Metabolism Flashcards
(126 cards)
1
Q
Compartmentalization:
-Mitochondrial matrix
A
Mitochondrial matrix:
Citric acid Cycle
Oxidative phosphorylation
Beta oxidation of fatty acids
Ketone body formation
2
Q
Cytosol cellular compartmentalization of metabolism
A
Glycolysis
PPP
FA synthesis
3
Q
both mito an cytosol comparmentalization
A
Gluconeogenesis
Urea Synthesis
4
Q
Products of the citric acid cycle?
A
Succinate
Oxaloacetate
Citrate
Alpha ketoglutarate
5
Q
Rate determining step of Glycolysis
A
PFK-1
6
Q
Rate determining step of Gluconeogenesis
A
Fructose 1,6 BP
7
Q
Rate determining step of TCA cycle
A
Isocitrate Dehydrogenase
8
Q
Rate determining step of Glycogen Synthesis
A
Glycogen synthase
9
Q
Rate determining step of Glycogenolysis
A
Glycogen Phosphorylase
10
Q
Rate determining step of HMP shunt
A
G6PD
11
Q
Rate determining step of Urea Cycel
A
Carbamoyl phosphate synthetase II
12
Q
Rate determining step of Fatty acid synthesis
A
Acetyl-CoA carboxylase
13
Q
Rate determining step of Fatty Acid Oxidation
A
Carnitine Acyltransferase
14
Q
Rate determining step of Ketogenesis
A
HMG-CoA synthase
15
Q
Rate determining step of Cholesterol synthesis
A
HMG-CoA reductase
16
Q
Where is Hexokinase found and Km/Vmax/G6P inhibition
A
Hexokinase:
Muscle
low km high vmax
inihibited by G6P
17
Q
Where is Glucokinase found and km/Vmax/G6P
A
Glucokinase found in the liver
high km, high vmax, NOT inhibited by G6P
insulin dependent
18
Q
Pyruvate dehydrogenase Reaction required cofactors
A
NADH, Thiamin pyrophosphate, lipoic acid, FAD, CoASH
19
Q
Trypsin degrades proteins into which AAs
A
Arginine and Lysine
20
Q
Pepsin degrades proteins into which AAs
A
Tyrosine
Phenylalanine
Leucine
21
Q
Chymotrypsin degrades proteins into which AAs
A
Tryptophan Phenylalanine Tyrosine Methionine Leucine
22
Q
Elastase degrades proteins into which AAs
A
Alanine
Glycine
Serine
23
Q
How do amino acids get into the GI epithelial cell?
A
Sodium coupled transport
24
Q
How do amino acids get into the bloodstream from the GI epithelial cell?
A
facilitated diffusion
25
What within lysosomes act on proteins to degrade proteins all the way to free amino acids and how are the enzymes and proteins tagged for the lysosomes?
Lysosomal Proteases
Tagged with Mannose-6-phosphate marker
26
What disease stems from an inability to tag proteins with Mannose 6 phosphate
I cell disease
27
Ketogenic Amino /acids
Leucine, lysine
28
Glucogenic and Ketogenic AAs
```
Phenylalanine
Tyrosine
Tryptophan
Isoleucine
Threonine
```
29
MEtabolic intermediates derived from the carbons from AAs
pyruvate
Acetoacteyl CoA
Acetyl CoA
Alpha ketoglutarate
Succinyl CoA
Fumarate
Oxaloacetate
30
Source of Alanine
pyruvate
31
Source of Aspartic Acid which then creates Asparagine
Oxaloacetate
32
Source of Glutamic acid which then creates Glutamine and Proline
alpha ketoglutarate
33
Glutamic acid creates which Amino Acids
Proline, Glutamine
34
Serine which then creates Glycine source
3-phosphoglyceric acid
35
Source of Cysteine
Serine and Methione
36
Source of tyrosine
Phenylalanine
37
which essential amino acids are needed during periods of growth (children or after traumatic event)
Histidine
| Arginine
38
imporant chemical compound on coenzyme A
Sulfhydryl end
39
what is a carrier for free fatty acids?
albumin
40
Free fatty acid is turned into acyl-Coa by?
Acyl-CoA synthetase
41
beta oxidation enzymes/cofactor and respective reaction
Acyl coA dehydrogenase w/ FAD--double bond in LFA
Enoyl CoA hydratase--Addition of water (hydroxy compound)
BEta-hydroxyl Acyl CoA Dehydrogenase w/NAD---Oxidation
Beta-Keto ThiolaseCleavage to LFA-2Carbon and Acetyl CoA
42
What is left after complete Odd Chain Fatty Acid and how is carbon added to that to form methylmalonyl CoA?
