercise
glucose ==> lactic acid
C6H12O6 ==> 2C3H6O3
Differences between anaerobic and aerobic respiration
Aerobic respiration requires oxygen
During aerobic respiration, many of chemical bonds in a glucose molecule are broken down. The energy released is high
Anaerobic doesn’t require oxygen
During anaerobic respiration, glucose molecules are only partly broken down so far less energy is released compared to aerobic respiration
Examples of when anaerobic respiration can happen
When not enough oxygen reaches the muscles during periods of intense activity
In diving animals like whales and seals
Important note.
Even when a muscle cell is respiring anaerobically, aerobic respiration is also taking place and using all the oxygen available.
Where aerobic respiration cannot supply all the energy needed only the additional energy needed comes from anaerobic respiration.
During anaerobic respiration
the concentration of lactic acid builds up in the cells and in the blood
Describe the role of anaerobic respiration in yeast for bread making, beer and wine
Ethanol is formed when sugars in barley or grapes are broken down.
We use yeast in bread making because CO2 released forms bubbles in the dough. making the bread light and spongy
