Which vitamin does skin make when exposed to sunlight?
AnswerVitamin D
UVB light lets skin make vitamin D from a cholesterol-based compound.
Health · Facts & stats
Diet facts & stats
7 fact-checked facts about diet and nutrients, each with the reason behind it. 5 more are in today's round and join this page after it closes.
The basics
What does a food calorie (kilocalorie) measure?
AnswerEnergy
A kilocalorie is a unit of energy, the heat needed to warm 1 kg of water by 1°C.
Going deeper
About how many kilocalories does one gram of fat provide?
Answer9
Fat gives about 9 kcal per gram, compared with about 4 for carbohydrate and protein.
Proteins are made of chains of what?
AnswerAmino acids
Proteins are long chains of amino acids folded into specific shapes.
In which organ does most nutrient absorption take place?
AnswerSmall intestine
The small intestine's lining, folded into villi, absorbs most nutrients.
Expert level
Lactose, the sugar in milk, is made of glucose joined to which sugar?
AnswerGalactose
Lactose is a disaccharide of glucose and galactose.
Which enzyme in saliva starts breaking down starch?
AnswerAmylase
Salivary amylase begins splitting starch into sugars while you chew.
Know these cold?Today's round is five questions like these, 20 seconds each. Your streak and level follow you to every arena.Play today's round