B2: Organisation Flashcards
What is a tissue?
A group of similar cells that work together to carry out a particular function.
What is a organ?
A group of similar tissues that work together to carry out a particular function.
What is a organ system?
A group of similar organs that work together to carry out a particular function.
What is a organism?
Several groups of organ systems that form an individual animal, plant, or single celled organism.
What is an enzyme?
A substance produced by a living organism which acts as a catalyst to bring about a specific reaction.
How do enzymes work?
- the substrate collides with the enzyme and becomes attached.
- the enzyme catalyses breakdown of substrate
- the enzyme is unchanged and can be used again
What factors effects the rate of a reaction?
Temperature, pH, enzyme concentration, substrate concentration, surface area, pressure.
What is meant by the term optimum?
The temperature and pH value where an enzyme works best.
What is meant by an enzyme denaturing?
An enzyme being destroyed by high temperatures and pH(too acid or too alkali)
What happens to the active site when an enzyme denatures?
The active site changes so the substrate can no longer fit in it.
What is the lock and key theory?
The unique fit of the enzyme with the substrate.
What is the relationship between the active site and substrate?
They are complementary to each other.
How do you investigate the rate of enzyme activity?
- place a drop of iodine starch indicator on to each spot of the spotting tile.
- measure 3cm3 of starch using a syringe and dispense into a boiling tube and put pH5 buffer and amylase into another small test tube.
- set up a water bath with 150ml of cold water and add boiling water until it reaches 35-37*C
- place the test tubes in the water bath and when they reach 37*C add the test tube into the boiling tube and start the stopwatch immediately.
- after 15s, using a clean pipette remove one drop from the starch and amylase mix and drop this onto the first spot of the spotting tile.
- repeat this until there is no colour change.
- repeat these steps using pH6, pH7, and pH8
What is digestion?
The breakdown of large insoluble food molecules into small, soluble food molecules.
What are the two types of digestion?
Mechanical and chemical
What is mechanical digestion and what are two examples of it?
Breaking down large pieces of food through physical processes such as chewing and squeezing of the stomach.
What is chemical digestion and what are two examples of it?
Breaking down large pieces of food through the use of digestive enzymes.
Why do large food molecules need to be broken down?
To be absorbed into the bloodstream.
What do the liver and gallbladder do in digestion?
Bile is made in the liver but stored in the gallbladder and improves fat digestion. It does this because it’s an alkali meaning it neutralises stomach acid and it emulsifies fat so it’s easier for lipase to breakdown.
What do carbohydrates do?
Provide energy.
What do proteins do?
For growth and repair.
What do lipids do?
To provide energy. Also to store energy in the body and insulate it against the cold.
How do you prepare for food tests?
- Grind up the food and transfer it to a small beaker and add distilled water
- stir the mixture so that some of the food dissolves in the water
- fold the piece of filter paper and place that in the funnel
- pour the mixture form the beaker through the filter paper so you collect about a 1cm depth watery liquid
How do you test for simple carbohydrates (sugars)?
- add 10 drops of benedict’s solution to the solution into one of the test tubes with the filtrate in
- put hot water from the kettle in a large beaker. the water should not be boiling and put the test tube in for around 5 minutes
- a positive test goes from blue to brick red/ cloudy orange/ yellow/ green (depends on concentration)
How do you test for complex carbohydrates (starch)?
- add a few drops of iodine solution to a different test tube with your filtrate in it.
- a positive test goes from orange to blue/ black
How do you tests for proteins?
- add 2 good squirts of biuret solution to the filtrate in the third test tube and shake gentle to mix
- a positive test goes from blue to pink/ purple
How do you test for fats?
- add a few drops of sudan III and shake gentle to mix
- a positive test has a red stained layer
What is gas exchange?
Oxygen passing into the blood through diffusion from the lungs to the cells and at the same time carbon dioxide is being breathed out as it diffuses out of the blood.
What is the function of red blood cells?
Bind to oxygen and carry it around the body.
What is an artery?
A blood vessel that carries blood away from the heart.
What is a vein?
A blood vessel that carries blood towards the heart.
What is a capillary?
A blood vessel that carries blood closely towards all the cells.
What is the structure of an artery?
Thick layer of muscle and elastic and small lumen
What is the structure of an vein?
Thin layer of muscle and elastic and a large lumen with valves.
What is the structure of an capillary?
Thin walls- one cell thick
What do valves do?
Prevent backflow
What is the function of an artery?
Carry blood away from the heart and carries oxygenated blood and high pressure blood
What is the function of a vein?
Carry blood towards from the heart and carries deoxygenated blood and low pressure blood
What is the function of a capillary?
Connect arteries and veins. Substances diffuse from cells to blood.
What is the difference between the muscle on each side of the heart?
It is thicker on the left side.
Why is the muscle thicker on the left side of the heart?
It pumps blood around the body.
What are the white string like features in the heart called?
Valves
What is a pacemaker?
A group of cells in the right atrium that controls the resting heart rate. They produce a small electrical impulse to near by cells making them contract.
What is the difference in the blood on each side of the heart?
Left: oxygenated
Right: deoxygenated
Why are artificial pacemakers used?
Control the heartbeat if the pacemaker cells don’t work properly e.g an irregular heart beat
What does the vena cava do?
Bring blood from the body to the heart.
What does the pulmonary artery do?
Takes blood to the lungs.
What does the pulmonary vein do?
Takes blood from the lungs to the heart.
What does the aorta do?
Take blood to the body.
What pathway does blood take through the heart?
Vena cava- right atrium- right ventricle- pulmonary artery- pulmonary vein- left atrium- left ventricle- aorta
What is a red blood cells function and how is it adapted?
