France Terminale ST2S (health and social sciences) — Terminale specialties
Chapters: 4
1. Chemistry
Road safety chemistry · Food safety chemistry · Chemical safety in the environment · Waves and radioactivity in diagnosis · Chemical analysis of media · Biomolecules and trace elements · From molecule to medicine · Responsible use of cosmetics
- Chemical Reactions and Balancing Equations – In a chemical reaction atoms are not made or destroyed; they only change partners. So a chemical equation must have the same number of each kind of atom on both sides. We balance it by changing the numbers in front of formulas, never the formulas themselves.
- Food Science: The Chemistry of What We Eat – Food science studies what food is made of and how it changes from farm to plate. Food contains carbohydrates, proteins, fats, water, vitamins and minerals. Cooking changes them: heat unfolds proteins (denaturation), starch swells in water (gelatinisation), and dry heat browns food through the Maillard reaction and caramelisation. Microbes ferment food into bread, curd and pickles, but can also spoil it. Processing, preservation and safe temperatures keep food safe and nutritious for a growing world population.
- Pollution: Air, Water, Land and Noise – Pollution is the release of harmful substances or energy into air, water or land faster than nature can remove them. Main air pollutants are particulates, carbon monoxide, sulfur dioxide, nitrogen oxides and ozone; they cause acid rain and smog. Water pollution by nutrients, sewage and toxins causes eutrophication and biomagnification. We reduce pollution by cutting emissions at the source, cleaning waste before release, and the 3Rs.
- Medical Physics: Ultrasound, X-ray, CT and Radiation Safety – Ultrasound sends sound pulses into the body and times the echoes: depth = speed × time ÷ 2. X-rays pass through the body and bone stops more of them, making a shadow picture. CT joins many X-ray views from all angles into slices. X-rays are ionising, so we cut the dose with short time, long distance and a shield. Ultrasound uses sound and is not ionising.
- Solutions: How Things Dissolve and How Much Can Dissolve – A solution is a uniform mixture of a solute dissolved in a solvent. In water (an aqueous solution) the solute breaks into particles too small to see, so it never settles and passes through filter paper. Concentration tells how much solute is present (mass % = solute ÷ solution × 100). Solubility is the most that can dissolve in 100 g of solvent at a given temperature; beyond it the solution is saturated. Evaporation, crystallisation and distillation separate solutions.
- Biomolecules – A cell is mostly water, plus four big families of carbon compounds: proteins, carbohydrates, lipids and nucleic acids. Grinding tissue in acid separates small molecules (acid-soluble pool) from big ones – proteins, polysaccharides and nucleic acids (acid-insoluble pool). Proteins are chains of amino acids folded into four levels of structure. Polysaccharides are chains of sugars; lipids are fatty acids on glycerol; nucleic acids are chains of nucleotides. Enzymes are protein catalysts that bind a substrate at the active site, lower the activation energy, and are affected by temperature, pH, substrate level and inhibitors.
- Drug Design: From Molecule to Medicine – A medicine is a molecule that fits a target in the body, like a key in a lock. Many drugs started in plants (natural), then chemists changed them in the lab to fit better and cause fewer side effects (synthetic). Nanomedicines are tiny capsules that carry a drug to the right place.
- The Chemistry of Cosmetics – A cosmetic is a product put on skin, hair, nails or teeth to clean, protect or change how they look. Most creams are emulsions: tiny oil drops held in water (or water in oil) by an emulsifier. Sunscreens absorb or reflect UV light: UVB burns the surface, UVA goes deeper and ages skin; SPF tells how much UVB is blocked. Antioxidants mop up free radicals. Using cosmetics responsibly means knowing your skin type, reading the ingredient list, patch testing and thinking about cost and the environment.
2. Human biology and pathophysiology
Internal environment and homeostasis · Immune system and defence · Reproduction · Genes and genetic information
- Homeostasis – Homeostasis is how the body keeps its internal environment (blood and tissue fluid) steady even when the outside world changes. It controls body temperature (about 37 °C), blood glucose (about 4–6 mmol/L), water and salt, and blood pH (about 7.4). It mostly uses negative feedback: a receptor senses a change, a control centre decides, and an effector brings the level back to its set point.
- Human Health and Disease – Health means the body, mind and social life all work well. Diseases can be caused by germs (pathogens) like bacteria, viruses, protozoa, worms and fungi. Our body fights them with two kinds of immunity: innate (we are born with it) and acquired (it learns and remembers). Vaccines use this memory. HIV destroys helper T cells and causes AIDS. Cancer is cells dividing without control. Drugs and alcohol harm the body and mind, especially in teenagers.
- Reproduction in Human Beings and Reproductive Health – At puberty, hormones from the brain make the testes and ovaries start working. The male system makes and carries sperm; the female system makes eggs and provides a place (uterus) where a baby develops. Fertilisation happens in the oviduct, and the embryo is fed through the placenta. Reproductive health includes safe choices, contraception, avoiding female foeticide, and preventing sexually transmitted diseases such as HIV/AIDS.
- Molecular Basis of Inheritance – DNA is the genetic material in most living things (some viruses use RNA). It is a double helix: two antiparallel strands of nucleotides, A pairs with T by 2 hydrogen bonds and G with C by 3. Long DNA is packed on histones into nucleosomes and then chromatin. DNA copies itself semi-conservatively (Meselson–Stahl). The central dogma says DNA → RNA → protein. Transcription makes RNA from one strand; in eukaryotes the hnRNA is capped, tailed and spliced. The genetic code is a triplet, has 64 codons (61 for amino acids, 3 stops), starts with AUG, is nearly universal and degenerate. Ribosomes translate mRNA into protein with tRNA adaptors. Genes are switched on and off; the lac operon is the classic example. The Human and Rice Genome Projects read whole genomes, and DNA fingerprinting uses repeat DNA (VNTRs) to identify people.
3. Health and social sciences: thematic strand
Public health policies · Social policies and action
- Health Care System: Where to Go, Your Rights and Who Pays – A health care system is the set of people, places and money that keep a population healthy. Care comes in levels: self-care and the pharmacy for small problems, primary care (family doctor) as the first door, specialists and tests by referral, hospitals for serious illness, and the emergency department reached through 112 when life is in danger. Patients have rights: information, consent, privacy, dignity and complaint. E-health (online records, e-prescriptions, telemedicine) makes access easier. Money comes from taxes, insurance contributions and out-of-pocket payments, pooled to pay for services.
- The Welfare State and Social Security – A welfare state is a state that protects people against the big risks of life: illness, job loss, old age, disability and poverty. It does this with a safety net made of three parts. Social insurance is paid from contributions taken from wages. Social assistance is paid from taxes to people in need. Public services such as schools and hospitals are open to everyone. Countries mix these parts in different ways: liberal (low tax, small help), conservative (help linked to your job) and social-democratic (high tax, help for all). Today welfare states face ageing populations, rising costs, global competition and many informal workers.
4. Health and social sciences: methods strand
Project approach in health and social work
- Project Management – A project is a one-time piece of work with a clear goal, a start and an end. Project management means planning and controlling it so it meets its scope on time and within cost. The life cycle runs initiate, plan, execute, monitor and close. Planners break the work into tasks (WBS), place them on a Gantt chart, find the critical path, manage risks and review lessons learned at the end.