B2: organisation Flashcards
Salivary glands
Produces amylase enzyme in the saliva
Oesophagus/ gullet
Transports food from mouth to stomach
Stomach
Pummels food with its muscular walls
Produces protease enzymes (pepsin)
Produces hydrochloric acid for -killing bacteria
-to give the right PH for the protease enzyme to work
Liver
Bile is produced
Pancreas
- Produces protease, amylase, lipase enzymes
* Release the enzymes into the small intestine
Gall bladder
Bile is stored before being released in to the small intestine
Large intestine
Excess water is absorbed from food
Small intestine
- Produces protease , amylase and lipase enzymes to complete digestion
- where the digested food is absorbed out of the digestive system into the blood
- absorbs soluble food molecules
Rectum
Faeces are stored
Testing for sugar benedicts solution
BENEDICTS SOLUTION
1) 5cm3 Of food sample into a test tube
2) water bath set to 75 °c
3) add 10 drops of benedicts solution to the test tube using a pipette
4) place test tube in to the water bath and leave for 5 minuets
5) if the food sample contains sugar it will change from yellow to brick-red
Testing for starch- iodine solution
IODINE SOLUTION
1) 5cm3 Of food sample to test tube
2) add a few drops of iodine solution and gently shake the test tube
If it contains stretch it will change from a browny-orange to a black
Testing for proteins - using biuret solution
1) 2cm3 Of food into a test tube
2) add 2cm3 Of biuret solution to the sample and mix the contents
3) if contains proteins it should change from blue to pink/ purple
Testing for lipids - using ethanol
1) add ethanol to the solution
2) shake the test tube and leave for a minute
3) pout ethanol in to a test tube of water
4 if the solution contains lipids it will turn and cloudy colour
Definition Of denatured
Where the shape of the enzyme changes due to PH or temperature and the bonds in the enzyme are broken which mean the lock and key mechanism will no longer work as the lock has changed shape and denatured
How does the heart pump blood
1) blood flows into the atria from the vena cava and the pulmonary vein
2) the atria contracts, pushing blood into the ventricles
3) the ventricles contract forcing the blood into the pulmonary artery and the aorta and out of the heart
4) blood flows to the organs through arteries and returns through veins
5) the atria fills again and the whole cycle starts over
Arteries
Carry blood away from the heart
1) the heart pumps the blood out at a high pressure so the artery walks are strong And elastic
2) contains thick layers of muscle to make them stronger and elastic fibres to allow them so stretch and spring back
Capillaries
Involved in the exchange of materials at the tissues
1) arteries branch into capillaries
2) carry blood close to every cell in the body to exchange substances with them
3) permeable walls so substances can diffuse in and out
4) supply food and oxygen and take away waste (CO2)
5) walls are one cell thick - increase the rate of diffusion by decreasing the distance over which it occurs
Veins
1) capillaries join up to form veins
The blood is at a lower pressure in the veins so the walls don’t need to be thick
2) valves to keep the blood flowing in the right direction
Platelets
- Small fragments of cells
- No nucleus
- Help blood clot at a wound to stop you from bleeding and to stop microorganisms from getting in
- Lack of platelets can cause excessive bleeding and bruising
Artificial heart advantages
ADVANTAGES: less likely to be rejected by the body’s immune system and they are made from metals or plastics so the body doesn’t recognise them as foreign and attack like with a living tissue
How do Faulty heart valves occur
Valves can be damaged or weakened by heart attacks , infection, old age
Biological valves
Taken from humans or other mammals
Medical valves
Man made
Benign Tumour
- Where a tumour grows until there is no room
- Tumour stays in one place rather than invading other tissues in the body
- Not normally dangerous and tumour isn’t cancerous
Malignant tumour
- Where the tumour grows and spreads to neighbouring healthy tissues
- Cells can break off and spread to other parts of the body by traveling in the blood stream
- Invade healthy tissues anywhere in the body and form secondary tumours
- Dangerous and can be fatal , cancers
Risk factors of cancers associated with life style
- Smoking
- Obesity
- UV exposure
- Viral infection
What cancers is smoking linked to
- Lung cancer
- Mouth cancer
- Bowel cancer
- Stomach cancer
- Cervical cancer
What cancers are obesity linked to
- Bowel
- Liver
- And kidney cancer
( second biggest preventable cause of cancer after smoking )
What cancers are UV exposure linked to ? And who are at a higher risk?
