Phytochemicals

Question 1

Primary Metabolites

Answer 1

Compounds in the plant that are needed for the plant to grow and function.
– Starch for energy storage.
–Chlorophyll for carbohydrate production.
– Cellulose to withstand cellular pressure.
– Lignin for structural support.

Question 2

Secondary metabolites

Answer 2

Assist the plants’ survival within its environment e.g., defence against plant pathogens, protection from decomposition, compounds that attract pollinators.

• They are pharmacologically active in humans and central to the effects of herbal medicines e.g., coffee beans contain the alkaloid caffeine,a natural pesticide that protects the fruits against insect attacks. In human physiology caffeine acts as a CNS stimulant.
• Tannins in plants e.g., green tea protect the woody parts of the plant from decomposition and insects. Tannins astringe mucous membranes and reduce watery secretions (runny nose, diarrhoea).

Question 3

Alkaloids

Answer 3

Effects: Strong stimulant effects on the nervous system
Herbs: Berberis vulgaris (berberine)

Question 4

Anthraquinones

Answer 4

Effects: Cause powerful evacuation
Herb: Senna

Question 5

Flavonoids

Answer 5

Effects: Antioxidant and anti-viral
Herb: Hawthorn berry

Question 6

Saponins

Answer 6

Effect: Adaptogenic and steroid-like effect
Herb: Liquorice

Question 7

Tannins

Answer 7

Effect: Astringent (bind to proteins) and dry out wounds
Herb: Yarrow

Question 8

Terpenes

Answer 8

Effect: Antispasmodic in the GIT and lungs, antimicrobial
Herb: Lavender