Organisation Flashcards
Cells
Basic building blocks of all living organisms
Tissue
Group of cells with a similar structure and function
Organs
aggregations of tissues performing specific functions
Organ systems
Organs organised which work together to form organisms
Differentiation
Process by which cells become specialised for a particular job
When does differentiation occur?
During the development of a multicellurlar organism
Muscular tissue
Contracts to move whatever its attached to
Glandular tissue
Makes/secretes chemicals like enxymes/hormones
Epithelial tissue
Covers some parts of the body eg inside of gut
What tissues is the stomach made of? What do they do?
- Muscular tis. - moves stomach wall to churn up the food
- Glandular tis. - makes digestive juices to digest
- Epithelial tis. - covers outside/inside stomach
Glands
Produce digestive juices
Stomach
- Pummels food with its muscular walls
- Produces protease enzyme, pepsin
- Produces HCL to kill bacteria + give right pH for protease to work in
Liver
Makes bile
Small intestine
- absorbs soluble food mol.
- Produces protease, lipase, amylase
Large intestine
Absorbs water from undigested food, leaving faeces
Probs with increasing temp for reactions
- Requires lots of energy
- Speeds up unwanted reactions
- Cells might get damaged if its too high
Enzymes
- Biological catalysts that speed up useful chemical reactions
- Large proteins made from chains of AA
- Folded into unique shapes
What is a catalyst?
substance which increases speed of reaction w/o being changed/used up in the reaction
Lock and Key Theory
- Simpler model
- Substrate fits perfectly into active site
Active site
Unique shape where specific and complementary substrates only bind to
2 theories about enzymes
- Lock and Theory model
- Induced fit model
Induced fit model
- More realistic
- Enzyme actually changes shape slightly asit binds to substrate
- AS is complementary to substrate
What happens if the temp gets too hot for enzymes?
- Denature
- bonds holding enzymes break
- changes shape of AS so substrate wont fit
What is the optimum temp and pH?
- Temp they work best at is 37C / up to 40
- Mostly 7 but pepsin is 2
2 factors that affect enzymes?
- Temp
- pH
How does pH affect enzymes?
- Interferes with bonds holding it together
- Changes shape if too low/high, denatures it
What do digestive enzymes do?
Break down big molecules (starch,proteins,fats) into smaller soluble molecules so they can pass easily through walls of digestive system, allwoing them to be absorbed into the blood
What is amylase? What does it do? Where is it made?
- Exmaple of a carbohydrase
- Breaks down starch into simple sugars (glucose,maltosE)
- Made in the salivary glands, small intestine, pancreas
What is protease? What does it do? Where is it made?
- Breaks down proteins into AA
- Made in Stomach, SI and pancreas
What is lipase? What does it do? Where is it made?
- Breaks down lipids (fats ) into 3 fatty acids and 1 glycerol molecule
- Found in the pancreas and SI
3 digestive enzymes
- Amylase
- Lipase
- Protease
What is bile? Where is it produced, stored,released?
- Produced in liver
- Stored in gall bladder
- Released into SI
What does bile do?
- HCl in stomach makes pH too acidic for enzymes in SI to work props
- Bile is alkaline so it neutralises making conditions alkaline
- Enzymes in SI work best in alkaline conditions
- Also emsulfies fats - breaks it down to tiny droplets - gives a bigger SA for lipase to work on - faster digestion
Emsulsification
Bile emsulfies fats - breaks it down to tiny droplets - gives a bigger SA for lipase to work on - faster digestion
Where are digestive enzymes produced in and by?
By specialised cells in glands and gut lining
Salivary glands
- Produce amylase in saliva
Rectum
Rectum
Stores faeces before it leaves through the anus
What does iodine test for?
Starch
What does Benedict’s solution test for?
Reducing Sugars
What does biuret test for?
Proteins
What does emulsion test for?
Lipids
What colour does iodine change from and to when starch is present?
Orange-brown to Blue-black
What colour does biuret change from and to when protein is present?
