Chapter 2 - Organisation Flashcards
What is a tissue?
The tissue is a group of similar cells that work together to carry out a particular function
What is an organ?
And organ is a group of different tissues that work together to perform a certain function
What is an organ system?
A group of organs working together
What are examples of organ systems?
The digestive system
it is made up of glands e.g. the pancreas and salivary glands
the stomach and small intestine which digests food
the liver which produces bile
the small intestine which absorbs soluble food molecules
the large intestine which absorbs water from undigested food leaving faeces
What is a catalyst
A catalyst is a substance which increases the speed of a reaction without being changed or used up in the reaction
What are enzymes
Enzymes are all large proteins and all proteins are made up of chains of amino acid’s
They act as biological catalysts
What do enzymes do
They reduce the need for high temperature and we only have enzymes to speed up useful chemical reactions in the body
Do you chemical reactions usually involve?
They usually involve things being either split apart or joined together
what does every enzyme have
Every enzyme has an active site with a unique shape that fits onto substance involved in a reaction
What is the name of the model that shows an enzyme in action
The lock and key model
What can change the rate of an enzyme catalysed reaction
The temperature and pH
However if it gets too hot some of the bonds holding the enzyme together break this changes the shape of the enzymes active site so the substrate won’t fit anymore the enzyme is said to be denatured
If the pH is too high or too low it interferes with the bonds holding the enzyme together this changes the shape of the active site and denatures the enzyme
On average what is the optimum pH that enzymes work best at
Neutral pH 7
How do you calculate the rate of reaction
Rate=1000/time
What do you digestive enzymes do
They break down big molecules such as starch, proteins and fats. These are too big to pass through the walls of the digestive system so digestive enzymes break these big molecules down to smaller ones such as sugars, amino acids, glycerol and fatty acid’s so they can pass easily through the walls of the digestive system allowing them to be absorbed into the bloodstream
What enzyme converts carbohydrate and what do they convert it into
Carbohydrates this convert carbohydrates into simple sugars
What is an example of carbohydrase
Amylase
What does amylase do?
It breaks down starch
Where is Amylase made
salivary glands
pancreas
small intestine
What does amylase break down starch into?
Maltose
What enzyme convert proteins and what into?
Proteases convert proteins into amino acid’s
Where is protease made?
Protease is made in:
the stomach
the pancreas
the small intestine
What enzyme converts lipids and what into
Lipases convert lipids into glycerol and fatty acid’s
Where are lipases made?
The pancreas and
small intestine
What does the body use the products of digestions to do
They can be used to make new carbohydrates proteins and lipids and some of the glucose that’s made is used in respiration
Where is bile produced?
Where is it stored?
Where does it go once it is released?
File is produced in the liver it stored in the gall bladder before it’s released into the small intestine
What does bile do
The hydrochloric acid in the stomach makes the pH to acidic for enzymes in the small intestines to work properly. Bile is an Alkaline - it neutralises the acid and makes conditions alkaline
It’s emulsifies fats which means it breaks the fat into tiny droplets. This gives a much bigger surface area of fat for the enzyme lipase to work on which makes digestion faster
Where are the enzymes used in digestion produced?
Enzymes used in the digestive system are produced by specialised cells in glands and in the gut lining
What do the salivary glands produce
These produce amylase in the saliva
What does the stomach do during digestion?
It pummels the food with its muscular walls
it produces the protease enzyme
it produces hydrochloric acid for two reasons:
-to kill bacteria to give the right pH
-for the protease enzyme to work which is pH 2 (acidic)
What does the liver do during digestion
This is where bile is produced
Bile neutralises stomach acids and emulsifies fats
What does emulsifies mean
To make something into smaller droplets
What does the gall bladder do during digestion?
This is where bile is stored before it’s released into the small intestine
What does the pancreas do during digestion
The pancreas produces protease, amylase and lipase enzymes. It releases these into the small intestine.
What does the large intestine do during digestion?
This is where excess water is absorbed from the food
What does the rectum do during digestion?
