Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

BIOSCI106 2017 SEM 2 > Plants > Flashcards

Plants Flashcards

1
Q

Where does aspirin (salcylic acid) come from?

A

Willow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Where does taxol (anti cancer) come from?

A

Pacific yew

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Where does digoxin (heart conditions) come from?

A

Fox glove

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Where does artemesinin (maleria) come from ?

A

Artemisia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Vitamin C is an antioxidant, what does this mean?

A

It protects from reactive oxygen species and free radicles.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Can vitamin C be stored in the body?

A

Nope

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is vit C used to regenerate?

A

A-tocopherol which is vitamin E

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the range of reccommended doses for vit C per day?

A

90mg to 2g

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What do high doses of Vit C result in?

A

Diarrhea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are poor sources of Vit C?

A

Lettuce, cucumber, banana, apple

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the Order of highest to lowest vit C content?

A

Camu camu - 2g
Black currant/bell pepper - 200mg
Kiwifruit/broccoli - 90mg
Orange - 50mg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the pathways of Vit C synthesis in plants?

A
  1. Smirnoff-wheeler pathway (glalactose)
  2. Myo-inositol pathway
  3. Galacturonate pathway
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the best way to cook broccoli to maximise Vit C synthesis?

A

Raw or steamed, boiled is worst

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the major pathway in plants?

A

Smirnoff-wheeler pathways

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Where does the Smirnoff-wheeler pathway occur?

A

Mitochondria, so it requires specific transporters for ascorbic acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Describe mutants that cannot synthesise ascorbic acid:

A

They have reduced growth and reduced chlorophyll content

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are the 2 main roles of ascorbate in plants?

A

Antioxidant

Role in plant development - cell division and cell expansion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

In a healthy plant, what should the ratio of DHA t ascorbate be?

A

10% DHA

90% ascorbate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What does APX ascorbate perioxidase do?

A

Detoxify H2O2 in cholorplasts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What does DHA reductase do?

A

2GSH + DHA = ascorbate + 2GSSG

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is special about cooking vitamin A containing foods?

A

The vitamin is not destroyed during any part of the cooking

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is reccommedended daily intake for VitA?

A

800 microgram

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are the top 3 vegetable sources of Vit A?

A

Sweet potato - 961
Carrots - 840
Spinach - 500

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is the precursor of Vit A?

