B2 - Organisation Flashcards
(164 cards)
1
Q
Large multicellular organisms are made up of what?
A
Organ systems
2
Q
Talk about these types of tissues
a) Muscular tissue
b) Glandular tissue
c) Epithelial tissue
A
a) it contracts (shortens) to move whatever it’s attached to
b) it makes and secretes chemicals like enzymes and hormones
c) it covers some parts of the body, such as the inside of the gut
d) Tissues you cry into, ha
e) Tissue, by Imitiaz Dharkah
3
Q
What is the definition of a tissue?
A
A group of similar cells that work together to carry out a particular function
4
Q
What tissues is the stomach made of and why?
A
Muscular tissue - which moves the stomach and churns up the food
Glandular tissue - makes digestive juices to digest food
Epithelial tissue - which covers the outside and inside of the stomach
5
Q
What is an organ?
A
A group of different tissues that work together to perform a certain function
6
Q
What is an organ system?
A
A group of organs working together to perform a particular function
7
Q
What organs is the digestive system made of?
A
Glands (pancreas & salivary glands for example) - produce digestive juices to digest food
The stomach & small intestine - digest food
Liver - produces bile
Small intestine - absorbs soluble food molecules
Large intestine - which absorbs water from undigested food, leaving faeces (ha, poo)
8
Q
What are organisms?
A
Organ systems working together
9
Q
What is the function of the digestive system?
A
To break down and absorb food
10
Q
Chemical reactions are what make us work, but what makes them work?
A
Enzymes
11
Q
What are enzymes?
A
Catalysts produced by living things - biological catalysts
A catalyst is a substance which increases the speed of a reaction by lowering the activation energy, without being changed or used up in the reaction
12
Q
If increasing the temperature can increase the rate of reactions anywhere including in the body, why does our body use enzymes instead of focusing on being warm?
A
Because it would increase the rates of reactions of unwanted reactions too
Also, there’s a limit to how far you can raise the temperature inside a living creature before its cells start getting damaged
Using enzymes mean that they only can speed up the useful reactions that our bodies want
13
Q
What are enzymes made of?
A
Large proteins, which are made from long chains of amino acids
These chains are folded into unique shapes, which enzymes need to do their jobs
14
Q
Why do enzymes have special shapes?
A
So they can catalyse reactions - its substrate has a specific shape, so the enzyme needs to match it by having a specific shape too
15
Q
What’s a substrate?
A
The substance an enzyme acts upon (protein, carbohydrates, lipids, etc)
16
Q
Talk about the lock and key mechanism
A
Enzymes have an active site, which the only substrate it breaks down fits into
If the substrate doesn’t fit into the active site, the reaction won’t be catalysed
Once the correct substrate binds to the active site of the enzyme, it speeds up the reaction of the substrate into becoming its products
17
Q
What is the induced fit model of enzyme action?
A
Because in reality the lock and key mechanism doesn’t completely work - the active site changes shape a little as the substrate binds it to get a tighter fit
18
Q
What happens if enzymes don’t have the right temperature and pH?
A
Too low temp - the reaction is slower than it could be
Too high temp - the active site denatures (some bonds holding the enzyme together break), so the substrate can no longer fit into the active site, so the reaction can’t be catalysed
Too extreme pH - the active site denatures
19
Q
What is the optimum pH and temperature of an enzyme?
A
pH optimum depends on the enzyme, but temperature is 37 degrees
Often the pH is 7, but for pepsin (breaks down proteins in the stomach), it works best at pH 2 because teh stomach is VERY acidic
20
Q
The rate of reaction of the enzyme is affected by what?
A
pH
Temperature
Probably more but who cares
21
Q
How can you investigate the effect of pH on Enzyme activity? - rearrange these instructions of the practical
1) Next, use a different syringe to add 5 cm cubed of a starch solution to the boiling tube
2) Repeat the whole experiment with buffer solutions of different pH values to see how pH affects the time taken for the starch to be broken down
3) Use a syringe to add 1 cm cubed of amylase solution and 1 cm cubed of buffer solution with a pH of 5 to a boiling tube. Using the test tube holders, put the tube into the beaker of water and wait for 5 minutes
4) Put a drop of iodine solution into every well of a spotting tile, then leave to use later
5) Remember to control any variables each time (e.g. concentration and volume of amylase solution to make it a fair test
6) Use continuous sampling to record how long it takes for the amylase to break down all of the starch. To do this, use a dropping pipette to take a fresh sample from the boiling tube every 30 seconds, and put a drop into a new well. When the iodine solution remains browny-orange, starch is no longer present, and the reaction is complete
7) Immediately mix the contents of the boiling tube and start a stop watch
8) Place a Bunsen burner on a heat-proof mat, and a tripod and gauze over the Bunsen burner. Put a beaker of water on top of the tripod and heat the water until it is 35 Celsius (use a thermometer to measure the temperature) Try to keep the temperature of the water constant through the experiment, as it is a control variable
A
4) Put a drop of iodine solution into every well of a spotting tile, then leave to use later
8) Place a Bunsen burner on a heat-proof mat, and a tripod and gauze over the Bunsen burner. Put a beaker of water on top of the tripod and heat the water until it is 35 Celsius (use a thermometer to measure the temperature) Try to keep the temperature of the water constant through the experiment, as it is a control variable
3) Use a syringe to add 1 cm cubed of amylase solution and 1 cm cubed of buffer solution with a pH of 5 to a boiling tube. Using the test tube holders, put the tube into the beaker of water and wait for 5 minutes
1) Next, use a different syringe to add 5 cm cubed of a starch solution to the boiling tube
7) Immediately mix the contents of the boiling tube and start a stop watch
6) Use continuous sampling to record how long it takes for the amylase to break down all of the starch. To do this, use a dropping pipette to take a fresh sample from the boiling tube every 30 seconds, and put a drop into a new well. When the iodine solution remains browny-orange, starch is no longer present, and the reaction is complete
2) Repeat the whole experiment with buffer solutions of different pH values to see how pH affects the time taken for the starch to be broken down
5) Remember to control any variables each time (e.g. concentration and volume of amylase solution to make it a fair test
22
Q
What solution is used to alter the pH of a solution?