- Skin cancer
- People in sunny climates , people who spend a lot of time outside and people who use sun beds are at a higher risk of getting skin cancer
What cancers are linked to viral infections
- Some viruses have been shown to increase the chance of developing certain types of cancer
- The chance of becoming infected is sometimes due to lifestyle- spread through unprotected sex or sharing needles
Risk factors of cancer through genetics
- Inherit faulty genes meaning you’re more susceptible to cancer
- Mutations in the BRCA genes have been linked to an increased likelihood of developing Breast and ovarian cancer
Epidermal tissue in the leaf
- Covers the whole plant
* covered with a waxy cuticle, which helps to reduce water loss by evaporation
Palisade mesophyll tissue in the leaf
- This is part of the leaf where most photosynthesis happens
- has Lots of chloroplasts , meaning that they’re near the top of the leaf where they ca get most light
Spongy mesophyll tissue in the leaf
Contains big air spaces to allow gases to diffuse in and out of cells
Xylem and phloem in the leaf
•Transports water, mineral ions and food Around the plant
a network of vascular bundles , which deliver water and other nutrients to the entire leaf and take away glucose produced by photosynthesis, help support the structure
Meristem tissue in the leaf
- Found at the growing tips of shoots and roots and is able to differentiate into lots of different types of plant cells allowing the plant to grow
- are adapted for efficient gas exchange
Structures of the tissues that make up the leaf
- Epidermal tissues -
- upper epidermis-
- palisade layer-
- Xylem and phloem-
- Tissues -
Upper epidermis in leaf
is transparent so that light can pass through it to the palisade layer
Lower epidermis in leaf
Full of stomata which let CO2 diffuse directly into the leaf
Guard cells in the leaf
- Control the opening and closing of the stomata and adapter for gas exchange and controlling water loss in the leaf
- When the plant has lots of water the guard cells fill with it and go plump and turgid
- When the plant is short of water the guard cells lose water and become flaccid making the stomata close - stopping water vapour escaping
Air spaces in the leaf
The air spaces in the spongy mesophyll tissue increase the rate of diffusion of gases
Where is amylase enzymes made?
Salivary glands
Pancreas
Small intestine
What does amylase enzymes break down
Breaks down starch into maltose
Where is protease enzymes made
Stomach (pepsin)
Pancreas
Small intestine
What does protease enzymes break down
Breaks proteins down to amino acids
Where is lipase enzymes made
Pancreas
Small intestine
What do lipase enzymes break down
Breaks lipids down to glycerol or fatty acids
Bile
Produced in the liver
Stored in the gall bladder before being released into the small intestine
What does bile do
The hydrochloric acid in the stomach makes the ph too acidic for enzymes in the small intestine to work properly
Bile is alkaline so it neutralises the acid and makes conditions alkaline
Emulsifies fats , giving a much bigger surface area of fat for the enzyme lipase to work on making digestion faster
Alveoli
Carry’s out gas exchange in the body
How alveoli carry out gas exchange in the body
The Blood passing next to the alveoli has just returned to the lungs so it contains lots of carbon dioxide and very little oxygen
Oxygen diffuses out of the alveolus into the blood
CO2 diffuses out of the blood into the alveolus to be breathed out
Calculation of breathing rate in breaths per minute
Breaths per minute = number of breaths / number of minutes
Calculating rate of blood flow
Rate of blood flow = volume of blood / number of minutes
Communicable diseases
Can spread from person to person or between animals and people - contagious
Non communicable diseases
Cannot spread between organisms
Generally last for a long time and get worse slowly
Risk factors that cause disease directly
Smoking - cardiovascular disease, lung disease and lung cancer
Obesity- type 2 diabetes
Smoking when pregnant- cause lots of problems for the unborn baby - drinking alcohol has similar effects
Radiation- cancer can be caused by long exposure to radiation
Disadvantage of artificial heart
DISADVANTAGE: don’t work as well as healthy natural hearts , heart can wear out, electrical Motor could fail, blood doesn’t flow smoothly causing blood clots or strokes so patient has to take drugs to thin blood which can cause bleeding if they are hurt in an accident
What is an artificial heart
Mechanical devices that pump blood
Temporary
What can faulty heart valves damage
The damage can cause valve tissue to stiffen, so it won’t open properly, valve may become leaky, allowing blood to flow in both directions rather than forward - blood is not circulating properly
What is a catalyst
Is a substance which increases the speed of a reaction without being changed or used up in the reaction
What is an enzyme
- Are catalyst produced by living things
* Biological catalyst
Lock and key model of enzyme action
•Every enzyme has an active site with a unique shape that fits onto the substance
- Substrate fits into the active site
- Reaction occurs
- The enzyme is unchanged but the substrate comes out as a product
What is an indices fit - lock and key model
When the active site changed shape a little as the substrate brings to it to get a tighter fit
Temperature affect on enzymes
- changing the temperature changes the rate of an enzyme catalysed reaction
- higher the temperature increases the rate but if it’s to hot some of bonds holding the enzyme together beak changing the active site and denaturing it
Ph affect on enzymes
• if it’s too high or too low it interferes with the bonds holding the enzyme together ,denaturing it
• normally the optimum ph is 7 (neutral)
However not always pepsin works best st ph2 (acidic)
Carbohydrases convert carbohydrates into simple sugars (amylase) what does it convert to
Starch —- amylase enzyme—> maltose
Where is amylase made
Salivary glands
Pancreas
Small intestine
Protease convert proteins into amino acids
Proteins — protease enzyme —> amino acids
Where is protease made
Stomach(pepsin)
Pancreas
Small intestine
Lipase convert Lipids into glycérol and fatty acids
Lipid — lipase enzyme —> glycerol and fatty acids
Where is lipases made
Pancreas
Small intestine
How does bile neutralise stomach acid ?