This is where faeces are stored before they leave through the anus
What does the small intestine do during digestion?
It produces protease lipase and amylase enzymes to complete digestion
this is also where the digested food is absorbed out of the digestive system into the blood
How do you prepare a food test
1) Get a piece of food and break it up using a pestle and mortar
2) Transfer the ground up food to a beaker and add some distilled water
3) Give the mixture a good start with a glass rod to dissolve some of the food
4) filter the solution using a funnel lined with filter paper to get rid of the solid bits of food
What test can you use to test for sugars
You can use the Benedict’s test
How do you do the Benedict’s test?
1) prepare a food sample and transfer 5 cm³ to a test tube
2) prepare a water bottle that it set to 75°C
3) add some benedicts solution to the test tube (about 10 drops) using a pipette
4) Placed the test tube in the water bath using a test tube holder and leave it in there for five minutes
5) If the food sample contains a reducing sugar the solution in the test tube or change from the normal blue colour to green yellow or brick red it - depends on how much sugar is in the food
What solution can use to test for starch and what colour will the solution be at the start and at the end of the test?
You can use the iodine solution to test for starch.
The colour of the solution will change from browny orange to black or blue-black
What test can you use to test for proteins?
What colour will the solution be at the start and at the end of the test?
You can use the biuret test
The solution will change from blue to pink or purple. If no protein is present, the solution with a blue
What test can you test for lipids?
Sudan III Test
What is the thorax?
The thorax is the top part of your body
What did the alveoli do?
The alveoli carry out gas exchange in the body
What happens during gas exchange in the alveoli?
Blood passes next to the alveoli. This blood has just returned to the lungs from the rest of the body so it contains lots of carbon dioxide and very little oxygen. Oxygen defuses alt of the Alveolus and into the blood. Carbon dioxide defuses out of the blood into the alveolus to be breathed out.
When the blood reaches body cells, oxygen is released from the red blood cells and diffuses into the body cells
At the same time carbon dioxide defuses out of the body cells into the blood. It’s carried back to the lungs
What are the walls of the heart mostly made of
Muscle tissue
How does the heart use it for Chambers the pump blood around?
1) blood enters the right atrium through the vena cava and then flows into the right ventricle. This blood is deoxygenated. The blood is then taken to the lungs to take in the oxygen before being pumped back to the heart.
Then the blood enters the pulmonary vein Before entering the left atrium. The blood then goes into the left ventricle before being pumped back around the body. This blood is oxygenated
Why does the heart have valves.?
The heart has valves to make sure that blood flows in the right direction-they prevent it flowing backwards
How is your heart rate controlled?
Your resting heart rate is controlled by a group of cells in the right atrium that acts as a pacemaker. The cells produced a small electric impulse which spreads to the surrounding muscle cells causing them to contract.
How do you Artificial pacemakers Control heartbeat?
It’s a little device that is implanted under the skin and has a wire going to the heart. It produces an electric current to keep the heart beating regularly
What are the three types of blood vessels? What do they do?
Arteries- these carry the blood away from the heart
capillaries- These are involved in the exchange of materials at the tissues
veins- These carry the blood to the heart
Describe what an artery is and what it does?
They pump the blood out at high-pressure
The artery walls are strong and elastic
They have a small lumen
They contain thick layers of muscle to make them strong and elastic fibres to allow them to stretch and spring back
Describe what the capillary is and what it does?
Capillaries are really tiny they are too small to see.
They carry the blood really close to every cell in the body to exchange substances with them
They have permeable walls so substances can diffuse in and out
They supply food and oxygen and takeaway waste such as CO2
The wall is the only one cell thick. This increases the rate of diffusion by decreasing the distance over which it’s occurs
Describe what a vein is and what it does?
The blood is that lower pressure in the veins so the walls don’t need to be as thick as artery walls
They have a bigger lumen than arteries to help the blood flow despite the lower pressure.
