Lecture exam 2 (Anaerobic glycolysis) Flashcards
What is anaerobic glycolysis
breakdown of sugar (glucose) with out oxygen in environment (oxygen can be present0
where does glucose come from for anaerobic glycolysis
blood circulation and glycogen stored in the muscle
anaerobic glycolysis is the primary energy form in activities that last this long
20-30 sec to 2-3 min
intermediate =
reactant or product in a metabolic pathway
first and last intermediate of anaerobic glycolysis in an anaerobic environment
glucose
lactate
glucose in the blood comes from here
glycogen stores in the liver
foods we eat
ATP produced in anaerobic glycolysis is used for this
crossbridge recharging
step 1: How does glucose get into the cell
glucose enters cell facilitated by the pancreatic hormone insulin
step 1:When glucose enters the cell this immediately happens, and results in
glucose is phosphorylated by HK (hexokinase)
glucose-6-phosphate
step 1: What are two important points of this step when glucose come from outside the cell
costs 1 ATP to initially phosphorylate glucose
once phosphorylated the 6 carbons are restricted to the cell
step 1: Glucose can come from glycogen in the cell that has been acted on by this enzyme
phosphorylase
step 1: what are two important points of this step when glucose come from inside the cell
does not require atp when substrate is glucose
once phosphorylated the 6 carbons are restricted to the cell
step 1: final intermediate
glucose-6-phosphate
step 2: what happens (isomerase)
glucose-6-phosphate is acted on by an isomerase to produce fructose-6-phosphate
step 3: what happens (PFK)
fructose-6-phosphate is acted on by PFK (phosphofructokinase) to produce fructose-1,6-bisphosphate + ADP
Step 3: Two important aspects of this step
This step uses 1 ATP
PFK is the rate limiting step of glycolysis (lowest urnover rate in the pathway)
NAD is a derivative of this vitamin
B3
step 4: what happens (Aldolase)
fructose-1,6-bisphosphate is acted on by the enzyme aldolase to produce 2, 3 carbon compounds
step 4: what are the 2, 3 carbon compound intermediates of this step
DHAP (dihydroxyacetone phosphate)
G-3-P (glyceraldehyde-3-phosphate)
step 4: this is acted on by this to produce a second molecule of this
DHAP is converted by an isomerase to produce a second molecule of G-3-P
Step 5: what happens (G3PDH)
G-3-P is acted on by glyceraldehyde-3-phosphate dehydrogenase to produce 1,3-bisphosphoglycerate and NADH+H+
step 5: this type of reaction occurs at this step
oxidation-reduction reaction
oxidation-reduction is this type of reaction
coupled reaction
When something is reduced you do this
add H+
When something is oxidized you do this
remove H+
step 5: G-3-P is oxidized or reduced in this reaction
gives up 2 hydrogen and is thus oxidized
step 5: NAD is oxidized or reduced in this reaction
gains hydrogen and is reduced to NADH+H+
Easy way to remember names of enzymes in redox reactions
name of the reactant + dehydrogenase
step 6: what happens (PGK)
1-3, bisphosphoglycerate acted on by PGK (phosphoglycerate kinase) to produce 3-phosphoglycerate + ATP (from ADP)
gross
gained
net
gained - used
step 7: what happens (mutase)
3-phosphoglycerate acted on by a mutase to produce 2-phosphoglycerate
step 8: what happens (enolase)
2-phosphoglycerate acted on by enolase to produce phosphoenolpyruvate (PEP)
Step 9: what happens (PK)
PEP acted on by PK (pyruvate kinase) to produce pyruvate and ATP from ADP
Net ATP from 1 glucose (blood) makes this much ATP
2
Gross ATP from 1 glucose (blood) makes
4
Step 10a: what happens (LDH)
anaerobic cellular environment, pyruvate is reduced to form lactate by the enzyme LDH (lactate dehydrogenase)
Step 10a: what happens to NADH+H+ (LDH)
NADH+H+ is oxidized to NAD
Where does glycolysis occur in the cell
sarcoplasma
Step 10b: what happens (AT)
pyruvate is converted to alanine by alanine transaminase
Step 10b: why does the cell form alanine
alanine can leave the cell and is deaminated in the liver. It can now reform glucose in the liver and re-enter circulation
Glucose-alanine-glucose cycle
glucose can be used in cell, converted to alanine, which can then be converted back to glucose
What is the draw back of the glucose-alanine-glucose cycle
pyruvate converted to alanine cannot be converted to lactate which inhibits ATP production
How much lactate or alanine is produced is dependent on this
law of mass action
T/F: exercise has no effect on alanine transaminase concentration
F, exercise increases
Step 10c: pyruvate can be converted to acetyl-CoA with this enzyme
Pyruvate dehydrogenase
Step 10c: When pyruvate is acted on by PDH to make acetyl-CoA these two things are formed
NAD is reduced two NADH+H+
CO2 is released
Step 10d: pyruvate can be converted to oxaloacetate by this enzyme
Pyruvate carboxylase
Step 10d: when pyruvate is acted on by PC to form oxaloacetate these two things occur
ADP from ATP
CO2 is picked up
