Interactive lab

Four core activities

Every activity uses real chapter content and keeps your progress in both study modes. Each also appears inside the topic where it helps most.

Centerpiece

Seven exposures and two deficiencies. Choose the agent or deficiency, the molecular target and the finding; then one more clue tests your interpretation.

In context: 6.2 Toxins, metals and venom →

Centerpiece · Exposure-to-mechanism case lab

Exposure to mechanism

For each exposure or deficiency, choose the agent, then its molecular target, then the key finding. One more clue is then revealed: decide whether it changes your interpretation.

A firefighter is pulled unconscious from a burning house. He has soot in his airway and a severe lactic acidosis. His arterial PaO₂ is normal.

1 · Agent

Which exposure clue decides the agent?

Decisive exposure clue

2 · Target

You first suspect carbon monoxide. What is its molecular target?

Enzyme, cofactor or metabolite

3 · Finding

Which lab finding fits carbon monoxide?

Key lab or image

Causal chain

Trace ethanol → high NADH → the lab finding.

In context: 6.1 Tobacco, alcohol and drugs →

Core activity · The Missing Arrow

The Missing Arrow

Complete the causal chain. Place the missing step by dragging a card onto a gap, or tap a card and then tap the gap. Some gaps need an event; others need the mechanism that links one event to the next.

A hepatocyte oxidizing a steady load of ethanol. Complete the chain from the raised NADH/NAD⁺ ratio to the lab findings.

Two gaps ask for a mechanism (the reaction the high NADH ratio pushes); do not drop an event there.

  1. Ethanol is oxidized by ADH, then acetaldehyde by ALDH
  2. each oxidation reduces NAD⁺ to NADH
  5. Lactate accumulates; pyruvate is no longer available
  7. Gluconeogenesis stalls; the TCA cycle slows; acetyl-CoA is diverted
  8. fat synthesis rises and β-oxidation falls

Cards

Tap or drag a card. Placing a used card moves it.

Look-alikes

B12 vs folate, scurvy vs vitamin K, pellagra vs Hartnup.

In context: 6.5 Vitamins →

Core activity · Almost Twins

Almost Twins

Two look-alikes side by side. Decide what they share, then pick the clue that separates them and say why it works.

Look-alike A

Vitamin B12 deficiency

B12 (cobalamin)

  • Megaloblastic anemia
  • Neurologic: subacute combined degeneration
  • ↑ methylmalonic acid + homocysteine
Cobalamin deficiency (ileal disease, pernicious anemia, vegan diet).
  • Megaloblastic anemia, hypersegmented neutrophils
  • Neurologic: subacute combined degeneration, neuropathy
  • Methylmalonic acid high and homocysteine high
  • Stores last years

Step 1 · What they share

What do they share?

Select every feature that both show.

Case reasoning

Change the segment or the exposure; decide what moves.

In context: 6.6 Trace elements →

Core activity · One Fact Changes

One Fact Changes

Answer a case and name the decisive clue. Then exactly one fact changes. Decide whether the answer moves, and why.

1 · The original case

A 37-year-old man has Crohn disease. His terminal ileum was resected. Three years later he takes no supplements. He is examined for a deficiency.

Which deficiency is most likely?

Which fact decided it?