Topic 2 - Organisation Flashcards
What is a cell?
Cells are the basic building blocks that make up all living organisms.
What is an example of a cell in plants?
Root hair cell.
What is an example of a cell in animals?
Epithelial tissue.
What is a tissue?
A tissue is a group of similar cells that work together to carry out a particular function.
What is an example of a tissue in animals?
Epithelial tissue covers some parts of the body.
Muscular tissue contracts to move whatever its attached to.
Glandular tissue which makes and secretes chemicals like enzymes and hormones.
What is an organ?
An organ is a group of different tissues that work together to perform a particular function.
What is an example of an organ?
The stomach which is made out of muscular tissue, glandular tissue and epithelial tissue.
Muscular tissue moves the stomach to churn up the food.
Glandular tissue which makes digestive juices to digest food.
Epithelial tissue which covers the outside and inside of the stomach.
What is an organ system?
It is a group of organs working together to perform a particular function.
Give an example of an organ system.
The digestive system breaks down and absorbs food. It is made up of; Salivary Glands Pancreas Stomach Small intestine Large intestine Liver
What is the role of each organ in the difestive system?
Pancreas and Salivary Gland-Produces digestive juices
Stomach and Small Intestine-Digests food
Liver-Produces bile
Small Intestine-Absorbs soluble food molecules
Large Intestine-Absorbs water from undigested food
What is a catalyst?
A substance that increases the speed of a reaction without being changed or used up in the reaction.
How do enzymes work?
Every enzyme has an active site with a unique shape that fits onto the substance involved in the reaction.
The substrate complimentary to the enzyme collides creating an enzyme substrate complex.
The substrate breaks down in the active site.
The product is then released so the enzyme can be reused.
How does temprature effect enzymes?
At first the higher temprature increases the rate.
But then when the enzyme passes optimum temprature the bonds holding the enzyme together begins to break which denatures the enzyme.
This means the substrate wont fit into the active site anymore.
How does pH effect enzymes?
If it is too high or too low it changes the shape of the active site and it denatures.
Explain how you investigate how pH effecrs amylase activity.
Put a bunsen burner on a heat proof mat and s tripod and gauze over it. Put a beaker of water over it and heat the water until it is 35 degrees.
Use a syringe and add 1cm cubed of amylase soultion and 1cm cubed of buffer solution with pH 5 to a boiling tube.
Using test tube holders, put the tube into the beaker of water and wait five minutes.
Then add 5cm cubed of starch solution to the boiling tube.
Mix the contents and start a stop clock.
Use continuous sampling and record how long it takes for the amylase to break down the starch.
Take a fresh sample from the boiling tube every 30 seconds and put a drop into a well.
When the iodine solution remains browny orange starch is no longer present.
Repeat the experiment wirh different pH values and see how it effexts the time for starch to be broken down.
How do you calculate the rate of reaction?
Rate = 1000
———
Time
Where is amylase found?
Salivary Glands
Pancreas
Small Intestine
Where is protease found?
Stomach
Pancreas
Small Intestine
Where is lipase found?
Pancreas
Small Intestine
What is the role of bile in the digestive system?
The stomach makes the pH to acidic for the enzymes in the small intestine so bile neutralises the acid because it is an alkaline.
It emulsifies fats which gives a much bigger surface area for lipase meaning faster digestion.
What is the role of hydrochloric acid in the digestive system?
To kill bacteria.
To give the right pH for protease to work.
How do you test for sugars in foods?
Prepare a food sample and put 5cm cubed into a test tube.
Prepare a water bath and set it to 75 degrees.
Add Benedict’s solution (about 10 drops)
Put the test tube into the water bath and leave it there for five minutes.
If the food sample contains a sugar it will go from blue to green, yellow or brick-red depending on how much sugar.
How do you test for starch in food?
Put 5cm cubed of food sample into a test tube.
Add a few drops of iodine solution abd gently shake in the tube.
If the contents contains starch the colour will change from browny-orange to black or dark blue.
How do you test for proteins in food?
Prepare a food sample and put 2cm cubed of your sample in a test tube.
Add 2cm cubed of biuret solution to the sample and mix by gently shaking it.
