What does healthy urine contain?
Reveal answer
Water, urea, salts — no glucose or protein.
Key words: urea
3(i) EXCRETION · RECALL
3.29B Composition of urine
15 recall questions · Biology only (B): not in Science (Double Award). Answer from memory, reveal the answer, then rate yourself. Ratings stay on this device.
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What is meant by the term urine?
Reveal answer
Fluid excreted by kidneys after filtration and selective reabsorption.
Key words: urine
What is meant by the term concentration?
Reveal answer
Amount of solute per unit volume of solution.
Key words: concentration
What is meant by the term nitrogenous waste?
Reveal answer
Waste containing nitrogen, such as urea.
Key words: nitrogenous waste
Substances in final urine: for Water, give the normal presence and the reason.
Reveal answer
Normal presence: Present; variable. Reason: Solvent and route for waste removal.
Key words: Water
Substances in final urine: for Urea, give the normal presence and the reason.
Reveal answer
Normal presence: Present. Reason: Nitrogenous metabolic waste.
Key words: Urea
Substances in final urine: for Mineral ions, give the normal presence and the reason.
Reveal answer
Normal presence: Present; variable. Reason: Excess ions are regulated/excreted.
Key words: Mineral ions
Substances in final urine: for Glucose, give the normal presence and the reason.
Reveal answer
Normal presence: Normally absent. Reason: Selectively reabsorbed.
Key words: Glucose
Substances in final urine: for Cells/large proteins, give the normal presence and the reason.
Reveal answer
Normal presence: Normally absent. Reason: Retained by filtration barrier.
Key words: Cells/large proteins
True or false, and why? “Urine is filtered blood.”
Reveal answer
False. It is processed filtrate after extensive selective reabsorption.
True or false, and why? “Healthy urine contains only urea and water.”
Reveal answer
False. It also contains variable mineral ions and other small waste solutes.
True or false, and why? “One unusual dipstick result proves a diagnosis.”
Reveal answer
False. Screening findings require confirmation and clinical interpretation.
Why is there normally no glucose in urine?
Reveal answer
All of the filtered glucose is selectively reabsorbed into the blood.
Key words: selectively reabsorbed
Glucose in urine can be a sign of which condition?
Reveal answer
Diabetes.
Key words: diabetes
Why is there no protein in healthy urine?
Reveal answer
Protein molecules are too large to be filtered out of the blood in the glomerulus.
Key words: large