topic 2- organisation Flashcards
what is a tissue
group of similar cells that work together to carry out a particular function
organ definition
a group of different tissues that work together to perform a particular function
organ system definition
a group of organs that work together to perform a particular function
catalyst definition
a substance that increases the speed of a reaction without being changed or used up in the process
how do enzymes work
they take a substrate and break it down to smaller pieces called products
all enzymes do here is speed up the process
what is the active site in an enzyme
part of the enzyme that has a unique shape that is complimentary to the substrates
how the enzyme “lock and key model”actually works
the enzyme changes shape slightly as it binds to the substrate so the active site is complimentary to the substrate
how does temperature affect the rate of reaction
the higher the temperature the faster the rate of reaction but too high of a temp the bonds start to break apart that hold the enzyme together so the active site starts to change and if it changes shape enough the enzyme wont be able to bind with the substrate so the enzyme has been denatured.
what is optimum temperature?
optimum temperature is where the rate of reaction is at its highest point.
how does ph affect the rate of reaction
ph can speed up the rate of reaction but too high of a ph or too low of a ph can cause some of the bonds to break holding the enzymes together. the active site starts ti change shape active site changes so much that substrate cant fit.
what is optimal ph
where rate of reaction is at its highest where ph causes this
why do we need carbohydrates?
they are an energy source to carry out chemical reactions and for us to function e.g. move around
role of lipids
provide energy but they are longer term store of energy
keep us warm by insulating us
and protecting organs
role of proteins
grow
repair damaged tissue
what breaks down carbohydrates
it is broken down by amylase
where is amylase made
salivary glands
pancreas
small intestines
how are proteins broken down
broken down by protease
where is protease made
stomach
pancreas
small intestine
what are breaks down fats (lipids)
broken down by lipase
where are lipases made
pancreas
small intestine
what is the point of digestion
to break down food into tiny pieces so we can absorb it into our bodies cells
digestive system roles of each part of the system
mouth-break down food physically by chewing then salivary glands produce amylase to break down carbohydrates
stomach-contracts muscular walls to mix food. produces pepsin to break down proteins. produce’s hydrochloric acid to kill bacteria and provide environment for pepsin to work.
small intestine- digested food absorbed into blood stream. produces enzymes to aid digestion
pancreas- lots of digestive enzymes which is juiced into the small intestine
gall bladder- produces bile to neutralise acid from stomach so digestive enzymes can function. also emulsifies fats by giving big surface area for enzymes to work on.
how is small intestine adapted to its function
it is an example of an exchange surface
small intestine walls have villi which increase surface area of wall so digestive food can be absorbed into blood stream quickly.
villi only have a single layer of surface cells so nutrients diffuse in a short distance. they have a very good blood supply.
what are the food tests practical
benedict test for sugars
biuret test for proteins
iodine test for starch
sudan III test for lipids
how to prepare food test practical
break up the food
put crushed food in a beaker with distilled water
stir with glass rod till some dissolves
filter out solution with funnel and filter paper to get rid of solid bits of food we dont need
how to do benedicts test
benedicts test- transfer 5cm^3 of the solution to the test tube and prepare water bath and have it at 75 degrees add 10 drops of benedicts solution to test tube and place in water bath for 5 mins. use test tube holder to place in bath. if no reducing sugars are present the solution will stay blue but if they are reducing sugars present it should turn to green yellow or brick red.
how to do the starch test (iodine test) for food test practical
iodine test- take 5cm^3 of food sample and add few drops of iodine solution this will turn solution brown/ orange colour.
shake the test tube solution
if contains starch the colour will change to a blue black colour.
protein/biuret test for food practical how to do
biuret test- add 2cm^3 of the sample to a test tube add 2cm^3 of biuret solution to the sample which turns sample blue
shake sample
if the sample contains proteins solution will change from blue to pink/purple.
how to do lipids/sudan III test for food test practical
sudan III- 5cm^3 of non filtered solution added to a test tube add three drops of sudan III stain solution to test tube and gently shake it. if the lipid was present it should get stained by the sudan III solution as the lipid separates from the water because its not soluble it will have a bright red layer at the top.