A
A buffer solution
You can then use a pH meter to accurately measure the pH of the solutions
23
Q
How do you calculate the rate of reaction when:
a) doing the experiment on investigating the effect of pH on enzyme activity
b) Normally, by measuring how much something changes over time
A
a) 1000 ÷ time - units = s to the power of -1
b) Change in product ÷ time
24
Q
At pH 6, the time taken for amylase to break down all of the starch in a solution was 90 seconds. So what is the rate of reaction?
A
1000 ÷ 90 = 11 s^-1 (to 2 significant figures)
25
The enzyme catalase catalyses the breakdown of hydrogen peroxide into water and oxygen. During an investigation into the activity of catalase, 24 cm cubed of oxygen was released in 50 seconds. Calculate the rate of reaction, write your answer in cm^3 s^-1
Amount of product formed = change = 24 cm cubed
Rate of reaction = change ÷ time
24 ÷ 50 = 0.48 cm cubed s^-1
26
Enzymes used in digestion are produced by cells and then...
Released into the gut to mix with food
27
What do digestive enzymes break down?
Big molecules - starch, proteins and fats
28
Why do digestive enzymes have to break down big molecules?
Because they are too big to to pass through the walls of the digestive system. Then, the small, soluble molecules can pass easily through the walls of the digestive system, allowing them to be absorbed into the bloodstream then taken somewhere they're needed
29
What does each enzyme break down, and into what?
a) Carbohydrases (like amylase)
b) Proteases (like pepsin in the stomach)
c) Lipases
a) Converts carbohydrates (starch is a carbohydrate) into simple sugars (e.g. glucose, maltose, dextrins)
b) Converts proteins into amino acids
c) Converts lipids (fats and oils) into glycerol and fatty acids
30
Where do each of the enzymes work?
Carbohydrase works in 3 places - the salivary glands (mouth), the pancreas, the small intestine
Protease works in 3 places - the stomach (pepsin there), the pancreas, the small intestine
Lipase works in 2 places - the pancreas, the small intestine
31
What does the body do with the products of digestion - simple sugars, amino acids, glycerol, fatty acids, etc
It makes good use of them - they can be used to make new carbohydrates, proteins and lipids. Some of the glucose (a sugar) that's made is used in respiration
32
What does bile do?
It neutralises the stomach acid and emulsifies fats (so it breaks the fat into tiny droplets, giving a bigger surface area of fat for the lipase to work on - speeds up digestion).
The hydrochloric acid in the stomach makes the pH too acidic for enzymes in the small intestine. As bile is alkaline, it neutralises the acid and makes conditions alkaline, so the enzymes there can work as they work best in these alkaline conditions
33
Bile is created in the gall bladder and stored in the liver before it's released into the small intestine. True or false?
False - it is created in the liver, stored in the gall bladder before it's released into the small intestine
34
What are enzymes?
Biological catalysts (that speed up the rate of reaction, but aren't used or depleted during the reactions)
35
Where are enzymes produced?
In the glands and in the gut lining
36
Talk through these different features of the digestive system, in the right order
1) Rectum
2) Salivary glands
3) Stomach
4) Gullet
5) Large intestine
6) Gall bladder
7) Pancreas
8) Liver
9) Small intestine
(number) means food doesn't actually go there, but it's still relevant
2) Salivary glands - produce amylase in the saliva
4) Gullet, or oesophagus - a pipe that channels the food into the...
3) Stomach - 1, pummels food with it's muscular walls. 2, produces the protease enzyme pepsin. 3, it produces hydrochloric acid to kill bacteria & for the optimum pH of protease
(8) Liver - where bile is produced, which neutralises stomach acid and emulsifies fats
(6) Gall bladder - where bile is stored before released into small intestine
(7) Pancreas - produces protease, amylase and lipase enzymes, which are released into the small intestine
9) Small intestine - 1, produces protease, amylase and lipase to complete digestion. 2, where digested food is absorbed out of digestive system into blood
5) Large intestine - where excess water is absorbed from the food
1) Rectum - where the faeces (mainly made up of indigestible food) are stored before "they bid you a fond farewell through the anus"
37
Give 2 reasons as to why the stomach produces hydrochloric acid
To kill bacteria
| To give the optimum pH for the protease enzyme pepsin (pH 2) in the stomach
38
What is the difference between the small intestine and the large intestine?
