Pentose phosphate pathway Flashcards
What does the pentose phosphate pathway make
Ribose-5-phosphate
What is the starting materal for pentose phosphate pathway
Glucose-6-phosphate
Where does pentose phospate pathway occur
Cytoplasm
What is the main enzyme of pentose phosphate pathway
Glucose-6-phosphate dehydrogenase
What is ribose used for
Nirtogenous base
Converted into glycolosis intermediates
What are the potential products of Pentose phosphate pathway
Ribose-5-phosphate
2x NADPH + H
(can continue to form Glyceraldehyde-3-p and Fructose-6-p)
What is the difference between NADH and NADPH
NADH = Oxidized in ETC to make ATP
NADPH = electron donor
What do the oxidative reaction of pentose phosphate pathway make
NADPH
What are the individual steps in the pentose phosphate pathway
Dehydration
Hydrolysis
Oxidative decarboxylation
Isomerization
What is the enzyme used in the dehydrogenation reaction of the pentose phosphate pathway
Glucose-6-phophate dehydrogenase
What are the reactants of the dehydrogenation reaction of the PPP
Glucose-6-phosphate + NADP+
What are the products of the dehydrogenation reaction of the PPP
NADPH + 6-phosphoglucono lactone
What are the reactions of the PPP that produce NADPH
Dehydrogenation
Oxidative decarboxylation
What pathway is linked with the PPP
glycolosis
What is NADPH used for in the body
Reductive biosynthesis
detoxification
respiratory bursts
antioxidant reactions
What are the reductive biosynthesis pathways talked about in class that use NADPH
Building fat
Building Cholesterol
Building Steroid hormones
Building Bile salts
How does NADPH detoxify the body
Converts toxins into water soluble substances by adding electrons to water
Allows us to excrete it out
What enzyme is used in detoxification
Cytochrome P-450 mono-oxygenase system
What organ is Cytochrome P-450 mono-oxygenase found.
the liver
what organelle in liver cells is Cytochrome P-450 mono-oxygenase found
Endoplasmic reticulum
Where does detoxification take place
Endoplasmic reticulum in liver cells
What does Cytochrome P-450 mono-oxygenase do
Convert the toxin into ROH from RH using NADPH
What is the purpose of respiratory burst
Create harsh chemistry to kill bad bacteria using NADPH
What does the respiratory burst do to white blood cells
Allows them to take up more oxygen
What do NADPH and O2 combine to form during harsh chemisrty
HOCl
What enzyme turns O2- into hydrogen peroxitde
Superoxide dismutase
What enzyme turns hydrogen peroxide into HOCl (hypochlorous acid)
Myeloperoxidase
How does NADPH help in antioxidant regenration
Adding electrons to antioxidants so they can keep protecting body from free radicals
What is the job of antioxidents
Inihibit oxidation and counteracts damaging effects of oxidation in body tissue
What is a free radical
Atom or molecule that has one or more unpaired electrons
What is the reactive part of a free radical
The unpaired free electron
What is ROS and RNS
ROS = Reactive oxygen species RNS = Reactive nitrogen species
Do reactive species have free radicals
No always
What are the reactive species discussed in class
Superoxide radical Hydrogen peroxide Hydroxyl radical Carbon-centered peroxides Single molecular oxygen
What can generate Reactive species
Smog Ozone Chemicals Drugs Radiation High O2 concentration
What are the most common radicals
Superoxide O2-
hydrogen peroxide H2O2
Hydroxyl OH
What do free radicals attack
Polyunsaturated fat in phospholipids
Protein in cells
Nucleic acids in DNA
What is quenching
Process by which electronically excited m/c are inactivated
What happens to antioxidents when free radicals are quenched
They become oxidized
What is regeration
Process by which the antioxidant’s reducing power is restored
What happens when antioxidents are regenrated
They are reduced
What do antioxidants do
They give electrons free radicals to protect protein, fat and DNA
What regenerated Antioxidants
NADPH gives electrons to antioxidants
What enzymes can also quench free radicals
Superoxide dismutase
Catalase
Gultathione peroxidase
What does superoxide dismutase quench
Superoxide
What does Catalase quench
Hydrogen peroxide
What does glutathione peroxidase
Hydrogen peroxide
What is the location of Superoxide dismutase
Extracellular
Cytoplasm
Mitochondria
What is the function of superoxide dismutase
Eliminate superoxide
Produce hydrogen peroxide
What causes a superoxide radical
Addition of an electoron to molecular oxygen
is a superoxide radical lipid soluble
No,
How is superoxide dismutase produced in the mitochondrial production
it is formed in the ETC
Where is catalase located
Mostly in cell peroxisomes
What does catalase require to function
Iron
What is the fuction of catalase
Eliminate hydrogen peroxide
What cells have lots of catalase
Neutrophils
What enzyme removes most of the hydrogen peroxide
Glutathineperoxidase
What is a problem associated with Glucose-6-phosphate dehydrogenase deficiency
Cannot detoxify oxidizing compounds