Definition of alveoli
the site of gas exchange
characteristics of alveoli
they have one layer of thin cells so they can have a short diffusion rate so they can increase the rate if co2 and 02 diffusing across
large surface area
what is oxygen carried by and co2
oxygen by red blood cells and co2 in blood plasma
role of circulatory system
transport oxygen and nutrients to our bodies tissues
what does the circulatory system rely on
blood heart and blood vessels
what are the chambers in the heart called
two top chambers are called atriums
bottom two chambers called ventricles
what do we find between the chambers and what do they do
we find valves they prevent blood flowing backwards ensuring it always flows in the right direction
how does blood flow into the heart
on the right side of the heart which is my left it flows into the vena cava
and on the left side which is my right via the pulmonary vein
where does the blood come from when it flows in
in the pulmonary vein its just come from the lungs so it’s oxygenated
the vena cava comes from the rest of the body and is de oxygenated
what do the two veins do at the top and what are they called
the left one which is the right of the heart is called the pulmonary artery and pumps de oxygenated blood to the lungs
and the right one which is the left of the heart is the aorta which pumps oxygenated blood to the rest of the body
what does the pace maker do
pace maker which is in the right atrium of the heart has small electrical impulses which spread through muscular walls of the heart to cause it to contract
what happens if the pacemaker cells dont work
doctors can make artificial pacemakers which is an artificial device placed under the skin above the heart and has a wire which carries a current to tell it to contract
artery definition
carries blood away from the heart
vein definition
carries blood to the heart
capillaries definition
exchange nutrients and oxygen with tissues
artery characteristics
blood will be higher at high pressures
so arteries are strong and elastic so they have a thick layer of muscle and elastic tissue lumen is thin and wall of lumen is thick
capillaries characteristic
they are really small they exchange substances with cells
they take away waste products
there walls are single cell thick and they are permeable
lumen is tiny
blood pressure is lower than arteries
veins characteristics
big lumens
thin walls with small layer of elastic fibres and smooth muscles
low pressure
have valves so they prevent blood from flowing backwards
role of red blood cells
carry oxygen from lungs to our tissues for cellular respiration
what can haemoglobin do
bind oxygen to make oxyhemoglobin
characteristics of red blood cells
dont have a nucleus
shaped like a biconcave disk giving them a large surface area
role of white blood cells
defend us against pathegons
what are the types of ways white blood cells fight off pathogens
by producing phagocytosis which engulfs pathogens
or
produce antibodies which binds onto pathogens and helps destroy them
or
anti toxins which neutralise any toxins
what do platelets do
float about in the blood until we get a cut and patches up the cut the process is called clotting.
this stop microorganisms getting in to cause an infection
what does plasma do
makes blood watery so it can flow
carries everything such as rbc wbc and platelets co2 urea glucose amino acids hormones proteins anti bodies and anti toxins
how to increase amount of blood in a person if they have lost too much blood
artificial blood which consists of salt water it adds volume to circulatory system downside it doesn’t contain any red blood cells
blood transfusions which is donated by other blood donors
what is coronary heart disease
coronary arteries that supply blood to heart are blocked because of fatty material causes lumen of arteries to become narrower so less oxygen reaches the heart which can cause a heart attack
treatments of coronary heart disease
stents and statins
stent- an expandable tube placed inside artery to keep blood flowing
statins-alters the balance of cholesterol
statins decrease LDL and increase HDL so lowers risk of coronary heart disease
and heart attacks
benefits and issues of using stents
surgery is quick
lasts a long time
always requires surgery so has risks
small risk of patient developing a blood clot near stent
benefits and risks to statins
lower risk of coronary heart disease and heart attacks
have to be taken regularly
and side effects such as headaches and kidney failure
how to fix faulty valves
replace them with biological valves from humans or pigs or cows
or replace them with mechanical valves
both require surgery though so risk of bloodclots
what is heart failure and how to fix it
heart cant pump blood
can only be replaced with either an artificial heart but is only temporary
or wait to find a biological heart from another human but heart may be rejected by body so immune system might try destroy it
factors that affect health
diet exercise sleep access to medical care stress
communicable disease definition and examples
can pass from person to person
viruses bacteria parasites fungi
non communicable disease definition and examples
not spread between people
asthma CHD diabetes cancer
what is a tumor
abnormal mass of cells when cells undergo uncontrolled growth and division only malignant are cancerous
what can malignant tumours do
spread to different parts of the body and form more tumours
