Organisms

gas exchange

The transfer of gases between an organism and its environment.

lungs

The organ in which gas exchange takes place.

ribs

Bones which surround the lungs to protect them and form the rib cage.

respiratory system

Organ system which replaces oxygen and removes carbon dioxide from the blood.

Label the diagram

nose, trachea, ribcage, muscle, heart, lung, bronchus, bronchiole, alveolus (air sac), rib, diaphragm

trachea

Tube which carries air from the mouth and nose to the lungs.

bronchus

One of the two tubes which carry air into the lungs.

bronchiole

Small tube in the lung.

alveoli

Small air sacs found at the end of each bronchiole where gas exchange takes place with the blood.

breathing

The movement of air in and out of the lungs.

inhale

Breathing in, to take in oxygen.

respiration

Process that transfers energy in plants and animalsGlucose reacts with oxygen to make carbon dioxide and water

exhale

Breathing out, to remove carbon dioxide.

condense

The change of state from gas to liquid.

State the step by step process of respiration.

Air enters body through mouth and nose.Air moves down trachea (windpipe) - a large tube.Air moves down a bronchus - a smaller tube.Air moves through a bronchiole - a tiny tube.Air moves into alveolus - air sac.Oxygen diffuses into blood.

Which specific features of the alveoli aid gas exchange? ie. their adaptations

Millions of alveoliCreate large surface areaThin walls - one cell thickGas exchange can occur quickly and easily

Why do we breathe in and out?

Breathing - movement of air in and out the lungsWhen we breathe, we inhale to take in oxygenOxygen in used in respiration to transfer energyRespiration produces carbon dioxide, which must be removed from the bodyWhen we breathe out, we exhale to remove carbon dioxide

What determines how fast you breathe?

Amount of oxygen required by body cells

How does exercise impact the amount of oxygen your body requires?

More oxygen required during exerciseHarder you exercise → faster breathing rate → greater volume of breathingAllows you to take in the oxygen you need to respire moreTransfers more energy to muscle cells

State how much nitrogen, oxygen, carbon dioxide and other gases are present in inhaled air.

Nitrogen: 78%Oxygen: 20.96%Carbon dioxide: 0.04%Other gases: 1%

State how much nitrogen, oxygen, carbon dioxide and other gases are present in exhaled air.

Nitrogen: 78%Oxygen: 16%Carbon dioxide: 4%Other gases: 2%

Why does a cold mirror steam up when you breathe on it?

Water vapour in the air you breathe out condenses on the cold surface

What happens when you inhale?

Muscles between ribs contract - pulls ribcage up and outDiaphragm contracts - moves downVolume inside chest increasesPressure inside chest decreases - draws air into lungs

How is inhaling showed in a bell jar model?

Rubber sheet is pulled downVolume inside jar increasesPressure inside jar decreases - air rushes into jarBalloons inflate

What happens when you exhale?

Muscles between ribs relax - pulls rib cage down and inDiaphragm relaxes - moves upVolume inside chest decreasesPressure inside chest increases - pushes air out of lungs

How is exhaling showed in a bell jar model?

Rubber sheet is pushed upVolume inside jar decreasesPressure inside jar increases - causes air to rush out balloons and jarBalloons deflate

How can you measure lung volume using a plastic bottle?

As you breathe out into plastic tube, air from lungs takes the place of water in the bottleVolume of water pushed out bottle is equal to volume of air your lungs can hold

How can lung volume be increased?

Regular exercise

Name three factors that can reduce lung volume.

SmokingAsthmaOld age

Suggest why your doctor would say that the plastic bottle method to measure lung volume is not an accurate result.

Resolution of water bottle is poor → imprecise results

contract

To get shorter or smaller

diaphragm

A sheet of muscle found underneath the lungs which is used for breathing.

lung volume

Measure of the amount of air breathed in or out.

asthma

A lung disorder in which inflammation (swelling) causes the bronchi to swell and narrow the airways, creating breathing difficulties.

How can medicinal drugs cause harm?

Can cause harm if not taken in right wayUnwanted side effectsWhen prescribing drugs, doctors must weigh up the benefits of a person taking a drug over any possible risks

addiction

A need to keep taking a drug in order to feel normal.

withdrawal symptoms

Unpleasant symptoms a person with a drug addiction suffers from when they stop taking the drug.

drugs

Chemical substances that affect the way your body works.

medicinal drug

Drug with medical benefit to health

recreational drugs

Drugs taken for enjoymentRelaxation, to stay awake

Examples of medicinal drugs

Paracetamol - relieves painAntibiotics - treat chest infections

Describe three differences between medicinal and recreational drugs.

