Flashcards in B2 - Organistation Deck (63):
What are cells?
The basic building blocks that make up all living organisms.
How are cells organised?
-Similar cells form tissues
-Groups of tissues for organs
-Organs work together to form organ systems
What are enzymes?
What is a catalyst?
A substance that increases the speed of a reaction, without being changed or used up.
What is the lock and key model?
It is used to show how enzymes catalyse reactions:
-Every enzyme has a unique site so only catalyse one specific reaction
-A substrate has to match the active site exactly to catalyse the reaction.
What happens to a catalyst when you change the temperature?
Changing the temperature changes the rate of reaction.
Catalysts do have an optimum temperature which they work best at.
If the temperature exceeds this the bonds holding together the enzyme will break.
Does ph also have an effect on catalysts?
Yes, catalysts also have an optimum ph.
What breaks down starch into maltose?
Where is amylase produced?
The salivary glands
The small intestine
What breaks down proteins into amino acid?
Where is protease produced?
The small intestine
What breaks down lipids into fatty acids and glycerol?
Where is lipase produced?
The small intestine
What does bile do?
It neutralises stomach acid so enzymes have the correct ph to work with and emulsifies fat to create a larger SA
Where is bile produced/released?
It is produced in the liver, stored in the gall bladder and released from the small intestine.
What are the roles of the stomach in digestion?
-It pummels food
-It produces hydrochloride acid to kill bacteria and give the right ph for enzymes
What does the liver do?
-It produced bile to neutralise stomach acid.
What does the gall bladder do?
-It stores bile before it is released by the small intestine
What does the large intestine do?
It absorbs excess water from food
What does the small intestine do?
-Where digested food is absorbed
What is the structure of the lungs/breathing?
-The lungs are protected by the ribcage
-When we breathe in: air splits through trachea, into two tubes called bronchi, into tubes called bronchioles which ends with smaller bags called alveoli.
How do alveoli carry out gas exchange?
-Blood passing next to alveoli has come from the body to lungs so has (low O2 and high CO2).
-O2 diffuses out of alveolus to blood to be transported to cells
-CO2 diffuses into alveolus to be passed out by breathing
How do you work out breaths per min?
No. of breaths/no. of mins
What does the right ventricle do?
It pumps deoxygenated blood to the lungs.
What does the left ventricle do?
Pumps oxygenated blood to organs in the body
Describe the process in the heart:
-Blood enters through the vena cava (deoxygenated) or pulmonary vein (oxygenated)
-The atria contract and push blood into the ventricles
-The ventricles contract pushing blood out through the pulmonary artery and aorta
-Blood travels to the blood or to organs in the body
How does the atria contract?
Through cells surrounding it that produce electrical impulses.
What is the role of arteries and how are they adapted for it?
Arteries carry blood away from the heart at high pressure.
-They have thick elastic walls compared to lumen to carry this high pressure blood.
What is the role of capillaries and how are they adapted?
Capillaries are involved in the exchanging of materials. They supply water and food and get rid of CO2
-They are really small and have permeable walls which are one cell thick to help with diffusion.
What is the role of the vein and how is it adapted?
The vein carry’s blood back to the heart at low pressure.
-They have a large lumen to help blood flow and valves to keep the blood in the right direction.
How do you calculate the rate of blood flow?
Rate of blood flow = vol. of blood/no. of minutes
What is plasma and what does it carry?
Plasma is the liquid that carries everything in the blood:
-Red/white blood cells
What is the red blood cells job and how is it adapted?
It’s job is to carry oxygen to cells in the body.
-It has a biconcave shape and no nucleus for more SA
What are white blood cells jobs?
To defend against infection.
-Had antibodies to fight bacteria
-Goes through phagocytosis
What do platelets do?
They clot a wound to stop blood getting out and microorganisms getting in.
What are cardiovascular diseases?
Diseases of the heart/blood vessels.
What is coronary heart disease?
When the coronary arteries that supply blood to the muscle of the heart get blocked by layers of fatty material building up. Lack of 02 could lead to a heart attack.
What are stents and some advantages/disadvantages?
They are tubes inserted inside arteries to keep them open for better blood flow.
+Lower the risk of a heart attack and are effective for a long time
-Risks if complications
What are statins and some advantages/disadvantages?
Statins are a drug that can reduce the amount of ‘bad cholesterol’ in the body. This slows down fatty acids building up.
+Reduces risks of strokes, coronary heart disease and heart attacks
-Long term regular drug that can have negative side effects
What are artificial hearts?
Mechanical devices that can pump blood around the body if organ donors aren’t an option.
What are advantages and disadvantages of artificial hearts?
+Less likely to be rejected by the body’s immune system
-Surgery can lead to blessing/infection
What are biological/mechanical valves?
They are either human/mammal or man made valves to replace faulty ones in the body that have stiffened or become leaky.
What is artificial blood?
A blood substitute that can replace lost blood: it is safe and can keep people alive.
What are communicable diseases?
Diseases spread from person to person or animal to person (by bacteria etc)
What are non-communicable diseases?
Diseases that can’t spread through people/animals
What factors can affect health?
-Amount of stress
What are risk factors?
Factors that increase the likelihood that a person will get a disease
What things can directly cause a disease?
Smoking, obesity, excessive drinking etc.
How can non-communicable diseases be costly?
It is costly to research/treat and can be hard for families emotionally and financially.
What is cancer caused by?
Uncontrolled cell growth and division.
What is a benign tumour?
A non-cancerous tumour which stays in one place rather than invading other cells.
What is a malignant tumour?
A cancerous tumour which spreads to healthy tissues and can break off into the blood stream.
What risk factors can cause some cancers?
Smoking, obesity, uv infection and viral infection.
What does the epidermal tissue do?
It covers the whole plant and is transparent to allow light in
What does the Pali side tissue do?
It is where photosynthesis takes place (lots of chloroplasts)
What does the spongy tissue do?
Contains big air spaces to allow gases to diffuse in and out
What does the meristem tissue do?
It grows in the tips and roots and is able to differentiate into any type of cell.
How is the plant adapted for gas exchange?
-Stomata lets CO2 diffuse directly into the leaf
-Opening and closing of stomata is controlled by guard cells
What do phloem tubes do?
They transport food and minerals both ways for immediate use or storage.
-Go in both directions
What do xylem tubes do?
They take water up.
-Carry mineral and water from the stems to the leaves
-This is called the transpiration stream.
What is transpiration?
The loss of water through the plant.
Water diffuse into roots and is evaporated through the leaves.
What can the transpiration stream be affected by?
Light intensity: the brighter the light the ...
Temperature: the warmer the faster due to more energy
Air flow: stronger wind = greater
Humidity: the drier the air the ... as it is a high concentration to low