Lecture 16: Plants as Chemical Factories

Question 1

True or False: The same plant may be poisonous, medicinal or even hallucinogenic depending on the dose

Answer 1

True

Question 2

What are the two ways a substance could be secreted?

Answer 2

Remain deposited inside the secretory cell/tissue: for example, the laticifers.

They may be released from the secretory cell/tissue: for example, the resin ducts, secretory hairs.

Question 3

Active ingredients” are usually ______

Answer 3

secondary metabolites.

Question 4

______ secrete latex which is released only if the plant is cut or damaged. Laticifers usually form a 3D network in the entire plant

Answer 4

Laticifers

Question 5

______ laticifers are composed of a series of cells joined together.

______ laticifers, consisting of one long cell.

Answer 5

Articulated

Non-articulated

Question 6

Why does the plant secrete latex used for in laticifers?

Answer 6

At the slightest touch in this area (e.g. by an insect), the laticifers bursts and spays the “invader” with latex that has insecticide properties

Question 7

True or False: Resin and gum ducts are present in all the organs of the plants: e.g. root, stems, leaves, inflorescences

Answer 7

True

Question 8

the term gum duct is more commonly used with reference to ______ while resin ducts are employed more for _______.

Answer 8

Dicots,

Gymnosperms

Question 9

True or False: Resin and gums have antimicrobial and antifungal properties and serve as an aid in the healing of plant wounds.

Answer 9

True

Question 10

What is an example of a human use of resin ducts?

Answer 10

Incense being burnt

Question 11

What are 3 plant examples that have secretory cavities?

Answer 11

Hypericum perforatum (St John’s wort)
Eucalyptus,
Ginkgo, etc.

Question 12

True or False: Secretory cavities usually have antiviral, antibacterial, and antifungal properties

Answer 12

True

Question 13

What family of plants is characterised by the presence of secretory cavities?

Answer 13

Apiaceae (ie, anise, caraway, carrot, celery, chervil, )

Question 14

True or False: With secretory hairs, most have insecticide, antiviral, antibacterial, and antifungal properties.

Answer 14

True

Question 15

In Cannabis, glandular hairs secrete ______ and _____.

Answer 15

cannabidoids, terpenoids

Question 16

What are the compounds in stinging hairs?

Answer 16

formic acid in combination with histamine, acetylcholine, 5-hydroxytryptamine, and even serotonin

Question 17

What is the pathogenesis of a stinging plant such as Uritica?

Answer 17

The tip of the stinging hair is brittle and breaks off upon slight contact, leaving a sharp point that readily pierces skin and allows fluid contents of the hair to enter flesh through the body of the hair, which acts as a miniature hypodermic needle

Question 18

In the ______ family, secretory hairs secrete essential oils, which are volatile.

Answer 18

Lamiaceae (mint family)

Question 19

True or False: The mint family (Lamiaceae) has antiviral, antibacterial, and antifungal properties.

Answer 19

True

Question 20

_____ in general they contain N, they taste bitter, they have a marked physiological effect on insects and animals, especially on the nervous system, and have a anti-herbivory role

Answer 20

Alkaloids

Question 21

What are examples of alkaloids?

Answer 21

caffeine, nicotine, morphine, ephedrine, quinine.

Question 22

______ are very diverse chemically but generally they have a sugar molecule attached to the active component.

Answer 22

Glycosides

Question 23

_______ glycosides release cyanide (HCN). No medicinal use.

_______ glycosides have a steroidal nucleus. Act on the heart muscle.

_______ have a also a steroidal nucleus. Give a froth when shaken with water. Various effects: expectorant, anti-inflammatory, phytohormones, and hemolysis of red blood cells.

______ glycosides: e.g. salicin with analgesic, antipyretic, and anti-inflammatory effects. Salicylic acid is a plant hormone.

Answer 23

Cyanogenic

Cardiac

Saponins

Alcoholic

Question 24

What are the 4 characteristics of tannins?

Answer 24

Astringent, bitter, polyphenolic compounds that bind to and precipitate proteins.

Their function in plants is aid in the healing of wounds, and have antiviral, antibacterial and antifungal action.

Present in the wood, bark and many other tissues.

For us they have antioxidant and anti-inflammatory effect

Question 25

_____ are complex carbohydrates, have same functions as the tannins and they are secreted in canals or ducts

Answer 25

Resins

Question 26

______ are concentrated hydrophobic fluids containing volatile compounds
Defense against viruses, bacteria and fungi

Answer 26

Essential Oils (LAMIACEAE)

Question 27

True or False: Resins are water insoluble and thus render any surface impervious to moisture.

Answer 27

True

Question 28

Question: One of the following chemicals is not a alkaloid:

Answer 28

A: E saline

Question 29

Q: What is the role of alkaloids in plants?

Answer 29

A: D They provide a defense against animal and insect herbivores