JCE Home Economics 21 cheat sheet

The six nutrient classes are carbohydrates, proteins, fats, vitamins, minerals and water; only the first three supply energy, at 4, 4 and 9 kcal per gram respectively.

Macronutrient energy check: total kcal = (g carbohydrate x 4) + (g protein x 4) + (g fat x 9); alcohol adds 7 kcal per gram.

Percent energy from a nutrient = (energy from that nutrient / total energy) x 100; a 2000 kcal diet caps added sugars near 10 percent of energy.

Fat-soluble vitamins A, D, E and K require dietary fat for absorption and are stored in body tissue; water-soluble B vitamins and vitamin C are not stored in large amounts.

Water accounts for roughly 60 percent of adult body weight; mild dehydration of 1-2 percent body weight can reduce concentration and physical performance.

Amino acids from animal proteins generally match human needs closely (complete proteins), while most single plant proteins are limiting in one or more essential amino acids; combining cereals with legumes offsets this.

Deficiency patterns: iron deficiency causes microcytic anaemia, vitamin C deficiency causes scurvy, vitamin D deficiency causes rickets in children, iodine deficiency causes goitre.

Food-borne illness risk zone is 5-60 degrees Celsius; bacteria multiply fastest between 20 and 50 degrees Celsius, and toxins produced by Staphylococcus aureus are not destroyed by reheating.

Cooking methods divide into moist heat (boiling, steaming, poaching, stewing), dry heat (baking, roasting, grilling) and fat-based (frying, sauteing); method choice determines nutrient retention and texture.

Water-soluble vitamins B and C leach into cooking water, so steaming or using minimal water preserves more than boiling; adding acid (lemon, vinegar) helps retain vitamin C.

Maillard browning occurs between reducing sugars and amino acids above about 140 degrees Celsius and produces flavour and colour without charring.

Caramelisation is sugar breakdown at about 160-180 degrees Celsius, producing brown colour and bitter notes; it does not require protein.

Gluten forms when wheat flour proteins glutenin and gliadin hydrate and are worked in water; fat and sugar shorten gluten strands and tenderise baked goods.

Gelatinisation: starch granules absorb water and swell on heating, then thicken a liquid; cooling sets the gel, and stirring during cooling breaks it.

Emulsions combine immiscible fat and water; oil-in-water (milk) and water-in-oil (butter) types are stabilised by emulsifiers such as lecithin in egg yolk.

Yeast fermentation converts sugars to carbon dioxide and ethanol; salt controls fermentation rate, and dough proofing temperature of 25-28 degrees Celsius balances gas production with flavour.

Knife rule: cut away from the body, keep fingers curled (claw grip) behind the knuckles, and never leave a knife in a sink of soapy water.

Pan handles turn inward over the hob, not into walkways; pot holders replace wet cloths because wet fabric conducts heat rapidly.

Fire response by type: fat pan fires are smothered with a lid or fire blanket, never water; electrical fires use carbon dioxide extinguishers, never water or foam.

The danger zone for food safety is 5-60 degrees Celsius; cooked food should be cooled from 60 to 5 degrees Celsius within two hours and refrigerated promptly.

Cross-contamination control: separate chopping boards for raw meat and ready-to-eat food, and wash hands for at least 20 seconds with soap before and after handling raw meat.

Internal cooking temperatures: poultry and stuffed meats should reach 74 degrees Celsius; minced meat 71 degrees Celsius; leftovers reheated to 74 degrees Celsius.

Electrical safety in the kitchen: dry hands, unplug before cleaning, avoid trailing cords near water, and never use equipment with a damaged flex or plug.

Burns are cooled under running water for at least 20 minutes; do not apply butter or ice, and do not burst blisters.

Resources are classified as human (time, energy, skills, knowledge) and non-human (money, goods, equipment, community facilities).

The management process follows planning, implementing, evaluating and revising; feedback from evaluation feeds the next plan.

Opportunity cost is the value of the next best alternative forgone when a resource is allocated to one use.

A budget equation: income minus fixed expenses minus variable expenses minus savings equals the surplus or deficit.

SMART goals are specific, measurable, achievable, relevant and time-bound; vague goals such as 'save more' are not measurable.

Time management tools include priority matrices (urgent versus important), to-do lists and time logs; peak-energy scheduling matches demanding tasks to high-energy periods.

Decision-making steps: identify the problem, list alternatives, weigh criteria, choose, act, then evaluate the outcome.

Standard of living refers to quantity of goods and services available; quality of life includes health, relationships and satisfaction, so higher income does not automatically raise quality of life.

Fibres are natural (cotton, linen, wool, silk) or man-made (regenerated such as viscose, synthetic such as polyester, nylon, acrylic).

Wool has natural crimp and scales that trap air and give warmth; the scales also cause felting and shrinkage in hot water and agitation.

Cotton is absorbent, strong when wet, and prone to creasing and mildew; linen is stronger than cotton but creases more and resists mildew.

Silk is a continuous filament protein fibre with high lustre and strength but poor resistance to sunlight and perspiration.

Polyester is strong, quick-drying, crease-resistant and thermoplastic; it melts at high iron temperatures and holds odours because it absorbs little moisture.

