Organisation Flashcards
1
Q
What is an enzyme
A
- catalyst
- made from large proteins
2
Q
What is a catalyst
A
A substance which increases the speed of a reaction without being changed or uses up in the reaction
3
Q
Lock and key model explanation
A
Substrates temporarily bind to the active site of a specific enzyme, which leads to a chemical reaction and the formation of a product which is released
4
Q
How temperature affects enzymes
A
-higher temp, enzyme becomes denatured as active site changes
-optimum temp is when enzyme is most active
-lower temp, not enough energy
5
Q
How pH affects enzymes
A
- if too high or low, it interferes with the bonds and changes shape of active site and denatures enzyme
- optimum pH is where enzyme is most active
6
Q
Calculation for rate of reaction
A
Rate= 1000/time
7
Q
Amylase experiment
A
- Put drop of iodine solution into every well of a spotting tile
- Put beaker of water on top of tripod (with Bunsen Burner) and heat until 35Cº (use thermometer)
- Use syringe to add 1cm^3 of amylase solution and 1cm^3 of buffer solution of pH 5 in boiling tube. Put tube into water and wait 5 mins.
- Use different dyeing to ad 5cm^3 of starch solution to boiling tube
- Mix contents and start stop clock
- Record how long it takes for amylase to break down all of the starch
- Keep adding
- When iodine solution remains browny orange, starch is no longer present
8
Q
Enzymic reaction (starch)
A
Starch broken down by amylase into maltose
Made in salivary glands, pancreas, small intestine
9
Q
Enzymic reaction (protein)
A
Proteins broke down by protease into amino acids
Made in stomach pancreas and small intestine
10
Q
Enzymic reaction (lipids)
A
Lipid broken down by lipase into glycerol and fatty acids
Made in pancreas and small intestine
11
Q
Bile
A
- produce in liver, stored in gall bladder before it’s released into small intestine
- bile is alkaline and neutralises acidic conditions of the stomach. The enzymes in the small intestine work best in these alkaline conditions
- it emulsifies fat. Basically break fat into tiny droplets. This gives it a bigger surface area for the lipase to work on. Digestion is faster
12
Q
Salivary glands
A
These produce amylase enzyme in the saliva
13
Q
Stomach
A
- pummels food with muscular walls
- produces protease (also known as pepsin)
- produces HCl to kill bacteria and tube right pH for protease enzyme to work
14
Q
Liver
A
Where bile is produced. Bile neutralises stomach acid and emulsifies fats
15
Q
Gall bladder
A
Where bile is stored before it’s released into the small intestine
16
Q
Páncreas
A
Produces protease, amylase and lipase enzymes. It releases these into the small intestine
17
Q
Large intestine
A
where excess water is absorbed from the food
18
Q
Small intestine
A
Produces protease, amylase and lipase enzymes to complete digestion
This is also where the digested food is absorbed out of the digestive system into the blood
19
Q
Rectum
A
Where the faeces are stored before they exit through the anus
20
Q
How to prepare for food tests
A
- Get a piece of food an break it up using a pestle and mortar
- Transfer the ground up food to a beaker and add some distilled water
- Give the mixture a good stir with the glass rod to dissolve some of the food
- Filter the solution using a funnel lined with filter paper to get rid of the solid bits of food
21
Q
Benedict test for sugar
A
-if food sample contains reducing sugar, it will change from blue to brick red
- if not,it will remain blue
22
Q
Iodine test for starch
A
- if sample contains starch, it will change change from browny-orange to black or blue-black
- if not it will remain orange
23
Q
Biuret test for proteins
A
- if sample contains protein, solution will change from blu to purple
- if not it will remain blue
24
Q
Memorise parts of lungs
A
- intercostal muscle (on top of lungs)
- oesophagus
- trachea (wind pipe)
- bronchiole (medium)
- bronchus (big)
- alveoli (small)
- diaphragm (below everything)
- pleural membranes (underneath intercostal muscle, on top of lung)
- rib
- heart
25
What are alveoli
- the lungs contain millions of little air sacs- alveoli
- they’re surrounded by a network of blood capillaries
- this is where gas exchange happens
26
Explain gas exchange
- the blood passing next to the alveoli has just returned to the lungs from the rest of the body, so it contains lots of carbon dioxide and very little oxygen
- oxygen diffuses out of the alveolus into the blood
- carbon dioxide diffuses out of the blood into the alveolus to be breathed out
- when the blood reaches body cell, oxygen is released from red blood cells and diffuse into the body cells
- at the same time time, carbon dioxide diffuses out of the body cells into the blood, is then carried back o the lungs
27
What is the circulatory system
- made up of heart, blood vessels and blood
- humans have a double circulatory system
28
Explain double circulatory system
- in the first 1, the right ventricle pumps deoxygenated blood to the lungs to take in oxygen. The blood then returns to the heart
- in the 2nd one, the left ventricle pumps oxygenated blood around all the other organs of the body. The blood gives up it’s oxygen at the body cells and the deoxygenated blood returns to the heart to be pumped out to the lungs again
29
Explain how heart functions
- the heart is a pumping organ that keeps the blood flowing around the body. The walls of the heart are mostly made of muscle tissue.
