Flashcards in Plant Bio 1; Vitamin C Deck (26):
How many prescription drugs come from plants?
Function of anti-oxidants?
Protects proteins, lipids, carbs, nucleic acids from reactive oxygen species
What regenerates other antioxidants?
What is vitamin C required for?
Synthesis of collagen, norepinephrine, carnitine
What are free radicals?
Chemical containing an unpaired electron in its outer shell
Reactive oxygen species
Example of vitamin C?
What is aspirin derived from?
Willow (bark salicylic acid)
What is digoxin derived from?
What is malaria derived from?
Can humans (and guinea pigs) synthesise ascorbic acid?
No- due to the mutation in the last enzyme required for ascorbate synthesis
Why must vitamin c be obtained regularly?
Because it can't be stored in the body
Good sources of vitamin C?
Kiwifruit, broccoli, peppers
Bad sources of vitamin c?
How does cooking affect vitamin C content?
It reduces it
Best/worst way to cook broccoli?
Best= raw, steamed
Three pathways of vitamin C synthesis?
Pathway of Smirnoff-wheeler pathway?
D-mannose to L-galactose to ascorbic acid
Model plant= arabidopsis
Important in fruit
Describe the myo-inositol pathway?
Inositol 1-P to my-inositol to ascorbic acid
Describe the D-galacturonate pathway?
Link to final step of Smirnoff-wheeler pathway
Galacturonate to ascorbic acid
Function of vitamin C in plants?
Carbon dioxide+ water + sunlight to carbohydrates+ oxygen
What happens to a mutant where vitamin C synthesis is affected?
Less chlorophyll (senescence occurs rapidly)
What does vitamin C function in plants do?
Acts as a response to abiotic and biotic stress
Increases production of free radicals
In regards to ascorbic acids, how is DHA formed?
APX; asc peroxidase detoxifies H2O2 in chloroplasts
Ascorbate+ H2O2 to 2H2O + DHA
What DHAR do to ascorbic acid?
DHA reductase converts DHA+ 2GSH to ascorbate and GSSG