The small intestine produces protease, amylase and lipase to complete digestion. AND where digested food is absorbed out of digestive system into blood
The large intestine is where excess water is absorbed from the food
39
What is faeces?
Poo, ha. No, it's mainly made up of indigestible food
40
How do you prepare a food sample so that you can conduct a food test on it later?
1) Get a piece of food then break it up with a mortar and pestle
2) Transfer the ground up food to a beaker and add some distilled water
3) Give the mixture a stir with a glass rod to dissolve some of the food
4) Filter the solution using a funnel lined with filter paper to get rid of the solid bit of food
41
What must you do before testing a piece of food for sugars or starch or whatnot?
Create a food sample:
1) Get a piece of food then break it up with a mortar and pestle
2) Transfer the ground up food to a beaker and add some distilled water
3) Give the mixture a stir with a glass rod to dissolve some of the food
4) Filter the solution using a funnel lined with filter paper to get rid of the solid bit of food
42
What are these testing for and the colours for:
a) Benedict's solution
b) Sudan III stain solution
c) Iodine solution
d) Biuret solution
a) Sugars - goes from blue -- green, yellow or brick red (depending on how much sugar is present)
b) Lipids - goes from white -- a separate red layer on top
c) Starch - goes from browny-orange -- black or blue black
d) Proteins - goes from blue -- pink or purple
43
Which solution is used to test for and the colours:
a) Sugars
b) Lipids
c) Starch
d) Proteins
a) Benedict's solution - goes from blue -- green, yellow or brick red (depending on how much sugar is present)
b) Sudan III stain solution - goes from white -- a separate red layer on top
c) Iodine solution - goes from browny-orange -- black or blue black
d) Biuret solution - goes from blue -- pink or purple
44
What is the test for sugars?
To test for reducing sugars (doesn't detect non-reducing sugars, whatever that means)
1) Prepare a food sample and transfer 5cm^3 to a test tube
2) Prepare a water bath set to 75C
3) Add some BENEDICT'S solution to the test tube (about 10 drops) using a pipette
4) Place the test tube in the water bath using a test tube holder and leave it there for 5 minutes. Make sure the tube is pointing away from you
5) If the food sample contains a reducing sugar, the solution in the test tube will change from its natural blue colour to green, yellow or rick red, depending on how much sugar is in the food
45
What is the test for starch?
1) Make a food sample and transfer 5cm^3 of your sample to a test tube
2) Then add a few drops of IODINE solution and gently shake the test tube to mix the contents.
3) If the sample contains starch, the solution in the test tube will change from its natural browny-orange to black or blue-black
46
What is the test for proteins?
1) Prepare a food sample and transfer 2cm^3 of your sample to a test tube
2) Add 2cm^3 of BIURET solution to the sample and mix the contents of the tube by gently shaking it
3) If the food sample contains protein, the solution will change from blue to pink or purple
47
What is the test for lipids?
1) Prepare a food sample (but you don't need to filter it). Then transfer about 5cm^3 into a test tube
2) Use a pipette to add 3 drops of SUDAN III stain solution to the test tube and gently shake it
3) Sudan III stain solution stains lipids. So:
4) If the sample contains lipids, teh mixture will separate out into 2 layers, teh top layer being bright red. If no lipids are present, no separate layer will form
48
```
What type of food are these?
a) Biscuits
b) Pasta
c) Potatoes
d) Cheese
e) Meat
f) Bread
g) Cereal
h) Milk
i) Olive oil
j) Rice
k) Margarine
(Starch, lipids, proteins or sugars)
```
a) Sugars
b) Starch
c) Starch
d) Proteins
e) Proteins
f) Sugars
g) Sugars
h) Lipids
i) Lipids
j) Starch
k) Lipids
49
Which of the food tests:
a) Need to be shook?
b) Create 2 layers if it's present?
c) Needs to have the test tube pointed away from you, when left for around 5 minutes?
d) Need a food sample produced beforehand?
e) Need a food sample, but it doesn't need to be filtered?
f) Start blue?
g) Need a water bath?
a) Iodine test for starch, Biuret test for proteins, Sudan III test for lipids
b) Sudan III test for lipids
c) Benedict's test for sugars
d) All of them
e) Sudan III test for lipids
f) Benedict's test for sugars, Biuret test for proteins
g) Benedict's test for sugars
50
How do you spell the fancy test for proteins?
B I U R E T
51
Why do you need to get oxygen into your bloodstream?
To supply the cells for respiration
| You also need to get rid of carbon dioxide form your blood, which happens in the lungs when you breathe in and out
52
Where are the lungs? How is is separated from the other part of the body?
In the thorax - (the top part of the body)
| It is separated from the lower part of the body with the diapragm
53
Give a function of the ribcage
To protect the lungs
54
Where and what are pleural membranes?
They are thin layers which reduce friction between the chest walls and the lungs when breathing.
The 2 layers also have pleural fluid between them, which further reduces the friction
55
What helps reduce the friction between the lungs and the chest walls/ ribcage?
Pleural membranes (2 layers with pleural fluid between)
56
Talk through the lungs and pipes and gas exchange stuff
1) Trachea (wind pipe)
2) Splits into 2 tubes called Bronchi (to the 2 halves of the lungs)
3) Each broncus splits into Bronchioles
4) Finally end at small bags called alveoli, where gas exchange takes place
57
Where does gas exchange take place?
