B2 (part 2) Flashcards
what is CHD?
Coronary heart disease
why does the heart need oxygen?
to respire
what do the arteries supply? to what?
supply blood containing oxygen to the heart muscles
what are the arteries called?
coronary arteries
what do the coronary arteries do?
supply the heart with blood so the heart muscles have oxygen to respire
what happens when someone is effected with coronary heart disease?
- Fatty acids build up on the walls of the coronary artery
- this means the blood flow is restricted
- so less oxygen reaches the heart muscle
- this means the heart muscle can’t respire
- This results in a heart attack
- the heart can’t beat so the heart stops
what are stents?
small mechanical devices that are implanted into people’s coronary arteries
what do stents do?
help prevent heart attacks in people with CHD
how do stents help prevent heart attacks in people with CHD?
they hold open the block arteries
Using a stent…
increases blood flow –> meaning more oxygen will reach the heart muscle —> so it can respire
what are 4 advantages of using stents to treat CHD?
- blocked arteries are held open
- blood to flow to the heart muscles increased
- stays in place for a long time -> so prevents heart attack for long time
- rapid recovery
what are 3 disadvantages of using stents to treat CHD?
- risk of infection from operation
- risk of surgery e.g heart attack or bleeding
- risk of blood clotting –> blood clots causes heart attacks
what are statins?
a tablet that you take when you have CHD
what do statins do?
prevent heart attacks in people with CHD
how do statins work?
they reduce cholesterol —> which reduces the build up of fatty deposits in coronary arteries
what are 3 advantages of using statins to treat CHD?
- they reduce blood cholesterol
- slows down the build up of fatty deposits in arteries
- increases blood flow to the heart muscle cells
what are 4 disadvantages of using statins to treat CHD?
- people forget to take the drug
- need to be taken long term
- side effects
- takes long time to have an effect
how many chambers does the heart have?
4
what are the 4 chambers if the heart?
left atrium
left ventricle
right atrium
right ventricle
PRACTICAL: investigating pH
- add a drop of iodine to each well in a spotting tile
- place 2cm^3 of amylase, starch and Ph5 buffer solution into 3 different test tubes
- place in water bath for 10 mins
- add all test tubes together and start stopwatch
- use stirring rod to transfer solution from test tube to an iodine well every 30 secs
- record the time when iodine no longer changes colour
- repeat steps 1-6 for pH 6,7 ,8 and 9 buffer solution
what is enzyme activity?
how fast the enzyme catalyses the reaction
( how fast enzyme breaks substrate into products)
how does increasing the temp increase enzyme activity?
increasing temp —> increases frequency of collisions—> so enzyme activity increases
what happens when you increase the temp above the optimum?
the enzymes become denatured and changes the shape of their active site —> substrate can no longer fit into active site so enzyme activity decreases
what happens to the enzyme activity when you increase/ decrease pH above/ below optimum?
denatures the enzymes and changes the shape of the active site –> so the substrate can no longer fit in –> so enzyme activity decreases
(for both increase and decrease)
what are 2 issues and solutions for investigating pH practical
- only takes samples ever 30 secs
- means we have approx time for reaction to complete
solution: take samples every 10 secs instead - hard to spot colour change
solution: use multiple people to agree when colour change happens
variables for investigating enzyme activity (temperature)
IV –> temperature
DV–> enzyme activity
CV—> enzyme, substrate
variable for investigating enzyme activity (pH)
IV —> pH
DV —> enzyme activity
CV—> temp, enzyme used
what is the optimum pH for amylase?
pH7
what is the function of the large intestine?
where excess water is absorbed from food
what are the 2 functions of the small intestine?
- produces amylase, protease and lipase
- where digested food is absorbed out of the digestive system into the blood
what are the 3 functions of the stomach?
- pummels food with it’s muscular walls
- produces protease (pepsin)
- produces hydrochloric acid
what 2 things does hydrochloric acid do?
kills bacteria and gives right pH for protease to work
what is the function of the gall bladder?
stores bile before being released into the small intestine
what is the function of salivary glands?
produces amylase in the saliva
what is the function of the pancreas?
produces prtoease, amylase and lipase and releases them into the small intestine
what is the function of the liver?
produces bile
what 2 things does bile do?
neutralises stomach acids and emulsifies fats
what is the function of the rectum?
where the faeces is stored before they go into the anus