If it contains protein it should change from blue to pink or purple.
How do you test for lipids in food?
Prepare a sample of food and put around 5cm cubed into a test tube.
Using a pipette add 3 drops of Sudan III solution and gently shake the tube.
If the sample contains lipid the mixture will spearate out into two layers and the top layer will be bright red.
Describe the journey of the heart.
Deoxygenated nlood enters the right atrium via the vena cava.
It the pass through the tricuspid valve and into the right ventricle.
The heart then contracts and pushes the blood out of the right ventricle into the pulmonary artery and transports blood to the lungs.
Oxygenated blood then enters the left atrium via the pulmonary vein.
It then goes through the bicuspid valve and into the left ventricle.
The blood then goes into the aorta and takes oxygenated blood to the muscles and body.
What does the aorta do?
Takes oxygenated blood to the body.
What does the pulmonary vein do?
Takes oxygenated blood to the heart.
What does the pulmonary artery do?
Takes deoxygenated blood to the heart.
What dies the vena cava do?
Takes deoxygenated blood to the heart.
What is plasma?
It makes up 50% of your blood, it contains red blood cells, hormones, and dissolved substances.
What are red blood cells?
Carries oxygen for the lungs to the cells in the body.
It is biconcave to give a large surface area for absorbing oxygen.
The dont have a nucleus which allows for room to carry oxygen.
It also carries harmoglobin which binds to oxygen to form oxyhaemoglobing in the lungs.
In the body the revese happens where the oxygen and haemoglobin split to release oxygen into the cells.
What are white blood cells?
They engulf unwelcome microorganisms in phagocytosis.
They produce antibodies to fight microorganisms and anti toxins to neutralise toxins.
What are platelets?
Small fragments of cells with no nucleus, they help blood to clot around a wound.
How does the structure of arteries help its function?
The heart pumps out blood at high pressure so the walls are strong and elastic.
The walls are thick compared to the lumen.
Thick muscle lauer makes them strong and elastic fibries allows them to stretch and spring back.
How are capillaries structures related to their function?
They have permeable walls so substances can diffuse in and out.
Close to every cell in the body to exchange substances with them.
Wall is only one cell thick so increases rate of diffusion.
They supply food and oxygen and take away waste like carbon dioxide.
How is the structure of a vein related to its function?
Blood comes at a lower pressure so the walls dont have to be as thick.
They have bigger lumen to help blood flow.
They have valves to prevent backflow.
What is the difference between a double and single circulatory system?
One passes the heart twice.
Mammals have double because they need to respire more than smaller animals like fish.
How do you calculate cardiac output?
Heart Rate x Stroke Volume
What is coronary heart disease?
When the coronary arteries get blocked by lauers of fatty material building up.
What are the symptoms of coronary heart disease?
Breathlessness
Fatigue
What are replacement valves?
When a diseased valve is replaced with a new one, it may be mechanical or tissue.
What are the advantages and disadvantages of pacemakers?
They can improve quality of life.
Most common type of heart surgery.
May feel heavy and uncomforable.
What are the advantages and disadvantages of replacement valves?
Strong and durable.
Enables natural flow of blood.
Hear the valves opening and closing.
Have to take anti-clot drugs.
Desribe inspiration.
Ribs pull up and out.
Volume in chest increases.
Diaphragm contracts.
Increased volume decreases the pressure.
Pressure in the chest is less than the atmospheric pressure.
Air moves into the lungs from outside and inflates.
Describe expiration.
Ribcage goes down and in.
Diaphragm relaxes.
Volume in chest decreases.
Decreased volume i creases the pressure.
Pressure in chest is more than the atmospheric pressure.
Air moves from inside the lungs to outside and they flatten.
What is the role of the epidermal tissue?
It covers the whole plant.
What is the role of the palisade mesophyll?
The part of the leaf where most photosynthesis happens.
What is the role of the spongy mesophyll?
This is in the leaf and it contains large air spaces for gases to diffuse in and out of cells.
What is the role of xylem and phloem?
To transport things like water, mineral ions and food around the plant.
What is the role of the meristem?
It is found at the growing tips and shoots and it is able to differentiate into lots of types of plant cell to allow it to grow.
