ORGANISATION Flashcards
What is a tissue?
A group of similar cells that work together to carry out a particular function
What do muscular tissues do?
Contract to move whatever it is attached to
What do glandular tissues do?
Make and secrete chemicals like enzymes and hormones
What do epithelial tissues do?
Cover some parts of the body
What is an organ?
A group of different tissues that work together to perform a certain function
What do the different tissues in the stomach do?
Muscular = move stomach wall to churn food
Glandular = makes digestive juices to digest food
Epithelial = covers outside and inside of stomach
What is an organ system?
A group of organs working together to perform a particular function
What is the function of the glands?
To produce digestive juices
What is the function of the stomach and small intestines?
To digest food
What is the function of the liver?
To produce bile
What is the function of the small intestine?
To absorb soluble food molecules
What is the function of the large intestine?
Absorb water from undigested food
What are enzymes?
Biological catalysts
They reduce the need for high temperatures and speed up only the useful chemical reactions taking place in the body
What are enzymes made up of?
Large proteins which are made up of chains of amino acids
How do enzymes only catalyse one specific reaction?
They have an active sit which only a specific substrate can fit into
If the substrate doesn’t match then the reaction won’t be catalysed
How does temperature affect an enzyme?
Increasing the temp too much means some of the bonds in the enzyme will break therefore changing the enzymes active site so it has become denatured
How does the pH affect an enzyme?
If the pH is too high or too low it interferes with the bonds holding the enzyme together and therefore making it denatured
What is the optimum pH of an enzyme?
The pH the enzyme works best at (usually neutral pH 7)
What are examples of big molecules?
Starch
Proteins
Fats
Why do starch, proteins and fats have to be broken down?
Because they are too big to pass through the walls of the digestive system so they are broken down into smaller soluble molecules that can pass easily through the walls
What is starch broken down into?
Maltose (and then glucose by the enzyme maltase)
What enzyme breaks starch down into maltose?
Amylase
Where is amylase made?
Salivary glands
Pancreas
Small intestine
What are proteins broken down into?
Amino acids
What enzyme breaks proteins down into amino acids?
Protease
Where is protease made?
Stomach
Pancreas
Small intestine
What are lipids broken down into?
Glycerol and fatty acids
What enzyme breaks down lipids into glycerol and fatty acids?
Lipase
Where is lipase made?
Pancreas
Small intestine
Where is bile made and stored?
Made in the liver
Stored in the gall bladder
How does bile work with stomach acid?
Acid in the stomach makes the pH too acidic for enzymes in the small intestine to work properly
Bile is alkaline so neutralises the acid so enzymes work better
Where are enzymes used in the digestive system made?
They are produced by specialised cells in glands and gut lining
What do the salivary glands do?
Produce amylase enzyme in the saliva
Why does the stomach produce hydrochloric acid?
To kill bacteria
To give the right pH for the protease enzyme to work
What solution is used to test for sugars?
Benedicts solution (blue)
What colour will the food turn if sugars are present?
Blue to green/yellow/brick-red depending on how much sugar is present
What solution is used to test for starch?
Iodine solution (browny orange)
What colour will the food turn if starch is present?
Browny orange to blue-black
What solution is used to test for proteins?
Biuret solution (blue)
What colour will the food turn if proteins are present?
Blue to purple
What solution do you use to test for lipids?
Sudan III stain solution
What will happen to the food if lipids are present?
The liquid will separate into two sections and the top one will be red
What is the top part of your body called?
The thorax
What happens when oxygenated blood meets body cells?
Oxygen diffuses from the blood to the cells (area of high to low concentration)
Opposite with carbon dioxide
Where does the right ventricle pump blood to?
Pumps deoxygenated blood to the lungs to take oxygen back to the heart
Where does the left ventricle pump blood to?
Pumps oxygenated blood around all the other organs in the body and deoxygenated blood returns to the heart to be pumped to the lungs again
What is the journey of blood into the heart?
Vena cava
RA RV
pulmonary artery
LA LV
Pulmonary vein
Aorta
How is your resting heart rate produced?
By a group of cells in the right atrium (pacemaker) and produce small electric impulses which spread to the muscle cells causing them to contract
What is health?
The state of physical and mental wellbeing
What are communicable diseases?