Function: gas exchange
Adaptations: concave shape for a large surface area, no nucleus to have more space for haemoglobin that binds with oxygen to form oxyhaemoglobin
What is a white blood cells function and how is it adapted?
Function: protect the body from disease and produces antibodies
Adaptations: large nucleus can change their shape
What is a platelet function and how is it adapted?
Function: produce tiny fibres to clot blood at open wounds
Adaptations: smaller than red and white blood cells, do not have a nucleus
What is a plasma function and how is it adapted?
Function: transports hormones and nutrients
Adaptations: a liquid that substances can dissolve in can dcells can float around in
What is coronary heart disease?
When arteries that supply blood to the heart get blocked by layers of fatty material build up
What lifestyle factors can increase the risk of coronary heart disease?
Diet high in fats, smoking , stress, alcohol, lack of exercise
What are statins?
Statins are drugs that help to lower cholesterol in the blood.
What are the advantages and disadvantages of taking statins?
Advantages: lower cholesterol meaning less of a risk of getting coronary heart disease
Disadvantages: they need to be taken long-term, cholesterol levels will rise again if a person stops taking them, some patients taking statins experience side effects such as headaches and memory loss, statins are not suitable for everyone
What do stents do?
Coronary arteries that are blocked or have become narrow can be stretched open and have a stent inserted to restore and maintain blood flow.
What are the advantages and disadvantages of stents?
Advantages: long term solution to fat build up, safe, doesn’t involve surgery
Disadvantages: risk of heart attack, bleeding or stroke
What is a heart transplant?
Where a donor heart can be transplanted to replace originals, can be rejected.
What are the advantages and disadvantages of a heart transplant?
Advantages: patients live longer, patients enjoy a better quality of life
Disadvantages: surgical risks (bleeding, rejection), will take powerful medicines to suppress rejection, might not work well enough to maintain circulation
What is meant by health?
Someone’s physical, mental and social well-being.
What is meant by disease?
A disorder or malfunction of the mid or body, which destroys good health.
What is a communicable disease?
A disease that is passed from person to person, an animal or object by pathogen.
What is a non-communicable disease?
A disease that can not be spread from person to person.
What factors increase the chance of getting a non-communicable disease?
.smoking
.poor diet
.lack of exercise
.excessive alcohol
.UV light
.genes
What are some interactions between diseases?
.problems with immune systems
.some types of cancer can be triggered by infections
.rashes/ allergic reactions
.mental health issues
What is a risk factor?
Something that is linked to an increased likelihood that a person will develop certain diseases
What disease does diet, smoking and lack of exercise cause?
Cardiovascular disease
What disease does obesity cause?
Type two diabetes
What disease does drinking excessive alcohol cause?
Liver and brain damage
What disease does smoking cause?
Lung disease and lung cancer
What is cancer?
A disease resulting from uncontrolled growth and division of an abnormal mass of cells.
What are the two types of cancer?
Benign and malignant
What is a tumor?
Swelling caused by abnormal growth and reproduction of cells in an area.
What is a benign tumor?
Swellings that are kept in one area of the body. They may be harmless but can cause blockages or release hormones
What is a malignant tumor?
Aggressive cell division and growth that invades surrounding cells. They break off and travel in the blood and for tumours around the body. This is cancer.
What do the leaves do?
Allow an entry and exit for gases that are needed by plants.
What do the stems do?
Connect the roots and leaves, flowers and fruits. They contain cells specially adapted for transportation of water minerals and sugars.
What do the roots do?
Absorbs water and minerals form the soil.
What is photosynthesis?
Using energy from the sun to convert carbon dioxide and water into glucose and oxygen.
Why does photosynthesis occur?
Makes glucose so plants can live.
Where does photosynthesis occur?
In the leaves- palisade cells- chloroplasts
What is the waxy cuticle?
A waterproof layer that stops water loss out of the leaf.
What is the upper epidermis?
Layers of cells with no nucleus that allows light to pass through.
What is the palisade mesophyll?
Cells that are packed with chloroplasts and are long to maximise photosynthesis.
What is the spongy mesophyll?
The lower part of the mesophyll layer that has many air spaces for carbon dioxide and oxygen to diffuse in and out of the leaves easily.
What is the guard cells?
The underside of the leaf is covered in these pores that open and close to allow gases in and out of the leaf
What is the stomata?
Two cells that form a pore in the bottom of the leaf
What is a xylem?
A tissue that transports water and minerals up the plant
What is a phloem?
A tissue that transports glucose from the leaves to the other parts of the plant
What is transpiration?
The movement of water and mineral ions up the plant
How is a xylem adapted?
Consists of hollow tubes strengthened by lignin, they are made from dead cells, only flow up the plant(osmosis)
What is translocation?
The movement of food substances around the plant
How is a phloem adapted?
Made of living cells, tubes of elongated cells with small pores in the ends of the walls for cell sap, goes up and down the plant
What is a transpiration stream?
The movement of water from plant roots through the xylem and out of the leaves
What factors effect transpiration rate?
Temperature- increases molecular movement so that more water molecules evaporate from cell surfaces the rate of osmosis of in the plant increases.
Light intensity- increases the rate of photosynthesis so the stomata opens and more water diffuses out
Wind- removes water vapor from leaf surfaces so more water diffuses out of the leaf
Humidity- reduces the concentration of water molecules outside the leaf: diffusion of the leaf increase
What are stomata sensitive to?
Light
Give four ways in which plants reduce water loss from them
Cools down, photosynthesis, support, carries dissolved minerals