In the alveoli (in the lungs)
58
The trachea is where food gets taken into the stomach. True or false?
False - the trachea is where air gets taken to the lungs.
| The oesophagus is where food gets taken to the stomach
59
The alveoli has a good supply of what?
Blood - they are surrounded by a network of capillaries
60
How does gas exchange occur in the alveoli? Fill the blanks:
The blood passing in the ____________ next to the ______ has just returned to the lungs from the rest of the body, so it contains lots of ______ _______* and little ______. The latter diffuses out of the alveolus (____ concentration) into the _____ (___ concentration).
The other gas* diffuses out of the blood (____ concentration) into the alveolus (___ concentration) to be breathed ___
```
Capillaries
Alveoli
Carbon dioxide
Oxygen
High
Blood
Low
High
Low
Out
```
61
What happens when oxygenated blood reaches the body cells?
Oxygen is released, as the blood has a high concentration of oxygen but as the cells have a low concentration, so the oxygen diffuses into them
62
When on about breathing, what can you calculate?
The breathing rate per minute (number of breaths/ minutes)
63
What is the function of the circulatory system?
To carry food and oxygen to every cell in the body.
| As well as delivering, it also collects waste products and takes them to where they can be removed from the body
64
Why is the heart described as a double circulatory system?
Because it is 2 circuits joined together by the heart - one going to the lungs, one going to the rest of the body.
Because it passes through the heart twice before it does a complete cycle
65
What controls your resting heart rate?
A group of cells in the right atrium wall that act as a pacemaker.
These cells produce an electrical impulse which spreads to the surrounding muscle cells, causing them to contract
66
How does the heart get the oxygen it needs to respire?
There are coronary arteries that branch off the aorta and surround the heart, so it can get all the oxygen it needs
67
How does an artificial pacemaker help?
It is used to control the heartbeat if the natural pacemaker cells in the right atrium walls don't work properly (e.g. if the patient has an irregular heartbeat)
It is a little device implanted under the skin and has a wire going to the heart, which produces an electrical current to keep the heart beating
68
What parts if the circulatory system have valves? WHy?
The 4 chambers in the heart do, the veins do (as they flow with a low pressure
These are to prevent back flow, which is very dangerous
69
Which side of the heart transports deoxygenated blood?
The right side, because it comes from the rest of the body then goes to the lungs to be oxygenated
70
Talk about the properties of:
a) Arteries
b) Veins
c) Capillaries
a) high pressure (to get round body fast) so walls are strong with elastic fibres & smooth muscle for strength
Thick walls compared to inside (lumen)
b) low pressure, Thin walls, still elastic fibres and smooth muscle, Large lumen
Also valves to keep blood going forward & back to heart
c) TINY - 1 cell thick wall for easy diffusion - permeable
Very small lumen
Carry blood really close to every cell in the body, supply food & oxygen, take away waste like CO2
71
Arteries branch out to form ___, which branch back together to form veins
Capillaries
72
How does the fact that capillaries have 1 cell thick permeable walls help the rate of diffusion
It helps the rate of diffusion because it decreases the distance over which it occurs
73
How do you calculate the rate of blood flow?
volume of blood ÷ number of minutes
| ml ÷ min = ml/min
74
DID YOU KNOW, that the more red blood cells you have, the more oxygen you can take in. So people who live at high altitudes...
Produce more red blood cells to compensate for the lack of oxygen in the air
75
Give the job of the red blood cells
To carry oxygen from the lungs to all the cells in the body, through the circulatory system
76
What are some features of red blood cells?
They're shaped like a biconcave disc, which gives them a large surface area to absorb oxygen
They have no nucleus, giving them more room to carry oxygen
They contain a red pigment called haemoglobin, which in the lungs it binds to oxygen to form oxyhaemoglobin. In body tissues, the reverse occurs - oxyhaemoglobin splits up into haemoglobin and oxygen, to release oxygen into the cells
77
Red blood cells contain a red pigment called ___________, which in the _____ it binds to oxygen to form ___________. In ____ _______, the reverse occurs - ___________ splits up into __________ and oxygen, to release oxygen into cells
```
Haemoglobin
Lungs
Oxyhaemoglobin
Body tissues
Oxyhaemoglobin
Haemoglobin
```
78
What causes the red colour of red blood cells?
Haemoglobin - which is what oxygen binds to to form oxyhaemoglobin
79
What is the function of white blood cells?
They defend against infection - part of the immune system, but travel in the circulatory system
80
Blood is a tissue. True or false?
True
81
Give the 4 main parts of the blood and their function
Red blood cells - to carry oxygen
White blood cells - to defend against infection
Platelets - to help blood clot at wounds
Plasma - a pale straw-coloured liquid to carry everything in blood, including all the above
82
What types of things does plasma carry in the blood?
Red blood cells
White blood cells
Platelets
Nutrients - glucose, amino acids (which are soluble products from digestion which are absorbed from the gut and taken to the cells of the body)
Carbon dioxide from the organs to the lungs
Urea from the liver to the kidneys
Hormones
Proteins
Antibodies and antitoxins from white blood cells
83
What is the function of platelets?