What is the function of phloem?
Transports food substances made in the leaves to the rest of the plant for immediate use or storage.
The transport goes in both directions.
This process is called translocation.
What is the fuction of xylem?
Carries watter and mineral ions from the roots to the stem and leaves.
The movement of water from the roots through thr xylem and out the leaves is called the transpiration stream.
Desribe transpiration.
Evaporation causes a slight shortage of water in the leaves so water is drawn up from the roots through the xylem to replace it so there is a constant transpiration stream of water through the plant.
How does light intensity effect transpiration?
The brighter the light the greater the transpiration.
Stomata begin to close as it gets darker.
Photosynthesis doesnt happen in the dark so they dont need to open to let CO2 in.
When the stomata are closed not much water can escape.
How does light intensity effect transpiration?
When its warmer the faster transpiration happens.
The water particles have more energy to evaporate and diffuse out the stomata.
How does air flow effect transpiration?
Better air flow better transpiration.
If air flow is poor the water vapour surrounds the leaf meaning there is a high concentration of water particles outside the leaf as well as inside so diffusion doesnt happen as quickly.
If air flow is good water vapour is swept away low concentration outside meaning diffusion happens quicker.
How does humidity effect transpiration?
The drier the leaf the faster transpiration happens.
If the air is humid there is alot of water in it already so the inside and outside are at equilibrium.
Diffusion happens fastest when one area has a high concentration and the other area has a really low concentration.
What does amylase break down?
Starch.
What does protease break down?
Protein.
What does lipase break down?
Lipids.
What does amylase break starch down into?
Sugars (maltose).
What does protease break proteins down into?
Amino acids.
What does lipase break lipids down into?
Fatty acids and glycerol.
Where is bile produced?
Liver.
Where is bile stored?
Gall bladder.
What is protease called in the stomach?
Pepsin.
What do you do to prepare your food sample? (Food tests practical).
Get food and break it up using a pestle and mortar.
Transfer the food into a beaker with distilled water.
Give the mixture a stir with a glass rod to dissolve some of the food.
Filter the solution using a funnel lined with filter paper to get rid of the sid bit of food.
What is the test for sugars?
Benedicts test.
What is the name of the test for starch?
Iodine solution.
Whats the name of the test for proteins?
Biuret test.
What is the name of the test for lipids?
The Sudan III test.
What is the hearts natural pacemaker?
SAN node.
Where is the SAN node usually found?
Right atrium.
How does the SAN node keep the heart beating regularly?
Sends a small electrical impulse to the surrounding muscle cells causing them to contract.
How do artificial pacemakers work?
They are for people whos natural pacemaker cells dont work properly.
It is implanted under the skin with a wire going to the heart which produces an electric current to keep the heart beating properly.
What do the arteries do?
Carry blood away from the heart.
What do capillaries do?
Exchange of materials at the tissues.
What do veins do?
They carry the blood to the heart.
What can lack of platelets cause?
Excessive bleeding and bruising.
What are stents?
Tubes that are inserted inside of arteries to keep them open so blood can pass through to the heart muscles keeping the persons heart beating.
What are the advantages of stents?
They lower heart attack in people with coronary heart disease.
They are effective for a long time and the recovery time is quick.
What ate the disadvantages of stents?
There are risks of complications during a surgery and a risk of infection from surgery.
There is also a ridk of patients developing a blood clot near the stent.
What does bad cholestrol do to your body?
Causes fatty deposits to form in arteries which can cause coronary heart disease.
What are statins?
Drugs that reduce the amount of LDL cholestrol present in the bloodstream. This slows down the rate of fatty deposits forming.
What are the advantages of statins?
Can reduce the risks of strokes, coronary heart disease and heart attacks.
As it decreases bad cholestrol it can also increase the beneficial type of cholestrol ( HDL cholestrol ) in your bloodstream.
Some studies suggest it can prevent some other diseases.
What are the disadvantages of statins?
Long term drugs that should be taken regularly. Someone may forget.
Can have negative side effects-headaches.
Other side effects can be serious such as- kidney failure, liver damage and memory loss.
The effect isnt instant it takes time for the effect to kick in.
