Organisation Flashcards
What is a tissue
a group of cells working together to complete a specific function
What is an organ
a group of tissues working together to complete a specific function
What is an organ system?
a group of organs working together to complete a specific function
What are the three main nutrients gained from foods?
- Carbohydrates
- proteins
- lipids (fats)
- all these are large molecules. They have to be digested as they can’t be absorbed into the blood stream
What is digestion?
The break down of large food molecules into smaller ones via digestion so it can be absorbed into the blood stream
What is the first stage of the digetive system?
- first food is chewed in the mouth
- amylase in the saliva begin to digest starch into smaller sugar molecules
- the saliva helps make the food into a bulas, so the food can pass down into the oesphagus
What is the second stage of the digestive system
- the oesphagus squeezes the food down the oesphagues into the stomach
- the food passes into the stomach. This is where the digestion of proteins begins. There is also HydroCloric acid in the stomach. This helps to break down the proteins.
- There is a churning action in the stomach that turns the food into a fluid, increasing surface area for enzymes to digest
What is the third stage of the digestive system
- the fluid passes into the digestive system.
- the pancreaus and liver release chemcials into the small intestine.
- the pancreus releases amylase, lipase and protease that continue digestion of starch and protein.
- the liver releases bile and speeds up the digestion of lipids as it neutrilises acid from the stomach.
What is the fourth stage to the digestive system
-the walls of the small intestine release protease and lipease to continue the breakdown of protein and lipids. as the food molecules are smaller, some are absorbed into the blood stream by active transport or diffusion
What is the fith stage of the digestive system
- the fluid makes its way through the large intestine, where the water is absorbed into the bloodstream
- feeces are released from the body
What are the products of the digestive system used for
- new carbohydrates
- new lipids
- new proteins
- glucose produced is used in respiration
What are enzymes?
-large protein molecules that speed up reactions
What is the active site
-This is where the substrate (molecule breaking down) locks on to
How is the substrate described to attach to the active site?
- like a lock and key
- only some elements are able to break down with the enzymes
What enzyme breaks down proteins?
-protease
What are proteins
-these are long chains of chemicals called ammino acids
What happens when protease breaks down the proteins
-the proteins are broken down into there induvidual acids where they are absobed into the blood stream
What happens to the structure of the proteins when they are absored into the bloodstream.
They are re structured to make human proteins - these are used for growth and repair
What is the structure of starch?
-chains of glucose molecules
What is the enzyme that breaks down carbohydrates?
-carbohydrases
what enzyme breakes down starch specifically
-amylase
What happens when carbohydrates are digested
-simple sugars are produced
Where is amylase found
- saliva
- pancreatic fluid
What is the structure of a lipid
one molecule of glycerol and three molecules of fatty acids
What are lipid molecules digested by?
-lipase
What product is formed when lipids are broken down?
- glycerol
- fatty acids
Where is lipase found?
- pancreatic fluid
- small intestine
Where is bile made and stored
- made in the liver
- stored in the gullbladder
What is the function of bile
- speed up the digestion of lipids
- neutrilise acids
how does bile speed up the digestion of lipids
- it converts small droplets of lipids into larger droplets
- it is said that it emulsifies
- it largly increases the surface area and increases the rate of lipid breakdown by lipase
How does bile neutrilise acids
- bile is very alkiline
- this neutrilises stomach acids creating alkiline conditions in the small intestine
- this increases the rate of digestion by lipase as the enzymes are ment for a more neutral Ph
What are enzymes made of?
Simple proteins
What happens to the activity of the enzyme as the tempreture increases?
- as the temp. inceases, the activity increases as they are moving and colliding more times a second - increases reaction
- the optimum tempreture is the best temp to have an enzyme at as they are most productive.
- as it goes past this, it rapidly decreases as the enzyme starts to become denatured
Where is the optimum tempreture for the enzyme
37 celcius
Why does the enzyme start to decrease in activity?
-beacuse the enzyme starts vibrating, changes shape and becomes denatured - the substrate can’t fit in
What effect does the Ph have on the enzymes
- if the enzymes are too acidic or too alkaline, it rapidly drops to 0 as it becomes de natured
- each enzyme has an optium ph - depending on where it is released and used.