To help clot the blood at a wound - both stopping all your blood pouring out and stopping microorganisms from getting in
They have no nucleus
84
What can a lack of platelets cause?
Excessive bleeding and bruising
85
Which components of the blood don't have a nucleus?
Red blood cells - for more room to carry oxygen
Platelets- for reasons the book doesn't say?
Plasma I guess technically as it is a pale straw-coloured liquid that carries all sorts of other stuff. But it might so never mention is
86
What is phagocytosis?
The process of white blood cells changing shape to engulfing microorganisms
87
What can white blood cells do?
Phagocytosis - where they change shape to engulf microorganisms
Produce antibodies to fight microorganisms by attaching themselves onto pathogens' antigens
Produce antitoxins to neutralise the toxins produced when bacteria multiplies
88
Give the advantages and disadvantages of statins (they are drugs that can reduce the amount of LDL (bad) cholesterol in the blood, which slows down the rate of fatty deposits forming)
+ Can reduce the risk of strokes, coronary heart disease and heart attacks
+ It can also increase the amount of HDL (good) cholesterol, which is beneficial as it helps remove LDL cholesterol from the blood
+ Some studies suggest it can help prevent some other diseases
- They are a long term drug that must be taken regularly, with the risk of forgetting to take them
- Negative side effects sometimes caused (such as headaches), but some serious ones (kidney failure, liver damage, memory loss)
- Not an instant effect, takes a long time to start working
89
What is cardiovascular disease?
A term used to describe diseases of the heart or blood vessels, e.g. coronary heart disease
90
How do stents tackle coronary heart disease?
```
They are tubes that are inserted inside arteries. They keep the arteries open, making sure that blood can pass through to the heart muscles
If successful (which it generally is) his will keep the person's heart beating, and they will live
```
91
What is coronary heart disease?
When the coronary arteries (going from aorta, surround heart to give it oxygen too) get blocked by layers of fatty material building up
This causes the arteries to become narrow, so blood flow is restricted and there's a lack of oxygen to the heart muscle
This can result in a heart attack
92
What are stents
They are a tube that is inserted inside arteries allowing blood to pass through an area that was blocked by fatty material
They are a way of lowering the risk of a heart attack in people with coronary heart disease
93
Give some advantages and disadvantages of stents
+ Lowers the risk of a heart attack in people with coronary heart disease
+ Effective for a long time
+ Recovery time of surgery is relatively quick
- Risk of complications during the operation (e.g. heart attack)
-Risk of infection form the surgery
- Risk of patients developing a blood clot near the stent - called thrombosis
94
What is thrombosis?
When a patient develops a blood clot near a stent
95
What is cholesterol?
An essential lipid that the body produces and needs to function properly
But too much LDL (bad) cholesterol can cause health problems, as it is a fatty material that can block the arteries
96
HDL is bad cholesterol. LDL is good cholesterol. True or false?
False - HDL is good cholesterol
| LDL is bad cholesterol
97
What can having too much LDL cholesterol in the blood cause?
Fatty deposits to form inside arteries, which can lead to coronary heart disease
HDL cholesterol and statins help reduce this
98
Why would a doctor it an artificial heart during a heart transplant if the patient has a heart failure, rather than from an organ donor who has recently died?
Donor organs might not be currently available
They might not be the best option
The patient may not have a match, so the new heart could be rejected by the body
99
What can an artificial heart do?
Dance. Ha no, if only. They are mechanical devices that can pump blood around the body for someone whose own heart has/ will fail. They are usually in only temporary, to keep them alive until a donor heart is found
100
Can the heart and lungs be transplanted?
Yep, at the same time I think, as it says "heart and lungs transplant if the lugs are also diseased"
101
Are artificial hearts temporary or permanent?
Both - normally they are temporary, kept only until a suitable donor heart is found
In some cases though, they are a permanent fix, which reduces the need for a donor heart
102
Give some advantages and disadvantages of artificial hearts
+ Less likely to be rejected by the bodies immune system than a donor heart, because they're made from metals and plastics, which the body don't recognise as foreign and attack it the same way it does with living tissue
+ Reduces the need of an organ donor
+ often safer than their current heart, and works when donor hearts aren't available
- Surgery can lead to bleeding and infection
- Don't work as well as natural healthy hearts - parts can wear out, or the motor can fail
- Blood doesn't flow through as smoothly, which can cause blood clots and lead to strokes
- For this, the patient has to take drugs to thin their blood, which can cause bleeding problems if they get injured in an accident
103
What parts of the circulatory system can be replaced (even if temporarily) by fake versions should cardiovascular diseases occur?
The heart, with an artificial heart (and donor hearts)
Heart valves, with biological or mechanical valves
Blood, with artificial blood to keep you alive in an emergency
104
How can the valves in the heart be damaged? What can this damage do?
Heart attacks, infection, age
May cause valves to stiffen, so it won't open properly
Or a valve may become leaky, allowing blood to flow in 2 directions rather than just forward. This means blood doesn't circulate as effectively as normal
105
Which procedure is more drastic: replacing a heart valve or a heart transplant?
Replacing a heart valve, but it is still serious as it is a major surgery still and can cause blood clots too
106
What are biological heart valves when used to replace faulty ones in an operation? What is the alternative
Ones that can be taken either from humans or other mammals (e.g. cows or pigs)
Or, man-made mechanical valves can be fitted, and as far as I'm aware, these aren't temporary like an articial heart normally is
107
What is always a risk of surgery?