Propionyl CoA
+ Biotin, CO2 or HC03
43
Why does the blood pH reduce in Ketocidosis with diabetics?
beta hydroxybutyric acids are moderately strong acids and require buffers, when buffering capabilities are surpassed, pH lowers
44
What is the principal control of Fatty acid oxidation via Acetyl CoA Carboxylase
Acetyl CoA carboxylase (key enzyme) stimulated by insulin
inhibited by Glucagon and high levels of Acyl CoA
45
What is the principal control of Fatty acid oxidation via Carnitine Palmitoyl-Transferase
Palmitoyl-transferase inhibited by increased levels of Malonyl CoA so the transfer of fatty acids into the mitochondrion slows down
46
how is biotin attached typically
lysine residue zzz
47
What cousin of NAD is required for FA biosynthesis?
NADPH from the pentose phosphate pathway
48
How is pyruvate transported from the mitochondrial matrix to the cytosol so it can be used for fatty acid synthesis?
broken down into oxaloacetate (CO2 input) and acetyl coA then forms citrate which enters in the cytsol, acetyle coa given off and oxaloacetate turns into malate, gives off NADPH and CO2 and goes back into Pyruvate
49
What stimulates acetyl coa carboxylase?
insulin (citrate) stimulates protein phosphatase which removes a phosphate from Acetyl Coa Carboxylase thus activating it
50
what inhibits acetyl coa?
Glucagon (and palmitoyl coA) stimulates cAMP thus stimulating cAMP dependent protein kinase which stimulates AMPKK which somehow makes ATP phosphorylate Acetyl CoA carboxylase
51
what prosthetic group is contained within acyl carrier protein?
Pantotheine
52
What do desaturase do?
oxidative, add double bonds, require O2 and NADH
53
Essential fatty acis
Linoleic
Linolenic
Arachidonic Acid
54
Essential fatty acids are required in the synthesis of?
Prostaglandin
Thromboxane
Leukotriene
Lipoxin
Structural lipids of the cell
Structure of the Mito membrane
55
why are essential fatty acids unable to be made endogenously?
we can't add the second or third double bond to oleic acid to make the linolenic and linoleic
56
Phosphatidic acid is phosphorylated glycerol that is dephosphorylated to create?
Diacylglycerol
and then Triacylglycerides and Phospholipids
57
unsaturated ether linkage at C1 Phospholipids called?
Plasmologens
58
Thinking about MS, white matter contains what phospholipids that are lost in MS resulting in white matter resembling grey matter?
Sphingomyelins (also ethanolamine plasmalogen)
59
Where are sphingolipids degraded?
lysosomes
60
What is the basis of sphingolipids?
ceramide
61
Deficiency of Hexosaminidase A?
Tay Sachs
62
Cherry red spot on retina, muscle atrophy, paralysis, seizures, Ashkenzi Jews, Cajun populations
Tay-Sachs
63
Beta Glucocerebrosidase deficiency
Gaucher's
64
bone marrow transplant is curative, no brain involvement in type I, hepato/splenomegaly, death by 3mos
Gaucher's, beta glucocerebrosidase deficiency
65
sphingomyelinase defiency
Niemann-Pick
66
lack of muscle coordination, learning problems, brain degeneration, feeding and swallowing difficulties, slurred speech, spastic, hepato/splenomegaly, cherry red halo around retina
Niemann-Pick
67
NADPH donate
electrons in reductive synthetic reactions
68
NAD _____Acceptor
electron acceptor in oxidative degradative reactions
69
NADH feeds electrons into the ______ and produce ATP
ETC
70
How is fatty acids transported into the mitochondrial matrix for beta oxidation?
carnitine
71
Where does FA synthesis take place?
Cytosol, transported via citrate
72
Glucose to G6P is an example of a _______ cycle
Futile cycle
73
net yield of ATP from glycolysis
2 ATP
74
Key intermediates n TCA
oxaloacetate, citrate, succinate, alpha ketoglutarate
also precursors of AAs feed into other cycles
75
Glutamate dehydrogenase reaction generates?
NH3------> Carbamoyl Phosphate + Ornithine----> Citrulline
76
The urea cycle creates which intermediate in TCA which produces Asparate that then feeds back into the Urea Cycle at Argininosuccinate
Fumarate
77
Which metabolic pathways is found exclusively in the cytosol?
Glycolysis
PPP
FA synthesis
78
Which metab pathway is in both the mito and the cytosol?
gluconeogenesis
79
The Pyruvate dehydrogenase reaction converts Pyruvate to _________
Acetyl CoA
80
What cofactors are required for the pyruvate dehydrogenase reaction?
NADH
Thiamin pyrophosphate lipoic acid
FAD
CoASH
81
In times of fasting, Acetyl CoA is converted into Acetoactyl CoA to produce?
betahydroxybutryate (ketone bodies)
82
the net flow of carbons from Acetyl CoA?
glucose
83
What is the beignning of the PPP?
