B2 Organisation Flashcards
What is a tissue
A group of similar cells that carry out a function
What is an organ
A group of different tissues that work together to perform a certain function
What is an organ system
A group of organs working together to perform a function
What is the digestive system
An organ system found in humans and other mammals
The liver produces
Bile
The stomach
Digests food
The pancreas produces
Digestive juices
Salivary glands produce
Digestive juices
Large intestine
Absorbs water from undigested food, leaving faeces ( poo)
Small intestine
Digests food and absorbs soluble food molecules
Enzymes are
Large proteins
Every enzyme has an
Active site with a unique shape
If the temperature is too hot what will happen to the enzyme
Some of the bonds holding the enzyme together break
All enzymes have an optimum
Temperature that they work best at
Ph can affect the
Rate of reaction involving an enzyme
I the ph is too low or too high it affects
The bonds holding the enzyme together
If the ph is too low or too high it can also change
The shape of the active site and denature the enzyme
Digestive enzymes break down
Molecules
Arteries carry
Blood away from the heart
The heart pumps blood at high pressure so
Artery walls are strong and elastic
Artery walls have
Thick layers of muscle to make them strong
Capillaries
Carry blood really close to every cell in the body to exchange substances with them
Capillaries have
Gaps in their walls, so substances can diffuse in and out
Veins also have valves these help
Keep the blood flowing in the right direction
Job of red blood cells
To carry oxygen from the heart to the rest of the body.
Red blood cells shape gives them a
Largs surface area for absorbing oxygen
Red blood cells do not have a
Nucleus
White blood cells are
Part of your immune system
Some white blood cells
Gobble up unwelcome microorganisms while others produce antibodies to defend against microorganisms
White blood cells have a
Nucleus
Why don’t red blood cells have a nucleus
To leave more space for carrying oxygen
What are platelets
Small fragments of cell.
Job of platelets
Help blood to clot ( clump together) at a wound
What is plasma
The liquid that carries everything in the blood such as white and red blood cells, food molecules ,proteins and hormones
What do the coronary arteries do
Supply the heart muscles with blood
What is coronary heart disease
When layers of fatty material build up in the coronary arteries.This causes the arteries to become narrow
Why is coronary heart disease bad ?
Because the arteries become narrow.This reduces blood flow to the heat muscle.This means less oxygen can get to the heart muscle which can lead to a heart attack
What are stents
Stents are tubes that are put inside coronary arteries by surgery
What do stents do ?
They keep the arteries open which allows blood to reach the heart muscles and reduces the risk of heart attack
Risks of having stents
Could have a heart attack during the operation.
Might get an infection after surgery
Too much cholesterol can cause
Fatty deposits to form inside arteries
What are statins
Statins are drugs that can reduce the amount of cholesterol in the blood
Advantages of statins
Statins reduce the risk of hert attacks,strokes and coronary heart diseases.
Disadvantages of statins
Statins must be taken regularly over a long period of time.
Statins can cause unwanted side affects.
The effect of statins is not instant.
What is heart failure
When the heart can’t pump enough blood
What is an artifical heart
A machine that pumps blood around the body
Why might someone use an artifical heart
Can be used to keep a person alive or to help them recover by allowing the heart to heal / rest
Advantages of artificial hearts
Artifical hearts are made from plastics.Less likely to be attacked by the body’s immune system
Disadvantages of artificial heart
Surgery can lead to bleeding and infection.
Artifical hearts don’t work as well as normal ones.
Blood doesn’t flow as smoothly as through a normal heart.
What do valves do
They help keep blood flowing in the right direction
Valves can be damaged by
Heart attacks, infections or old age
When a valve becomes damaged
The blood flows in both directions instead of just forward
Communicable diseases
Diseases that can spread from one person to another or between animals and people
Communicable diseases can be caused by
Bacteria, viruses, parasites and fungi
Non communicable diseases
Cannot spread between people or between or between animals and people
Example of non communicable disease
Coronary heart disease
What is an immune system reaction
An allergic reaction caused by a pathogen such as a skin rash.Or may worsen the symptoms of asthma.