- the heart has valves to make sure that blood flows in the right direction (prevent it from flowing backwards)
- this is how the heart uses it 4 chambers (right atrium, right ventricle, left atrium and left ventricle) to pump blood around
30
Explain cycle of heart
1. Blood flows into the two atria from the vena cava and pulmonary vein
2. The atria contract, pushing the blood into the ventricles
3. The ventricles contract, forcing the blood into the pulmonary artery aorta, and out of the heart
4. The blood then flows to the organs through arteries and returns through veins
5. The atria fill again and the whole cycle starts over
31
Does heart need own oxygenated blood
- the heart need its own supply of oxygenated
- coronary arteries branch off the aorta and surround the heart, making sure that it gets all the oxygenated blood it needs
32
Make sure to memorise parts of heart
RIGHT SIDE:
- in order flow of blood
- vena cava, right atrium, valve, right ventricle, valve, pulmonary artery
LEFT SIDE:
- in order of flow of blood
- pulmonary vein, left atrium, valve, left ventricle, valve, aorta
33
What is a pace maker
- resting heart rate is controlled by group of cells in right atrium that act as a pacemaker
- these cells produce a small electric impulse which spreads to the surrounding muscle cells, causing them to contract
34
What and why is an artificial pacemaker used
- often used to control heartbeat if the natural pacemaker cells don’t work properly.
- its a little device thats implanted under the skin and has a wire going to the heart
- it produces an electric current to keep the heart beating regularly
35
3 different type of blood vessel
1. Arteries
2. Capillaries
3. Veins
36
Arteries
- carries blood away from heart
- walls are strong and thick
- walls are thick compared to the lumen
- contain thick layers of muscle to keep them strong
- have elastic fibres to allow them to stretch and spring back
- carry blood under pressure
37
Capillaries
- arteries branch into capillaries
- really small
- thin wall- only one cell thick: increases rate of diffusion by decreasing distance
- very small lumen
- they carry blood really close to every cell in the body to exchange substances with them
- permeable walls so substances can diffuse in and out
- they supply food and oxygen ad take away waste like CO2
-
38
Lumen
Hole down the middle of blood vessels
39
Veins
- capillaries eventually join up to form veins
- the blood is at a lower pressure in the veins s the walls don’t need to be as thick artery
- bigger lumen than arteries to help blood flow
- have valves to help keep the blood flowing in the right direction
- elastic fibres an smooth muscle
40
Rate of blood flow
Rate of blood flow= volume of blood / number of minutes
41
Breaths per minute
= number of breaths / number of minutes
42
Job of red blood cells in circulatory system
- carry oxygen from the lungs to all cells in the body
- shape: biconcave disc - gives a large surface area for absorbing oxygen
- don’t have a nucleus, allows more room to carry oxygen
- continue red pigment called haemoglobin
43
Wha happens to haemoglobin in lungs
- binds to oxygen to become oxyhaemoglobin
44
What happens to oxyhaemoglobin in body tissues
- oxyhaemoglobin splits up into haemoglobin and oxygen to release oxygen to the cells
45
What do white blood cells do in circulatory system
- some can change shape and eat unwelcome microorganisms (phagocytosis)
- other produce antibodies to fight microorganisms as well as antitoxins
- they do have a nucleus
46
What do platelets do in circulatory system
- they’re small fragments of cells
- have no nucleus
- help the blood to clot at a wound: to stop all the blood pouring out and microorganisms getting in
- lack of platelets can cause excessive bleeding and bruising
47
What does plasma do in circulatory system
- pale straw coloured liquid that carries just about everything:
1. Red and white blood cels and platelets
2. Nutrients like glucose and amino acids
3. Carbon dioxide
4. Urea
5. Hormones
6. Proteins
7. Antibodies and antitoxins
48
What is coronary heart disease
- when the coronary arteries that supply the blood to the muscle of the heart get blocked by layers of fatty material building up
- this causes the arteries to narrow so blood flow is restricted and there’s a lack of oxygen to the heart muscle- this can result in a heart attack
49
What are stents
- tubes that are inserted inside arteries
- they keep them open, making sure blood can pas through to the heart muscles
- this keeps the person’s heart beating
50
Pros of stents
- they’re a way of lowering risk of a heart attack in people with coronary heat disease
- effective for a long time
- recovery time from the surgery is relatively quick
51
Cons of stents
- risk of complications during operation
- risk of infection from surgery
- risk of patient developing a blood clot near the stent, this is called thrombosis
52