Medicinal drugs are used in medicine, benefit health, treat symptoms, or cure an illness. Recreational drugs are used for enjoyment, may help a person relax or give them more energy, have no health benefit, are harmful in some cases, and many are illegal.

Examples of illegal recreational drugs

HeroinCocaineCannabisEcstasy

Examples of legal recreational drugs and their effects

Alcohol - affects nervous system and damages liverTobacco - increases risk of cancer and heart disease

Examples of withdrawal symptoms

HeadachesAnxietySweating

Name the drug found in alcoholic drinks.

ethanol

What happens when you drink alcohol?

Ethanol is absorbed into bloodstreamTravels to brain - affects nervous systemIt is a depressant as it slows down your body’s reaction

depressant

A drug that slows down the body’s reaction by slowing down the nervous system.

alcoholic

A person who is addicted to alcohol.

unit of alcohol

10 ml of pure alcohol.

Name three factors that affect the way a person’s body reacts to alcohol.

HeightWeightGender

How much alcohol for adults does the government recommend consuming?

Do not regularly drink more than 14 units a week

Name four conditions that are more likely to occur if a person drinks alcohol for a long time.

Stomach ulcersHeart diseaseBrain damageLiver damage

How does alcohol damage the liver?

Liver breaks down harmful chemicals (including ethanol) into harmless waste productsThey are excreted from your bodyLiver has to break down large amounts of ethanolLivers of heavy drinkers become scarredLiver works less efficientlyTakes longer to break down alcohol and other chemicalsCondition is called cirrhosis of the liverCan result in death

Name four reasons why pregnant women should not drink alcohol.

Increases risk of: MiscarriageStillbirthPremature birthLow birth weight baby

How does alcohol affect pregnant women?

When she drinks alcohol, it diffuses into baby’s blood streamCan damage developing organs and nervous systemFoetal Alcohol Syndrome (FAS) affects baby’s brain developmentResults in children with learning disabilities, facial problems, poor immune systems

How does alcohol reduce fertility in men and women?

Makes them less likely to conceiveeg. a man produces less sperm

Name four conditions a smoker can suffer from.

Increases chances of: Breathing problemsHeart attackStrokeDying prematurely eg. male smokers are 20% more likely to die from lung cancer than non smokers

State what is meant by passive smoking.

Smoking endangers the health of othersBy breathing in other people’s smokeRisk of developing circulatory and respiratory conditions increase

Why should pregnant women not smoke?

Increases risk of miscarriage and low birth weight baby and Affects foetus’ development

What risks of conditions are increased in the baby by parents smoking after the baby is born?

SIDS

Respiratory illnesses

Bronchitis

Pneumonia

What do cigarettes contain?

Tobacco

Name three harmful chemicals in tobacco smoke.

TarNicotineCarbon monoxide

What is tar and what is its effects?

Sticky black material that collects in the lungsIrritates and narrows airwaysSome of its chemicals are cancer causing

What is nicotine and what is its effects?

Addictive drug that speeds up nervous systemStimulantMakes heart beat fasterNarrows blood vessels

What is carbon monoxide and what is its effects?

Poisonous gas which stops blood from carrying as much oxygen as it shouldBinds to the red blood cells in place of oxygen

How does smoking cause heart disease?

Arteries become blockedPrevents blood flowing properlyCan cause heart attack or stroke

How does smoking cause Emphysema? (lung disease)

Tobacco chemicals weaken alveoli walls, not properly inflating. May burst during coughingr educes amount of oxygen that can pass into bloodMakes person breathless

How does smoking cause respiratory infections?

Cells lining windpipe produce mucus and trap dirt

Keep airways clean

Have cilia that sweep mucus into stomach

Tobacco chemicals stop cilia `from` moving

Allows mucus to flow into lungs

Makes it harder to breathe and causes infection

Smokers cough mucus up, which further damages lungs

nutrients

Important substances your body requires to survive and stay healthy.

Name the seven types of nutrients your body requires and what their function is.

Carbohydrates - provide body’s main source of energyLipids - (fats and oils) - provide store of energy and insulate bodyProteins - build new tissue used for growth and repairVitamins and minerals - small amounts keep you healthyWater - needed in all cells and body fluidsDietary fibre - Parts of plants which cannot be digested, helping body eliminate waste by providing bulk to keep food moving through digestive system

balanced diet

Eating food containing the right nutrients in the correct amounts.

