Assignment - Infographics - 156

A Note on What Makes This an Infographic

Drawing a tongue with four colored regions labeled “sweet,” “sour,” “salty,” “bitter” is a textbook illustration - and one that is partly outdated. An infographic about the tongue tells a more complete story: what a taste bud actually is, how it detects chemical molecules in food, what the five basic tastes are and what they were originally designed to detect, and why most of what we call “flavor” comes from smell rather than the tongue alone. Your infographic should correct a common misconception while explaining the full process.

Objective

Create a journey narrative infographic in Canva that follows the experience of taste from food entering the mouth to the brain producing a flavor, explaining the biology of taste buds, the five basic tastes, and the role of smell in flavor.

The Journey to Follow

Stage 1: Food Enters the Mouth When food or drink enters the mouth, chewing breaks it apart and saliva dissolves the chemical compounds in it. These dissolved molecules are what the taste receptors can actually detect - the tongue does not taste solid food directly.

Stage 2: Taste Buds The tongue is covered with small bumps called papillae. Most of the papillae contain taste buds - small clusters of 50-100 taste receptor cells. An adult has approximately 10,000 taste buds, most on the tongue but also some on the palate and throat.

Taste buds have tiny hair-like projections (microvilli) that poke through a taste pore on the surface of the tongue. These microvilli are coated with taste receptor proteins.

Stage 3: Chemical Detection When a dissolved food molecule binds to a matching taste receptor protein on the microvilli, the receptor cell generates an electrical signal. Different receptor proteins detect different types of chemicals - producing different basic tastes.

Stage 4: The Five Basic Tastes

Note: the old idea that different regions of the tongue detect different tastes (the “tongue map”) has been largely disproved. All taste bud types are distributed across the whole tongue.

• Sweet - Detects sugars and carbohydrates. Signals energy-rich food. Glucose, fructose, sucrose.
• Sour - Detects acidity (hydrogen ions). Signals fermentation or food that may be spoiled. Citrus, vinegar, yogurt.
• Salty - Detects sodium ions. Signals minerals needed for nerve and muscle function. Table salt, soy sauce.
• Bitter - Detects alkaloids and certain plant compounds. Originally a warning system for poisons. Coffee, dark chocolate, leafy greens.
• Umami - Detects glutamate, an amino acid. Signals protein-rich food. Meat, fish, mushrooms, cheese, soy sauce.

Stage 5: The Nerve Signal Signals from taste receptor cells travel to the brain via two cranial nerves: the facial nerve (VII) carries taste from the front two-thirds of the tongue; the glossopharyngeal nerve (IX) carries taste from the back third. Both nerves travel to the gustatory cortex in the parietal lobe of the brain.

Stage 6: Flavor - Taste + Smell The brain combines taste signals from the tongue with smell signals from the nose (retronasal smell - the path from the back of the throat to the olfactory epithelium while chewing). This combination is what we experience as flavor.

Add a striking fact: approximately 80% of flavor comes from smell, not taste. Block your nose and chocolate tastes like sweet paste. A blocked nose during illness is why food seems to lose all its taste.

Design in Canva

• A tongue illustration showing the distribution of papillae and taste buds.
• A zoom-in inset showing a single taste bud with microvilli and taste pore labeled.
• The five basic tastes in five color-coded panels, each with what it detects and why.
• A journey diagram from mouth to brain via the cranial nerves.
• A prominent flavor panel showing taste + smell = flavor.
• A correction box noting that the old tongue map is inaccurate.

Required Elements

• How taste buds work, with the taste pore and microvilli explained.
• All five basic tastes with what chemical they detect and why the body has that receptor.
• The nerve pathway to the brain.
• The taste + smell = flavor relationship.
• The tongue map correction.
• Title: “How the Tongue Works: The Journey of Taste.”