What happens if you have too much ‘bad’ cholesterol in the bloodstream
- can cause fatty deposits to form inside arteries which can lead to CHD
53
What is a statin
- drugs that can reduce the amount of ‘bad’ cholesterol present in the bloodstream
- this slows down the rate of fatty deposits forming
54
Advantages of statins
- reduce amount o bad cholesterol, so reduce risk of strokes, CHD, and heart attacks
- can increase amount of beneficial type of cholesterol in blood stream. This can remove bad cholesterol from the blood
- some studies suggest that satin may also help prevent other diseases
55
Disadvantages of statins
- long term drug that must be taken regularly, risk that someone could forget to take them
- can cause negative side effects like headaches. Some can be serious like kidney failure, liver damage and memory loss
- the effect of statins isn’t instant, it takes time for the effect to kick in
56
What are artificial hearts
- mechanical devices that pump blood for a person whose own hart has failed
- usually only a temporary fix to keep the person alive until a donor heart can be found
57
Pros of an artificial heart
- less likely to be rejected by the bods immune system than a donor heart
- this is because they’re made from metals or plastics, so the body doesn’t recognise them as foreign and attack in the same way as it does with living tissue
58
Cons of artificial hearts
- surgery can lead t bleeding and infection
- don’t work as well s healthy natural ones
- parts of heart could wear out or electrical motor could fail
- blood don’t flow though artificial hearts as smoothly which can cause blood clots and lead to strokes
- patient has to take drugs to thin their blood and make sure this doesn’t happen, which can cause problems with bleeding if they’re hurt in an accident
59
How can severe valve damage be fixed
- ca be treated by replacing the valve
- replacement valves can come from humans or other mammals
- these are biological valves
- or they can be man made: mechanical valves
- replacing a valve is a much less dramatic procedure than a whole heart transplant but fitting artificial valves is still a major surgery and there ca still be problems with blood clots
60
What happens when valve is damaged
- can be damaged or weakened by heart attacks, infection or old age
- the damage may cause the valve tissue to stiffen, so it wont open properly
- or a valve may become leaky allowing blood to flow in both directions rather than just forwards
- this means blood doesn’t circulate as effectively as normal
61
What is artificial blood and why is it used
- a blood substitute which is used to replace the lost volume of blood
- its safe if no air bubbles get into blood
- can keep people alive even if they’re hurt in lose 2/3 of their blood cells
- this can give patient time to produce new blood cells if not, patient will need a blood transfusion
62
What is health
The state of physical and mental wellbeing
63
What are communicable diseases
- those that can spread from person to person or between animals and people
64
What is a non communicable disease
- those that cannot spread between people or between animals and people
- generally last for a long time and get worse slowly
65
What are risk factors
- things that are likely to increase the likelihood that a person will develop a certain disease during their lifetime
- usually an aspect of someone’s lifestyle or environment
66
Direct risk factors
- smoking: causes cardiovascular disease, lung disease, lung cancer. Damages walls of arteries and the cells in the lining of the lungs
- obesity: causes type 2 diabetes by making the bod less sensitive or resistant to insulin
- drinking too much alcohol: causes liver disease or brain function. Can damage the nerve cells in the brain causing the brain to lose volume
- smoking when pregnant: causes health problems for unborn baby. Drinking has similar effects
- cancer: can be caused by exposure to certain substances or radiation
67
Other health factors
- diet: provides body with everything’s it needs in the right amounts
- stress
- life situation: access to medication to treat or prevent illness (able to buy healthy food or condoms)
68
Human cost of non-communicable diseases
- lower quality of life
- can die: shorter life span
- affects loved ones
- weight loss
69
Financial cost of non-communicable diseases
- medication and treatment (if private)
- families have to move or adapt their home to help family member with disease
- if family member with disease gives up work or dies, the family’s income is reduced
- reduction in number of people able to work ca also affect a country economy
70
What is cancer caused by
- uncontrolled cell growth and division
- its a result of changes that occur to the cells and results in the formation o a tumour
71
What is benign tumour
- this is where the tumour grows until theres no room
- it isn’t cancerous
- isn’t normally dangerous
