Topic 2 - Organisation Flashcards
1
Q
What are tissues?
A
Tissues are groups of similar cells that act together to perform a specific function.
2
Q
What are organs?
A
Organs are a group of tissues that work together to perform a specific function.
3
Q
What is an organ system?
A
An organ system are groups of organs that work together to perform a specific function.
4
Q
What is in the digestive system?
A
- Glands
- Large Intestine
- Stomach
- Liver
- Small intestine
5
Q
What are the glands and what do they do?
A
The glands are the pancreas and salivary glands and they produce digestive juices.
6
Q
What does the large intestine do?
A
The large intestine absorbs water molecules from the remaining undigested food, producing faeces.
7
Q
What does the stomach do?
A
The stomach digests food.
8
Q
What does the liver do?
A
The liver produces bile.
9
Q
What does the small intestine do?
A
The small intestine digests food and absorbs soluble food molecules.
10
Q
What is an enzyme?`
A
An enzyme increases the speed of reactions - they are called biological catalysts.
11
Q
What is the active site?
A
The active site is if a reaction is trying to be sped up, the reacting chemical (substrate) must bind to the enzyme’s active site. The active site will only fit specific substrates.
12
Q
What is the lock and key explanation?
A
The active site is a lock and the substrate is like a key. There is only one enzyme for every substrate - one key for each lock
13
Q
What factors affect the rate (speed) of enzyme action?
A
- Temperature
- pH (measure of acidity)
14
Q
How does temperature affect the rate (speed) of enzyme action?
A
Increasing the temperature of a working enzyme increases the reacting activity. Enzymes have an optimum temperature. Once this temperature is reached, the activity decreases. Past this certain temperature, the active site changes shape, and the enzyme is denatured.
15
Q
What does it mean when an enzyme is denatured?
A
When an enzyme is denatured, the enzyme loses its catalytic activity.
16
Q
How does pH affects the rate (speed) of enzyme activity?
A
Enzymes have an optimum pH. If the pH changes away from the optimum pH, then the enzyme activity decreases. If the pH is too high or too low, then the enzyme is denatured and will not function.
17
Q
How do you calculate rate of reaction?
A
Calculating rate of reaction is like calculating the gradient of a line. y^2 - y^1 / x^2 - x^1. Change in mass / Change in time
18
Q
Where are digestive enzymes made and released?
A
Digestive enzymes are made by specialised cells in the glands and the lining of the gut. They are then secreted (released) out of the body cells and into the cavity of the digestive system.
19
Q
What are digestive enzymes used for and how?
A
They are used to breakdown large food molecules. The digestive enzymes catalyse (speed up) the breakdown of large, insoluble food molecules into smaller, soluble (can be dissolved) molecules that are then small enough to be absorbed into the bloodstream.
20
Q
What can digestive molecules be used to construct?
A
Digestive molecules can be used to construct new carbohydrates, proteins and lipids in the body.
21
Q
What can glucose produced by digestion be used for/
A
Glucose produced by digestion is used for respiration.
22
Q
What are the 3 main digestive enzymes?
A
The three main digestive enzymes are:
- Amylase
- Protease
- Lipase
23
Q
What does carbohydrase break down into sugars?
A
Carbohydrases break down carbohydrates into sugars.
24
Q
What is amylase, where is it produced, what is its purpose and where is its action sites?
A
Amylase is a type of carbohydrase. It is produced in the small intestine, the pancreas and the salivary glands. It breaks down starch into sugars (maltose mainly). Starch –> Maltose (+ other sugars). The action sites of amylase are the small intestine and the mouth.
25
What is protease, where is it produced, what is its purpose and where is its action sites?
Protease is a type of digestive enzyme that breaks down proteins into amino acids. It is produced in the small intestine, the pancreas and the stomach. Protein --> amino acids. The action sites of protease is the small intestine and stomach.
26
What is lipase, where is it produced and what is its purpose?
Lipase is a type of digestive enzyme that breaks down lipase into glycerol and fatty acids. It is produced in the small intestine and the pancreas. Lipid --> Glycerol + Fatty acids.
27
What is bile?
Bile is an alkaline substance that is stored in the gall bladder after having been produced in the liver.
28
What is emulsification?
Emulsification is a process where bile breaks up fats into tiny droplets. The droplets have a higher SA than the original fat drop. This increases the rate of the lipase-catalysed reactions that breaks fats down.
29
Why is bile important for optimal enzyme conditions?
Enzymes in the small intestine operate best in alkaline conditions. Bile neutralises acid from the stomach to stop these enzymes becoming denatured.
30
What are reagents and how do you test with certain reagents?
Reagents can be used to test for the presence of various food substances. Grind up the food and add distilled water to dissolve some of the food. Finally add the specific reagent and find out!
31
How do you test for sugars?
