glycolysis Flashcards
1
Q
what glucose units are absorbed by intestine and transported to bloodstream
A
D-glucose
2
Q
what do amylases do
A
- randomly break down internal alpha 1-4 bonds
3
Q
what will amylase not digest
A
cellulose
4
Q
where is amylase located
A
in saliva and small intestine
5
Q
what type of digestion doesn’t occur in the stomach
A
starch because it is stopped by HCL
6
Q
what sugar is in the small intestine
A
alpha glucosidase (maltase)
7
Q
what is D glucose
A
absorbed by intestine and transported to the bloodstreem
8
Q
what bonds have energy
A
c-h, c-c and c-oH
9
Q
you can capture energy from oxidizing what
A
carbon
10
Q
what is an example of oxidizing energy from carbon
A
- make reduced redox factors NADH
- high energy compounds like PEP and 1,3 BPG
11
Q
what is the most reduced state of carbon
A
CH2
12
Q
what is the most oxidized state of carbon
A
CO2
13
Q
where does glycolysis occur in prok
A
in the cytosol
14
Q
in euk where does glycolysis occur
A
in the cytosol
15
Q
where does Krebs, ETC/Ox phos occur
A
in the mitochondria
16
Q
what do they do to the C’s in glycolysis
A
oxidize them to release energy
17
Q
what do they capture some of the enrgy as
A
NADH and use it to make high energy phosphate 1,3-BPG and PEP
18
Q
what do they make ATP from
A
substrate level phosphorylation
19
Q
what atom do the steps involving atp + enolase
A
need Mg+2 because it is a metal ion cat
20
Q
what are the main control points for glycolysis
A
step 1
step 3
step 10
21
Q
how many Kcal do carbohydrates have
A
4 Kcal
22
Q
what is the name of the glucose transporter and what transport does it do
A
GLUT4
23
Q
in glut4 what does hexokinase do
A
traps Gle as G6P in cytosol
24
Q
what does Metal ion catalysis by charge shielding do to the gamma phosphorous
A
makes it more accessible for nucleophillic attack C-6 oH
25
when fructose turns into glucose what intermediate is used
the enediol
26
describe phosphoglucose isomerase
- rxn is reversible
-general acid base catalysis
- enediol intermediae
27
describe phosphofructokinase PFK
- reversible step
- adds phosphate groups to other molecules
-MAIN CONTROL POINT
28
what does aldolase do
enzyme tht turns 1,6FBP to GAP and DHAP
29
describe aldolase
-lyase that removes dhap and gives double bond
- reversible because lyases are reversible
30
what clevage does aldolase go through
aldol cleavage
- retro/reverse aldol condensation
31
Triose Phosphate isomerase
- reversible
-general acid base catalysis
-enediol intermediate
32
does equilibriym favor DHAP or GAP
it favors DHAP
33
what type of motif does triose phosphate isomerase (TIM) have
alpha/beta barrel fold
34
glycolysis stage II starts with what
GAP3DH) its a dehydrogenase
35
why is glyceraldehye-3-phosphate Dehydrogenase important
it generates the first high energy intermeduate
36
what does GAP3DH use to generate the intermediatre
inorganic Pi
37
what are dehydrogenases
reeox enzymes (oxireductases)
38
what is a oxireductase
- electrons are transferred between molecules
- example dehydrogenase
39
what is a transferase
- transfer functional groups like methyl and phosphate
example: kinases
40
what is a hydrolase
catalyze the cleavage of bonds through the addition of water
ex: proteases, nucleases, lipases
41
what is a lyase
catalyze the addition or removal of groups to form double bonds or break
ex: decarboxylases, aldolases
42
what is a ligase
catalyze the joining of two molecules
ex: dna ligase, synthetases
43
what does isoermase
rearrangement of atoms within molecule
ex. epimerases, racemases
44
how much NADH +h does GAP3DH generate per g;ucose
2 NADH + H+( from NAD)
45
what are the proofs of the GAPDH mechanism
-phosphate source is inorganic
- hydride is transfereed to NADH to oxidize GAP
46
what is vitamin B3
nicotinamide (NAD+/ NADP+)
47
what are the enzymes of vitamin b3
Nad Nadp+
48
what reaction is vitamin b 3 and what disorder can you get
oxidaton reduction and pellegra
49
what structure is this
nicotinamide adenine phosphate or dinucleotide
50
what are the redox cofactors
-FAD= flavin adenine dinucleotide
- FMN= flavin adenine mononucleotide
-NAD
NADP
51
what do redox factors do
-electron transfer
- energy production
- catabolic and anabolic pathways