Yarn properties: staple (short) fibres give softness and pilling; filament (continuous) fibres give smoothness and strength; higher twist increases strength and reduces lustre.

Weaves: plain weave is strong and firm, twill has diagonal lines and drapes well, satin has long floats giving lustre but low abrasion resistance.

Knit fabrics stretch because loops allow movement; they ladder or run more easily than woven fabrics and are less stable for tailored garments.

Pattern symbols: grain line arrow aligns with the lengthwise grain, notches match pieces, and the fold line is placed on folded fabric.

Fabric layout follows the lengthwise grain for least stretch; nap, pile and one-way prints require all pattern pieces to face the same direction.

Seam allowance is the distance from the stitching line to the raw edge, commonly 1.5 cm; it is marked on the pattern and transferred to fabric.

Staystitching is a line of straight stitching just inside the seam line on curved edges such as necklines to prevent stretching before construction.

Clipping releases concave curves and notching releases convex curves so seams lie flat; cutting too far severs the seam.

Darts shape fabric to body contours; they are stitched from the wide end to the point and tied off rather than backstitched at the point.

Interfacing adds body and support to collars, cuffs and waistbands; fusible interfacing is bonded with heat and pressure, sew-in is attached by stitching.

Fit adjustments: a full-bust adjustment adds width and length at the bust only; a swayback adjustment removes excess length at the centre back waist.

Cleaning agents work by different mechanisms: detergents lower surface tension, abrasives remove by friction, solvents dissolve grease, acids dissolve mineral scale.

Never mix chlorine bleach with ammonia or acid cleaners; the reaction releases toxic chlorine gas.

Care label symbols: a washtub with a number gives maximum wash temperature, a triangle means bleach is permitted, a square with a circle means tumble dry.

Washing machine load reduces efficiency when overloaded; clothes need free movement for detergent and water to circulate.

Stain rule: blot, do not rub, and treat from the back of the fabric; cold water removes protein stains such as blood, hot water sets them.

Hard water contains dissolved calcium and magnesium ions that reduce detergent lather; water softeners or sequestering agents counteract this.

Regular maintenance extends equipment life: clean refrigerator coils, descale kettles and irons, and empty lint filters after every dryer load.

Pest and mould prevention depends on controlling moisture and food access; ventilating kitchens and bathrooms reduces condensation and mould growth.

Housing functions include shelter, security, privacy, space for activities and a base for family and community life.

Tenure types: owner-occupied, private rented, social or public housing, and shared ownership; each carries different rights, costs and security.

Housing costs are affordable when rent or mortgage plus utilities consume no more than about 30 percent of gross household income.

Universal design features include step-free entrances, wide doorways, lever handles and adjustable counters so housing suits all ages and abilities.

Thermal comfort depends on air temperature, radiant temperature, humidity, air movement and clothing; recommended indoor relative humidity is roughly 30-60 percent.

Ventilation controls indoor air quality; without adequate air exchange, carbon dioxide, moisture and volatile organic compounds accumulate.

Ergonomics in the home matches work surfaces to user height: kitchen worktop typically 85-90 cm, with the main work triangle linking sink, hob and refrigerator.

Safety in the home targets falls (handrails, lighting on stairs), burns (guards on heaters), poisoning (locked cupboards) and drowning (supervised baths).

Developmental domains are physical, cognitive, language, social and emotional; development proceeds in predictable sequences but at individual rates.

Milestones: sitting unsupported around 6-8 months, first words around 12 months, walking around 12-15 months, two-word phrases around 18-24 months.

Piaget's sensorimotor stage (birth to about 2 years) is characterised by learning through senses and action and by object permanence developing near 8 months.

Erikson's first stage, trust versus mistrust (birth to about 18 months), is resolved by consistent, responsive caregiving.

Attachment is the emotional bond with a primary caregiver; secure attachment predicts better social and emotional outcomes.

Play is developmental work: solitary, parallel and cooperative play emerge in that order during early childhood.

Nutrition needs change rapidly in the first year; exclusive milk feeding is recommended for about the first 6 months, with solid foods introduced from around 6 months.

Family life cycle stages (beginning, childbearing, parenting, launching, later life) each bring different resource demands and role changes.

Consumer rights typically include safety, information, choice, redress, representation and consumer education.

A contract requires offer, acceptance, consideration and intention to create legal relations; a cooling-off period may apply to distance sales.

Unit pricing compares value: price per 100 g or per litre allows comparison across package sizes, whereas a multibuy offer may raise total spend.

Advertising techniques include bandwagon appeal, testimonials, emotional appeal and false urgency; recognising the technique reduces impulse buying.

Warranties are express (written guarantees) or implied (goods must be of satisfactory quality and fit for purpose); statutory rights generally override store policies.

Budgeting safeguards: keep receipts, check statements, compare total cost of credit, and note that a low monthly payment can hide a high annual percentage rate.

Community resources include libraries, health centres, public transport, recycling facilities and voluntary organisations; mapping them reveals gaps and duplication.

Sustainable consumption decisions weigh durability, repairability, energy use and end-of-life disposal, not only purchase price.