Blue to purple
What colour does emulsion change from and to when lipid is present?
No emulsion to white emulsion (milky white)
What colour does Benedict’s solution change from and to when reducing sugars are present?
Blue to green to yellow/orange to red
Blue means no reducing sugars. It ascends from green to red.
Explain the method for biuret.
- 2cm3 to test tube of food solution
- As 3cm3 biuret solution to sample, gently shake it to mix
- Yes protein = blue to purple
- None = blue
Explain the method for iodine.
- Make sure that the food solution is not solid but a bit liquid, grind it with a pestle and mortar
- Put 5cm3 into test tube
- Add a few drops of iodine onto test tube and shake gently
- Results will be shown - orange/brown to blue/black
Explain the method for Benedicts.
- Add 5cm3 food solution to test tube
- Prepare water bath with 75 water
- Add 10 drops of Benedicts solution to test tube with a pipette
- Put test tube in water bath using a test tube holder and leave there for 5 min
- Make sure tube is pointing away from you
Explain the method for emulsion.
- Add food solution into test tube
- Add few drops of distilled water
- Add a few drops of ethanol
- Shake the test tube gently
- Results would be shown.
How do you prepare a food sample to test for a particular molecule?
- Break peice of food using a pestle and mortar
- Transfer ground up food to a beaker, add some distilled water
- Give a stir to the misxture with a glass rod to dissolve some of the food
- Filter solution using a funnel with filter paper to get rid of solid food bits
What is the Sudan III test for?
For lipids
Method for Sudan III test
- Use unfiltered sample of food you’re testing
- Add 5cm to test tube
- Use pipette add 3 drops of Sudan III stain solution to test tube and gently shake
- If sample has lipids, mixture will separate out into 2 layers. Top layer = bright red.
- If no lipids, no separate red layer will form at the top
Results for Sudan III test
- Sudan III stain lipids stains lipids
- Lipids present = 2 layers, top bright red separate layer
- Not present - no bright red layer at the top
Thorax
- Top part of body
- Seoarared from lower part of the body by diaphragm
What are the lungs protected by and surrounded by?
- Protected by ribcage
- Surrounded by pleural membranes
Where does the air travel when you breathe in order?
- Trachea
- Splits into 2 tubes called bronchi (one is a bronchus) going to each lung
- Bronchi split progressively into smaller tubes called bronchioles
- Reach small bags called alveoli where gas exchange happens
Where does gas exchange happen?
Alveoli
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Process of gas exchange
- Blood passing next to alveoli contains lots of CO2 and little oxygen
- Oxygen diffuses out of alveolus due to its high conc into the blood (low conc)
- CO2 diffuses out of blood into alveolus (low conc)
- CO2 is breathed out
- Blood reaches body cells - oxygen released from RBC (high conc) which diffuses into body cells (low conc)
- CO2 diffuses out of body cells (high conc) into blood (low conc)
- Blood carried back to the lungs to gain oxygen
How to calc breathing rate in breaths per minute?
Breaths per minute = number of breaths / number of min
What is the cirulatory system made out of?
Blood, heart, blood vessels
What does double circulatory system mean?
2 circuits joined together
1. Right ventricle pumps deox blood to lungs to take in oxygen
2. Blood returns to the heart
3. 2nd one, left ventricle pumps oxyg. blood around all the organs
4. Blood gives up its oxygen at body cells and deoxy. blood returns to heart to be pumped out of lungs again
What does the heart do and what is it made of?
- Pumps blood around the body
- Walls made of muscular tissue
- Has valves
- 4 chambers - right/left atrium and right/left ventricle
What do the valves in the heart do?
Prevent blood flowing backwards
Process on how the heart + lungs oxygenates blood
- Vena cava
- Right atrium
- right ventricle
- pulmonary artery - deox blood to lungs
- blood is oxygenated
- leaves from pulmonary vein
- left atrium
- left ventricle
- aorta, to whole body
What does the pacemaker in the heart do? How?
