5.2 Respiration Flashcards
Location of glycolysis
Cytoplasm
Is glycolysis aerobic or anaerobic
Anaerobic
What are the 3 steps of glycolysis
- Glucose –> 1,6-fructosebiphosphate (using ATP)
- 1,6-fructosebiphosphate –> 2 x Triose Phosphate
- 2 x Triose Phosphate –> 2 x pyruvate + 2ATP + 2 Reduced NAD
Net products of glycolysis
- 2 Pyruvate
- 2 ATP
- 2 Reduced NAD
What reaction is triose phosphate to pyruvate
Oxidation
What is required to turn glucose into 1,6-fructosebiphosphate
ATP
What is reduced into what, as triose phosphate is oxidised to pyruvate
NAD is reduced to reduced NAD
What is the product of glycolysis, and how does it enter the Link Reaction
- Pyruvate
- Activly transported into mitochondrial matrix
- As can cross mitochondrial membranes
Location of Link Reaction
Mitochondrial matrix
How many times does the link reaction occur, per glucose molecule
Twice
What are the two stages of the Link Reaction
- Pyruvate –> Acetate + CO2 + Reduced NAD
- Acetate + CoenzymeA –> AcetylcoenzymeA
What type of reaction is pyruvate –> acetate
Oxidation
Substrate for Kreb’s Cycle
AcetylcoenzymeA
Where does Kreb’s Cycle occur
Mitochondrial Matrix
How many times does the Kreb’s Cycle occur for each molecule of glucose
Twice
What are the two stages of the Kreb’s Cycle
- AcetylcoenzymeA + 4C –> 6C + CoenzymeA
- 6C –> 4C + 2CO2 + Reduced FAD + Reduced NAD + ATP
Explain what is occuring during the second stage of the Kreb’s cycle
The 6C molecule undergos a series of redox reactions to reform the 4C molecule
What are the end products of one Kreb Cycle
- 4C
- 2 x CO2
- Reduced NAD
- Reduced FAD
- ATP (one per cycle)
How many ATP are produced per Kreb Cycle
ATP
How many molecules of ATP are produced in the Kreb’s Cycle, per molecule of glucose
2
Location of Oxidative Phosphorylation
Inner mitochondrial membrane
Describe and explain the process of oxidative phosphorylation, until an electrochemical gradient is established
- Reduced NAD and reduced FAD are oxidised, forming NAD and FAD, releasing electrons
- Electrons move down the electron transport chain, releasing energy to proteins by redox reactions
- Energy is used to actively transport protons from matrix, to inter-membrane space
- This establishes an electrochemical gradient
Describe and explain the process of oxidative phosphorylation from the establishement of an electrochemical gradient
- Protons diffuse through ATP synthase back into the matrix
- Energy released allows ADP + PI –> ATP
- Oxygen acts as terminal electron acceptor
- Combines with electrons and protons to form water
Why is oxygen so important by acting as a terminal electron acceptor
Absorbs the excess protons, maintaining the electrochemical gradient, allowing protons to continue to diffuse through ATP Sythase
How many molecules of ATP are synthesised per glucose molecule in aerobic respiration (how many from each stage)
- 30-32
- 2 in glycolysis
- 2 in Kreb’s Cycle
- 26-28 in Oxidative Phosphorylation
Per glucose molecule, how many molecules of ATP are synthesised during oxidative phosphorylation
26-28
Where does anaerobic respiration occur
Cytoplasm
Describe the process of anaerobic respiration
- Glycolysis occurs
- Producing 2 pyruate, 2 ATP and 2 Reduced NAD
- Reduced NAD is oxidised to NAD to allow glycolysis to continue
- As NAD is reduced in glycolysis
What is pyruvate reduced to in anaerobic respiration in animals
Lactate
What is pyruvate reduced to in anaerobic respiration in plants
- Ethanal
- Then ethanol + CO2
How many molecules of ATP are synthesised during anaerobic respiration per glucose molecule
2
What must always be refered to when given a question of respirometers
- Increase/decrease in volume of gases
- Pressure change
In respiration experiments, why do organisms need time before the experiment begins at different temperatures
To equilibrate
