Card Set Information
How many different chemicals are there is cigarettes?
many are harmful
What is the addictive substance in cigarettes?
What does nicotine do to the body?
increases the heart rate
What does the carbon monoxide in cigarettes do?
Carbon monoxide reduces the oxygen-carrying capacity of the blood
It combines with haemoglobin in red blood cells, preventing oxygen combining with the haemoglobin.
This causes an increase in heart rate to compensate for the reduced amount of oxygen carried in the blood.
What is fitness?
fitness is the ability to do physical activity
What is health?
health is the amount of freedom from disease.
name 6 ways to measure fitness?
stamina – endurance or staying power
agility – how easily someone moves
cardiovascular efficiency – how well a person's circulatory system works
What immediate effect does exercise have on the respiratory system?
It causes an increase in the
tidal volume (the volume of air breathed in or out in one breath)
What effect does regular exercise have on the respiratory system?
an increase in the
strength of the diaphragm and intercostal muscles
vital capacity (volume of air that can be forcibly exhaled after inhaling fully)
how many adult deaths are linked to smoking?
It’s estimated that nearly one in every five deaths (of adults aged over 35 in England) is connected to smoking
name four harmful substances in cigarettes?
What does tar from cigarettes do?
Tar causes cancer of the lungs, mouth and throat
It coats the inside of the lungs, including the alveoli, causing coughing
It damages the alveoli, making it more difficult for gas exchange to happen
What does the smoke from cigarettes do?
Cells in the lining of the trachea, bronchi and bronchioles produce sticky mucus.
This traps dirt and microbes.
Cells with tiny hair-like parts, called cilia then move the mucus out of the lungs.
However, hot smoke and tar from smoking damages the cilia.
As a result of this, smokers cough to move the mucus and are more likely to get bronchitis.
What are the cells with tiny hair-like parts in the lungs called?
What does nicotine do?
Nicotine is addictive.
It causes a smoker to want more cigarettes.
Nicotine also increases the heart rate and blood pressure, and makes blood vessels narrower than normal.
This can lead to heart disease
Name four organs of the digestive system, in order?
oesophagus or gullet
describe four stages of digestion?
food is digested in the mouth, stomach and small intestine
digested food is absorbed into the bloodstream in the small intestine
excess water is absorbed back into the body in the large intestine
any undigested food passes out of the anus as faeces when we go to the toilet
What does the liver do?
The liver produces bile, which helps the digestion of lipids (fats and oil).
What does the pancreas do?
The pancreas produces biological catalysts called digestive enzymes which speed up the digestive reactions
What are enzymes?
Enzymes are not living things.
They are just special proteins that can break large molecules into small molecules.
Different types of enzymes can break down different nutrients
what do amylase and other carbohydrase enzymes do?
amylase and other carbohydrase enzymes break down starch into sugar
what does protease do?
protease enzymes break down proteins into amino acids
what does lipase enzymes do?
lipase enzymes break down lipids (fats and oils) into fatty acids and glycerol
How are carbohydrates digested?
Carbohydrates are digested in the mouth, stomach and small intestine.
Carbohydrase enzymes break down starch into sugars.
The saliva in your mouth contains amylase, which is another starch digesting enzyme.
If you chew a piece of bread for long enough, the starch it contains is digested to sugar, and it begins to taste sweet
How are proteins digested?
Proteins are digested in the stomach and small intestine.
Protease enzymes break down proteins into amino acids.
Digestion of proteins in the stomach is helped by stomach acid, which is strong hydrochloric acid.
This also kills harmful microorganisms that may be in the food
How are lipids (fats and oils) digested?
Lipase enzymes break down fat into fatty acids and glycerol.
Digestion of fat in the small intestine is helped by bile, made in the liver.
Bile breaks the fat into small droplets that are easier for the lipase enzymes to work on.
Bile is not an enzyme.
What are not digested?
Minerals, vitamins and water are already small enough to be absorbed by the body without being broken down, so they are not digested.
Digestive enzymes cannot break down dietary fibre, which is why the body cannot absorb it
What is the respiration?
Respiration is a chemical reaction that happens in all living cells, including plant cells and animal cells.
It is the way that energy is released from glucose so that all the other chemical processes needed for life can happen.
Do not confuse respiration with breathing (which is properly called ventilation).
What is aerobic respiration?
Glucose and oxygen react together in cells to produce carbon dioxide and water and releases energy.
The reaction is called aerobic respiration because oxygen from the air is needed for it to work.
What is the word equation for aerobic respiration?
glucose + oxygen → carbon dioxide + water
Where does most respiration happen?
The mitochondria, found in the cell cytoplasm, are where most respiration happens
When does anaerobic respiration happen?
During hard exercise, not enough oxygen can reach your muscle cells.
So, aerobic respiration is replaced with anaerobic respiration.
This does not need oxygen for it to happen
What is lactic acid?
Anaerobic respiration produces much less energy than aerobic respiration.
The waste product, lactic acid, builds up in the muscles causing pain and tiredness
This leads to cramp. Lactic acid is only broken down when you start aerobic respiration again.
Anaerobic respiration happens in microorganisms such as bacteria because they need to release energy from glucose too
Yeast, which are unicellular fungi, can carry out an anaerobic process called fermentation.
What is the windpipe called?
The windpipe divides into two...what?
What are the smaller tubes in each of the two bronchi called?
what are at the end of the bronchioles?
group of tiny air sacs
these air sacs have bulges called alveoli to increase their surface area.
Features of the alveoli?
The alveoli are adapted to make gas exchange in lungs happen easily and efficiently.
they give the lungs a really big surface area
they have moist, thin walls (just one cell thick)
they have a lot of tiny blood vessels called capillaries
The gases move by diffusion from where they have a high concentration to where they have a low concentration
oxygen diffuses from the air in the alveoli into the blood carbon dioxide diffuses from the blood into the air in the alveoli