Biochemistry for Nurses: Complete Semester 1 Study Notes

Biochemistry explains the chemical basis of life. For nursing students, the most useful approach is to connect molecules and reactions with nutrition, metabolism, acid-base balance, laboratory values, and common clinical problems.

1. Basic Chemistry

Matter is made of atoms. Elements contain one type of atom; compounds contain atoms chemically combined. Chemical bonds include ionic, covalent, and hydrogen bonds. Chemical reactions involve breaking and forming bonds, and many body reactions occur in water.

2. Acids, Bases and pH

pH reflects hydrogen-ion concentration. A low pH is more acidic; a high pH is more alkaline. The body uses buffers, lungs, and kidneys to keep pH within a narrow range. Acid-base imbalance can affect enzymes, heart rhythm, consciousness, and oxygen delivery.

3. Water and Electrolytes

Water is the main solvent of the body and supports transport, temperature regulation, and chemical reactions. Important electrolytes include sodium, potassium, calcium, chloride, bicarbonate, magnesium, and phosphate. Their concentrations influence fluid balance, nerve conduction, muscle contraction, and cardiac function.

4. Carbohydrates

Carbohydrates are a major energy source. Glucose is central to cellular energy production. Excess glucose may be stored as glycogen in liver and muscle. Insulin promotes glucose uptake and storage; glucagon helps raise blood glucose during fasting.

5. Lipids

Lipids include triglycerides, phospholipids, and cholesterol. They store energy, form cell membranes, protect organs, and serve as precursors for some hormones. Fatty acids can be saturated or unsaturated. Lipid metabolism becomes clinically relevant in cardiovascular risk, obesity, diabetes, and malnutrition.

6. Proteins and Amino Acids

Proteins are made from amino acids and function as enzymes, structural components, transport molecules, antibodies, receptors, and hormones. Essential amino acids must be obtained from the diet. Protein deficiency can impair wound healing, immunity, and muscle mass.

7. Enzymes

Enzymes accelerate biochemical reactions without being consumed. Their activity depends on temperature, pH, substrate concentration, and cofactors. Many laboratory tests measure enzymes because tissue injury may release them into blood.

8. Nucleic Acids

DNA stores genetic information. RNA helps express that information during protein synthesis. Genes influence protein structure and function, which is why genetic changes can produce disease.

9. Metabolism and ATP

Metabolism includes catabolism, which breaks molecules down and releases energy, and anabolism, which builds molecules and requires energy. ATP is the main immediate energy currency of cells. Glucose metabolism, fat oxidation, and amino-acid metabolism all contribute to energy production.

10. Clinical Connections

Nurses encounter biochemistry in blood glucose, electrolytes, ketones, liver and kidney tests, nutrition, dehydration, acid-base disorders, and medication metabolism. Focus on understanding relationships rather than memorizing isolated pathways.