- Add Benedict's reagent and heat for about two minutes
- It will turn any of green, yellow or red if sugar is present.
- The colour depends on the concentration
32
How do you test for lipids?
- Add Sudan III
| - If lipids are present, a red-stained oil layer will float on the water surface
33
How do you test for starch?
- Add iodine solution
| - It will turn blue-black if starch is present
34
How do you test for proteins?
- Add Biuret solution
| - It will turn purple if proteins are present
35
How do blood move around the body?
Blood moves around the body in three different types of blood vessels.
36
What are the three different types of blood vessels?
Veins, capillaries and arteries.
37
What do arteries do?
Arteries transport blood away from the heart to the organs. They carry oxygenated (contains oxygens) blood (apart from the pulmonary artery).
38
How are arteries' structure adapted to perform their function?
The walls have elastic fibres, which allows them to stretch and spring back. The walls also have thick layers of muscle. This makes them strong and able to cope with the high pressure at which blood is pumped out by the heart.
39
What do capillaries do?
First of, arteries branch off into much smaller vessels that are capillaries. Waste products (like CO2) move out the cells and into the blood. Food and oxygen move out of the blood and into the cells. They have thin walls and pass very close to the body cells.
40
What do veins do?
Veins form when capillaries join up after passing through the body. They transport deoxygenated blood (apart from the pulmonary vein) from the organs back to the heart.
41
How are veins different to arteries?
Veins have thinner walls than arteries as the blood is at a lower pressure. Veins have a wider cross section than arteries - low pressure hinders blood flow - veins must have a wide cross section through which blood can flow to counteract this. Veins have valves to prevent the backflow of blood.
42
What does pulmonary mean?
Pulmonary means anything related to the lungs.
43
What is the pulmonary artery and the pulmonary vein's job?
The pulmonary vein transports oxygenated blood from the lungs to the heart. The pulmonary artery transports deoxygenated blood from the heart to the lungs.
44
What is the heart?
The heart is the muscular organ that pumps blood around the body.
45
What are the four chambers of the heart and what is strange about it?
The 4 chambers are the left and right atria and the left and right ventricles. From a normal viewpoint the right atria and ventricle are on the right side. Vice versa for the left atria and ventricle.
46
What does the heart contain other than the four chambers?
The heart also contains valves and a pacemaker.
47
What do valves do?
Valves prevent blood flowing backwards.
48
What is the pacemaker and where is it in the heart?
The pacemaker controls the pumping heart. The pacemaker is a group of cells in the right atrium.
49
What happens when a heart beats?
Blood enters the heart via the atria. Once the heart is filled with blood, the atria contract, forcing blood down into the ventricles below. When the ventricles contract, they force the blood to exit the heart.
50
What is the job of the vena cava?
The vena cava takes in deoxygenated blood from the body into the heart.
51
What is the job of the aorta?
The aorta takes oxygenated blood from the heart to the body.
52
What are the coronary arteries?
The coronary arteries supply the heart muscle with oxygenated blood.
53
What do the veins and arteries of the heart do?
The veins (pulmonary vein and vena cava) take blood in from the body to the heart. The arteries (aorta and pulmonary artery) takes blood from the heart to the body.
54
What is the first part of the double circulatory system?
Deoxygenated blood from the body enters into the right atrium of the heart. This deoxygenated blood is pumped out of the heart and towards the lungs by the right ventricle. At the lungs, deoxygenated blood exchanges carbon dioxide for oxygen, making the blood oxygenated.
55
What is the second part of the double circulatory system?
Oxygenated blood returns to the left atrium of the heart. This oxygenated blood is pumped out the heart and to the body by the left ventricle through the aorta. The oxygenated blood gives its oxygen to body cells in exchange for carbon dioxide. The blood becomes deoxygenated and returns to the heart.
56
In mammals where is blood oxygenated/
Blood is oxygenated at the lungs.
57
How does oxygen reach the blood through the lungs?
Air is breathed into the lungs through the trachea (windpipe). The trachea divides into two tubes called the bronchi. The bronchi divide to form bronchioles. The bronchioles divide until they end up in tiny sacs called alveoli.
58
How does gas exchange happen in the lungs?
Millions of alveoli are surrounded by a network of capillaries, allowing for oxygen and carbon dioxide to be exchanged between the blood in the capillaries and the air in the lungs by diffusion.
59
How is blood oxygenated in the lungs?
Deoxygenated blood arrives at the lungs from the heart via the pulmonary artery. The lungs oxygenate the blood before it returns through the pulmonary vein back to the heart.
60
How are alveoli adapted for exchanging substances?
- Alveoli have a large surface area
| - As they are surrounded by capillaries, alveoli has a rich oxygen supply and the distance for gases to diffuse is small
61
What is blood made up of?
Blood is made up of plasma.
62
What is in blood?