They also have valves to help keep the blood flowing in the right direction
Describe what a red blood cell is and how to specialised for its function
The drop of red blood cells is to carry oxygen from the lungs to all the cells in the body
The shape is the bio concave disk (like a doughnut). This gives them a large surface area for absorbing oxygen.
They don’t have a nucleus. This allows them to carry more oxygen
They contain a red pigment called Haemoglobin
In the lungs haemoglobin Binds to oxygen to become oxyhaemoglobin. In body tissues, the reverse happens. Oxy haemoglobin splits up the haemoglobin and oxygen to release oxygen to the cells
What is the function of white blood cells?
Some white blood cells can change shape to kill unwelcome microorganisms in a process called phagocytosis
Others produce antibodies to fight microorganisms as well as antitoxins to neutralise any toxins produced by the microorganisms
Unlike red blood cells, white blood cells to have a nucleus
What is the function of platelets in the blood?
These are small fragments of cells that have no nucleus
They help the blood to clot at a wound. This is to stop all your blood pouring out and to stop microorganisms getting in
Lack of platelets can cause excessive bleeding and bruising
What is plasma and what does it carry ?
Plasma is the liquid that carries everything in the blood. It is a pale straw coloured liquid. It carries: Red and white blood cells and platelets Hormones Proteins Antibodies and antitoxins Carbon dioxide - from the organs to the lungs Nutrients like glucose and amino acid
What are stents?
Stents or tubes that are inserted inside arteries. They keep them open making sure blood can pass through to the heart muscles. This keeps the persons heart beating
What is coronary heart disease?
Coronary heart disease is when the coronary arteries that supply the blood to the muscle of the heart get blocked by layers of fatty material building up. This causes the artery to become narrow so the blood is restricted and there is a lack of oxygen to the muscle. This can result in a heart-attack.
What are some advantages and disadvantages of using stents?
Stents our way of lowering the risk of a heart attack in people with coronary heart disease. There affective for a long time and the recovery time from the surgery is relatively quick
There is a risk that the patient may develop a blood clot near the stent. This is called thrombosis
What are statins?
Statins are drugs that can reduce the amount of “bad “cholesterol present in the bloodstream. This slows down the rate of fatty deposits for me
What is cholesterol?
Why is too much cholesterol bad?
Cholesterol was essential lipid that your body produces and needs to function properly
However too much of a certain type of cholesterol can cause health problems. It can cause fatty deposits to form inside arteries which can lead to colonary heart disease
What are the advantages of statins?
- Statins can reduce the risk of strokes coronary heart disease and heart attacks
- some studies suggest that statins may also help prevent other diseases
- Statins can increase the amount of beneficial types of cholesterol
What are some disadvantages of statins?
Statins are a long-term drug that must be taken regularly. There is a risk that someone could forget take them
The effects of statins isn’t instant. It takes time for their affect to kick in
Statins can cause side-effects e.g. headaches. Some of these side-effects can be serious e.g. kidney failure, liver damage and memory loss
What are artificial heart and when are they used?
Artificial hearts on mechanical devices that pump blood for a person whose own heart has failed. They are usually only use as temporary fixes to keep the person alive until a donor heart can be found or to help a person recover by allowing the heart to rest and heal.
What is an advantage to artificial hearts?
What is the disadvantage?
Artificial hearts are less likely to be rejected by the bodies immune system
However fitting an artificial heart can lead to bleeding and infection. They also don’t work as well as healthy natural ones
What are the two types of diseases and what are they?
Communicable diseases are those that can be spread from person to person or between animals and people. These are caused by things such as bacteria viruses parasites and fungi
Noncommunicable diseases are those that cannot spread between people between animals and people. They generally last for long time and get worse slowly such as cancer and asthma etc
What are some factors that can affect your health?
A good balanced diet
Stress
Your life situation e.g. having access to medicine, being able to buy healthy food, access to condoms
What are some of the risk factors that can increase your chance of getting a disease?
Smoking
Obesity
Drinking too much alcohol
How is cancer caused?
Cancer is caused by uncontrolled cell growth and division
What are the two types of tumours?