- Hydrochloric acid in the stomach makes the PH too acidic for enzymes in the small intestine to work properly. Bile is alkaline it neutralises the acid and makes conditions alkaline
- enzymes in the small intestine work better in alkaline conditions
How does bile neutralise emulsifies
Bile emulsifies fats
It breaks down fats into tiny droplets giving a much bigger surface area of fat for the enzyme lipase to work on making digestion faster
Thorax
- Thorax is the top part of your body
2. It’s separated from the lower part of the body by the diaphragm
Alveoli carrying out gas exchange
- The lungs contain millions of little air sacs called Alveoli surrounded by a network of blood capillaries. This is where gas exchange takes place
- The blood passing next to the Alveoli has returned to the lungs so it contains CO2 - oxygen diffuses out of the Alveolus into the blood CO2 diffuses out of the blood into the alveolus to be breathed out
- When the blood reaches body cells oxygen is released from RBCs and diffuses into the body cells
- At the same time CO2 diffuses out of the body cells into the blood . Its then carried back to the lungs
Calculating the breathing rate in breathes per minute
Breathes per minute = number of breaths / numb of minutes
Double circulatory system
Two circuits
Right ventricle and left ventricle
What does the right ventricle do
Pumps deoxygenated blood to the lungs to take in oxygen
The blood then returns to the heart
What does the left ventricle do
Pumps oxygenated blood around all the other organs if the body
The blood gives up its oxygen at the body cells and the deoxygenated blood returns to the heart to be pumped out to the lungs again
How Heart contracts to pump blood around the body
- 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 and out of the heart
- The blood then flows to the organs through arteries and returns through veins
- The atria fill gain and the whole cycle starts over
How does the heart get it’s own supply of oxygenated blood
Arteries called coronary arteries branch off the aorta and surfing the heart making sure that it gets all the oxygenated blood it needs
The Hearts Pace maker
•the resting heart rate is controlled by a group of cells in the right atrium wall that acts as a pacemaker
• these cells produce a small electric unlike which spread to the surrounding muscle cells causing them to contract
•
Arteries
Carry the blood away from the heart
•The heart pumps blood at a high pressure so the artery walls are strong and elastic
• the walls are thick compared to the size of the lumen
•they contain this layer of muscle to make them strong and elastic fibres to allow them to stretch and spring back
• branch Into capillaries
Capillaries
Involved in the exchange of materials at the tissues
• arteries branch into capillaries
• really tiny
• carry blood really close to every cell in the body to exchange substances with them
• permeable walls so substances can diffuse in and out
• they supply food and oxygen and take away waste
• walls are one cell thick which increases the rate of diffusion be decreasing the distance over which it occurs
• join up to make veins
Veins
Carry blood to the heart
• capillaries join up to form veins
• blood is at a Lower pressure in the veins so the walls aren’t as thick as arteries
• bigger lumen to help the blood flow despite lower pressure
• have valves to help keep blood flowing In The right direction
How can the arteries carry blood under pressure
- The heart pumps blood at a high pressure so the artery walls are strong and elastic
- the walls are thick compared to the size of the hole down the middle ( the lumen)
- they contain this layer of muscle to make them strong and elastic fibres to allow them to stretch and spring back
Calculate the race of blood flow
Rate of blood flow = volume of blood / number of minutes
What is the job of the red blood cell
To carry oxygen from the lungs to all the cells in the body
What is the structure of the red blood cell
- Is a shape of Biconcave disc which gives a large surface area for absorbing oxygen
- no nucleus allowing more room for oxygen
- Contains haemoglobin (red pigment)
What does haemoglobin(RBCs) do in the lungs
In the lungs haemoglobin binds oxygen to become oxyhaemoglobin
What does haemoglobin(RBCs) do in body tissues
The reverse of what happens in the lungs oxyhemoglobin splits into haemoglobin and oxygen to release oxygen to the cells
How do white blood cells defend against infection
- some change their shape to consume the pathogen the process is called phagocytosis
- others produce antibodies to fight microorganisms as well as antitoxins to neutralise any toxins produced by the microorganisms (pathogens)
- they do have a nucleus
What do platelets do
Clot blood at a wound Stop microorganisms getting in Lack of platelets e can cause excessive bleeding and bruising Small fragments of cells No nucleus
What does plasma do
Carries everything RBCs ,WBCs Glucose and amino acids CO2 urea Hormones proteins Antibodies and antitoxins
What is coronary heart disease
Is when arteries that supply the blood to the muscle of the heart get blocked by layers of fatty material building up causing arteries to become narrow so blood flow is restricted and there’s a lack of oxygen to the heart
