Topic 2: Organisation: Animal Flashcards
(a) Why could the blockage in coronary artery cause cells in the heart to die?
less blood flows through
less oxygen
Explain how a stent works as a treatment for a person with a blockage in a
coronary artery
opens / widens (artery)
so (more) blood can flow through
Evaluate the use of anti-clotting drugs in patients who have had a stent
pros:
only have to take the tablet once a day
tablets are easy to take
* (drugs are effective so) less likely to get a blood clot
* drugs are cheap so less cost to NHS
Cons:
* patients could forget to take the drugs (every day)
* restrictions on lifestyle because patient can’t eat certain foods
* risks associated with puncturing skin / infection
Name the three parts of the human digestive system that produce
amylase.
salivary gland - ignore mouth
pancreas
small intestine
Explain how amylase breaks down starch.
Answer in terms of the ‘lock and key theory’.
substrate binds to active site (of enzyme)
shape of active site and substrate are complementary
a chemical reaction occurs to produce smaller molecules
or bonds between the (starch) molecules are broken to produce smaller
molecules
(a) Describe what happens to cells when a tumour forms.
(a) cells grow / divide abnormally / uncontrollably
Explain how a very low number of blood components in the body can
cause tiredness, bleeding, infections
Tiredness
* fewer red blood cells
* so less haemoglobin
* so less oxygen transported around the body
so less (aerobic) respiration can take place
* so more anaerobic respiration takes place
Frequent infections
* fewer white blood cells / phagocytes / lymphocytes
* so fewer antibodies produced
* so fewer pathogens / bacteria / viruses killed
Bleeding
* fewer platelets
* so blood does not clot as easily
must reference all
It is dangerous for a patients with a diff blood group to receive red blood cells
recipient will bind to type B
antigens on donor’s red blood cells
(so) red blood cells clump together and block capillaries
(so) cells have reduced supply of oxygen / glucose
) Explain why blood group O red blood cells can be given to patients with
any blood group
no antigens (on type O red blood cells)
1
(so) antibodies cannot bind (to the antigens / red blood cells)
Explain why a person with a tumour blocking the tube leading from the gall bladder to
the small intestine. would have difficulty digesting fat. 5
no / less bile reaches the small intestine
ignore less / no bile produced
(so) less / no emulsification of fat
(so) smaller surface area for lipase to break down fat
pH of small intestine is not neutralised / alkaline
(so) lipase is not at its optimum pH to break down fat
(b) Explain how the structure of an artery is related to its function.
thick(er) (muscle) walls / tissue (1)
to push blood (all) around the body (1)
(b) Explain the ‘lock and key theory’ of enzyme action.
(b) enzyme binds to the substrate because they are complementary (shapes)
(so) substrate is broken down (into products)
(so) products are released
(c) What is the function of the valves in the heart?
(c) prevent backflow (of blood)
(a) Explain why a person with a leaking heart valve has difficulty exercising.
backflow can occur or some blood flows backwards
* less blood is pumped around the
body
* less oxygen supplied to muscles / cells
* (so) less aerobic respiration
* (so) less energy released
* (so) less (efficient) muscle contraction
* anaerobic respiration takes place
What is an enzyme? 2
- (chemical which) catalyses / speeds up reactions in living organisms
protein