Other factors that can affect your health
Poor diet
Lots of stress
Life situation
What is a tumour
Changes in cells can lead to uncontrolled growth and division.This results in a tumour.
Benign tumours
Are masses of abnormal cells.They stay in one place
Benign tumours are usually not
Dangerous and don’t cause cancer
A malignant tumour can
Spread to different parts of the body
Malignant tumours the cells can
Get into healthy tissues and form secondary tumours
Malignant tumours are very dangerous they can be
Fatal - they are cancers
Lifestyle factors that increase the chance of some cancers
Smoking
Obesity
Viral infection
UV exposure
Genetic factors that increase chances of getting some cancers
Genes are inherited from parents
Sometimes genes you have inherited can be faulty genes that make you more likely to get cancer
Why are people more likely to survive cancer now ?
Treatment have improved.
Doctors can diagnose cancer earlier.
More people are being screened ( checked for cancer )
People know more about the risk fftors of cancers
Plants are made of
Organs
Epidermal tissue
Covers whole plant
Palisade mesophyll tissue
Part of the leaf where photosynthesis happens
Spongy mesophyll tissue -
Part of the tissue that has big air soaces.Allows gas to diffuse in and out of cells
Xylem and phloem -
These transport things like water, mineral ions and food around the roots , stems and leaves.
Phloem tubes are made up of
Elongated living cells
What do plants make in their leaves
Food substances
Phloem tubes have pores ( small holes) to allow
Cell sap to flow through
Xylem tubes are made up of
Dead cells
Phloem tubes tranport food substances around the plant for immediate use or storage.What is this process called.
Translocation
Xylem tube carry
Water and mineral ions from the roots to the stem and leaves
Transpiration system
Movement of water from the roots, through the xylem and out of the leaves
Transpiration rate can be affected by 4 things
Air flow
Temperature
Humidity
Light intenisty
How does air flow affect transpiration rate ?
Faster moving air means water vapour around the leaf is swept away.Higher concentration of water inside the leaf then out .
How will the temperature affect transpiration
The warmer the temperature the faster transpiration happens.This is because the particles have more energy
How does light intensity affect transpiration
The brighter the light the greater the transpiration rate .Photosynthesis can’t happen in the dark so the stomata begins to close as it gets dark.When the stomate closes very little water can escape
A double circulatory system is two
Circuits joined together
In the first circuit of a double circulatory system , thr heart
Pumps deoxygenated blood to the lungs.This blood picks up oxgen in the lungs.
The oxygenated blood then returns to the heart
In the sexond corcuit of a double ciculatory system,
The heart pumps oxygenated blood around all the other organs of the body.This delivers oxygen to body cells
Blood flows into the two atria from the
Vena cava and the pulmonary vein
The atria pump the blood into the ventricles.The ventricles pump
The blood out of thr heart
Blood from the right ventricle goes through the
Pulmonary artery to the lungs
Blood from the left ventricle goes theough the
Aorta to the rest of the body
When testing for proteins what solution should you use
Biuret solution
When testing for starch you should use
Iodine
When testing for sugars yiu should use
Benedict solution
When testing for fats you should use
Ethanol
Iodine
From orange to blue / black
Benedicts solution
From blue to red
Biuret solution
From blue to purple
Transpiration is the loss
Of water from the plant
How is transpiration rate affected by air flow
The more windy it is the faster transpiration happens
How does temperature affect the transpiration rate
The warmer it is the faster transpiration happens.Because the water particles have more energy.They evaporate and diffuse fasterout of the stomata faster
How does humidity affect transpiration rate
If the air is humid there’s a lot of water in it already.This means there isn’t much of a difference between the inside and the outisde of the leaf.This means diffusion will not happen very fast
How does light intensity affect transpiration rate
The brighter the light the faster transpiration happens.Photosynthesis can’t happen in the dark so the stomata closes.When the stomata closes very little water can escape