Infection occurring
108
When is artificial blood used?
Only in an emergency - when someone loses a lot of blood (in an accident for example), the heart can still pump the remaining red blood cells around to get oxygen to their organs, as long as the volume of blood can be topped up
109
If someone loses a lot of blood in an accident, can the heart still pump?
Yes - the heart can still pump the remaining red blood cells around to get oxygen to their organs, as long as the volume of blood can be topped up (by artificial blood)
110
Fill the blanks:
Artificial blood is a blood ___________ (e.g. a salt solution "______"), which is used to replace the ____ ______ of blood. As long as no ___ _______ get into the blood, it's safe, and can keep people alive even if they lose _/_ of their red blood cells. This may give the patient enough time to _______ ___ blood cells. If not, the patient will need a _____ ___________
```
Substitute
Saline
Lost volume
Air bubbles
2/3
Produce new
Blood transfusion
```
111
Artificial blood can keep the patient alive, even if they have lost how much blood?
2/3 of their red blood cells
112
What is artificial blood often made from?
Saline - a salt solution
113
Why give a patient artificial blood?
To give them enough time to live, so then they may produce new blood cells
If not, they need a blood transfusion
114
Ideally, an artificial blood product would do what?
Replace the lost red blood cells, so there would be no need of a blood transfusion. (Scientists are currently working on this)
115
If the artificial blood doesn't solve the problem, what will the patient need?
A blood transfusion
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What is a danger of receiving artificial blood?
It is safe, unless air bubbles get into the blood (I think because then the heart wouldn't be able to pump as effectively, and the lack of pressure would slow down the rate of blood flow, which could mean some cells don't get oxygen in time, and die. BUT THAT IS A GUESS)
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What is the definition of health?
Health is the state of physical and mental well being. Diseases are often responsible for causing ill health
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What is a:
a) Communicable disease
b) Non-communicable disease
a) Those that can spread from person to person, or between animals and people. They can be caused by things like bacteria, viruses, parasites or fungi. Sometimes known as contagious or infectious diseases
b) Those that cannot spread between people or between animals and people. They generally last a long time and get worse slowly
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Give some examples of
a) Communicable diseases
b) Non-communicable disease
a) Measles, a cold, influenza (flu) and malaria
| b) Asthma, cancer, coronary heart disease and diabetes
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What can different types of diseases do?
Sometimes they can interact - this will cause other physical and mental health issues that don't immediately seem related. For example
People with immune system issues have an increased chance of suffering from communicable disease like the flu, because their body's less likely to be able to defend itself against pathogens
Some types of cancer can be triggered by certain viruses
Immune system reactions in the body caused by an infection of a pathogen can sometimes trigger allergic reactions (skin rashes, or worsen asthma)
Mental health issues like depression can be triggered from severe physical health problems
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Talk about what happens when certain types of diseases interact:
Problems with immune system & communicable diseases
People with immune system issues have an increased chance of suffering from communicable disease like the flu, because their body's less likely to be able to defend itself against pathogens
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Talk about what happens when certain types of diseases interact:
Certain viruses & cancer
Some types of cancer can be triggered by infection or certain viruses. For example, infection with some types of hepatitis virus can cause long-term infections in the liver, where the virus lives in the cells. This can lead to an increases chance of developing liver cancer.
Another example is infection with HPV (human papilloma virus), which can cause cervical cancer in women
123
Talk about what happens when certain types of diseases interact:
Immune system reactions caused by infections & allergies
Immune system reactions in the body caused by an infection of a pathogen can sometimes trigger allergic reactions (skin rashes, or worsen asthma symptoms for example)
124
Talk about what happens when certain types of diseases interact:
Mental health issues & severe physical health problems
Mental health issues like depression can be triggered from severe physical health problems, particularly if they have an impact on the individual's ability to carry out everyday activities, or if they affect the person's life expectancy
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What factors can affect your health?
If you have a good, balanced diet (providing the body with everything it needs, and in the right amounts) - a poor diet can affect physical and mental health
Stress - constantly under lots of stress can lead to health issues
Life situation - how easy access one has to medicine to treat illness, access to things that can prevent you from getting ill in the first place (able to buy healthy food, able to get contraceptives)
Hygiene
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What do risk factors do?
Increase the chance of getting a disease
They are linked to the likelihood that a person will develop certain diseases during their lifetime. THEY DON'T GUARANTEE THAT SOMEONE WILL GET THE DISEASE THOUGH
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What are often risk factors?
Aspects of a person's lifestyle (how much exercise they do)
Presence of certain substances in the environment (air pollution),
or substances in the body (asbestos fibres - a material used in buildings until it was realised the fibres could build up in your airways and cause diseases such as cancer in later life)
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Many non-communicable diseases are caused by what?
Several different risk factors interacting with each other rather than 1 factor alone
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What do your individual choices affect? (risk factor stuff)
The local incidence of disease
130
Fill the blanks:
Lifestyle factors can have different impacts _______, __________ and ________. For example, in _________ countries, non-communicable diseases are ____ common as people generally have higher income and can buy ___-___ food. Nationally, people from ________ areas are more likely to _____, have a ____ diet and not ________. This means that the incidence of cardiovascular disease, obesity and Type _ diabetes is ______ in those areas.