G6P----->6phosphgluconate
84
Glucose produces Glucose 6 phosphate which can be convereted into?
G1P
F6P
6PG
85
Pyruvate in anaerobic conditions produces _______
Lactate which is converted back to pyruvate
86
Pyruvate also transaminated to create
alanine
87
irreversible reaction of Pyruvate
Acetyl CoA
88
If Pyruvate + Biotin
Oxaloacetate
89
Importan branchpoints
G6P
| Pyruvate
90
NADP+ increase and which pathway is stimulated?
Pentose Phosphate Pathway
91
How is Phosphofructokinase regulated
Activated by F26BP
Inhibited by ATP and citrate
92
Principal control step in Gluconeogenesis?
Fructose 1,6 Bisphosphate to
Fructose 6 Phosphate
93
Glucose 6 phosphotase can lead to inability to convert F6P to G6P and so a failure o the last step in gluconeogenesis leading to
poorly controlled blood sugar levels (hypoglycemia)
94
ATP allosterically inhibits
glycolysis
95
ATP activates
gluconeogenesis
96
the principal controlled step in glycolysis occurs at
Phosphofructokinase 1
97
Gluconeogenisis controlled step enzyme?
Fructose 1,6, Bisphosphatase
98
Liver glycogen levels are lowest at?
4am
99
Glucoses linked 1,x
linked 1,4 in glycogens
100
The ends of glycogen branches can be reduced at the non-reducing ends by_____ plus ______and this creates ______
Glycogen Phosphorylase plus debranching enzyme (alpha 1,6 glucosidase)
creating Glucose 1 phosphate and some free glucose
101
where is most of our glycogen stored?
muscle
102
Glycogen synthesis carried our by ______ and ______
Glycogen synthase and branching enzyme
103
How does the liver differ in terms of the mechanism by which it releases a form of glucose from glycogen?
glucose can be released into the blood
104
how does insulin affect cAMP levels in cells?
decreases cAMP levels, this affects the kinase cascade resulting in dephosphorylation of kinase which keeps the glycogen synthase dephosphorylated and thus activated
105
is glycogen synthase active or inactive when phosphorylated?
it is more active when dephophorylated (so decreased levels of cAMP = more active= more glycogen synthesis)
106
Is Glycogen Phosphorylase active or inactive when phosphorylated?
active when phosphorylated (so increased levels of cAMP means more active glycogen phosphorylase= more glycogen breakdown and more glucose available
107
Glucose and alanine cycle differ in that
Alanine carries a nitrogen group that can be excreted
108
Principal controlled step in fatty acid synthesis occurs at
Acetyl CoA to Malonyl CoA via
Acetyl CoA Carboxylase + Biotin
109
Glutamate + Glutamate Decarboxylase =
GABA
110
GABA degraded to create?
succinate
111
Tyrosine can be created into what neurotransmitter precursor?
DOPA
112
DOPA can be fully metabolized to
Epi and Norepi
113
Tyrosine also precursor
Thyroid Hormone
114
Tryptophan precursor for what NT?
Serotonin which can turn into melatonin
115
Arginine turns into ornithine then _____ and is also a precursor for
Glutamate
Putrescine, spermidine, spermine.
116
which enzyme that's part of the debranching enzyme generates free glucose during the enzymatic breakdown of glycogen in the skeletal muscles.
alpha 1,6-amyloglucosidase
117
disorder characterized by hypoglycemia, hyperlipidemia, lactic acidosis and ketosis, convulsions and glycogen accumulation in liver and kidneys
gkycogen storage disease: Von Gierkeon of
118
glucagon increases....
glycogenolysis
gluconeogenesis
mobilization of fatty acids
119
insulin dependent Glut transporter
Glut-4 in the muscle heart and adipose
120
insulin dependent Glut transporter
Glut-4 in the muscle heart and adipose
121
Insulin binds a membrane receptor which stimulates what pathway?
Tyrosine kinase pathway
122
Alanine and glutamine released by skeletal muscles in post-absorptive humans. they carry
nitrogens
123
which tissues exclusively depend on glucose?
RBCs
Lymphocytes
Renal Medulla
retina
brain (can also utilize ketone bodies)
124
Skeletal muscle and adipose tissue use Glut #
Glut 4
125
Glucose as sole energy source
RBCs
126
what happens during starvation re:Fatty acids, Gluconeogenesis, Glycogen synthesis, glycogenolysis, and ketone bodies
Fatty acids are released from adipose tissue
gluconeogenesis occurs in the liver
glycogen synthesis decreases
glycogenolysis increases in liver and muscle
ketone bodies synthesized by the liver
