Plant Bio 1; Vitamin C Flashcards Preview

Biosci106 > Plant Bio 1; Vitamin C > Flashcards

Flashcards in Plant Bio 1; Vitamin C Deck (26):
1

How many prescription drugs come from plants?

1/4

2

Function of anti-oxidants?

Protects proteins, lipids, carbs, nucleic acids from reactive oxygen species

3

What regenerates other antioxidants?

Vitamin E

4

What is vitamin C required for?

Synthesis of collagen, norepinephrine, carnitine

5

What are free radicals?

Chemical containing an unpaired electron in its outer shell
Reactive oxygen species
Highly reactive

6

Example of vitamin C?

Ascorbic acid

7

What is aspirin derived from?

Willow (bark salicylic acid)

8

What is digoxin derived from?

Foxglove

9

What is malaria derived from?

Artemisia (artemisin)

10

Can humans (and guinea pigs) synthesise ascorbic acid?

No- due to the mutation in the last enzyme required for ascorbate synthesis

11

Why must vitamin c be obtained regularly?

Because it can't be stored in the body

12

Good sources of vitamin C?

Kiwifruit, broccoli, peppers

13

Bad sources of vitamin c?

Rice
Pears
Potatoes
Apples
Tomatoes

14

How does cooking affect vitamin C content?

It reduces it

15

Best/worst way to cook broccoli?

Best= raw, steamed
Worst= boiled

16

Three pathways of vitamin C synthesis?

Smirnoff-wheeler pathway
Myo-inositol pathway
D-galacturonate pathway

17

Pathway of Smirnoff-wheeler pathway?

D-mannose to L-galactose to ascorbic acid

Model plant= arabidopsis

Important in fruit

18

Describe the myo-inositol pathway?

Inositol 1-P to my-inositol to ascorbic acid

Example; kiwifruit

19

Describe the D-galacturonate pathway?

Link to final step of Smirnoff-wheeler pathway

Galacturonate to ascorbic acid

20

Function of vitamin C in plants?

Plant growth
Photosynthesis

21

Photosynthesis equation?

Carbon dioxide+ water + sunlight to carbohydrates+ oxygen

22

What happens to a mutant where vitamin C synthesis is affected?

Slow growth
Less chloroplast
Less chlorophyll (senescence occurs rapidly)

23

What does vitamin C function in plants do?

Acts as a response to abiotic and biotic stress

Increases production of free radicals

24

In regards to ascorbic acids, how is DHA formed?

APX; asc peroxidase detoxifies H2O2 in chloroplasts

Ascorbate+ H2O2 to 2H2O + DHA

25

What DHAR do to ascorbic acid?

DHA reductase converts DHA+ 2GSH to ascorbate and GSSG

10% DHA
90% ascorbate

26

How do you get more vitamin c into your diet?

Eat fresh fruit and vege
Enhance vit c concentration in highly consumed fruit and vegetable
Avoid vitamin C loss during storage and cooking