Today Taste Experiments/projects

Bumps on your tongue are NOT taste buds Few. At the back of tongue Taste buds Most common type NO taste buds Taste buds Taste buds

Papillae Increase surface area of tongue Makes tasting ‘easier’

Taste Buds Chemo receptors ‘down inside’ papillae Some also produce saliva

Taste Buds

Taste Sweet, Salty, Sour, Bitter, Umami(amino acids, proteins) Receptor proteins on/in taste buds are coded for via genes Mutations (and gene duplications) happen You get variation among and between individuals and groups

Taste Sweet – your body needs sugar Umami – protein (proteins can also taste sweet) Salt – need salts (Na+, K+, etc.) Sour – “bad” or ‘rotting’ food - acid Bitter – poison, “bad” food Fat usually tastes “sweet”

Taste What you can taste has evolved within groups/species Cats – can’t taste sweet No cat can – lion, tiger, house cat, etc. Appears to have happened at least different times

Taste Pandas – NO umami They eat bamboo No/little protein – no need to taste it Most birds can’t taste sweet One group (hummingbirds) regained ability

Taste Dolphins – No bitter OR umami receptors But mostly meat diet… Swallow meals whole – no need to ‘taste’

Taste Humans – Some can taste bitter better than others Helps avoid alkaloids/poisons Also helps avoid foods that interrupt thyroid function “We” can produce up to 25 different bitter receptors (25 different genes) Dogs – 16 Rats- 37!

Taste Humans – Some can taste bitter better than others Variation within populations PTC – Phenylthiocarbamide You either taste it, or you don’t

Taste Humans – Some can taste bitter better than others Variation within populations PTC – Phenylthiocarbamide You either taste it, or you don’t Do YOU taste it?

Taste How about ‘spicy’ foods?

Homework Quiz on how taste and smell work tomorrow?