Year 8 Science Revision Guide: Health and Lifestyle & The Periodic Table

Flashcards providing comprehensive vocabulary coverage for Year 8 Science Assessment Point 1: Unit B4 (Health and Lifestyle) and Unit C5 (The Periodic Table).

Carbohydrates

The nutrient that serves as the body's main source of energy; commonly found in bread, rice, and pasta.

Lipids (fats)

Nutrients used by the body as a store of energy and for thermal insulation; found in butter, oil, and nuts.

Protein

A nutrient required for growth and tissue repair; found in meat, fish, eggs, and beans.

Vitamins

Nutrients that keep the body healthy, such as vitamin C which prevents scurvy; found in fruit and vegetables.

Minerals

Inorganic nutrients needed for a healthy body, such as calcium for bones and iron for blood; found in milk, red meat, and spinach.

Fibre

A substance that keeps food moving properly through the gut; found in cereals and vegetables.

Water

A vital nutrient needed for chemical reactions to occur inside cells; taken in through drinks and food.

Balanced diet

A diet that contains the right amount of each nutrient needed by the body.

Malnutrition

A condition resulting from having too much or too little of a particular nutrient in the diet.

Scurvy

A deficiency disease caused by having too little vitamin C in the diet.

Kwashiorkor

A deficiency disease caused by having too little protein in the diet.

Obesity

A medical condition resulting from consuming too much energy in the diet, leading to excess energy stored as fat.

Iodine test

A chemical test used to detect starch; iodine changes color from orange-brown to blue-black when starch is present.

Benedict's test

A chemical test for glucose (sugar) where Benedict's solution is heated in a water bath, changing from blue to brick red in the presence of sugar.

Biuret test

A chemical test used to identify protein; the reagent changes color from blue to purple when protein is present.

Ethanol test (Emulsion test)

A test for fats (lipids) in which food is mixed with ethanol and then added to water, turning cloudy white if fat is present.

Digestion

The breakdown of large insoluble molecules into small soluble molecules so they can be absorbed into the blood.

Oesophagus

The muscular tube in the digestive system that carries food from the mouth to the stomach.

Stomach

A digestive organ where acid kills bacteria and protein digestion starts.

Small intestine

The organ of the digestive system where digestion finishes and nutrients are absorbed into the blood.

Large intestine

The organ of the digestive system where water is absorbed.

Enzymes

Biological catalysts that speed up chemical reactions in living organisms.

Amylase (carbohydrase)

An enzyme that breaks down starch into sugars.

Protease

An enzyme that breaks down protein into amino acids.

Lipase

An enzyme that breaks down lipids (fats) into fatty acids and glycerol.

Optimum temperature

The specific temperature at which an enzyme works best and fastest (about $37\,^{\circ}\text{C}$ in humans).

Denatured

The state of an enzyme when high temperatures cause its structure and active site to change shape, preventing it from functioning.

Nicotine

The addictive chemical found in tobacco smoke.

Tar

A harmful substance in cigarette smoke that damages lungs and causes cancer.

Carbon monoxide

A gas found in cigarette smoke that binds to red blood cells (haemoglobin), causing less oxygen to be carried by the blood.

Depressant

A substance, such as alcohol, that slows down bodily reactions and can damage the liver and brain.

Group (Periodic Table)

A vertical column of elements in the Periodic Table with similar chemical properties.

Period (Periodic Table)

A horizontal row of elements in the Periodic Table.

Metals

Elements found to the left of the zig-zag line that are shiny, malleable, ductile, good conductors of heat and electricity, mostly have high melting points, and form basic oxides.

Non-metals

Elements found to the right of the zig-zag line that are dull, brittle when solid, poor conductors (insulators), mostly have low melting points, and form acidic oxides.

Group 1 (Alkali metals)

Soft metals cut with a knife and stored under oil that react with water to form a metal hydroxide and hydrogen gas, with reactivity increasing down the group.

Group 7 (Halogens)

Non-metal elements that exist as pairs of atoms ($\text{Cl}_2$) whose melting and boiling points increase down the group, while their reactivity decreases down the group.

Displacement reaction

A reaction where a more reactive halogen displaces a less reactive one from its compound (e.g., $\text{chlorine} + \text{potassium bromide} \rightarrow \text{potassium chloride} + \text{bromine}$).

Group 0 (Noble gases)

Very unreactive gases with full outer electron shells whose boiling points increase going down the group (e.g., helium, neon, argon).