lecture 14 Flashcards
metabolism
biochemical reactions for the breakdown and synthesis of carbs, lipids and amino acids
glycogenosis
glucose storing disorder
carbs are stored as
starch and gylcogen
excess carbs converted to
fat
salivary a amylase
found in mouth, starts breakdown but not for long
pancreatic a amylase
breaks disaccharides into
maltose, sucrose and lactose
maltase
breaks down maltose into glucose, fructose and galactose
sucrase
breaks down sucrose into glucose, fructose and galactose
lactase
breaks down lactose into glucose, fructose and galactose
lactose intolerance is caused by deficiency of
lactase
path of carbs
glucose in intestine
-liver to be stored as glycogen or continues as glucose
-glucose can be converted to fat
-can go to muscles to produce CO2 and glycogen
-can go to kidney to produce CO2
can do to brain to produce C)2
glucose
major carb
major fuel
can be stored as glycogen
can be used to form glycoproteins and proteoglycan
glycolysis
happens in cytoplasm
does NOT require oxygen
requires NAD+
breakdown of glucose to produce 2(ATP +NADH+ Pyruvate)
goes on to continue other pathways
hexose monophosphate shunt
glucose
NADPH, ribose 5’ phosphate and others
(use glucose for building blocks)
glycogen synthesis
glucose gets stored as energy in liver and muscles
when excessive amounts of glucose
pyruvate
product of glycolysis (breakdown of glucose)
pyruvate into Acetyl CoA
(Acetyl CoA can also be used for ketone body production and fatty acid synthesis)
Acetyl CoA
moves to mitochondria
starts TCA cycle
produces energy and CO2
TCA cycle general:
occurs in mitochondria
high energy yield
needs O2
glycolysis 2 main stages
stage 1 preparatory phase
-use ATP
stage 2 pay off phase
-get ATP
glycolysis 10 steps
- D-glucose
-hexokinase (irreversible step)
(ATP in ADP + H out) - glucose 6- phosphate
-phosphoglucose isomerase (forward or backwards step) - fructose 6-phosphate
-phosphofructokinase (PFK1)(irreversible step)
(ATP in ADP + H out) - fructose 1,6-bisphosphate
-adolase
(splits can create 5 or 6) - dihydroxyacetone phosphate
-triose phosphate isomerase
and/or
***6.
glyceraldehyde 3 phosphate
-glyceraldehyde 3- phosphate dehydrogenase
(Pi+NAD+ in NADH +H out)
*** 7.
1,3-bisphosphoglycerate
(ADP +H in and ATP out)
-phosphoglycerate kinase
- 3-phosphoglycerate
- 2-phosphoglycerate
(water out)
**10. phosphoenolpyruvate (ADP + H in ATP out) -pyruvate kinase (irreversible step)
Pyruvate
glucose + 2ATP + 2 NAD+ +4ADP + 2 Pi= 2 pyruvate+2 ADP +2NADH +2H + 4ATP + 2H20
net gain=2 ATP
glycolysis net gain
glucose + 2ATP + 2 NAD+ +4ADP + 2 Pi= 2 pyruvate+2 ADP +2NADH +2H + 4ATP + 2H20
net gain=2 ATP
which steps of glycolysis are (irreversible step)
- d-glucose
-hexokinase
(ATP in ADP out)
glucose 6- phosphate
(g (H)(+ATP)= g6p + ADP
- fructose 6- phosphate
-phosphofructokinase (PFK1)
(ATP in ADP out)
fructose 1,6-bisphosphate
F6P (PFK1)+ATP = F16B + ADP
- phosphoenolpyruvate
(ADP + H in ATP out)
-pyruvate kinase
Pyruvate
PPP (PK) +ADP=pyruvate +ATP
what is commitment step of glycolysis
- fructose 6- phosphate
-phosphofructokinase (PFK1)
(ATP in ADP out)
fructose 1,6-bisphosphate
F6P (PFK1) +ATP = F16B +ADP
why do you get two pyruvate from one glucose
step 4.
fructose 1,6-biphosphate
-adolase
can create both 5 and 6
dihydroxyacetone phosphate and glyceraldehyde 3- phosphate
galactose can enter glycolysis by converting to
glucose-6 phosphate
step2 of glycolysis
fructose can enter glycolysis by converting to
dihydroxyacetone-phosphate
step 5 of glycolysis
pyruvate can go to three things
fermentation to ethanol in yeast
(hypoxic or anaerobic conditions)
2 pyruvate= 2 ethanol + 2 CO2
aerobic conditions loses 2CO2 become 2 Acetyl- CoA goes through TCA cyle =4CO2 + 4H20
fermentation to lactate
(hypoxic or anaerobic conditions- in muscle, some red blood cells ect.)
2 pyruvate= 2 lactate
glycolysis produces
2 pyruvate+2NADH + 2ATP
the NADH produced by glycolysis goes to either
reducing agent in biochemical reaction
helps TCA cycle
pyruvate is converted to lactate by
LDH
lactate dehydrogenase
pyruvate is broken down into Acetyl CoA by
pyruvate dehydrogenase (PDH)
irreversible step
occurs in mitochondria
pyruvate + NAD+ +HS CoA
-pyruvate dehydrogenase
= Acetyl CoA + NADH + CO2
Acetyl CoA can go
into TCA cycle
or
into lipid synthesis
___ is coupled to reduction of NAD+ to NADH
oxidative decarboxylation
conversion of pyruvate to acetyl CoA is regulated by
glucagon and insulin
what are the five cofactors needed to convert Pyruvate to Acetyl CoA
TPP, lipoamide, FAD+, NAD+ and CoA
these help pyruvate dehydrogenase
pyruvate to acetyl Coa
TPP
thiamine pyrophosphate
one of the cofactors needed to make acetyl CoA from Pyruvate
PDH
pyruvate dehydrogenase
enzyme used to change pyruvate to acetyl CoA
explain PDH
pyruvate dehydrogenase
TPP gives acetate to lipoamide, FAD is reduced and lipoamide gives it to the SH of CoA.