Where are the products of digestion absorbed into the blood stream
in the small intestine thorugh the partially permeable membrane
How is the small intestiene adapted to absorb nutrients
- 5m long - large surface area
- covered with villi - massivly increase the surface area
- have microvilli
- high concentration gradient as there is a large amount of blood flow near villi
- villi have a thin membrane - short diffusion path
- if can’t be done by diffusion, active transport is used.
What type of circulatory system does the heart have?
- a double circulatory system
- heart to lungs to heart to organs to heart
What is the job of the heart
-pump blood round the body
How many chambers are there in the heart
4 chambers
What are the key features
- at the top is the left and right atrium (flipped)
- at the bottom is the left and right ventricle
- valves seperate atrium and ventricles
- four main blood vessles
descirbe each valve and what happens there
- The vena cave into the righ atrium
- the blood now passes from the heart to the lungs vis the pulmonary artery
- the newly oxygenated blood comes in from the pulmonary vein
- blood is then pumped around the body from the aorta
describe the blood flow in the heart
- blood comes in through pulmonary vein
- valve opens and lets blood come into the ventricle
- valve closes and ventricle contracts to push blood through aorta - this goes around the whole body.
- deoxygenated blood then comes from the vena cava
- this deoxygenated blood is pumped out the pulmonary artery and towards the lungs
Why does the left side of the heart have a thicker wall?
-this side contracts to push the blood away from the body
Where is the pacemaker located
- in the right atrium
- it controls heart rate
What is the job of the arteries
-cary large amount of blood to the body cells
how are arteries adapted
- thick walls - support the large amount of pressure
- contain elastic fibre - strech when the blood surges
What is the job of capilleries?
carry small amount of blood
What diffues to and from capilleries
- co2 diffues into the capilleries
- glucose and oxygen go to the blood.
- thin walls - short diffusion particles
Where do the veins take the blood
-back to the heart
How are veins adapted
- Thin veins - not a large blood pressure
- valves - if blood flows back, it stops the blood
What are the main parts of the blood
- blood plasma - liquid part
- white blood cells
- red blood cells
- platlets
What does the blood plasma carry?
red and white blood cells
- transports co2 to lungs
- transports digestion products (glucose)
- transports urea to kidney
What do red blood cells transport
- oxygen via hemoglobin
- adapted as they are bi-concaved disc - large surface area - carrys lots of oxyhaemoglobin
- no nucleus - have a large amount of haemoglobin
What do white blood cells do
- They form part of the immune system
- they have a nucleas - this has the jobs and functions they need to under go
What fo platelets do?
-They are tiny fragments and they help the blood to clott
What is the point in donaited blood?
- Used to replace blood during loss in injury
- given platelets to clott
- proteins to form antibodies
What can go wrong with blood transfusion
- Same blood type - may reject if not - critical
- infection - many diseases can travel
- low risk in UK
What are cardiovascular diseases?
- diseases of the heart and blood vessels
- non-communicable
- example - corany heart disease
What is Coranery heart diesase?
- build up of fatty substances in the coranary heart
- causes the artiries to narrow
- reduce the flow of blood- lack of oxygen and possible heart attack
What are treatments?
-statins - reduce cholestrol level - less fatty materials
however they can cause liver problems
-can use a stent - tube that is inserted to keep the blood open - will not treat the cause, fix the problem
Can any cardiovascular diseases concern the heart valves
- yes - sometimes these valves don’t fully open or they are leaky - this can make patients feel tired
- can be replaced by mechanical or by animals
What is heart faliure
- where the blood can not pump enough blood aroud the body
- is a cardio vascular issue
- they are given a donated heart
- however, lack of donated hearts, and take drugs to stop rejection
- can have a artificaial heart for short time
How is the alvioli adapted for gas exchange
- millions of alvioli
- very thin walls - small diffusion path
- large concentraion gradient
How does breathing increase the rate of diffusion?
