Organisation Flashcards
What is the process by which cells become specialised called?
Differentiation
name these in order of size: Organs, tissues, organs systems, cells
Cells
Tissues
Organs
Organ systems
What is tissue?
A group of similar cells that work together to carry out a particular function.
give some examples of tissues in mammals
muscular tissue, glandular tissue and epithelial tissue
What is an organ?
A group of different tissues that work together to perform a certain function.
 give an example of an organ system
The digestive system
What are enzymes?
Biological catalysts.
What is a catalyst?
A substance that increases the speed of reaction without being changed or used up in the reaction.
What are enzymes made up of?
they are made up of large proteins, which are made up of chains of amino acids.
High temperatures tend to increase reactions. Why is it better that enzymes are produced?
Because increasing temperature also speeds up unwanted reactions as well. Enzymes reduce the need for high temperatures and we only have them to speed up useful chemical reactions in the body.
What is the lock and key theory?
that an active site needs to be perfectly compatible to the substrate for it to work.
what is it called when the active site changes shape a little as the substrate binds to it to get a tighter fit?
The induced fit model of enzyme action.
Why do enzymes need the right temperature?
Because at first, a high temperature increases the rate. But if it gets too hot the enzyme will denature and the shape of the active site will change so the substrate wont fit.

How does pH affect enzymes?
if the pH level is too high or too low it changes the shape of the active site in denatures the enzyme.
What is usually the optimum pH for an enzyme?
It is usually PH7, but not always e.g. pepsin an enzyme used to break down proteins in the stomach, it works best to PH2 to suit the acidic conditions.
What does the enzyme amylase do?
catalyses the breakdown of starch to maltose.
How can you detect starch?
Iodine.
Why do we need digestive enzymes?
Because Starch, proteins and fats are big molecules so they’re too big to pass through the walls of the digestive system so the enzymes break them down (e.g. into sugars).
what do carbohydrases do?
Convert carbohydrates into simple sugars. Amylase is an example of a carbohydrase. It breaks down starch.
what do proteases do?
Convert proteins into amino acids.
Where is Amylase mean?
This after glands, the pancreas, and the small intestine.
where are proteases made?
The stomach, the pancreas, and the small intestine.
what do lipases do?
they convert the lip ids into glycerol and fatty acids.
where are lipases made?
The pancreas and small intestine.
What does bile do?
Neutralises stomach acid and emulsifies fat.
Where is bile produced and stored?
Produced in the liver and stored in the gallbladder until it’s released into the small intestine
Why is bile needed?
The hydrochloric acid in the stomach makes the pH too acidic for enzymes in the small intestine to work properly. The bile is alkaline, it neutralises the acid and makes conditions alkaline. The enzymes in the small intestine work best in these alkaline conditions.
What does ‘bile emulsifying fat’ mean?
It breaks the fat down into tiny droplets.
What does hydrochloric acid do in the stomach?
Kills Bacteria
Gives it the right pH for protease to work
What Enzymes do the pancreas produce?
Protease, amylase and lipase.
What enzyme does the salivary glands produce?
Amylase
What do you use to test for sugars? yeah
Benedicts solution. You need to heat it up before it works. The colour will change from blue to anywhere between green, yellow or brick red (depending on how much sugar there is)
What do you use to test for starch?
Iodine solution. Gently shake the contents and the colour will change from browny orange to black or blue-black
What do you use to test for proteins?
Biuret solution. Shake gently and the solution will change from blue to lilac
What do you use to test for fat?
Ethanol. It will turn from colourless to cloudy.
What are alveoli?
They are millions of little air sacs surrounded by a network of capillaries that carry out gas exchange. (diffusion of oxygen and carbon dioxide)
What kind of circulatory system do we have?
A double circulatory system
What does the right ventricle do?
pump deoxygenated blood to the lungs to take in oxygen.
What does the last ventricle do?
pumps oxygenated blood around the organs and rhen back to the heart
What are the walls of the heart mostly made up of?
Muscle tissue
What do the valves in the heart do?
They prevent blood from flowing backwards.
What are the hearts four chambers?