FAD is then oxidized back in a reaction of NAD+ to NADH
arsenite poisoning
happens by contaminated drinking water
arsenite inhibits the pyruvate dehydrogenase complex by inactivating one of the cofactors (lipoamide)
symptoms:
diarrhea, vomiting, organs of body are affected (lungs, skin , kidneys and liver), thickening of skin, metallic taste in mouth
pyruvate dehydrogenase deficiency diseases
autosomal and X lined mutations
autoimmune disease- circulating antibodies to PDH
thiamine/vit B1 deficiency: Beriberi
lipoamide deficiency, arsenic and heavy metal poisoning
what is beriberi
thiamine deficiency which leads to inhibition of pyruvate dehydrogenase- (prevents pyruvate to Acetyl CoA)
caused by: poor diet, raw fish
symptoms: gait problem, ataxia, anorexia and stress
treatment: thiamine supplementation and good diet
TCA cycle
ACIasSFMO
1.
acetyl-CoA
(H20 in CoA-SH out)
-citrate synthase
2 and 3 Citrate
-aconitase (two steps)
(H20 out then H20 in)
4: Isocitrate
- isocitrate dehydrogenase
(CO2 out and NADH out)
- a-ketoglutarate
-a-ketoglutarate dehydrogenase complex
(CoA-SH in CO2 and NADH out) - succinyl CoA
-succinyl CoA synthetase
(GDP + ADP + P = GTP+ ATP + CoA-SH) - succinate
(FADH2 out)
-succinate dehydrogenase - Fumarate
-fumarase
(H20 in) - malate
- malate dehydrogenase
(NADH out) - oxaloacetate
citrate to isocitrate
step 2 and 3 of TCA
dehydration and rehydration
-aconitase
isocitrate to a-ketoglutarate
step 4 of TCA cyle
oxidative decarboxylation
produces CO2 and NADH
-isocitrate dehydrogenase
a-ketoglutarate to succinyl Co A
step 5 of TCA cycle
ACIasSFMO
oxidative decarboxylation
(CoA-SH in CO2 and NADH out)
–a-ketoglutarate dehydrogenase complex
succinyl Co A to succinate
step 6 of TCA cycle
ACIasSFMO
substrate level phosphorylation
-succinyl CoA synthetase
(GDP + ADP + P = GTP+ ATP + CoA-SH)
succinate to fumarate
step 7 of TCA cycle
ACIasSFMO
-succinate dehydrogenase
(FADH2 out)
fumarate to malate
step 8 of TCA cycle
ACIasSFMO
-fumarase
(H20 in)
malate to oxaloacetate
step 9 of TCA cycle
ACIasSFMO
- malate dehydrogenase
(NADH out)
oxaloacetate to citrate
step 10/1 of TCA cycle
ACIasSFMO
-citrate synthase
(acetyl CoA + H20 in CoA-SH out)
simplified glycolysis 10 steps
- Glucose (H) (ATP in)
- G6P (PI)
- F6P (PRK1) (ATP in)
- F16B (A) = DP or G3P
- DP (TPI) =G3P
- G3P(G3PD) (Pi NAD+ in NADH out)
- 13B (PGK)(ADP +H in ATP out)
- 3P
- 2P (water out)
- PPP (ADP +H in ATP out) (PK)
- Pyruvate
1 st step glycolysis
- Glucose (H) (ATP in)
- G6P
glucose
-hexokinase
ATP in ADP + H out
glucose 6- phosphate
3rd step glycolysis
- F6P (PRK1) (ATP in)
- F16B
fructose 6 phosphate
-phosphofructokinase
(ATP in ADP H out)
fructose 1,6 bisphosphate
steps of glycolysis that produce ATP
- 13B (PGK) (ADP +H in ATP out)
- 3P
1,3-bisphosphoglycerate
(ADP +H in and ATP out)
=
3-phosphoglycerate
- PPP (ADP +H in ATP out)(PK)
- Pyruvate
phosphoenolypyruvate
-pyruvate kinase
ADP + H in ATP out
pyruvate
steps of glycolysis that produce NADH
- G3P(G3PD) (Pi NAD+ in NADH out)
7. 13B
glucose can go to three things
glycolysis
hexose monophosphate shunt
glycogen synthesis
tumors like to do ___ even if __ is present
glycolysis
O2
hexokinase
enzyme in glycolysis step 1
glucose to g6p
uses ATP
phosphofructokinase
(PFK1) enzyme in glycolysis
F6P to F16B
uses ATP
pyruvate kinase
enzyme in glycolysis
PEP to pyruvate
gain ATP
enzyme from pyruvate to Acetyl CoA
pyruvate dehydrogenase
inhibitor of pyruvate dehydrogenase
arsenic
prevents pyruvate to acetyl CoA
important steps of TCA that produce NADH
ACIasSFMO
I(ID) =+NADH +aK
aK(aKDC) =+NADH+ sCoA
M(MD) = +NADH + O
isocitrate
-isocitrate dehydrogenase
aKetoglutarate
aKetoglutarate
-aKetoglutarate dehydrogenase complex
succcinylCoA
malate
malate dehydrogenase
oxaloacetate
step of TCA when FADH2 is released
ACIasSFMO
S(SD)=F
succinate
-succinate dehydrogenase
(FADH2 out)
fumarate
step of TCA that produces ATP and GTP
ACIasSFMO
succinyl-CoA
-succinylCoA synthetase
succinate
one glucose gets ___ ATP
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