52
energy stored in NADH as what
2 high electron energy that is used to charge the ETC, and make more ATP by OxPhos
53
why is As (arsenic bad)
it is similar to phosphorous and it can be substituted for P and is poisonous
- As disrupts ATP production
54
what disrups atp production
As bc it looks like P and it disrups the GAPDH rxn
55
what functional group from carboxylic acid contains stored chemical energy
anhydrides
56
a compound with a large negative delta g hydrolysis can transfer what
its phosphate group to a compound with a smaller hydrolysis
57
what is substrate level phos SLP
production of atp from adp by direct transfer of Pi group ( large negative to smaller less negative)
58
what compounds form atp through slp
PEP and 1,3 BPG
59
what happens at PGK step (phosphoglyerate kinase)
first atp generation step meaning SLP
60
which reactions are thermo and ohysically coupled
GAPDH and PGK
61
what residue does the phosphoglyerare mutase mechanism have
active form of phosphohistidine in active site
62
what ec classification is enolase
lyase bc it removes H2O and its reversible bc all lyases are reversibl
63
why is PEP (phosphoenol pyrivate) the usain bold of high energy compounds
highest standard free energy of hydrolysis due to enol to keto tautomer -61.9Kj/mol
64
what does the loss of water in 2-PG do
- redistribution of energy
- increasing the hydrolyis making more negative
65
why is pyruvate kinase or PK important
second atp generation step
66
what happens in the pyruvate kinase reaction
-metal ion cat
-phosphoryl group transfer
- pep transfers phosphate
67
what is the net reaction of glycolysis
glucose + 2adp+ 2pi+ 2nad= 2 pyruvate + 2atp+ 2H+ + 2H2O
68
is glycolyisis anerobic or aerobic
anerobic
69
what amine is found in aldolase
lysine
used in schiff bases
70
what is the schiff base
electron sink that stabilizes negative charge
71
what happens in the aldolase mechanism
- covalent catalysis
-aldolase is a nuc. that forms covalent enz-substrate adduct that alters the reaction pathway
72
what enzyme has an alternative pathway through formation of a covalent adduct
aldolase
73
some characteristics of class I aldolase
1. cov cat by lys 229
- lys attacks c=o of FBP to form iminium cation
2. asp 33 is a gen base to cleave c3-c4
3. enamine and release GAP
4. hydrolysis of iminium cation bc asp 33 also works as a gen acid and pronantes enamine to iminium
74
where are class II aldolases found
in fungi and algae
- less efficient than class 1
75
what do class 2 aldolases not form
a schiff base bc a divalent cation Zn+2 polarizes the carbonyl intermediate
76
does GAP3DH like heavy metals
yes it does because of the cysteine thiol grouos in the active site
77
what is the GAPDH mechanism
1. cys thiol attacks
2. thiohemiacetal goes through oxidation to acyl thioester
3. nad+ replaces nadh
4. inorganic P attacks to form 1,3 BPG
78
what is the main control point
PFK-1
79
what is the name of an enzyme that removes or adds phosphoryl group
1. phosphatases
2. kinases
80
what is glycongen phosphorylase
control by reversible phosphorylation
81
what regulaiotn is gly. phos
allosteric bc atp is negative hettero affector and amp is a positive heterotrophic
82
what has to be regenrated to sistain glycolysis
nad+ thats why pyruvate depends on it
83
under aerobic conditions what can regenerate nad+
krebs, etc/ oxidative phos
84
what converts pyruvate to ethanol and co2
yeast and bacteria through alcoholic fementation this also generates Nad+
85
what cofactor does pyr. decarbox. need for alcoholic ferm
TPP fofactor from vitamin B1
it enables decarboxylation of alpha keto acids
86
b1 deficiency leads to what
beri beri
-thiamine deficiency
87
what is a coenzyme
carrier of specific functional groups, come from vitamins
88
what cofactor does alcoholic dehydrogenase need
Zn+2
89
ehtanol cant be what
excreted so it has to be metabolised in the liver
- leads to acetaldehye = toxic
90
homolactic fermentation
- anerobic respiraton
-some bacteria and animal cells
-lactobacillus (yogurt)
- pyruvate to lactate
91
what does ldh catalyze
prochiral differntiation
92
what is the warburg effect
- malignant tumor cells have glycotic rates that are 200x higher than normal cells
93