Benign- this is where the tumour grows until there is no more room. The tumour stays in one place. This tumour isn’t dangerous normally. The tumour is not cancerous
Malignant - This is where the tumour grows and spreads to neighbouring healthy tissues. Cells can break off and spread to other parts of the body by travelling in the bloodstream. Malignant tumours are dangerous and can be fatal. They are cancers
What are some of the risk factors that can increase the chance of some cancers?
Smoking-it is linked to lung cancer and other cancers to such as mouth bowel stomach and cervical cancer
Obesity-obesity has been linked to many different cancers including bowel liver and kidney cancer
However some risk factors can also be associated with genes. Sometimes you can inherit faulty genes that make you more susceptible to cancer
UV exposure-they have an increased chance of developing skin cancer
Viral infection-Infection with hepatitis B and hepatitis C viruses can increase the risk of developing liver cancer
What are examples of plant tissues and what are they?
Epidermal tissue-this covers the whole plant.
Palisade Mesophyll tissue-this is the part of the leaf when most photosynthesis happens
spongy Mesophyll tissue-this is also in the leaf and contains big air spaces to allow gases to the fuse in and out of cells
xylem and phloem-they transport things like water mineral ions and food. Around the plant
meristem tissue - this is found at the growing tips of shoots and roots and is able to differentiate into lots of different types of plant cell allowing the plant to grow
What are the different types of tissue going from top to bottom?
Epidermal tissue
Palisade mesophyll tissue
Spongy mesophyll tissue
Epidermal tissue
How are some of the structures of the tissue that make up the leaf related to their functions?
- The epidermal tissues are covered with a waxy cuticle which helps to reduce water loss by evaporation
- the upper epidermis is transparent so that light can pass through it to the palisade layer
- the palisade layer has lots of chloroplasts. This means that they are near the top of the leaf where they can get to most light
- the tissues of leaves are also adapted for efficient gas exchange. E.g. the lower epidermis is full of stomata. These let CO2 defuses directly into the leaf. Opening and closing of stomata is controlled by guard cells in response to environmental conditions
What is the function of phloem tubes and describe what they do
Phloem tubes transport food
They are made of columns of elongated living cells with small paws in the end walls to allow cell sap to flow through. They transport food substances made in the leaves to the rest of the plant for immediate use or for storage
This process is called translocation
What is the function of xylem tubes and what did they do?
Xylem tubes take water up
They carry water and mineral ions from the roots to the stem and leaves
They are made up of dead cells joined end to end with no end walls between them and hold down the middle.
There’re strengthened with a material called lignin
What is transpiration?
Transpiration is the loss of water from the plant
Transpiration is a side-effect of the way leaves are adapted for photosynthesis. They have a stomata in them so that gases can be exchanged easily. Because there is more water inside to plant them in the air outside, the water escapes from the leaves through the stomata by diffusion
What for things affect the rate of transpiration and why?
Light intensity-stomata Begin to close as it gets darker. Photosynthesis can’t happen in the dark, they don’t need to be open to let CO2 in.
Temperature-when it’s warm the water particles Have more energy to evaporate and diffuse out of the stomata
Airflow-if airflow around a leaf is pour the water vapour just surrounds the leaf and doesn’t move away. This means there is a high concentration of water particles outside to leave so the fusion doesn’t happen as quickly
Humidity-if the air is humid there’s a lot of water in it already so there’s not much of a difference between the inside and the outside of the leaf
How are guard cells adapted?
They have a kidney shaped which opens and closes the Stomata
When the Plant has lots of water at the Godsell feel with it and go plump and turgid.
This makes the stomata how open so gases can be exchanged for photosynthesis
When the plant is short of water the guard cells lose water and become flaccid making the stomata close. This helps stop the water vapour escaping
For an outer walls and second in the walls make the opening and closing work
They are also sensitive to light and close at night to save water without losing out on photosynthesis
Guard cells are therefore adapted for gas exchange and controlling water loss within a leaf