What are stents
They are tubes inserted inside arteries to keep them open making sure blood can pass through to the heart muscle keeping the persons heart beating
What do stents do
They lower the risk of a heart attack in people with coronary heart disease
They are effective for a long time and the receiver from surgery is quick
Risk of stents
- Risk of complications during the operation and a risk of infection from surgery
- risk of patients developing thrombosis-a blood clot near the stent
What is cholesterol and what happens when you have too much in your blood stream
- Is an essential lipid that your body produces and needs to function properly
- Cause fatty deposits to form inside arteries which can lead to coronary heart disease
How do stations reduce cholesterol in the blood
Are a drug that can reduce the amount of bad cholesterol ( LDL cholesterol)present in he bloodstream slowing down the rate of fatty deposits forming
Advantages of statins
• by reducing the bad cholesterol in the blood it reduces the risk of strokes , CHD and heart attacks
• reducing bad cholesterol can increase the amount of a beneficial type of cholesterol (HDL cholesterol)
Which can remove LDL cholesterol
• statins may also help prevent other diseases
Disadvantage of statins
- are a long term drug that must be taken regularly - risk of forgetting
- can cause negative side effects - headaches , kidney failure , liver damage and memory loss
- the effect is statins isn’t instant
What is an artificial heart
Mechanical devise that pumps blood for a person whose own heart has failed
What is artificial blood
Replaces the lost volume of blood to give the patient enough time to produce new blood cells or get a blood transfusion
What is a communicable disease caused by
Caused by bacteria, viruses, parasites and fungi
What can smoking do to your health
Cardiovascular disease
Lung disease
Lung cancer
It also damages the walls of arteries and the cells in the lining of the lungs
When pregnant it can cause health problems for the baby
What can obesity do to your health
Type 2 diabetes making you less sensitive or resistant to insulin meaning you struggle to control the concentration of glucose in the blood
What does drinking too much do to your health
Liver disease
Affects brain function by damaging the nerve cells in the breaks causing the brain to lose volume
What can too much UV exposure cause
Uv radiation increase the chance of skin cancer
How can viral infection affect your health
Some virus are shown to increase the chances of developing certain cancer e.g. hepatitis B and C can increase the risk of liver cancer
What are phloem tubes
Tubes made of columns of elongated living cells with small pores in the end walls to allow cell sap to flow through
What do phloem tubes do
A process called translocation where the tube transports food substances in both directions which was made in the leaves to the rest of the plant for immediate use or for storage
What are xylem tubes
Tubes made of dead cells joined end to end with no end walls between them and a hole down the middle
Strengthened by lignin
What do xylem tubes do
Transpiration stream which Carry’s water and mineral ions from the roots to the stem and leaves
What is transpiration and what causes it
- It’s the loss of water from the plant
- It’s caused by the evaporation and diffusion of water from a plants surface
- The evaporation Creates a shortage Of water in the leaf so more water is drawn up from the plant rejoint the xylem vessels to replace it
- More water is being drawn up from the roots and there’s constant transpiration steam of water through the plant
What is transpiration rate affected by
Light intensity
Temperature
Air flow
Humidity
How does light intensity affect the transpiration rate
- The brighter the light the greater the transpiration rate
- the darker it gets the stomata begins to close letting very little water out and photosynthesis can’t happen in the dark so they don’t need to be open to CO2 in
How does temperature affect the transpiration rate
The warmer it is the faster transportation happens as the water particles the more energy to evaporate and diffuse out of the stomata
How does air flow affect the transpiration rate
- The better the air flow around the leaf the greater transpiration rate as the water vapour is swept away maintaining a low concentration of water in the air outside of the leaf and the diffusion happens quickly
- If the flow is poor the water vapour surrounds the leaf and doesn’t move away meaning there’s high concentration of water particles so diffusion doesn’t work as quickly
How does humidity affect the transpiration rate
- The drier the air the faster transpiration happens
- And If its humid there is a lot of water so there’s not much of a difference between the inside and outside of the leaf and diffusion works fastest in high concentration to low concentration
Why do you find more stomata on the underside of the leaf
The lower surface is shaders and cooler to less water is lost through the stomata the the upper surface as the guard cells close more in darker places
What are guard cells adapted for
Gas exchange and controlling water loss in a leaf