Left and Right atrium and Left and right ventricle
What does the vena cava do?
Sends deoxygenated blood to the heart.
What does the pulmonary vein do?
sends oxygenated blood into the heart, from the lungs to be pumped around the body.
What does the pulmonary artery do?
Sends deoxygenated blood to the lungs.
What do veins do?
Return deoxygenated blood to the heart. (Apart from a pulmonary vein)
What do arteries do?
Send oxygenated blood around the body. (Apart from the pulmonary artery)
What do coronary arteries do?
branch off of the aorta and surround the heart to make sure it gets the oxygenated blood it needs.
what is a pacemaker?
A group of cells in the right atrium that produce small electrical impulses spread to the surrounding muscle cells, causing them to contract.
What is an artificial pacemaker?
It’s a little device implanted under the skin and has a way of going to the heart. Produces an electric current to keep the heart beating regularly. 
What are the three types of blood vessels?
Arteries, capillaries, and veins.
What is the lumen?
The walls of a blood vessel.
What are the physical features of an artery?
They need to carry blood at high-pressure so the walls are strong and elastic. The lumen is thick compared to the size of a hole in the middle. They contain thick layers of muscle to make them strong, and elastic fibres to allow them to stretch and spring back.
What are the physical features of capillaries?
Arteries branch into capillaries. How very small and they carry blood really close to every cell. Permeable walls so substances can diffuse in and out. They supply food and oxygen and takeaway waste Like CO2. The walls are usually only one cell thick. This increases the rate of diffusion by decreasing the distance of a widget occurs. They have a very small lumen.
What is a physical features of veins?
Capillaries eventually joined up to form veins. The lumen is larger and the walls less thick because blood is a lower pressure. They have valves to make sure the blood goes in the right direction.
What do red blood cells do?
They carry oxygen from the lungs to all the cells in the body.
What are some features of red blood cells?
They have a biconcave disc shape, this gives them a large surface area for absorbing as much oxygen as possible. They do not have a nucleus, this allows the more room to carry oxygen. They carry a red pigment called haemoglobin binds in the lungs to oxygen, and then in body tissues it splits up into haemoglobin and oxygen to release oxygen into the cells.
what do white blood cells do?
The fight against infection. Some can change shape to engulf unwelcome microorganisms (phagocytosis). Others produce antibodies as well as antitoxins.
What do white blood cells have that red blood cells don’t?
A nucleus.
What do platelets do?
they help blood clot. They are small fragments in cells. They have no nucleus. They help the blood to clot at a wound to stop all of your blood pouring out into stock microorganisms getting in.
What does plasma do?
Plasma is the liquid that carries everything. It carries all the other parts of the blood and carries nutrients like glucose and amino acids. It also carries proteins hormones and carbon dioxide.
What is coronary heart disease?
When coronary arteries that supply the blood to the muscle of the heart to get blocked by Lyth is a fatty material buildup. Discourses arteries become narrows the blood is restricted and there is a lack of oxygen to the heart
What do stents do?
they are inserted inside arteries. They keep them open, making sure the blood and passed through to the heart muscles.
What are the pros and cons of stents?
Positives of stents are that they lower the risk of a heart attack and have a relatively quick recovery time and are affective for a long time.
The cons are that there is risk of a heart attack during the operation and a risk infection. Patients may also develop a blood clot near the stent.
What are statins?
They are drugs to reduce the amount of bad cholesterol present in the bloodstream. This cholesterol can cause fatty deposits to form inside arteries if there’s too much of it.
What are the pros and cons of statins?
The pros are that it can decrease The risk of strokes, coronary heart disease and heart attacks. They can also increase the amount of good cholesterol.
The disadvantages are that it must be taken regularly and you may forget to take them. They can also cause negative side effects like headaches or even kidney and lung damage.
What are artificial hearts?
they are mechanical devices to pump blood. They are usually only temporary.
What are the pros and cons of an artificial heart?
The pros are that they’re less likely to be rejected by the bodies immune system.
The negatives are that they can lead to bleeding infection. They also don’t work as well as donor hearts. They can also cause blood clots that lead to strokes.