Resting heart rate is controlled by a group of cells in the right atrium wall
1. Produce small electrical impulse which spreads to the surrounding muscle cells, causing them to contract
Where are the pacemaker cells located?
Right atrium wall
What is an artifical pacemaker used for and how?
- Used to control heartbeat if natrual pacemaker cells dont work props eg irregular heartbeat
- Device implanted under skin and has a wire going to the heart
- Produces electric current to keep heart beating regularly
Order of the blood flow in the heart and lungs
- Body tissues
- Vena cava
- Right atrium
- Right ventricle
- Pulmonary artery
- lungs
- pulmonary vein
- left atrium
- left ventricle
- aorta
- body tissues
What do veins and arteries do?
Veins - blood towards heart
Arteries - away from heart
What do the coronary arteries do?
Supply heart muscle w/ oxygen and nutrients
What do the arteries do?
Carry blood away from heart
What do the veins do?
Carry blood to heart
What do the capillaries do?
involved in the exchange of matierals at the tissues
Characteristics of the arteries?
- High pressure
- Walls are strong and elastic
- Walls thick compared to the size of the hole (lumen)
- Thick layers of muscle to make them strong
- Elastic fibres allow them to stretch and spring back
Characteristics of the capillaries
- Tiny
- Carry blood rlly close to every cell
- Permeable walls so substances can diffuse in/out
- Walls are one cell thick - increases rate of diffusion by decreasing the distance over which it occurs
- Supply food and oxygen, take away waste like co2
Characteristics of veins
- Lower pressire
- larger lumen than arteries to help blood flow
- valves - blood flowing in right direction
What do capillaries join up to form?
Veins
What do arteries branch into?
Capillaries
What is the middle hole called in a blood vessel?
Lumen
How to calc rate of blood flow?
volume of blood / number of minutes
Which nutrients are exchanged between the blood in the capillaries and the body tissues?
Glucose and amino acids
Order of blood flow in blood vessles from and to the heart
Heart, arteries, capillaries, veins, heart
Job of RBC and characteristics
- Carry oxygen
- Biconcave disc gives large sA for absorbing oxygen
- No nucleus - allows more oxygen to be carried
- Haemoglobin - red pigment
- In lungs - haemoglobin binds to oxygen to become oxyhaemoglibn
- In body tissues - oxyhaemoglobin splits up into haemoglobin and oxygen to release O2 to cells
Job of WBC and characteristics
- Nucleus
- Some change shape and do phagocytosis (engulf microogransms)
- Some produce antibodies and antitoxins (neutralise toxins from bacteria)
Job of platelets and characteristics
- Small fragments of cells
- No nucleus
- Help blood clot a wound - stops blood escaping and microorganisms entering
- Lack of this = excessive bleeding and brusing
What is plasma what does it have?
Liquid thats pale yellow
* RBC, WBC, Platelets
* Hormones, proteins
* Urea, co2
* Antibodies, antitoxins
* Glucose, amino acids
Role of plasma
To carry substances and cells around the body
What is coronary heart disease?
When coronary arteries that supply blood to the muscle of the heart get blocked by layers of fatty material building up
What does layers of fatty material building up in the coronary artery cause?
Arteries become narrow, so blood flow is restricted and theres a lack of oxygen to the heart muscle - results in a heart attack
2 ways to treat coronary heart disease + what do they do
- Stents - oushes artery wall out, squashing faaty deposit, makes more space in the centre of artery
- statins - drugs that reduce LDL cholestrol - slows down rate of fatty deposits forming
Pros of stents
- Long time
- Recovery time from surgery is quick
Cons of stents
- Risk of complications during operation eg heart attack
- Risk of infection in surgery
- Risk developing blood clot near stent - called thrombosis
What does LDL cause?
Bad cholestrol causes fatty deposits in arteries - leads to CHD
Pros of statins
- Reduces risk of strokes, CHD and heart attacks
- Increases good cholestrol HDL which removes LDL
- Can prevent other diseases
Cons of statins
- Side effects - serious sometimes like kidney failure
- Effect not instant, takes time for their effect
- Long-term drug must be taken regularly - risk to forget
What happens if a patient’s heart fails?