Name the two types of carbohydrates, where they are found, and what their function is.

Simple carbohydrates (sugars) : found in sugar and fruit, provide quick source of energyComplex carbohydrates (starch) : found in pasta and bread, have to be broken down by body so energy is slowly released

What are lipids, where are they found, and what is their function?

Fats and oilsProvide you with store of energyKeep you warm by providing layer of insulation under skinProtect organs like kidneys and heart from damage

Where are proteins found, and what is their function?

Needed to repair body tissues and make new cells for growthMuscles, organs and immune system are mostly made of proteins

What are vitamins and minerals, and what is their function?

Essential substances to keep you healthyOnly need tiny amountsNeeded for you to grow develop and function normallyFruits and vegetables contain minerals

State three examples of vitamins and minerals and their function.

Vitamin A - good eyesightVitamin D and calcium - maintain healthy teeth and bonesIron - important to make red blood cells

What is the function of water and why do we need it so much, and which drinks can we find it in?

Cells are made up of 70% waterBody constantly loses water in:UrineFaecesSweatTearsExhalingMust drink over a litre of water dailyTea, juice, squash, fruit, or water on its own

What is dietary fibre and its functions?

Parts of plant your body can’t break downImportant as it adds bulk to foodKeeps food moving through gutWaste is pushed out body easilyHelps prevents constipationfood tests

Name the two steps you need to do to prepare a food solution.

Crush food using pestle and mortarAdd food drops of distilled water, and mix well

Why are you meant to use distilled water in a food solution?

It is pure and contains no other substances

How do you test for starch?

Add few drops of iodine solution to food solutionSolution contains starch if it become dark blue-black colour

How do you test for lipids in solid piece of food?

Rub some of food on piece of filter paperHold paper up to light - if paper has gone translucent, it contains lipids

How do you test for lipids in a food solution

Add few drops of ethanol to food solutionShake test tube and leave for one minutePour it (the ethanol) in test tube of waterIf cloudy, contains lipids

How do you test for sugar?

Add few drop of Benedict’s solution to food solutionHeat test tube in water bathContains sugar if solution is orange-red

How do you test for protein?

Add few drops of copper sulfate solution to food solution, then sodium hydroxide solutionIf solution turns purple, food contains protein.

digestive system

A group of organs that work together to break down food.

State what happens during digestion.

Large molecules broken down into small molecules of nutrientsNutrients can pass into blood and be used by body

Describe the process of digestion.

Food chewed and mixed with saliva in mouth. Teeth help break food into smaller chunks.Food passes through gullet.Food mixed with digestive juices and acids in stomach.In small intestine, digestive juices from liver and pancreas added - digestion is complete. Small molecules of nutrients pass through intestine wall into bloodstream.In large intestine, only food that cannot be digested gets this far. Water passes back into body, leaving solid waste of digestive food called faeces.Faeces are stored in rectum until they leave body.Faeces pass out of the body through muscular ring called anus.

Describe the adaptations of the small intestine to its function.

The small intestine has a thin wall large surface area duState what bacteria in digestive system live on, and why they are important.

gut bacteria

Microorganisms that naturally live in the intestine and break food down.

State what enzymes are and their role in digestion.

Special proteins that break large molecules of nutrients into small moleculesBiological catalysts - speed up digestion without being used

catalyst

A substance that speeds up chemical reactions without being changed at the end.

State the three main types of enzymes used in digestion.

CarbohydraseProteaseLipase

State the role of carbohydrase, and an example.

Breaks down carbohydrates into sugar moleculesCarbohydrase in saliva breaks down starch in bread into sugar

State the role of protease, and an example.

Breaks down protein into amino acidProtein digested in stomach and small intestine - acid in stomach helps digestion and kills harmful microorganisms in food

State the role of lipase, and an example.

Breaks down lipids into fatty acids and glycerolDigestion of lipids takes place in small intestineHelped by bile - substance made in liverBile breaks lipids into small dropletsMakes it easier for lipase to work on

Explain why live yoghurt should be a part of your diet.

Live yoghurt contains useful bacteria that remain in your gut. These help to break down fibre and produce important vitamins.e to villi and the villi are only one cell thick as it enables a shorter diffusion path for nutrients, and blood capillaries to carry away any nutrients absorbed.

What happens to the small molecules on nutrients produced during digestion?

Pass into bloodstream through small intestine’s wallTransported around body

State what bacteria in digestive system live on, and why they are important.

Live on fibre in your dietImportant as they make vitamins