Aerobic Respiration Flashcards
Give the overall equation for respiration.
6O2 + C6H12O6 -> 6CO2 + 6H2O
Where does glycolysis take place?
The cell cytoplasm.
Briefly describe the 3 things that glycolysis does.
Trapping the glucose in the cell and phosphorylating it.
Splitting the glucose molecule into 2.
How many carbon molecules in pyruvate?
3C
In the 1st stage of glycolysis, describe what happens to glucose.
Glucose is phosphorylated to form a 6C molecule with 2 phosphate groups attached.
How much ATP is hydrolysed in the first stage of glycolysis?
How many phosphates released?
2 ATP hydrolysed into 2 ADP and 2Pi
Why is ATP hydrolysed in the 1st stage of glycolysis?
Hydrolysis of ATP releases energy which is used to add the phosphates to the glucose (phosphorylation).
In the 2nd stage of glycolysis, what happens to the phosphorylated glucose?
Phosphorylated glucose is split into 2 molecules of triose phosphate. (3C)
In the 3rd stage of glycolysis, describe how the triose phosphate is oxidised.
Hydrogen is removed from each of the triose phosphate molecules.
After oxidation occurs in stage 3 of glycolysis, where does the hydrogen go?
Which molecule/how many of this molecule is produced and why?
Hydrogen is added to NAD to form reduced NAD.
This forms 2 molecules of reduced NAD as this occurs for each molecule of triose phosphate.
Give a balanced equation for the oxidation of NAD using hydrogen.
4H + 2NAD -> 2NADH + 2H+
Briefly states what happens in the 4th stage of glycolysis. Include descriptions of how much ATP is formed, what molecules are formed etc
ATP is produced as phosphate molecules are removed from each of the triose phosphates. These phosphates react with ADP to form 4 molecules of ATP overall, creating a net gain of two. Dephosphorylation of both triose phosphates will produce 2 pyruvates.
Give the names and amount of each molecule produced at the end of glycolysis.
2 Pyruvates (3C)
4 ATP (net gain 2)
2 Reduced NAD
Where does the link reaction occur?
In the matrix of the mitochondria.
What two stages of respiration does the link reaction connect?
Glycolysis and the Krebs Cycle.
How will pyruvate enter the mitochondrial matrix from the cytoplasm?
What conditions are required for aerobic respiration to continue?
Pyruvate will actively transport into the mitochondrial matrix.
This is when oxygen is available.
In the 1st stage of the link reaction, pyruvate is oxidised to what molecule?
What molecules are lost?
Pyruvate is oxidised to acetate and CO2 is lost.
This means acetate is a 2C molecule.
What is the process of removing CO2 from pyruvate called?
Decarboxylation
Describe the production of reduced NAD in the link reaction.
2 Hydrogen atoms are released per molecule of acetate.
One of these hydrogens is added to NAD to produce reduced NAD.
The other is released.
What is the process of adding hydrogen to NAD called?
Hydrogenation.
The acetate produced reacts with what enzyme to produce what products?
Acetate + Coenzyme A -> Acetyl coenzyme A + Reduced NAD + Co2
What is a coenzyme?
A molecule that helps enzymes carry out their function, but is not used in the reaction itself.
Where does the Krebs cycle take place?
The Krebs cycle takes place in the mitochondrial matrix.
In the 1st stage of the Krebs cycle, acetyl coenzyme A will firstly combine with a molecule with how many carbons in the chain?
Acetyl coenzyme A (2C) combines with a 4C molecule
What is formed after acetyl coenzyme A combines with the 4C molecule? What is released?
Citrate (6C)
Coenzyme A is released.
Citrate (6C) converted back to 4C through a series of what type of reactions?
Through a series of oxidation/reduction reactions.
How much CO2 is lost during decarboxylation of citrate (6C)?
2CO2
How many ATP molecules are formed in 1 Krebs Cycle?
What is this process called?
1 molecule of ATP produced.
This is called substrate level phosphorylation.
What molecule is regenerated at the end of the Krebs cycle?
4C. This can combine again with another acetyl coenzyme A at the end of the Krebs cycle.
For each molecule of pyruvate, how many ATP and CO2 are produced?
1 ATP
3 CO2
Give 2 importances of the Krebs cycle.
To break macromolecules into smaller ones.
To release H atoms that can be carried by NAD to the electron transport chain and provide energy for oxidative phosphorylation.
How are H atoms used in the ETC?
They provide energy for oxidative phosphorylation which leads to ATP production.
What do NAD and FAD do?
They accept hydrogen atoms that become available during respiration and transfer the H atoms from the different stages of respiration to the ETC.
Where does the electron transport chain take place?
On the inner mitochondrial membrane.
How do coenzymes get oxidised?
The hydrogen atoms get removed.
How do electrons join onto the electron transport chain?
Reduced NAD/FAD releases their hydrogen atoms to the electron transport chain.
How are electrons passed along electron carriers?
Through a series of oxidation/reduction reactions.
How is energy released during the electron transport chain?
When FAD and NAD get oxidised, their loss of hydrogen releases energy.
Where do H+ ions move from/to in the ETC?
H+ ions move from themitochondria matrix, through the inner mitochondrial membrane to the inter membranal space.
Describe where the high and low concentration of H+ ions would be found in the mitochondria.
Low concentration in the mitochondrial matrix.
High concentration in the inner mitochondrial space.
Oxidative phosphorylation results in the production of which 2 molecules?
ATP and water from oxygen.
What is chemiosmotic theory?
The theory that states that energy from electrons passed through the ETC is used to actively transport H+ ions up their concentration gradient into their intermembrane space.
How is ATP produced during the ETC?
What transport process is involved?
Described how energy is used during ATP production.
H+ ions pass down their concentration gradient through ATP synthase channels which releases energy, in facilitated diffusion, producing ATP.
Describe where facilitated diffusion and active transport take place in the ETC.
H+ ions are actively transported from the matrix to the inter membranal space.
They are then transported through ATP synthase channels back into the matrix in facilitated diffusion.
What does oxygen acting as the final electron acceptor mean?
It combines H+ ions with electrons to form water at the end of the ETC.
State the amount of NAD and FAD released during each stage of respiration. Consider that there are 2 Krebs cycles occurring for each molecule of glucose.
Reduced NAD:
2 x 1 = 2 from Glycolysis
2 x 1 = 2 from the Link Reaction
2 x 3 = 6 from the Krebs cycle
Reduced FAD:
2 x 1 = 2 from the Krebs cycle
How many molecules of ATP are produced overall during respiration?
32 ATP overall