```
Locally, nationally and globally
Developed
More
High-fat
Deprived
Smoke
Poor
Exercise
2
Higher
```
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Some risk factors can cause disease directly. True or false?
True, for example smoking, obesity (supposedly\), drinking alcohol, most of these whilst pregnant, exposure to stuff like radiation
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What disease can the risk factor smoking cause?
Cardiovascular disease, lung disease and lung cancer.
| It damages the walls of arteries and the cells in the lining of the lungs
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What can the risk factor obesity cause?
Thought it can directly cause Type 2 diabetes, making the body less sensitive/ resistant to insulin, meaning that it struggles to control the concentration of glucose in the blood
134
What can the risk factor of drinking too much alcohol cause?
Causes liver disease. Can affect brain function too - it can damage the nerve cells in the brain, causing the brain to lose volume
135
What can cancer be directly caused by?
Exposure to certain substances or radiation. Things that cause cancer are known as carcinogens. Ionising radiation (e.g. from X-rays) is an example of a carcinogen
Also from smoking (lung cancer for example)
136
What is a carcinogen?
Things that cause cancer - ionising radiation (e.g. from X-rays) is an example of a carcinogen
137
Risk factors are identified by scientists looking for correlations in data, and correlation always = cause. True or false?
False - correlation doesn't always = cause. Some risk factors aren't capable of directly causing a disease.
For example a lack of exercise and a high fat diet are heavily linked to an increased chance of cardiovascular disease, but they can't cause the disease directly - it's the resulting high blood pressure and high LDL cholesterol levels that actually cause it
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What costs are there of non-communicable diseases?
Human cost - 10s of millions of people around the world die from them, with perhaps a lower quality of life or a shorter lifespan, which means they and their loved ones suffer
Financial cost - NHS costs to research and treat disease is huge, families may have to move or adapt their home to help a family member with the disease. Also, if the family member has to give up work or they die, the family's income will be reduced. A reduction in the number of people able to work will also damage the country's economy
139
What is cancer caused by (cell wise, not risk factor wise)
It is caused by an uncontrolled cell growth and division, which results in a tumour (though not all tumours are cancerous)
140
What types of tumours are there?
Benign tumours - Where a tumour grows until there's no more room. It stays in one place (usually within a membrane) rather than invading other tissues in the body. NOT NORMALLY DANGEROUS - NOT CANCEROUS
Malignant tumours - Where the tumour grows and spreads to neighbouring healthy tissues. Cells can break off and spread to other parts of the body through the bloodstream. The malignant cells then invade healthy tissues elsewhere in the body and form secondary tumours. DANGEROUS AND CAN BE FATAL - CANCEROUS
141
Talk about the cancerous type of tumour
Malignant tumours - Where the tumour grows and spreads to neighbouring healthy tissues. Cells can break off and spread to other parts of the body through the bloodstream. The malignant cells then invade healthy tissues elsewhere in the body and form secondary tumours. DANGEROUS AND CAN BE FATAL - CANCEROUS
142
Talk about the non-cancerous type of tumour
Benign tumours - Where a tumour grows until there's no more room. It stays in one place (usually within a membrane) rather than invading other tissues in the body. NOT NORMALLY DANGEROUS - NOT CANCEROUS
143
What risk factors can increase the chance of some cancers?
Smoking - linked to lung cancer, but also others like mouth, bowel, stomach and cervical cancer
Obesity - linked t bowel, liver and kidney cancer. 2nd biggest preventable cause of cancer after smoking
UV exposure - People often exposed to this from the Sun have an increased chance of developing skin cancer. People living in sunny climates & spend lots of time outside are at a higher risk. Using sun beds also puts you at higher risk WEAR SUN CREAM FOLKS
Viral infection - Some types are shown to increase the chances of developing certain types of cancer. E.g. hepatitis B and C viruses can increase the risk of developing liver cancer. This disease can be spread through unprotected sex or sharing needles
144
Risk factors can also be associated with genetics - how?
Sometimes, you can inherit faulty genes which make you more susceptible to cancer
For example, mutations (changes) in the BRCA genes have been linked to an increased likelihood of developing breast and ovarian cancer
145
Explain and reorder the layers of a leaf:
a) Spongy mesophyll tissue
b) Epidermal tissue
c) Xylem and phloem tissue
d) Palisade mesophyll tissue
e) Lower epidermis
b) This covers the whole plant. Covered in a waxy cuticle too which helps reduce water loss by evaporation.
Also, the upper epidermis is transparent so light can pass through to the palisade layer
d) Lots of chloroplasts, so the part where most photosynthesis occurs. Also, near top so can get most light
a) Contains big air spaces to allow gases to diffuse in and out of cells
c) They transport minerals & food (phloem) and water (xylem) around the plant, though the roots, stems and leaves) - more like tubes than layers honestly. They form a network of vascular bindles, which deliver water and nutrients to the entire leaf, and take away the glucose produced by photosynthesis there (also help support the structure)
e) At the very bottom of the leaf, containing lots of little holes called stomata, which lets CO2 diffuse directly into the leaf for photosynthesis. The opening and closing of stomata is controlled by guard cells in response to environmental conditions. The air spaces in the spngy mesophyll increase the rate of diffusion of gases
146
What does "mesophyll" mean?