A

B carotene (provitamin A)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
How is B carotene made to retinal and where?
B carotene dioxygenase in the small intestine. Forms 2 retinal molecules
26
Once retinal is made in the small intestine, then what happens?
It forms retinol and then retinoic acid which are all fat soluble and stored in the liver
27
Is vitamin A fat or water soluble?
Fat
28
What are the roles of Vit A?
Visual pigment rhodopsin Gene expression Maintenance of epithelial tissues Regulation of growth and differentiation of cells, some cells of immune system
29
Where is Vit A found outside of vegetables?
In milk and liver, eggs, meat etc
30
How does Vit A regulate gene expression?
Retinoic acid binds to DNA receptors (transcription factors) which leads to modification of gene expressions
31
At what stage of life is retinoic acid involved the most?
Embryonic development
32
What are the symptoms of vit A deficiency?
1. Dry cornea and blindness 2. Night blindness 3. Impaired immune function
33
Where is Vit A synthesised in plants?
In choloplasts
34
What is the pathway as to how B carotene is synthesised in plants?
Geranylgeranyl-PP to phytoene to lycopene to B carotene
35
What enzyme converts Geranylgeranyl-PP to phytoene?
Phytoene synthase (PSY)
36
What enzyme converts phytoene to lycopene?
Phytoene desaturase (PDS) + 2 other enzymes
37
What enzyme converts lycopene to B carotene?q
Lycopene cyclase (LCY)
38
Out of the 3 enzymes, what genes for them were expressed in rice endosperm?
Only lycopene cyclase
39
What is special about agrobacterium tumefaciens and how does it transfer its DNA?
It has T-DNA that is able to transfer from a prokaryote to a eukaryote. If a plant has a wound and there is agrobacterium tumefaciens in the soil, it is able to transfer all the DNA from its plasmid in bteween the left and right borders to the plant
40
Which genes are put in the T DNA to transform rice?
PSY - from daffidol | Carotene desaturase from bacteria Erwina CRT1 (can replace all 3 enzymes)
41
In plant food source is iron non heme or heme?
Non heme - not well absorbed.
42
How do you get heme iron?
Through food derived from animals which is well absorbed
43
What are the 2 ways iron is used in the body?
1. Deoxyhemoglobin | 2. Ferrtin - stores
44
What are some ways that we can increase iron availability?
1. Chelation - increase siderophores (iron carriers that bind ferric form) 2. Reduce Fe3+ and make Fe2+ so acidify the soil
45
What is a way to increase translocation (shoot to root)?
Overexpressing a transporter - i.e ferroprotin
46
What is a way to increase storage of iron in the endosperm?
Increase the ferritin gene
47
What is the way to increase availibility of iron in plants to humans?
Phytates to reduce - a digestive enzyme phytase
48
What are plant medicinals called?
Secondary metabolites
49
What are the 3 types of secondary metabolites?
1. Terpenes - made from mevalonic acid with carbon and hydrogens 2. Phenolics - made from simple sugars 3. Nitrogen containing compounds - may also contain sugar
50
What are 2 examples of nitrogen containing compounds?
Alkaloids - caffeine, theobromine, theophylline, nicotine, opiotes Glucosinolates - broccoli (anti cancer properties)
51
What are alkaloids?
They are heterogenous group of chemicals where most are basic. Many are toxic to humans and animals
52
What are the 3 purine derivatives of alkaloids?
Caffeine, theobromine, theophylline
53
What are the 3 amino acid derivatives of alkaloids?
1. From typtophane - nicotine 2. From histadine - pilocarpine, histamine 3. From tyrosine - opiates (morphine and codeine)
54
Where does opium come from?
Dried latex of poppy
55
How does coffee and chocolate work to affect your body?
They competitively inhibit phosphodiesterase, resulting in an increase in cyclic AMP and release of adrenaline. This leads to increased CNS stimulation, relaxation of smooth muscle and induces diuresis
56
What is used for eye drops, the treatment of glaucoma and stimulation of sweat and lachrymal glands?
Pilocarpine
57
How do you get addicted to heroin?
Because morphine binds to the u-opiod receptors which leads to addiction
58
What are the therapeutic drug uses for opiates?
1. Analgesia - pain reliever 2. Antitussive - cough surpressent 3. Antidiarrhea
59
What is the solution for stopping people from getting addicted to opiates?
Make a mutant poppy that will not accumulate morphine/codeine. Mutagenesis using ethyl methyl sulfate (EMS) - alkylating agent on the guanine it switches a guanine for a A so transcribes a T. These poppies can be used as precursors for synthetic opiod production but carry little risk for addiction
60
Where is glucoraphanin found and what does it do?
It is a glucosinolate found in broccoli and cauliflower. It can be made into raphanin (an antibiotic) by the enzyme myrosinase and into sulforaphane for anticancer
61
Name and describe the 4 ways herbicides can affect plant growth:
1. Growth regulation - division and expansion - plant hormones (auxins and 2,4D), crops can catabolise high concs, weeds killed 2. Cell division - oryzalin blocks plant microtubules (not animals) 3. Photosynthesis - atrazin interferes with e- transport chain 4. Amino acid biosynthesis - glyphosate (roundup), affects aromatic amino acid synthesis
62
Describe how roundup works:
It gets absorbed by the plant and prevents it from making food. It is transported through the weed to kill the entire weed . Dead weeds cant regrow. It is non selective so it kills everything
63
How does roundup work enzymatically?
Shikimate 3 phosphate + PEP = 5-enolpyruvylshikimate-3-phosphate then to aromatic amino acids This is done by the enzyme EPSPS which is inhibited by glyphosate
64
How can you make plants that are resistant to herbacides?
By using T-DNA
65
How are bt crops (insect resistant) made?
They are engineered from bacillus thuringiensis a soil dwelling bacterium. It forms crystals of cry toxins which are encoded by cry genes and the cry toxins affect pests such as insects
66
What happens if a pest eats a plant with bt and cry toxins?
1. Ingestion and solubilisation at alkaline pH (12) in forgut of larvae. It is the protoxin. 2. Proteolytic cleavage of protoxin into active toxin 3. Binding to membrane receptor in the midgut epithelial membrane 4. Leads to pore formation and larvae death
67
How many countries are producing genetically engineered crops?
26

BIOSCI106 2017 SEM 2 (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions