Glycolysis Flashcards
___ carbon glucose is turned into 2 molecules of ___ carbon pyruvate
6, 3
cellular energy is found in high energy bonds of _____ molecules
ATP
glycolysis is able to provide an energy source by generating some ATP when ____ is limited
oxygen
what causes the high energy of ATP bonds?
bond between second and third phosphate groups
what pathways are shut down when oxygen is limited?
TCA and electron transport chain
there at ___ enzyme catalyzed reactions of glycolysis
10
how many phases are in glycolysis?
2 (5 reactions in each)
in phase 1, a series of 5 enzyme catalyzed reactions transforms each glucose molecule into 2 molecules of ______
glyceraldehyde 3 phosphate
in phase 2, five enzyme catalyzed reactions convert 2 molecules of glyceralydehyde 3 phosphate into 2 molecules of ____
pyruvate
phase 1 consumes ___ molecules of ATP
2
phase 2 generates ___ molecules of ATP
4
what is the net gain of ATP between phases 1 and 2?
2 (-2+4)
what is the more active phase?
phase 1
glycolysis enzymes are located in the cell _____
cytosol
ATP synthesis in phase 2 occurs in what way?
ADP to ATP by addition of phosphate group
ATP is used up in phase 1 in what way?
ATP energy is being used and converted to ADP
NAD+ is converted to ____ in phase 2
NADH
How many NADH are made per glucose?
2
why is NADH produced in phase 2?
to stimulate the electron transport chain
what is created with pyruvate when oxygen is present (aerobic conditions)?
energy
in aerobic conditions, the ____ from pyruvate can be directly linked to the TCA cycle via a _____ bond
carbons, covalent
when oxygen is limited, the pyruvate from glycolysis produces ___ ____
lactic acid
the production of lactic acid from pyruvate is commonly found in ____ _____
muscle cells
when there is no oxygen, the pyruvate produces _____
ethanol
the production of ethanol from pyruvate is common in ___
yeast
when ethanol is produced from pyruvate, what else is produced?
carbon dioxide
(1) ____ adds a phosphate group to glucose to form glucose-6-phosphate
hexokinase
(2) ______ converts glucose-6-phosphate into fructose-6-phosphate
phosphoglucose isomerase
why is glucose converted to fructose in step 2?
build up to the proper substrate that can bind to the active site of the enzyme that will split glucose into 2
In the case of pyruvate being converted into lactic acid, what happens when oxygen is later made available?
lactic acid is converted back to pyruvate and enters the TCA cycle
(3) ____ adds a second phosphate group to fructose-6-phosphate making it fructose,1,6-biphosphate
phosphofructokinase
(4) ______ is the correct enzyme for the substrate of splitting the glucose molecule, and converts fructose-1,6-biphosphate into glyceraldehyde-3-phosphate and dihydroxyacetone phosphate (2 3 carbon fragments)
aldolase
of the 2 3 carbon fragments produced at the end of phase 1, which is the desired one?
glyceraldehyde-3-phosphate
(5) what enzyme is used to convert dihydroxyacetone phosphate into the desired form, glyceraldehyde-3-phosphate?
triose phosphate isomerase
what ensures that the glucose remains inside the cell and does not go back to the extracellular fluid in phase 1?
by the phosphorylation of glucose to glucose-6-phosphate in step 1
what molecule donates the phosphate group to glucose in step 1 of phase 1 to keep the glucose within the cell?
ATP
glucose-6-phosphate is a ___ charged molecule to make it hard to get through the lipid bilayer and glucose transporter to leave the cytoplasm and go back to the extracellular fluid
negatively
(6) ____ adds a phosphate to glyceraldehyde-3-phosphate to produce 2 1,3-biphosphoglycerate
glyceraldehyde-3-phosphate dehydrogenase
(7) ____ removes the previously added phosphate group from 2 1,3-biphosphoglycerate to produce 2 3-phosphoglycerate and adds the phosphate to ADP to create ATP
phosphoglycerate kinase
the removal of the phosphate group in step 7 converts the ______ into a ______ group
aldehyde, carboxyl group
(8) ____ moves the phosphate group form carbon 3 to carbon 2, therofore converting 2 3-phosphoglycerate into 2 2-phosphoglycerate
phosphoglycerate mutase
(9) ______ removes a phosphate group from 2 2-phosphoglycerate to crease 2 phosphoenolpyruvate
enolase
(10) _____ adds a phosphate group to ADP to form ATP and therofore converts 2 phosphoenolpyruvate into 2 pyruvate molecules
pyruvate kinase
pyruvate is a combination of an ____ group and a ____ group
acetyl, carboxyl
what is the purpose of yeast cells making ethanol?
they gain NAD+ when acetaldehyde is converted to ethanol
what enzyme converts acetaldehyde to ethanol in yeast?
alcohol dehydrogenase
yeast cells need a balance of ___ and ____ and this is achieved by the conversion of acetaldehyde to ethanol
NAD+ and NADH
what enzyme converts pyruvate to lactate?
lactate dehydrogenase
in oxygen-depleted muscles, _____ is generated by the reaction of converting pyruvate to lactic acid
NAD+
if anaerobic conditions continue, excess lactic acid is transported in the blood to the ____ and is resynthesized as ____
liver, glucose
mannose is converted into what intermediate to enter the glycolysis cycle?
Fructose-6-phosphate
galactose is converted into what intermediate to enter the glycolysis cycle?
glucose-6-phosphate
fructose is converted into what intermediate to enter the glycolysis pathway?
DHAP, G3P