Why might a valve become damaged or weakened?
Heart attacks, infection or old-age.
What is artificial blood made up of and why is it useful?
It’s made up of a salt solution which can be used to replace the lost volume of blood. It’s safe and keep the patient alive so that they have time to make more blood cells.
What is a communicable disease?
Disease spread from person to person. They are caused by pathogens question.
What is a noncommunicable disease?
What disease that cannot be spread from person to person. The general last for a long time and get worse lately. E.g. cancer.
why might somebody with a poor immune system be more susceptible to communicable disease?
Because they are less likely to be able to defend themselves against the pathogen
name some other factors that can lead to poor health?
A poor diet, stress, and your life situation (for example if you have easy access to medicines)
What are the different costs of noncommunicable disease?
The human cost, this means a lower quality of life or short lifespan, it also affects the victims loved ones. 
There is also the financial cost.
What are some risk factors that can directly cause disease?
Smoking, obesity, alcohol and exposure to radiation.
What can drinking too much alcohol do you?
It causes liver disease, toxic chemicals can leak from the gut due to damage by alcohol, you can also affect brain function.
What are the attributes of a benign tumour?
tumour grows until there’s no more room, it stays in one place and it isn’t normally dangerous as it is not cancerous.
what are the attributes of 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 in the bloodstream. It can form secondary tumours and they are dangerous because they are cancers.
What are some risk factors for cancer?
Smoking, obesity, radiation exposure, and viral infection.
What causes tumours?
Uncontrolled growth and division of cells.
What is the epidermal tissue of a plant?
This covers the whole plant.
What is palisade mesophyll tissue?
This is the part of the leaf where most photosynthesis happens.
What is spongy mesophyll tissue?
It contains big ass basis to allow gases to diffuse in and out of cells.
What did the xylem and the phloem do?
They transport things like water, mineral irons in food around the plant.
What does meristem tissue do?
This is found at the growing tips of shoots and roots and is able to differentiate into lots of different types of cells, allowing a plant to grow.
What does the waxy cuticle do?
It covers the plant and helps reduce water loss by evaporation.
What are the features of the upper epidermis?
It’s transparent sunlight can pass through it to the palisade layer.
What is a feature of the palisade layer?
it has lots of chloroplasts for photosynthesis. It is near the top of the Leaf where they can get the most light.
What are the features of the lower epidermis?
It’s full of little holes called to Martha, which less CO2 directly diffuse into the leaf.
What does xylem tubes do?
They’re made of dead cells joined end to end with no middle roles, they carry water and mineral irons from the roots to the stem and leaves. The movement of water through the xylem is called the transpiration stream.
What does the phloem tube do?
Made of columns of elongated living cells, with small paws in the end walls to allow cell sap to fight through, to transport food substances (mainly dissolved sugars). This process is called translocation.
What is transpiration?
The loss of water from a plant.
Where does most transpiration happen?
At the leaves.
Why does transpiration happen?
The evaporation of water creates a shortage of it in the least, so more is drawn up from the roots through the xylem vessels.
What is transpiration rate affected by?
light intensity (Brighter the light, the greater the transpiration rate) , temperature (the warmer it is, the faster transpiration happens)
Airflow (the better the air flow, as agreed to the transpiration rate)
Humidity (drier the air around the leaf, the faster transpiration happens)
Why does light intensity affect transpiration?
Because the stomata close as it gets dark as photosynthesis can’t happen in the dark.
Why does temperature affect transpiration?
When it’s warmed up water particles have more energy to evaporate.
Why does airflow affect transpiration?
If there’s good airflow the water vapour swept away maintaining a low concentration of water in the air outside so diffusion happens quicker.
Why does humidity affect transpiration?
If there is less water in the air, diffusion happens quicker.
What can be used to estimate transpiration rate?
A potometer.
How are guard cells adapted to open and closed mate?
they have a kidney shape which opens and closes this to Martha. When the plant has lots of water the Godsells fill with it and go plump which makes this tomato open. When the plant is short of water, Godsells lose water and become flaccid making this tomato close. They are also sensitive to light and close at night. 
