organisation in animals 2 Flashcards
enzymes, enzyme practical, non - communicable diseases, cancer, treatments
what is an enzyme
protein molecule that acts as catalysts, speeding up chemical reactions without getting used up
what is a denatured enzyme
an enzyme where the active site has changed shape and the substrate will no longer fit
why are enzymes specific
only certain substrate will fit into the active site of each enzyme - LOCK N KEY THEORY
describe the enzyme action
substrate moves toward the site of the enzymes
the substrate collides with the active site
the products have collided and a substrate molecule was broken
how can enzymes be denatured
they can be denatured by:
- high temperatures
- low/high pH
what is optimum temperature/pH
the temperature/pH value an enzyme works best at
most enzymes have the same optimum temperature of 37 degrees C
there are a range of different optimum pH values depending on the enzyme function
3 important enzymes
pepsin - found in the stomach and helps digestion of protein
salivary amylase - helps digestion of carbohydrates
alkaline phosphatase - found in the bloodstream and helps in the breakdown of protein
enzyme temperature denature
at low temperatures , enzymes and substrates don’t have much energy
- collision don’t happen often
- rate of reaction is low (not 0)
as the temperature increases, the rate of collision increases
- more reactions will occur
- rate of reaction increases
after the optimum temperature, the enzyme molecules begin to denature so the rate of reaction decreases
enzyme pH denature
at pH levels too low below optimum pH
- enzyme is denatured
- rate of reaction is 0
each enzyme has an optimum pH where it works best
at pH levels too far above the optimum pH
- enzyme is denatured
- rate of reaction is 0
how do you measure rate of reaction in enzymes
rate of reaction - speed at which something occurs
for when ALL of something has happened:
1/time OR 1000/time
for when PART of something has happened:
change/time
lipase - substrate, products, production site, reaction site
substrate:
lipids
products:
fatty acids/glycerol
sites of production:
pancreas/small intestine
site of reaction:
small intestine
protease - substrate, products, production site, reaction site
substrate:
proteins
products:
amino acids
sites of production:
stomach/pancreas/small intestine
site of reaction:
stomach/small intestine
amylase - substrate, products, production site, reaction site
substrate:
starch
products:
sugars
sites of production:
salivary glands/pancreas/small intestine
site of reaction: mouth/small intestine
health definition
state of physical and mental wellbeing
disease definition
something responsible for causing ill health which is not an injury
non-communicable disease
a disease that cannot be passed from person to person
misconception around risk factors
exposure to risk factors doesn’t mean that someone is definitely going to develop a condition
e.g. clear link between smoking and lung cancer however not every smoker is going to get lung cancer
coronary arteries
cardiac muscles require energy to constantly contract
the heart is surrounded by a network of arteries - coronary arteries
they supply muscles of the heart with lots of oxygen and glucose to respire efficiently
statins
advantages!
disadvantages.
drugs that lower the amount of bad cholesterol in your blood
–> cholesterol is a required fatty acid but too much bad cholesterol causes build up in blood vessels and coronary heart disease
- reduces heart attack risk!
- has beneficial effects on other causes!
- not suitable for people with liver disease.
- side effects.
- taken for life.
- cannot take whilst pregnant/breastfeeding.
heart transplant
advantages!
disadvantages.
a heart too damaged or diseased to be repaired can be replaced with a healthy heart from a donor
- improves life quality significantly!
- only a few donor hearts.
- long recovery time.
- risk of rejection from immune system.
valve replacement
advantages!
disadvantages.
heart valves too diseased or damaged means they either don’t open properly (stenosis) or don’t close properly (regurgitation) which can stop your heart from working as it should.
faulty valves can be replaced by a mechanical or biological valve (from an animal)
- restores blood flow through the heart!
- biological valves may wear out.
- blood clots could stick to mechanical valves so anti
blood-clot tablets would need to be taken - major operation
stents
advantages!
disadvantages.
a stent is a small metal, mesh tube inserted into a blocked/collapsed coronary artery to reopen it and allow blood to flow through
- very effective!
- widens coronary arteries that haven’t responded to treatment!
- short recovery time!
- in a minority of cases, further treatment is required.
artificial hearts
if a patient is awaiting heart transplant or cannot wait for a donor any longer, they may be given an artificial heart
however they have to carry the heart mechanism with them in a bag
what is apoptosis
process of regulated cell death