Heart transplant using donor organs from ppl who have recently died. Or an artifical heart if unavailbile
What are artificial hearts?
- Mechanical devices that pump blood whose heart has ailed.
- Temporary fix until donor heart found or to help person recover by allowing heart to heal/rest
- Sometimes used as a permanent fix - reduces need for donor
Pros of artifical hearts
- Less likely rejected by immune system than donor heart
- Cuz they;re metal/plastic so body doesnt recognise them as ‘foreign’ and attack
Cons of artificial heart
- Surgery - leads to bleeding/infection
- Dont work as well as healthy ones - electrical motor can fail, parts of heart can wear out
- Blood doesnt flow smoothly - blood clots - strokes
- Needs drugs to thin blood so it moves smoothly - can cause probs if they are bleeding
How can valves be damaged/weakened?
- old age
- infection
- heart attacks
2 types of valves
- Mechanical
- Biological
What happens if a valve is damaged?
- Can cause valve tissue to stiffen - not open prop
- Valve can become leaky - blood in both directions
- Means blood doesnt circulate effectively
What is artifical blood?
- Blood substitute - eg salt solution saline used to replace the lost volume of blood
- Safe
- Can keep ppl alive even if they have lost 2/3 of red blood cells
- Gives patient time to produce new blood cells
- If not, patient will need blood transfusion
What is health?
State of physical and mental wellbeing
What is disease?
Responsible for causing ill health
What are communicable diseases?
- Disease that can spread from person to person or between animals and people.
- Caused by bacteria. viruses, parasites, fungi
- Contagious/infectious
- Eg malaria, measles
What are non-communicable diseases?
- Cant spread
- Last a long time
- Get worse slowly
- Eg cancer, asthma, CHD
Who has an increased chance of suffering from communicable diseases and how?
- PPl with probs with immune system
- Body less likely to be able to defend itself against pathogen
What can cancer be triggered by give 2 examples?
- Triggered by infection by certain viruses
- Eginfection w/ some types of hepatitis virus -> long term infections in liver ->increased chance of developing liver cancer
- Infection with HPV can cause cervical cancer in women
What can trigger allergic reactions like skin rashes?
- Immune system reactions in body caused by a pathogen
- Can also cause symptoms of asthma to worsen
What can cause mental health issues?
- Suffering from severe physical health probs
- particulary if it has an impact on ability to carry out everyday activities or affects life expectancy
Factors that affect health
- Good, balanced diet
- Stress you are under
- Life situation - if you’re able to have easy access to medicines or buy healthy food
What are risk factors?
Things that can increase likelihood a person will get a disease
Often aspects of their lifestyle
Risk factors that are able to directly cuase a disease
- Smoking - cardiovascular disease, lung disease, lung cancer - damages walls of arteries and cells in lining of lungs
- Obesity - Type 2 diabetes - body less sensitive or resistant to insulin - struggles to control conc of glucose in blood
- Too much alcohol - liver disease - can affect brain fuction - damage nerve cells in brain - brain loses volume
- Smoking when preg - health probs for baby
- Cancer - exposure to certain substances or radiation - caused by carcinogens eg ionising radiation
Carcinogens
things that cause cancer
How can non-communicble diseases be costly?
- Cost for NHS to research and treating is huge
- Families may move or adapt home to help fam member with disease
- If fam member dies or gives up work, fams income reduced
- Reduction in number of ppl who work affect countrys economy
What is cancer?
The uncontrolled growth and division is a result of changes that occure to the cells and results in the formation of a tumour
2 types of tumours
- Benign
- Malignant
Benign
- Tumour grows till there is no room
- Stays in one place (within a membrane(
- Not dangerous
- Not cancerous
Malignant
- Tumour spreads and grows to neighbouring healthy tissues
- Cells break off and spread to other parts of body via blood
- Malignant cells invade and form secondary tumours
- Dangerous
- Cancers
Risk factors of cancer and which one?
