B2 - Organisation Flashcards
cells
the basic building blocks that make up all living organisms
specialised cells
carry out a particular function
differentiation
the process of cells becoming specialised
differentiation occurs during
the development of a multicellular organism
tissue
a group of similar cells that work together to perform a particular function
muscular tissue in mammals
contracts to move whatever it’s attached to
glandular tissue in mammals
makes and secretes chemicals like enzymes and hormones
epithelial tissue in mammals
covers some parts of the body
organ
a group of different tissues that work together to perform a certain function
muscular tissue in the stomach
moves the stomach wall to churn up food
glandular tissue in the stomach
makes digestive juices to digest food
epithelial tissue in the stomach
covers the inside and outside of the stomach
organ system
a group of organs working together to perform a particular function
enzymes
biological catalysts
catalyst
a substance which increases the speed of a reaction without being changed or used up
lock and key model
- every enzyme has an active site with a unique shape that fits onto the substance
- for the enzyme to work, the substrate has to fit into its active site
if the temperature gets too hot, what happens to the enzymes?
some of the bonds holding the enzyme together break which changes the shape of the enzymes active site
what two things affect enzymes?
temperature and pH
denatured
when the shape of an enzymes active site changes so the substrate doesn’t fit anymore
carbohydrase
converts starch into sugars
where is carbohydrase found?
salivary glands, pancreas and small intestine
protease
converts proteins into amino acids
where is protease found?
stomach, pancreas and small intestine
lipase
convert lipids into glycerol and fatty acids
where is lipase found?
pancreas and small intestine
bile
- produced in the liver and stored in the gall bladder before being released into the small intestine
- alkaline
- neutralises the hydrochloric acid from the stomach and makes conditions best for enzymes
- emulsifies fats to make digestion faster
organs in the digestive system
salivary glands, liver, stomach, gall bladder, pancreas, large intestine, small intestine and rectum
salivary glands
produce the amylase enzyme in the saliva
liver
where bile is produced to neutralise stomach acid and emulsify fats
stomach
pummels the food with muscular walls and produces hydrochloric acid to kill bacteria and give the right pH for the protease enzyme
gall bladder
where bile is stored before being released into the small intestine
pancreas
produces enzymes before releasing them into the small intestine
large intestine
where excess water is absorbed from the food
small intestine
produces enzymes and is where digested food is absorbed out of the digestive system and into the blood
rectum
where the faeces are stored
benedict’s test
- tests for sugars
- changes colour to blue, green, yellow or brick red
iodine solution
- tests for starch
- changes colour to browny-orange, black or blue-black
biuret test
- tests for proteins
- changes colour to blue, pink or purple
sudan III test
- tests for lipids
- separates into two layers with a bright red top layer
parts of the heart
pulmonary artery, vena cava, right atrium, right ventricle, pulmonary vein, left atrium, left ventricle, aorta
how does the heart work?
- blood flows into the two atria from the vena cava and the pulmonary vein
- the atria contract, pushing the blood into the ventricles
- the ventricles contract, forcing the blood into the pulmonary artery and the aorta, out of the heart
- the blood then flows to the organs through arteries and veins before returning to the heart
pacemaker
a group of cells in the right atrium wall that control the resting heart rate
three blood vessels
arteries, capillaries and veins
arteries
- carry blood away from the heart
- walls are thick, strong and elastic to cope with high pressure
capillaries
- involved in the exchange of materials at the tissues
- one cell thick and have permeable walls so substances can diffuse in and out
veins
- take blood back to the heart
- have valves to keep blood flowing in the right direction because of low pressure
calculating rate of blood flow
rate of blood flow = volume of blood / number of minutes
four parts of blood
red blood cells, white blood cells, platelets and plasma
red blood cells
- carry oxygen from the lungs to all cells
- don’t have a nucleus to allow room for more oxygen
white blood cells
defend against infection through phagocytosis or by producing antibodies
platelets
help the blood clot at the wound to stop blood getting out and microorganisms getting in
plasma
a pale straw-coloured liquid that carries blood cells, nutrients, carbon dioxide, urea, hormones, proteins, antibodies and antitoxins
coronary heart disease
when the coronary arteries that supply blood to the heart get blocked by layers of fatty material building up§
stents
tubes that are inserted inside arteries to keep them open so blood can pass through
advantages of stents
- lower the risk of a heart attack
- effective for a long time
- recovery time is relatively quick
disadvantages of stents
- risk of complications during the operation
- risk of infection from surgery
- risk of developing a blood clot near the stent
cholesterol
an essential lipid that the body produces and needs to function properly
stains
drugs that reduce the amount of bad cholesterol present in the bloodstream
advantages of stains
- reduce the risk of heart attacks and strokes
- can increase the amount of beneficial cholesterol in the bloodstream
- may also help prevent some other diseases
disadvantages of stains
- could forget to take them
- sometimes have negative side effects
- the effect isn’t instant
communicable diseases
diseases that can spread from person to person or between animals and people
non-communicable diseases
diseases that can’t be spread but generally last for a long time and get worse slowly
three things that affect health
diet, stress and life situation
cancer
the uncontrolled growth and division is a result of changes that occur to the cells and results in the formation of a tumour
benign tumour
- where the tumour grows until there’s no more room
- stays in one place
- isn’t dangerous or cancerous
malignant tumour
- where the tumour grows and spreads to healthy tissues
- cells can break off and spread to other parts of the body by travelling in the bloodstream
- they invade healthy tissues to form secondary tumours
- dangerous and cancerous
