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reactions that use cofactors
oxidation/reduction reactions
anomeric carbon
the carbon in a sugar that is bound to 2 oxygens. usually involved in a glycosidic linkage
FAD+/FADH2
this is used when you want only one electron transferred. this has the capacity to transfer 1 or 2 electrons
isomerization reaction
reaction that converts one isomer to another without changing the molecular formula.
reducing sugar
has a freee OH on the 1 carbon. This allows it to act as a reducing agent, typically capable of donating electrons to other molecules.
epimer
a stereoisomer that varies only at one chiral center
enantiomer
a stereoisomer that is a non-superimposable mirror image of another.
anomer
a type of stereoisomer that differs in configuration only at the anomeric carbon, typically found in cyclic forms of carbohydrates. can be in an alpha or beta conformation
alpha anomer
-opposite directions of groups on 2, 5 carbons. one up and one down
beta anomer
-same directions of groups on 1, 5 carbons with both groups either up or down.
lactose enters as dietary starch and is broken down by:
is broken down by lactase
Lactose is broken down into:
galactose and glucose
sucrose is broken down by:
sucrase
sucrose is broken down into
glucose and fructose
galactose is broken down by
UTP
galactose is broken down into
glucose 1 phosphate
5 memebered carbon rings are
ketones
6 membered carbon rings
are aldoses
fructose is broken down by
fructokinase
fructose is broken into
fructose 6 phosphate or fructose 1 phosphate
endogenous glycogen starch is broken into
glucose-1-phosphate and glucose
endogenous glycogen starch is broken down by
phosphorylase
dietary glycogen starch is broken down by
malaise
dietary trehalose is broken down into glucose by:
trehalase
when blood glucose is low what is happens?
-glycolysis is inhibited and gluconeogenesis is stimulated and energy is put into glucose
when blood glucose is high or energy is low
glycolysis is performed to break down glucose and release energy
glycolysis transcription is regulated by what?
ChREBP
pyruvate orientation
the 1 or 6 carbon is at the end, part of carboxylic acid group
are NAD/NAHD and FAD/FAHD covalently bonded
nope. FAD is more tightly bound, but both are non-covalently associated cofactors
D Isomer of Glucose
-on the 5th carbon, (2nd to last) the OH is on the right side
L isomer of glucose
-on the 5th carbon (2nd to last) the OH group is on the left
glycogen subunit:
glucose
starch subunit:
glucose
chitin subunit:
N-acetylglucosamine
cellulose subunit:
glucose
glycogen linkage
-alpha 1-4 linkage
-alpha 1-6 linkage
starch linkage
-alpha 1-4 linkage
-alpha 1-6 linkage
chitin linkage
-beta 1-4 linkage
cellulose linkage
-beta 1-4 linkage (cellulose)
glycogen and starch function
energy storage
chitin and cellulose function
structural support
where are starch and cellulose located
plants
where is glycogen found
animals and bacteria
where is chitin found
exoskeletons of arthropods
what step of glycolysis does the 1st gluconeogenisis bypass
step 10
what step of glycolysis does the 2nd bypass of gluconeogenesis skip
step 3
what step of glycolysis does the 3rd gluconeogenisis bypass skip
step 1
which reactions in glycolysis are irreversible
steps 1, 3, and 10
what step of glycolysis produces water
step 9
what steps of glycolysis are the “pay-off stages”
steps 6-10
what steps of glycolysis are energy producing?
7 and 10
what steps of glycolysis are the energy investment steps?
steps 1 and 3
what reactions are not shared between glycolysis and gluconeogenisis?
any irreversible steps
amylose is what?
a non branched starch
amylopectin is what?
a branched starch
alpha anomers are
trans at anomeric carbons
beta anomer’s are
cis at anomeric carbons
glycosidic linkages are
covalent and formed via dehydration synthesis
pyranose is a
6 membered sugar ring
fructose
5 membered sugar ring
what enzyme has a bossman fold?
G-3-P dehydrogenase
catabolism
energy harvesting reaction
anabolism
energy consuming reaction
how do phosphorylated intermediates lower activation energy in glycolysis?
the binding energy of phosphates and contributes to the specificity if enzymes
in the presence of O2 in animals what happens to pyruvate
it undergoes cellular respiration
in the presence of low/no O2 what happens to pyruvate
it undergoes lactic acid fermentation
what does lactic acid fermentation do
converts pyruvate into lactate and is an example of an oxoreductase reaction. this reaction regenerates NAD+ and allows for glycolysis to continue
semiquinone FADH
this FADH molecule has a radical on the nitrogen
what does F-2,6-BP do?
inhibits FBPase and activates PFK-1
what is the net ATP gain from glycolysis
2 atp
what is gluconeogenisis
the formation of glucose from non carbohydrate sources
where does gluconeogenesis occur in the cell?
in the mitochondria
what is the mechanism by which insulin stimulates glycolysis?
activates the F-2,6-BP regulation which in turn increases F-2,6-BP levels which in turn enhances PFK activity.
what causes glycolysis to stop?
when NAD+ runs out as it acts as a cofactor in glycolysis and is specifically needed in step 6
phosphorylated intermediates are used to:
-push unfavorable reactions forward
-trap the intermediate within the cell
allosteric regulation of what three enzymes are important for regulation of glycolysis within the cell?
-hexokinase
-phosphofructokinase
-pyruvate kinase
endogenous glycogen starch
is already within the body
dietary glycogen starch
ingested into the body
1st step of glycolysis
glucose to G-6-P
enzyme for the 1st step of glycolysis
hexokinase
what inhibits hexokinase
G-6-P
2nd step of glycolysis
G-6-P —> F-6-P
enzyme for 2nd step of glycolysis
phosphohexose isomerase
3rd step of glycolysis
F-6-P —> F-1,6-BP
what step of glycolysis is the rate limiting step?
step 3. this step is also considered a committed step
4th step of glycolysis
F-1,6-BP —> G-3-P +DHAP
what C-C bond is cleaved in the 4th step of glycolysis?
C3-C4 Bond
what is formed as a result of step 4 of glycolysis?
2 3 carbon sugars are produced
what enzyme performs the 3rd step of glycolysis
PFK/phosphofructokinase
what enzyme performs the 4th step of glycolysis
F-1,6,BP Aldose
what is the 5th step of glycolysis
DHAP —> G3P
what enzyme perfoms the 5th step of glycolysis
triode phosphate isomerase
how is DHAP changed into G3P
triose phosphate isomerase changes an Alch into an aldehyde
what reactions of glycolysis happen twice per molecule of glucose?
steps 6-10
what is the 6th step of glycolysis
G3P—> 1,3 BPG + 2NADH
what enzyme performs the 6th step of glycolysis
Glyceraldehyde-3-phosphate dehydrogenase
what is the 7th step of glycolysis
1,3 BPG—> 3 PG +ATP
what enzyme performs the 7th step of glycolysis
phosphoglycerate kinase
what is the 8th step of glycolysis
3PG —> 2PG
Note 
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