Diseases that can be spread from person to person (usually bacteria, fungi, viruses and parasites)
What are non-communicable diseases?
Diseases that cannot spread from person to person
What do the arteries do?
Carry blood away from the heart
What do capillaries do?
These are involved in the exchange of materials at the tissues
What do veins do?
Carry blood to the heart
What are the properties of capillaries?
Permeable walls so substances can diffuse in and out
Carry blood really close to every cell to exchange substances
They supply food and oxygen and take away waste
How do you calculate the rate of blood flow?
Volume of blood / number of mins
What is the job of the red blood cells?
To carry oxygen from the lungs to the rest of the body
Large surface area for absorbing oxygen
No nucleus so more room for O2
What is the job of white blood cells?
To produce antibodies to fight microorganisms
To produce antitoxins to neutralise any toxins produced by microorganisms
What is the job of platelets?
They help clot your blood at a wound (stop blood pouring out and microorganisms getting in)
What is the job of plasma?
Pale straw colour and carries everything in the blood:
R/W blood cells and platelets
Nutrients (glucose or amino acids)
Carbon dioxide
Urea
Hormones
Proteins
Antibodies/antitoxins
What is coronary heart disease?
When the coronary arteries that supply the blood to the muscle of the heart get blocked by layers of fatty material building up
Arteries become narrow so blood flow is restricted so lack of oxygen to the heart muscle (can result in heart attack)
What are stents?
Tubes that are inserted inside arteries to keep them open making sure the blood can pass through the the muscle
What are the advantages of stents?
Effective for a long time
Reduces risk of heart attacks
Recovery time from surgery is quick
What are the disadvantages of stents?
Risk of complications during operation
Risk of infection from surgery
Blood clot can be developed near stent (thrombosis)
What is cholesterol?
Essential lipid that is needed for your body to function properly however too much of a certain bad type of it can cause health problems (CHD)
What are statins?
Drugs that can reduce the amount of ‘bad’ cholesterol present in the blood stream which slows down the rate of fatty deposits forming
What the advantages of statins?
Reduces risk of strokes, CHD and heart attacks
Can increase the amount of ‘good’ cholesterol
Can prevent other diseases
What the disadvantages of statins?
Must be taken regularly
Negative side effects (headaches, kidney failure, liver damage and memory loss)
Isn’t instant effect
What are artificial hearts?
Mechanical devices that pump blood for the person whose heart has failed
Usually only temporary until a donor heart is available or the person recovers
What are the advantages of an artificial heart?
Less likely to be rejected by the body’s immune system
What are the disadvantages of an artificial heart?
Surgery can lead to bleeding and infection
Don’t work as well as natural ones
Blood doesn’t flow through as smoothly which can cause blood clots and lead to strokes (patient has to take drugs to thin blood which can cause problems if they get hurt and bleed)
How can heart attacks, infection and old age affect valves in the heart?
They can cause the valve tissue to stiffen so it won’t open properly or become leaky allowing blood flow in both directions
How can damage to valves in the heart be treated?
Replace the valves with biological or man-made valves
Still problems with surgery and risk of blood clots
What is artificial blood?
It is a blood substitute which is a salt solution which gives the patient enough time to produce new red blood cells to replace the ones they lost
What factors can affect your health?
Diseases
Diet
Stress
Life situation (what you have access to)
What are risk factors?
Things that are linked to an increase in the likelihood that a person will develop a certain disease during their lifetime
What are some risk factors that can cause disease directly?
Smoking
Obesity
Drinking too much alcohol
Smoking when pregnant
What is cancer?
The uncontrolled growth and division of cells that results in the formation of a tumour
What is a benign tumour?
The tumour stays in one place as there is no more room to grow so doesn’t invade other tissues in the body so isn’t normally dangerous
What is a malignant tumour?
When the tumour grows and spreads to other healthy tissues in form secondary tumours
Cells can break off and travel to other parts of the body travelling in the blood stream
What are some risk factors that can lead to cancer?
Smoking
Obesity
UV exposure
Viral infection
Inheriting faulty genes
What does the epidermal tissue do?
Covers the whole plant
What does the palisade mesophyll tissue do?
Where most photosynthesis happens (in leaf)
What does the spongy mesophyll tissue do?
