Slides in this set
Glycolysis: A metabolic pathway where a glucose molecule is broken down
into 2 pyruvate molecules. It occurs in the cell cytoplasm and can be
performed both aerobic and anaerobically.
There are 4 sections to remember: Glucose
1ATP hydrolysed, phosphoryl group added
to glucose molecule.
Glucose-6-phosphate converted into ATP Hexose-1,6-
Another ATP is hydrolysed, phosphoryl
group added to carbon 6 on fructose
Energy from hydrolysed ATP activates
sugar and prevents it from leaving cell. NADred
This created a product called hexose-1,6-
bisphosphate, the "s" is very important, you 2ATP
get marked down for calling it a 2pyruvate
Oxidation of triosphosphate:
Although an anaerobic
pathway, there is oxidation.
Splitting of the Hexose residue: 2H removed by dehydrogenase
Each molecule of hexose-1,6-bisphosphate is enzymes plus coenyzme NAD.
split into 2trisphosphate, each with 1 NAD becomes reduced NAD
phosphoryl group attached. as it accepts the hydrogen
2ATP formed by substrate
Conversion to pyruvate:
4 enzymes catalyse reactions
Pyruvate will be actively transported into the
to convert each mitochondrial matrix during aerobic respiration.
triosphosphate into a pyruvate See "Respiration extras" to see what happens to
molecule. pyruvate under anaerobic conditions.
Another 2ATP molecules are
Products of glycolysis:
formed by substrate-level
Net gain: 2ATP, 2 used, 4 made
2 molecules of reduced NAD
2 molecules of Pyruvate…read more
The Link Reaction
The link reaction: converts pyruvate to acetate, NAD is reduced. It takes
place in the mitochondrial matrix.
Pyruvate decarboxylase and
pyruvate dehydrogenase catalyse Pyruvate
the reaction to produce Acetyl CoA
and reduced NAD and CO2. Reduced
Coenzyme A is also reduced, it's CO2
function is to transport the acetate to
the Krebs cycle. Acetyl CoA CoA
No ATP is produced , NAD take the
hydrogen atoms to the inner
membrane of the mitochondria to to
be used in oxidative phosphorylation
to make ATP.…read more
The Krebs Cycle
The Krebs cycle: oxidises acetate to produce CO2, NAD and FAD are
reduced and 1ATP formed by substrate phosphorylation, it takes place in the
Reduced FAD 5 Reduced
Reduced NAD 3…read more
The Krebs Cycle Continued
Acetate is offloaded from Coenzyme A and joins a 4 carbon compound
called Oxoloacetate to form Citrate.
Citrate is decarboxylated and de-hydrogenated to to form a 5 carbon
compound. The reduced NAD leave the Krebs cycle to mitochondrial
The 5 carbon compound is decarboxylated and dehydrogenated to form a 4
This is then converted into another 4 carbon compound where ATP is
created by substrate phosphorylation.
This 4 carbon compound is then converted into another 4 carbon compound,
an hydrogen atom is removed and FAD is reduced, this coenzyme also
travels to the mitochondrial intermembrane space.
The 3rd 4 carbon compound is dehydrogenated further to produce reduced
NAD and regenerates Oxoloacetate.…read more