Plant Bio 1; Vitamin C

Question 1

How many prescription drugs come from plants?

Answer 1

1/4

Question 2

Function of anti-oxidants?

Answer 2

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

Question 3

What regenerates other antioxidants?

Answer 3

Vitamin E

Question 4

What is vitamin C required for?

Answer 4

Synthesis of collagen, norepinephrine, carnitine

Question 5

What are free radicals?

Answer 5

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

Question 6

Example of vitamin C?

Answer 6

Ascorbic acid

Question 7

What is aspirin derived from?

Answer 7

Willow (bark salicylic acid)

Question 8

What is digoxin derived from?

Answer 8

Foxglove

Question 9

What is malaria derived from?

Answer 9

Artemisia (artemisin)

Question 10

Can humans (and guinea pigs) synthesise ascorbic acid?

Answer 10

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

Question 11

Why must vitamin c be obtained regularly?

Answer 11

Because it can’t be stored in the body

Question 12

Good sources of vitamin C?

Answer 12

Kiwifruit, broccoli, peppers

Question 13

Bad sources of vitamin c?

Answer 13

Rice 
Pears 
Potatoes 
Apples 
Tomatoes

Question 14

How does cooking affect vitamin C content?

Answer 14

It reduces it

Question 15

Best/worst way to cook broccoli?

Answer 15

Best= raw, steamed 
Worst= boiled

Question 16

Three pathways of vitamin C synthesis?

Answer 16

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

Question 17

Pathway of Smirnoff-wheeler pathway?

Answer 17

D-mannose to L-galactose to ascorbic acid

Model plant= arabidopsis

Important in fruit

Question 18

Describe the myo-inositol pathway?

Answer 18

Inositol 1-P to my-inositol to ascorbic acid

Example; kiwifruit

Question 19

Describe the D-galacturonate pathway?

Answer 19

Link to final step of Smirnoff-wheeler pathway

Galacturonate to ascorbic acid

Question 20

Function of vitamin C in plants?

Answer 20

Plant growth

Photosynthesis

Question 21

Photosynthesis equation?

Answer 21

Carbon dioxide+ water + sunlight to carbohydrates+ oxygen

Question 22

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

Answer 22

Slow growth
Less chloroplast
Less chlorophyll (senescence occurs rapidly)

Question 23

What does vitamin C function in plants do?

Answer 23

Acts as a response to abiotic and biotic stress

Increases production of free radicals

Question 24

In regards to ascorbic acids, how is DHA formed?

Answer 24

APX; asc peroxidase detoxifies H2O2 in chloroplasts

Ascorbate+ H2O2 to 2H2O + DHA

Question 25

What DHAR do to ascorbic acid?

Answer 25

DHA reductase converts DHA+ 2GSH to ascorbate and GSSG

10% DHA
90% ascorbate

Question 26

How do you get more vitamin c into your diet?

Answer 26

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