C1 - Respiration Flashcards
What bonds are broken in respiration?
C-C
C-H
C-OH
And then lower energy bonds are formed.
Does ATP produce energy?
NO
It releases it when hydrolysed.
What are the 4 main stages of aerobic respiration?
Glycolysis
Link reaction
Kreb’s cycle
Electron Transport Chain
Why does glycolysis happen in the cytoplasm?
Glucose can’t pass through the mitochondrial membranes.
+
Even if it could, enzymes for its breakdown aren’t present in the mitochondria anyway.
What is the result of the phosphorylated glucose - Glucose diphosphate?
Polar = less likely to diff. out of cell.
More reactive = less activation energy is required for the enzyme-controlled reactions.
Define dehydrogenation
Removal of 1 or more H atoms from a mol.
Define carboxylation
Removal of a carboxyl group from a mol. in which CO2 is released.
What is the link reaction?
Linking glycolysis to the Kreb’s cycle:
Pyruvate diff. from cytoplasm into mitochondrial matrix.
Pyruvate is dehydrogenated + decarboxylated to form an (2C) acetyl group each.
Both are picked up by CoA to then become AcCoA (2C)
What can happen to pyruvate if O2 is present during the Kreb’s cycle?
Some of the chemical potential energy in the pyruvate can be released.
What equation can be used to summarise the link reaction?
Pyruvate + NAD + CoA —- AcCoA + red. NAD + CO2.
Where does the link reaction and Krebs cycle take place?
Mitochondrial matrix
What is the function of red. NAD + red. FAD from the Krebs cycle?
Deliver H atoms to ETC on inner mitochondrial membrane.
What are the 2 significant types of reactions in the Kreb’s cycle?
DECARBOXYLATION (happens twice). 6C acid – 5C acid – 4C acid
DEHYDROGENATION (4 times). to give 3 mol. of red. NAD + 1 mol. of red. FAD.
What happens to the acetate group from the original glucose molecule by the end of the Krebs cycle?
Entirely broken down to CO2 + H20.
What is the energy in the bonds of the glucose mol. carried by?
By e- in the H atoms in red. NAD + red. FAD.
How many times does the Krebs cycle have to turn for each glucose molecule and why??
Twice for each glucose mol.
Because each glucose mol. makes 2 mol. of pyruvate so 2 mol. of AcCoA.
How many of each products is made per glucose put through glycolysis, the link reaction + the Krebs cycle?
CO2 = 6
Red. NAD = 10
Red. FAD = 2
ATP = 4
38 ATP is produced during aerobic respiration but only 4 in glycolysis, the link reaction + the Krebs cycle from one glucose molecule. Where does the rest come from?
For every red. NAD you get 3 ATP in the E.T.C = 30 ATP
For every red. FAD you get 2 ATP in the E.T.C = 4 ATP
Where is the electron transport chain located?
Cristae in the inner mitochondrial membranes.
What are cytochromes?
Proteins conjugated to iron or copper.
These metal ions are oxidised + reduced by e- transport.
The reactions they catalyse release energy which is carried by ATP.