- brings fresh oxygen
- takes away carbon dioxide
- high concentration gradient - increases diffusion
What is caner
uncontrolled growth and mitosis - when the genes can’t control when to stop mitosis
-produces a tumour
What are the two types of tumours
- benign
- maliligant
What is a benign tumour
- growth of abnormal cells in one area
- usually contained in a membrane and do no invade other parts of the body
What is a maliginant tumour
- invade neighbouring tissues and move into the bloodstreams
- can spread into the blood stram and spread to different parts of the body - form new tumours - secondary tumours
Why can we get cancer
- genertics
- breast and prostate
- lifestyles
- smoking
- exposed to differing elements
- radon - ionasing gas - damages DNA
What is a communicable disease?
- a disease that can spread and is infectious
- for example measels
How are communicable diseases spread?
-via pathogens
What are non-communicable disease?
- diseases that cannot be spread
- for example cancer
Define Health
-the state of mental and physical well being
What can ill health be caused by?
- communicable diseases
- non communicable diseases
- poor diet
- stress
- other dangerous life situations, like working with harmful chemicals
What is a defective immune system?
- an immune system which does not fucntion properly
- HIV positive means defective immune system
Are people with a defective immune system more likely to suffer from disease?
- yes as they can’t fight off any communicable diseases very easi;y
- for example TB can’t be fought off
How are diseases working together leathal?
- HIV can weaken immune system
- other disease can easily attack
- HPV - essentially harmless diseases
- causes cervical cancer in some women
How can a physical illness lead to a mental illness?
- find it difficult to move
- feel isolated and depressed
define epidemiology
-determineing the risk factors by studying a pattern of disease
Define causal mechanism
-how a link of lifestyle and diseases can cause the disease
How can a poor lifestyle cause a non-communicable disease
- name the disease
- name the lifestyle causing the diease
- cardiovascular diseases
- diet - high in fat and low in vegtables - builds cholestrol and fat. High in salt - high in blood suagr levels
- smoking increases chance
- no excersise increases chance
- Lung cancer
- smoking - smoke contains carcinogens
- liver cancer and memory loss
- drinking excessive amounts of alchol
- Type 2 diabetes
- obesity causes type 2
- this can be reached by excess alchool or poor diet
Name where the upper epidermis and lower epidermis is in the leaf
- top of leaf
- bottom of leaf
- they form epidermal tissue
What is the function of the epidermis?
-protects the surface of the leaf
What is the adaptaion of the upper epidermis
-transparent - allows light to pass to the potosyntesis cells
How is the lower epidermis adapted?
- has stomata so carbon dioxide can enter and allow oxygen to leave
- control the amount of water vapour lost
Where is the palisade mesophyll layer?
-under upper epidermis
How are the palisade mesophyll cells adapted?
- contains chloroplasts for photosynthesis
- has mitrochondria for energy
Where is the spongy mesophyll layer?
-under the palisade mesophyll
How is the spongy mesophyll adapted?
- has air spaces
- allows carbon dioxide to diffuse from stomata to paliside layer
- allows oxygen to diffuse to stomata from plaiside layer
Where are the xylem and phloem vessels located
-next to the spongy mesohpyll layer
What are the stages of the transpiration stream
- starts with evaporation of water from cells inside the leaf
- water vapour diffuses through the air spaces in spongy mesohpyll
- exits leaf via stomata
- water travels up xylem and goes to plaiside mesophyll layer
- water is then drawn into root hair cells and goes up the xylem
Why is the transpiration stream important
- brings water that is used in photosynthesis
- transports dissolved mineral ions, such as magnesium which is important
- cools down the leaf with the evaporation
What are the factors of rate of transpiration?
- higher temp - greater rate - evaportation is faster
- when in dry conditions - greater rate - evaporation is faster
- in wind conditions - greater - wind removes water vapour - allows more evaportation
- light intensity increases - greater rate - increases photosynthisis - allow co2 to enter and water vapour to leave
How to the gaurd cells regulate the rate of transpiration
- when they swell, they open the stomata
- they swell with high light intensity
- this allows the co2 to open
- under hot conditions, they do not swell
- stops water loss
- no photosynthesis
