Q 01/05

Which carbohydrate, the most abundant organic polymer on Earth, makes up 90% of cotton fibre?

A) Pectin

B) Cellulose

C) Amylopectin

D) Fructose

Answer · why

B) Cellulose

Cellulose passes through the human gut undigested as dietary fibre. Cows and termites can live on it only because microbes in their guts break it down...

Q 02/05

Which protein, the most abundant in the bodies of mammals, takes its name from the Greek word for glue?

A) Albumin

B) Fibrinogen

C) Elastin

D) Collagen

Answer · why

D) Collagen

Collagen turns into gelatin when skin, bones and sinews are boiled, which is how animal glue was made for centuries. It accounts for 25% to 35% of a m...

Q 03/05

Which tough protein builds human hair and fingernails as well as rhino horns and bird feathers?

A) Keratin

B) Myosin

C) Tubulin

D) Actin

Answer · why

A) Keratin

Keratin gets its strength from sulfur cross-links between its chains, which is why burning hair smells so sharp. The same protein makes hooves, claws ...

Q 04/05

Which protein network in wheat flour traps gas bubbles and gives bread dough its stretch and chew?

A) Casein

B) Gelatin

C) Gluten

D) Whey

Answer · why

C) Gluten

Gluten forms when two wheat proteins, gliadin and glutenin, are wetted and kneaded. It is also the base of seitan, the mock meat sold as vegetarian du...

Q 05/05

Which shape did James Watson and Francis Crick propose for the DNA molecule in their Nobel Prize-winning model?

A) Triple helix

B) Double helix

C) Alpha helix

D) Beta sheet

Answer · why

B) Double helix

Double helix became a household phrase after Watson used it as the title of his 1968 memoir. The two strands wind around each other like a twisted lad...