What is an artificial heart?
Mechanical devices that pump blood for a person whos own heart has failed.
What are advantages of artificial hearts?
Less likely to be rejected by the bodys immune system than a donor heart.
Helps a person to recover by allowing the heart to rest and heal.
Keeps a person alive until a donor heart can be found.
What are the disadvantages of an artificial heart?
The surgery can lead to bleeding and infection.
The dont work as well as natural hearts-parts of the heart could wear out or the electrical motor could fail.
Blood doesnt flow through artificial hearts smoothly which can cause blood clots and lead to strokes.
The patient has to take drugs to thin their blood which can cause problems with bleeding if they are hurt in an accident.
What happens if your valves are faulty?
They can be damaged from heart attacks, infection or old age.
It can cause the valve tissue to stiffen so it wont open properly.
Or it may become leaky allowing blood to flow in both directions so the blood doesnt circulate as effectively as normal.
What is artificial blood?
It is a blood substitue (saline) which is used to replace the lost volume of blood.
What is an advantage of artificial blood?
It can keep people alive even if the lose 2/3 of their red blood cells, maybe giving the patient enough time to produce new blood cells.
What is health?
A state of physical and mental wellbeing.
What is a communicable disease?
Disease that can be spread from person to person or between animals and people.
What is a non communicable disease?
They cannot spread between people or between animals and people.
What are risk factors?
Smoking Obesity Alcohol Radiation Viral infection
How are tumours caused?
Uncontrolled growth and division of cells.
What is a benign tumour?
Where a tumour grows until there is no more room.
It stays in one place rather than invading other tissues in the body.
It isnt normally dangerous and isnt cancerous.
What is a malignant tumour?
This is where the tumour grows and spreads to neighbouring healthy tissues.
Cells can break off and spread to other parts of the body through the bloodstream.
They can invade healthy tissues elsewhere in the body and form secondary tumours.
They are dangerous and can be fatal as they are cancers.
What is the structure of the epidermal tissue?
It is covered with a waxy cuticle which helps reduce water loss by evaporation.
What is the structure of the upper epidermis?
It is transparent so light can pass theough into the palisade layer.
What is the structure of the palisade layer?
It has lots of chloroplasts and they are at the top of the leaf where they can get the most light.
What is the structure of the xylem and phloem?
They form a network of vascular bundle which delivers water and other nutrients to the entire leaf and takes away the glucose produced by photosynthesis.
They also help support the structure.
What is the structure of the lower epidermis?
Is full of stomata which allows carbon dioxide diffuse directly into the leaf.
What is the structure of guard cells?
They respond to the environmental conditions and open and close the stomata.
What is the structure of the spongy mesophyll tissues?
Has air spaces to increase the rate of diffusion of gases.
What does the phloem do?
Transports food substances made in the leaves to the rest of the plant for immediate use or storage.
What is the process called that happens in the phloem?
Translocation.
What is the structure of the phloem?
Made of columne of elongated living cells with small pores in the end walls to allow cell sap to flow through.
What does the xylem do?
Carries water and mineral ions from the roots to the stem and leaves.
What is the structure of the xylem?
Made of dead cells joined end to end with no end walls between them and a hole down the middle. They are strengthed with a material called lignin.
What is the process that happens in the xylem?
The transpiration stream.
How can you estimate transpiration rate?
You set up a pootometer and record the starting position of an air bubble.
Start a stopwatch and record the distance moved by the bubble per hour.
Keep the conditions constant throughtout the experiment for example the temperature and air humidity.
How are guard cells adapted to open and close stomata?
They are a kidney shape which open and closes the stomata.
When the plants have lots of water the guard cells fill with it and go plump and turgid. This opens the stomata so gases can be exchanged for photosynethesis.
When the plants are short of water guard cells lose water and become flaccid which makes the stomata close. This stops water vapour escaping.
Thin outer walls and thickened inner walls make the opening and closing work.
They are light sensitive and close at night to save water without losing out on photosynthesis.
They are on the undersides of the leave as it is shaded and coller so less water is lost through the stomata than if they were on the upper surface.
They are adapted for gas exchange and controlling water loss in a leaf.