- Smoking - lung cancer also mouth, bowel, stomach , cervical
- Obesity - bowel, liver, kidney - 2nd biggest preventable cause of cancer after smoking
- UV exposure - skin cancer - sunny climates and outside more, sunbeds
- Viral infection - Hepatitis B and C -> liver cancer - viruses can spread from US and sharing needles
How can genes be a risk factor for cancer?
- You can inherit faulty genes that makes you more susceptible
- Eg mutations in BRCA genes have been linked to an increased likelihood of developing breast and ovarian cancer
Where is the stomate located in the leaf?
Lower epidermis
Order of plat tissues from top
Upper epidermis
Palisade Mesophyll
Spongy mesophyll
lower epidermis
Why does the spongy mesohpyll have so many gaps?
so that the gas can easily diffuse thrtough to the next layer to palisade mesophyll
What is the palisade mesophyll?
Most of photosynthesis hapens here
Palisade cells with chloroplast
Upper epidermis
Transparents so sun can reach chloroplasts
How is water loss reduced in plants?
- Waxy cuticle on top - thin layer of lipids, waterproof
- Stomata open for as short as possible
What do gaurd cells?
Controls opening and closing of stomata
What happens to the gaurd cells when the plant is short of water?
- Gaurd cells lose water due to osmosis
- Flaccid - causes stomata to close
- Stomata conserves water vapour
What happens to the gaurd cells when the plant has lots of water?
- Gaurd cells are hydrated and are turgid
- Makes gap larger, allowing more co2 to diffuse through
What are gaurd cells sensitive to? How?
Light, they close at night
Why is most of the stomata on the underside of the leaf
Lower surfaces are more shaded, cooler, less evaporation and water loss
What is the meristem tissue
- Found at the growing tips of the roots and shoots
- has stem cells
What is translocation?
- transportation of sugars
what is transpiration
transportation of water
Where does translocation happen and how?
- In phloem
- contains elongated living cells with small pores in the end walls - allows** sap to flow** through
- Transport goes in** both** directions
- transports food substances made in leaves to rest of plant for immediate use or storage
Where does transpiration happen and how?
- In xylem
- made of** dead cells** with **no walls **between them
- strengthed with a material called lignin
- carry water and mineral ions from roots to stem and leaves
- transpiration stream
What is the transpiration stream?
- Transpiration caused by evaporation from leaves
- evaporation creates slight shortage of water in leaf so more is frawn up from the rest of the plant through the xylem vessels to replace it
- Means more water is drawn up from the roots so there is a **constant transpiration stream **
4 factors that affect transpiraion rate
- Light intensity
- Temp
- Humidity
- Air flow
How does light intensity affect transp
- brighter - higher
How does temperature affect transp.
- warmer - faster
- when warm , particles have more energy to evaporate and diffuse out of stomata
How does air flow affect transp.
- stronger - greater
- if air flow is poor, water vapour surrounds leaf and doesnt move
- means high conc outside, so slower diffusion
- good air flow = swept away, mainitng low conc of wter outside = faster diffusion
How does humidity affect transp.
- drier air = faster trans.
- humid air = has lots of water, not much of a diff between outside and inside
- Diffusion fast if there is a high conc in one place and low conc in other
What does xylem transport?
WATER AND DISSOLVED MINERAL IONS
Explain how the human lungs are adapted for efficient exchange of gases
by diffusion.
- many alveoli = provide larger sa:v
- thin alveoli walls - short diffusion path
- lungs are ventilated - to bring in o2 + maintains conc gradient
- good blood supply = maintain conc gradient
What factors should be kept the same in a study?
- age
- gender
- BMI
- smoking habits
- diet
- medication
- family history
- ethnicity
- fitness lvels
- area of UK they live in
Why dont enzymes work at low temperatures?
- molecules have low kinetic energy
- so fewer collisions
