Session 1 oxidative stress Flashcards

1
Q

What is responsible for your hangover?

other than you

A

Acetaldehyde (ethanol broken down by alcohol dehydrogenase), which is a toxic metabolite which accumulates.

*eventually becomes acetate for ac-CoA via aldehyde dehydrogenase.

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2
Q

Excessive alcohol oxidation has detrimental effects. name a few.

A
  • Decrease in NAD+/ NADH ratio leading to accumulation of lactate, hypoglycaemia.
  • Increased Acetyl-CoA leading to not efficiently exported so fatty liver buildup.
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3
Q

Briefly describe how Disulfiram works.

A
  • inhibits Aldehyde dehydrogenase causing accumulations of acetaldehyde, creating hangover effects with small amount of alcohol.
  • Pavlovian association.
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4
Q

What is oxidative stress?

A

Imbalance between free radicals and antioxidant defences in body.
- causes CVKS, cancer, MS, COPD, crohns, alzheimers.

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5
Q

what are free radicals?

A

Atom or molecule that contains one or more unpaired electrons, making them very reactive.
(usually have an immune function).

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6
Q

Name the reactive oxygen species.

ROS

A

Oxygen - relatively stable as electron in dif. orbitals.
Superoxide
Hydrogen peroxide - not a free radical but reacts with
Fe2+ to produce them.
Hydroxyl radical - most reactive and damaging.

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7
Q

Name the reactive Nitrogen species.

NOS

A

Nitric oxide.

Peroxynitrite - superoxide and nitric oxide. not a free radical but powerful oxidant, damages cells.

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8
Q

Name some endogenous biological oxidants.

A
  • electron transport chain.
  • nitric oxide synthases.
  • NADPH oxidases.
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9
Q

Name some exogenous biological oxidants.

A
  • radiation ( cosmic, UV, X-rays)
  • pollutants.
  • drugs (primaquine)
  • toxins ( herbicide)
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10
Q

What is Respiratory burst?

A
  • phagocytic cells like neutrophils and monocytes rapidly produce superoxide and H2O2, which destroy invading bacteria.
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11
Q

Name some cellular defences our bodies have against these reactive oxidants.

A
  • SOD : superoxide to H202 + O2.
  • Catalase : H202 to water and O2.
  • Gluthione : Utilises NADPH to transfer electrons.
  • Vitamin E and C
  • GSH
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12
Q

Explain the link between heinz bodies and free radicals.

A

increase in free radicals causes disulphide bonds and the clumping of haemoglobin in RBC. removed by spleen.

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