2- deoxyglucose
- effective drug to inhibit cancer
- competitive inhibitor for glucose
- get’s taken into the cell by GLUT 1/3
- no O2, so can’t get phosphorylated
- can’t undergo glycolysis
- can’t produce ATP
- can’t do cellular respiration= no source of nutrients or energy for cancer cell
- cancer cells can’t use this
Tumor detection
-exploit the fact that tumors are glucose “hogs”
18F- 2 Fluoro-2-deoxyglucose (FdG)
- injected into patients
- gets phosphorylated to get taken up in cell
- scan patient with PET scanner
- detect cancerous tissue by viewing areas that are showing more glucose level than normally should be
- those with irregular high levels have high chance of being a tumor
Citric acid cycle as precursors for biosynthetic pathways
- intermediates of cit cycle can be drawn off as precursors in many biosynthetic pathways
- if we need any of these things that are derived from the precursors, we can take the precursor from the citric acid cycle to make those products that derive from them
- can be used to make things like a.a., fatty acids, PEP
glucose-6-phosphate dehydrogenase
- enzyme that converts glucose-6-phosphate into 6-phosphogluconate
- needed in the FIRST step (most important step) of the Pentose Phosphate Pathway (PPP)
NADP+ -> NADPH
-gets reduced
-1st time:
reduces GSSH-> 2GSH
-2nd time:
converts 6-phosphogluconate-> ribose-5-phosphate (precursor to make nucleotides)
ribose-5-phosphate
-precursor to make nucleoties
G6PD (Glucose 6-phosphate dehydrogenase)
- converts glucose 6-phosphate –> 6-phospho-gluconco-S-lactone
- makes NADPH
glutathione reductase
-requires NADPH –> NADP+
in order to reduce GSSG
-convert GSSG–> 2GSH (glutathione)
glutathione peroxidase
converts H2O2–> 2H20
-needs glutathione as a co-factor (2GSH)
Glutathione roles (2GSH)
- removes highly reactive oxygen derivatives
- converts toxic H2O2 into nontoxic 2H2O - also protects cells against other highly reactive molecules (N-acetyl-p-benzoquinelmine), from Tylenol
G6PD deficiency
-leads to destruction of RBC (hemolysis)
this is called a hemolytic episode
why free radicals can be used as an antiseptic
free radicals can kill bacteria
Gluconeogenesis
- new formation of sugar
- happens between meals or during longer fasts or vigorous exercise when glycogen is depleted
- occurs mainly in the liver
- 7/10 steps are reverse of glycotic reactions
Three irreversible steps of glycolysis
1) glucose + ATP –> glucose 6-phosphate + ADP
3) Fructose 6-phosphate + ATP –> fructose 1,6-biphosphate + ADP
10) Phosphoenolpyruvate + ADP —–> pyruvate + ATP
What step gluconeogenesis starts with
synthesis of phosphoenolpyruvate from pyruvate:
- bicarbonate + pyruvate —-(pyruvate carboxylase)—> oxaloacetate
- oxaloacetate —(PEP carboxykinase)—> Phosphoenolpyruvate
Why/how can most amino acids be converted into glucose?
they can be converted into pyruvate or citric acid cycle intermediates
prohormone convertases
cuts protein at different sites to give the hormones that you need
Example of oral steroid
oxymetholone
used to treat HIV wasting syndrome
