CHEMISTRY OF LIFE & HEALTH
Meet the molecules behind breathing, digestion, movement, and every busy cell. Start with the body, then explore nursing, everyday products, and the scientists who helped us understand them.
Why chemistry matters to Biology & NursingInside the Human BodyChemistry of Medicine
Arterial blood normally stays near pH 7.35–7.45. Buffers resist sudden changes, while the lungs and kidneys help regulate the balance. pH is logarithmic: a one-unit decrease means ten times the hydrogen-ion concentration.
Think about it: Why is a small change in blood pH more meaningful than it first appears?
Read the scienceRed blood cells contain hemoglobin, a protein with iron-containing heme groups. Oxygen binds reversibly, allowing it to be picked up in the lungs and released in tissues. Most oxygen in blood travels this way rather than simply dissolving in plasma.
Chemistry connection: molecular structure, binding, and equilibrium.
Read the scienceSodium, potassium, calcium, and chloride are charged particles in body fluids. Their distributions across membranes help support electrical signaling and muscle activity. “Electrolyte” describes a substance that supplies ions in solution, not a special kind of energy.
Chemistry connection: ionic compounds, solutions, and concentration gradients.
Read the scienceEnzymes help break food molecules into smaller building blocks. Hydrolysis uses water to split certain bonds. Proteins become amino acids, and starch is broken down toward sugars that can be absorbed.
Think about it: Is chewing the same kind of change as enzymatic digestion?
Read the scienceCells use ATP reactions to help drive processes that otherwise would not proceed readily. ATP hydrolysis can be coupled to transport, movement, and synthesis. Breaking a bond alone costs energy; the overall reaction releases usable free energy.
Chemistry connection: reaction energy and coupled processes.
Read the scienceA membrane’s lipid bilayer has a water-avoiding interior. Some small molecules cross easily; ions often need channels or transporters. Water moves by osmosis, and living cells also regulate transport actively.
Chemistry connection: polarity, diffusion, and selective permeability.
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