Red blood cells, white blood cells and platelets.
63
What do platelets have and do?
Platelets have no nucleus and they are responsible for triggering blood clotting at the sites of wounds.
64
What do red blood cells do?
Red blood cells transport oxygen from the lungs to all body cells.
65
What do white blood cells do?
White blood cells fight against infection.
66
What are the features of red blood cells?
- No nucleus
- Small
- Biconcave shape
- Have haemoglobin
67
Why is having no nucleus an adaptation for red blood cells?
Having no nucleus frees up more room for haemoglobin. This maximises the amount of oxygen that they can carry.
68
Why is the small size of a red blood cell an adaptation for red blood cells?
The small size of red blood cells means that they can pass through tiny capillaries.
69
Why is the shape of red blood cells an adaptation for red blood cells?
Red blood cells have dents on each side - this is a biconcave shape. This creates a large surface area and allows the rapid diffusion of oxygen.
70
Why is having haemoglobin an adaptation for red blood cells?
Haemoglobin is in red blood cells. It binds with oxygen in the lungs. Haemoglobin carries this oxygen around the blood before releasing it to the body cells to be used for respiration.
71
What are the features of white blood cells?
- Can change shape
| - Have a nucleus
72
Why is the ability to change shape an adaptation for white blood cells?
If they can change shape. They can squeeze through the walls of blood vessels into body tissues and to engulf harmful microorganisms.
73
What are the two types of disease?
Communicable - can be spread between organisms
| Non-communicable - can't be spread between organisms
74
How are allergies triggered?
Allergies can be triggered by an immune reaction to a pathogen (micro-organism that causes disease)
75
What happens if a disease suppresses the immune system?
It makes the person more likely to catch diseases.
76
What is a pathogen?
A pathogen is a micro-organism that causes disease.
77
Why do countries use sampling?
As every one in the country cannot be tested.
78
How does sampling work?
Say 100 people are tested for a disease. If 10 people are tested positive, the testers can use this data to predict that 10% of the country have the disease.
79
What are risk factors?
Risk factors are factors that increase the probability of developing a disease.
80
What are the two categories of risk factors?
Lifestyle and substances.
81
What is a risk factor for brain damage in babies?
If the pregnant woman drinks an excessive amount of alcohol.
82
What is a risk factor for liver and brain damage?
Drinking too much alcohol.
83
What are the risk factors for cardiovascular disease?
Having a poor diet, smoking and a lack of exercise.
84
What is a risk factor for Type 2 diabetes?
Obesity.
85
What is a risk factor for lung disease?
Smoking.
86
What is a risk factor for cancer?
Exposure to ionising radiation.
87
What is a risk factor for low birth weight of babies?
Smoking during pregnancy.
88
What is coronary heart disease and what happens during it?
Coronary heart disease is a non-communicable disease. The coronary arteries become narrower because of a build-up of fatty deposits. This reduces blood flow and leads of lack of oxygen to the heart.
89
What is heart valve disease?
Heart valve disease makes the heart valves faulty, either by leaking or being unable to fully open.
90
What happens during heart valve disease?
Leaky valves allow backflow of blood. This forces your heart to do more work to circulate the same volume of blood. This causes a strain on the heart. Also, valves that don't open fully obstructs blood flow. This leads to a greater force is required to force blood through the body. This also adds a strain to the heart.
91
How can faulty heart valves be fixed?
Animal or artificial valves are inserted. It is less drastic than a heart transplant, but it involves major surgery and problems with blood clots can happen.
92
What are benefits of artificial hearts?
Unlikely to be rejected by the patient's immune system, immunosuppressant drugs (prevent rejection) are not needed. They also provide the heart with rest to allow it to recover.
93
What are the drawbacks of artificial hearts?
They could lead to long and expensive stays in hospital. This can also cause blood clotting, which could lead to strokes.
94
What are statins?
Statins are drugs that can be taken to decrease blood cholesterol levels. They slow down the build up of fatty materials. They do have negative side effects.
95
What are stents?
Stents are inserted in order to keep coronary arteries open.
96
What are drawbacks of stents?
The stents causes irritation over time, so the artery can being to narrow again as scar tissue builds up. Drugs must be taken to prevent blood clotting of the stent.
97
What are the two common treatments for coronary heart disease?
Stents and statins.
98
What are the advantages and disadvantages for using drugs as treatment for heart disease?
Advantages - cheap to buy, don't require surgery
| Disadvantages - side effects, patient could forget to take them
99
What are the advantages and disadvantages for using mechanical devices as treatment for heart disease?
Advantages - used when a donor organ isn't available
| Disadvantages - require power supply, could wear out and needs replacing
100
What are the advantages and disadvantages for using transplants as treatment for heart disease?
Advantages - transplanted organs won't wear down and will function like the replaced organ
Disadvantages - requires a donor and immunosuppressant, increases the risk of patient developing another disease
101
What is cancer?