- the tumour stays in one place (usually within a membrane) rather than invading other tissues in the body
72
What is malignant tumour
- dangerous and can be fatal
- they’re cancers
- this is where the tumour grows and spreads to neighbouring healthy tissues
- cells can break off and spread to other parts of the body by travelling in the bloodstream
- the malignant cells then invade healthy tissues elsewhere in the body and form secondary tumours
73
Cancer risk factors
- smoking: lung cancer, can also be linked to mouth, bowel, stomach, and cervical cancer
- obesity: second biggest preventable cause of can’t after smoking
- UV exposure: skin cancer. Sunny climates or spending time outside have a higher risk. Sun bed usage higher risk
- viral infection: hepatitis b and c can increase the risk of of liver cancer
74
Risk factors associated to genes
- you can inherit faulty genes that make you more susceptible to cancer
75
Memorise formation of leaf
In order top to bottom:
- waxy cuticle
- epidermal tissue
- palisade mesophyll tissue
- spongy mesophyll tissue
- epidermal tissue
- air spaces, stomata, guard cells
76
Epidermal tissue
Covers whole plant
77
Waxy cuticles
Covers epidermal tissues which helps reduce water loss by evaporation
78
Upper epidermis
Transparent so that light can pass though it to the palisade layer
79
Lower epidermis
Full of little holes called stomata which let carbon dioxide diffuse directly into the leaf
80
Palisade mesophyll tissue
Has lots of chloroplasts as this is where mot photosynthesis happens. This man’s they’re near the top of the leaf where they can get the most light
81
Spongy mesophyll tissue
Contains big air spaces to increase rate of diffusion of gases
82
Meristem tissue
- found a the growing tips of shoots and roots
- able to differentiate into lots of different types of plant cell, allowing the plant to grow
83
Xylem and phloem cells
- form a network of vascular bundles which deliver and other nutrients to the entire leaf and take away the glucose produced by photosynthesis
- they also help support the structure
84
Phloem cells
- made of columns of elongated living cells
- small pores in the end walls to allow cell sap to flow through
- they transport food substances made in the leaves to the rest of the plant for immediate storage or use
- transport goes in both directions
- this is called translocation
85
Xylem cells
- 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
- carry water and mineral ions from the roots t the stem and leaves
- the movement of water from the rot, through the xylem and out of the leaves is called the transpiration stream
86
What is transpiration
- caused by evaporation and diffusion of water from plants surface
- mos of it happens at leaves
- this evaporation creates a slight shortage of water in the leaf
- so more water is drawn up from the rest of plant through the xylem vessels
- this means more water is drawn up from the roots and so theres a constant transpiration stream of water through the the plant
87
4 main things that affect rate of transpiration
- light intensity
- temperate
- air flow
- humidity
88
Light intensity effect on transpiration
- the brighter the light, the greater the transpiration rate
- stomata begin to close as it gets darker. Photosynthesis can’t happen in the dark so they don’t need to be open to let co2 in. When stomata are closed, very little water can escape
89
Temperature effect on transpiration
- the warmer it is, the faster transpiration happens
- when its warm, the water particles have more energy to evaporate and diffuse out of stomata
90
Air flow effect on transpiration
- the better air flow around the leaf, the greater the transpiration rate
- low airflow= high concentration of water particles around leaf so diffusion doesn’t happen as quickly
91
Humidity effect on transpiration
- the drier the air around leaf, the faster transpiration happens
- dry air= low concentration of water particles around leaf= fryer rate of diffusion
92
How to measure rate of transpiration
- measuring uptake of water using potometer
- you can assume water uptake is directly related to water loss by leaves
- set up apparatus, record starting position of the air bubble. Start stopwatch and record distance moved by the bubble per unit of time, keep conditions constant
93
Guard cell adaptations
- adapted to open and close stomata
- kidney shape
- when plant has lots of water the guard cells fill with it and go plump and turgid. This makes the stomata open o gases can be exchanged for photosynthesis
- when the plant is short of water, the guard cells become flaccid, making the stomata close. This helps stop vapour escaping
- thin outer walls and thickened inner walls make opening and closing work
- sensitive to light and close a night to save water without losing out on photosynthesis
- more stomata on underside on leaf than top so less ware is lost
- guard cells are therefore adapted for gas exchange and controlling water loss within leaf