Contains big air spaces to allow gases to diffuse in and out of cells (in leaf)
What do the xylem and phloem do?
They transport things like water, mineral ions and food around the plant
What does the meristem tissue do?
Found at growing tips of shoots and roots and can differentiate into lots of different types of plant cell so the plant can grow
How are the epidermal tissues related to their function?
Waxy cuticle to reduce water loss by evapouration
How is the upper epidermis related to its function?
Transparent so light can pass through to the palisade layer
How is the palisade layer related to its function?
Lots of chloroplasts so near the top of the leaf so they can get lots of light
How is the lower epidermis related to its function?
Has little holes called stomata which let co2 diffuse directly into the leaf (opening and closing of the stomata is controlled by guard cells in response to environmental conditions)
What do phloem tubes do (translocation)?
Transport food substances (mainly dissolved sugars) made in the leaves to the rest of the plant for immediate use or storage - translocation
What are phloem tubes made of?
Elongated living cells with small pores in the end walls to allow cell sap to flow through
What are xylem tubes made of?
Dead cells joined end to end with no walls between them and a hole down the middle (strengthened with material called lignin)
What do xylem tubes do (transpiration)?
Carry water and mineral ions from the roots to the stem and leaves - transpiration
What is transpiration?
Caused by evaporation and diffusion of water from a plants surface
Evaporation causes a shortage of water in the leaf so more water is drawn up through xylem vessels to replace it
Therefore constant transpiration stream of water through the plant
How is transpiration a side effects of the way leaves are adapted for photosynthesis?
They have stomata so gases (co2) can be exchanged easily
Because there is more water inside the plant than outside, water escapes from the leaves through the stomata by osmosis
What can affect transpiration?
Light intensity
Temperature
Air flow
Humidity
How does light intensity affect transpiration rate?
Brighter light means increased transpiration rate
If it is dark photosynthesis can’t happen so stomata (let co2 diffuse into the leaf) close so very little water can escape
How does temperature affect transpiration rate?
Warmer means increased transpiration rate
Water particles have more energy to evaporate and diffuse
How does air flow affect transpiration rate?
Increased air flow means water particles are swept away so diffusion can happen from the plant to the outside (high to low concentration) so increases the transpiration rate
How does humidity affect transpiration rate?
Less humid air increases transpiration rate as if air is humid then outside the leaf there is water particles which means diffusion cannot occur (no high to low concentration)
How are guard cells adapted to open and close the stomata?
Kidney shape which opens and closes the stomata
When plants have lots of water swell up with it and go plump which makes it open and ready for photosynthesis
Thin outer walls and thicker inner walls
Sensitive to light so close at night to water without losing photosynthesis
More on the undersides of leaves so less water is lost
What do nitrate ions do in a plant?
Absorbed by the roots to make amino acids, chlorophyll and nucleotides.
What do magnesium ions do in a plant?
To make chlorophyll in their leaves.
What does bile do?
Breaks down lipids
Alkali so neutralises stomach acid
Produces optimum pH for pancreatic enzymes
Where is bile made and stored?
Made in liver
Stored in gallbladder
What is the function of the liver?
The liver filters the blood and breaks down harmful substances.
What do the kidneys do?
Regulate water content in blood
Remove wastes and extra fluids from body
What does the pancreas do?
Regulates blood sugar levels using insulin and glycogen
How are muscle cells adapted for function?
Contain lots of mitochondria to provide energy for contraction
Protein fibres to change length when they contract
Digestive system?
Oesophagus
Stomach (proteins) and churns food into fluid
Small intestines (chemicals/enzymes from liver/pancreas)
Digestion of starch, protein and lipids
Bile from liver speeds up lipids
Small food molecules absorbed into blood stream
Large intestine water absorbed into blood stream
What do you do to test for sugars?
Benedicts solution (blue)
Mix then put in beaker with hot water for 5 mins
Green - small amount
Yellow - more sugar
Brick red - lots of sugar
What is the colour change for sugar test?
Blue to brick red
What is the colour change for protein test (biuret solution)?
Blue to violet
Why do we not filter the solution when testing for lipids?
Because lipid molecules can stick to filter paper
How do you tests for lipids?
Distilled water + ethanol
If present solution goes white and cloudy