Cancer is a group of diseases, where changes in cells lead to uncontrolled growth and division of cells
102
What are the two tumours that result from cancer?
Benign or malignant.
103
What are malignant tumours?
Malignant tumours can invade neighbouring tissues and spread throughout the body in the blood, leading to the creation of more secondary tumours.
104
What are benign tumours?
Benign tumours stay in a specific part of the body, often within a membrane.
105
What is it called when a risk of cancer is inherited from your parents?
Genetics.
106
What are the plant organs?
Leaves, roots, stems and reproductive structures.
107
What are the 4 main things of leaves?
Stomata, epidermal tissue, palisade mesophyll and spongy mesophyll.
108
What is the stomata?
The stomata is found in the lower epidermis, these gaps facilitate the diffusion of gases in and out of the leaf, if they are open. When necessary, specialised guard cells are capable of closing these gaps - in hot weather to reduce water loss
109
What is the epidermal tissue?
The epidermal tissue covers the outer surface of leaves as well as the rest of the plant.
110
What is the palisade mesophyll?
The palisade mesophyll is a row of cells located below the upper epidermis. The cells are exposed to lots of sunlight. The cells have lots of chloroplasts to maximise energy created by photosynthesis.
111
What is the spongy mesophyll?
The spongy mesophyll contains many air spaces, which help with gas exchange throughout the leaf.
112
How does transpiration work?
Transpiration transports water and the minerals dissolved in it through the plant. Water moves in one direction only, from the roots to the leaves.
113
What is transpiration?
Transpiration is when water is lost through the leaves.
114
How do root hair cells help transpiration?
Root hair cells absorb water from the soil via osmosis. Mineral ions are taken up by active transport.
115
How do xylem vessels help transpiration?
After being absorbed by the root hair cells, the water and minerals are transported in xylem vessels up the stem and into the leaves.
116
What happens when the water reaches the leaves in transpiration?
The majority of water evaporates and the water vapour diffuses out through open stomata.
117
What are the factors affect the rate of transpiration?
Air flow, light intensity, humidity and temperature.
118
How does air flow affect the rate of transpiration?
Increased air flow carries water away from the plant's leaves, encouraging more water to evaporate. Increased air flow increases the rate of transpiration.
119
How does light intensity affect the rate of transpiration?
Increased light intensity makes water evaporate faster, which increases the rate of transpiration.
120
How does humidity affect the rate of transpiration?
Increased humidity increases the amount of water in the air. This makes it more difficult for more water to evaporate. Increasing humidity decreases the rate of transpiration.
121
How does temperature affect the rate of transpiration?
Increased temperature makes water evaporate faster, which increases the rate of transpiration.
122
How do you measure the rate of transpiration?
Potometer is set up. It has the plant and a reservoir next to it, with the ruler measuring how far the air bubble goes in the capillary tube which goes into a beaker. As water is lost through the plant's leaves, the air bubble moves. The speed of the bubble's movement shows the rate of water uptake.
123
When measuring the rate of transpiration with a potometer, why is the calculation only an estimate?
A small amount of the water taken up by the shoot is used in the leaves and is not transpired.
124
What is translocation?
Translocation is the process by which food produced in photosynthesis is transported from the leaves to the growing regions of plants and storage organs.
125
What is the main feature of translocation?
Phloem tubes: Translocation happens through them. Phloem tubes are made up of columns of elongated cells that have holes in the end walls. These holes allow cell sap to pass through the cells.
126
What is the other feature of translocation?
Translocation is bidirectional - movement is up and down the plant.
127
How are xylem cells adapted for transpiration?
Lignin in the cell wall strengthens and waterproofs the elongated cells. Xylem cells are dead, meaning that the tubes are hollow so their resistance to water flow is low. No end walls - this means that successive cells form a long tube for ease of transport.
128
How are root hair cells adapted to help for transpiration?
Long projections - they stick out from the cell and into the soil to increase the surface area over which water and minerals can be absorbed. Mitochondria - they have lots of it - ensures that there is enough energy for active transport of minerals up the stem.
129
What are guard cells?
Guard cells open and close the stomata.
130
What happens when the guard cells open and close the stomata
Closing - the guard cells lose water and return to a limp state
Opening - to open the stomata, lots of water is taken in, causing them to swell
131
What happens to the stomata if water is abundant (lots available)?
The plant can afford to lose water. The guard cells open the stomata to allow gases for photosynthesis to move freely in and out of the leaf.
132
What happens to the stomata if water is scarce (rare)?
The stomata is closed to prevent any water loss. This is achieved by guard cells returning to a limp state after they lose water.
133
What happens to the stomata if the time of day is night?
Stomata close because, in the absence of sunlight, carbon dioxide is not required for photosynthesis.