Middle of a leaf
147
What is meristem tissue in a plant?
Found at the growing tips and shoots of roots & is able to differentiate into lots of different types of plant cell, allowing the plant to grow
148
Talk about the 1st layer of a leaf
Epidermis tissue - This covers the whole plant. Covered in a waxy cuticle too which helps reduce water loss by evaporation.
Also, the upper epidermis is transparent so light can pass through to the palisade layer
149
Talk about the 2nd layer of a leaf
Palisade Mesopyhll tissue - Lots of chloroplasts, so the part where most photosynthesis occurs. Also, near top so can get most light
150
Talk about the 3rd layer of a leaf
Spongy mesophyll - Contains big air spaces to allow gases to diffuse in and out of cells faster
151
Talk about the 4th and last layer of a leaf
Lower epidermis - At the very bottom of the leaf, containing lots of little holes called stomata, which lets CO2 diffuse directly into the leaf for photosynthesis. The opening and closing of stomata is controlled by guard cells in response to environmental conditions. The air spaces in the spngy mesophyll increase the rate of diffusion of gases
152
Talk about the xylem and phloem
They transport minerals & food (phloem) and water (xylem) around the plant, though the roots, stems and leaves) - more like tubes than layers honestly. They form a network of vascular bindles, which deliver water and nutrients to the entire leaf, and take away the glucose produced by photosynthesis there (also help support the structure)
153
Talk about the phloem tubes
They transport food -
Made of columns of elongated living cells with small pores in the end walls to allow cell sap to flow through
They transport food substances (mainly dissolved sugars, glucose) made in the leaves to the rest of plant for immediate use (e.g. in growing regions) or for storage
They transport in both directions
This process is called translocation
154
Talk about the xylem tubes
They take water up -
Made of dead cells joined end to end with no end walls between them and a hole down the middle. They're strengthened with a material called lignin
They carry water & mineral ions from the roots to the stems and leaves
The movement of water from the roots, through the xylem and out of the leaves is called the transpiration stream
155
What is lignin?
A material that strengthens the xylem
156
Which out of the xylem and phloem tubes does the process of:
a) Translocation
b) Transpiration stream
a) Phloem tubes - alive carrying food in both directions
| b) Xylem tubes - dead carrying water up
157
What is the definition of transpiration?
The loss of water from the plant
158
What is transpiration caused by?
The evaporation and diffusion of water from a plant's surface. Most transpiration occurs at the leaves
159
Talk about transpiration
Caused by the evaporation and diffusion of water from a plant's surface. Most transpiration occurs at the leaves
This evaporation creates a slight shortage of water in the leaf, and so more water is drawn up from the rest of the plant through the xylem vessels (only going up, process called transpiration stream) to replace it
This in turn means more water is drawn up from the roots, so there's a constant transpiration stream of water through the plant
160
Transpiration is just a side effect of what?
Of the way leaves are adapted for photosynthesis.
They have stomata in them so gases can be exchanged easily
Because there's more water inside the plant than in the air outside, the water escapes from the leaves through the stomata by diffusion
161
What are the 4 main things that affect the rate of transpiration?
Light intensity - brighter the light, greater transpiration rate
Temperature - the warmer it is, the faster transpiration occurs
Air flow - the better the air flow around a leaf (e.g. strong wind), the greater the transpiration rate. (If air flow around leaf is poor, water vapour surrounds leaf and doesn't move. So, high concentration of water particles outside the leaf as well as inside, so diffusion doesn't happen as quickly. If good air flow, water vapour swept away, so low concentration outside leaf, so diffusion can occur quickly, from high (inside) to low concentration (outside))
Humidity - the drier the air around the leaf, the faster transpiration occurs (Like air flow, if the air's humid, lot of water in it already, so not much of a concentration gradient, so slower diffusion)
162
How can you estimate the rate of transpiration?
By measuring the uptake of water by a plant. This is because you can assume the water uptake of a plant is directly related to the water loss by the leaves (transpiration)
Some weird experiment diagram thing, with stopwatch recording air bubble moving up water filled capillary tube (connected to plant) - as plant takes in water, air bubble moves towards it
163
How are guard cells adapted to open and close stomata?
They have a kidney (bean) shape which opens & closes the stomata in a leaf
When the plant has lots of water, the guard cells fill with it and go plump and turgid, making the stomata open so gases can be exchanged for photosynthesis
When the plant is short of water, the guard cells lose water and become flaccid, making the stomata close. This helps to stop too much water vapour escaping
Thin outer walls and thickened inner walls to make the opening & closing work
Also sensitive to light and close at night to save water for when photosynthesis can occur
Found more on undersides of leaves, as the lower side is shaded and cooler, so less water is lost through the stomata than if they were on the upper surface
ADAPTED FOR GAS EXCHANGE AND CONTROLLING WATER IN A LEAF
164
How do guard cells
a) open
b) close
a) When the plant has lots of water, the guard cells fill with it and go plump and turgid, making the stomata open so gases can be exchanged for photosynthesis
b) When the plant is short of water, the guard cells lose water and become flaccid, making the stomata close. This helps to stop too much water vapour escaping
