Chapter 12: Respiration Flashcards
What is meant by ‘respiration’?
Respiration refers to the process of breaking down glucose to provide energy for the cell
Plant and animal cells release the energy stored in glucose
Converting that energy into ATP an immediate source
The energy powers biological processes
What is the equation for respiration?
C6H12O6 + 6O2 — 6CO2 + 6H2O + energy
What are the 2 types of respiration?
The 2 types of respiration are aerobic and anaerobic respiration
True or False: Both aerobic and anaerobic respiration produce ATP
True. Although anaerobic respiration produces less ATP than aerobic
Aerobic respiration occurs in which conditions and produces what?
Aerobic respiration occurs when oxygen is present/available and produces:
CO2 + water + energy
Anaerobic respiration occurs in which conditions and produces what?
Anaerobic respiration occurs when there is no oxygen and produces:
CO2 + ethanol/lactate + energy
What are the stages of respiration?
The stages of respiration are:
For aerobic:
- Glycolysis
- the Link Reaction
- the Krebs Cycle
- Oxidative phosphorylation
For anaerobic:
- Glycolysis
- Alcoholic/Lactate fermentation
What is glycolysis?
Glycolysis is the first stage in both aerobic and anaerobic respiration
Site: cytoplasm of plant cells
Does not need oxygen - anaerobic process
Pyruvate is made from glucose
One 6-carbon molecule of glucose is split/converted into 2x 3-carbon molecules of pyruvate
Which stage in respiration is shared by aerobic and anaerobic respiration?
Glycolysis
Describe what happens in glycolysis.
Glucose is phosphorylated to make it more reactive (lowers activation energy for following enzyme controlled reactions)
- 1 molecule of ATP is hydrolysed
- Glucose becomes glucose phosphate
- Another ATP is hydrolysed
- Glucose phosphate becomes hexose biphosphate
- Hexose biphosphate splits into 2 molecules of triose phosphate
Each triose phosphate is oxidised to pyruvate by enzyme controlled reactions in which 2 molecules of reduced NAD and 4 molecules of ATP are formed/released
- TP is oxidised (hydrogen is removed)
- Forms 2 molecules of pyruvate
- and 2 molecules of ATP
- The hydrogen released is picked up by NAD
- Forming 2x reduced NAD
There is a net gain of 2 ATP molecules because 2 were used up at the start
What happens to the 2 molecules of reduced NAD made from glycolysis?
The two molecules go to oxidative phosphorylation.
What happens to the 2 molecules of pyruvate made in glycolysis?
The 2 molecules of pyruvate go to the Link reaction and are actively transported into the matrix of the mitochondria
What is the Link Reaction?
The second stage of aerobic respiration
Describe what happens in the Link reaction?
What is the Krebs cycle?