Organisation Mock Flashcards
1
Q
How do cells specialise?
A
Through the process of differentiation
2
Q
What is a tissue?
A
A group of similar cells that work together to carry out a particular function
3
Q
What is an organ?
A
A group of different tissues that work together to perform a certain function
4
Q
What is an organ system?
A
A group of organs working together to perform a particular function
5
Q
Organ systems work together to make _________
A
Organisms
6
Q
What are enzymes?
A
Catalysts produced by living things - biological catalysts
7
Q
What do enzymes do?
A
They reduce the need for high temperatures and only speed up useful reactions
8
Q
Every enzyme has a _____ ____ with a ____ shape that fits onto the substance involved in the reaction
A
active site
unique
9
Q
What has to fit into the active site of the enzyme?
A
The substrate
10
Q
How many reactions does each enzyme usually catalyse?
A
One specific reaction
11
Q
Enzymes need
A
The right temperature
The right pH
12
Q
What is meant by an enzyme becoming denatured?
A
The shape of the active site changes so the substrate no longer fits the enzyme meaning it no longer works
13
Q
What happens to an enzyme if the temperature increases too much?
A
Some of the bonds holding the enzyme together breaks, changing the shape of the enzyme’s active site, meaning the substrate no longer fits - denatured
14
Q
What is meant by the optimum temperature of an enzyme?
A
The temperature enzymes work best at
15
Q
What happens if the pH is too high or too low?
A
The pH interferes with bonds holding the enzyme together, changing the shape of the enzyme’s active site, meaning the substrate no longer fits - denatured
16
Q
What do digestive enzymes do?
A
They break down big molecules (starch, proteins and fats) that are too big to pass through the walls of the digestive system, into smaller ones (sugars, amino acids, glycerol and fatty acids)
17
Q
Carbohydrase converts _______ into _______ ________
A
Carbohydrates
Simple sugars
18
Q
What is an example of a carbohydrase and what does it do?
A
Amylase
Breaks down starch
19
Q
What is carbohydrase produced by?
A
The salivary glands
The pancreas
The small intestine
20
Q
Protease converts _______ into _______
A
Proteins
Amino acids
21
Q
What is protease produced by?
A
The stomach
The pancreas
The small intestine
22
Q
Lipase converts _______ into _______ and ____ _____
A
Lipids
Glycerol
Fatty acids
23
Q
What is lipase produced by?
A
The pancreas
The small intestine
24
Q
Where is bile produced and stored?
A
It’s produced in the liver and stored in the gall-bladder
25
Why can't enzymes in the small intestine work properly in the stomach?
Because the hydrochloric acid in the stomach makes the pH too acidic
26
What does bile's alkaline(ness) do?
It neutralises the acid and makes the conditions alkaline - enzymes work best in alkaline conditions
27
How does bile make digestion faster?
It emulsifies fat, breaking the fat into tiny droplets, giving a bigger surface area of fat for the enzyme lipase to work on
28
What factors affect the rate of reactions?
```
Temperature
pH
Enzyme concentration
Substrate concentration
Surface area
Pressure
```
29
What is a limiting factor?
Something that prevents a reaction from occurring at optimum rate
30
What happens in the large intestine?
Where excess water is absorbed from food
31
What does the small intestine do?
It produces protease, amylase and lipase enzymes
| Soluble food is absorbed out of the small intestine into the blood
32
What does the pancreas do?
It produces protease, amylase and lipase enzymes that is then released into the small intestine
33
What does the salivary glands do?
It produces amylase enzymes in the saliva and moisturise food
34
What does the stomach do?
It mixes food and and pummels it with muscular walls
It produces the protease enzyme, pepsin
It produces hydrochloric acid to: kill bacteria and give the right pH for the protease enzyme to work
35
What does the liver do?
It produces bile and stores carbohydrates
36
What does the gall-bladder do?
It stores bile before it's released into the small intestine
37
Where is excess water is absorbed from the food?
In the large intestine
38
What do you use to test for sugars (glucose)?
Benedict's solution
39
What would happen to the solution when Benedict's solution is added, if sugar is present?
blue --> green --> yellow --> brick-red
40
What do you use to test for starch?
Iodine solution
41
What would happen to the solution when Iodine solution is added, if starch is present?
browny-orange --> bleach or blue/black
42
What is the Biuret Test used to test for?
To test for proteins
43
What would happen to the solution when Biuret Reagant is added, if proteins are present?
blue --> pink/purple
44
What is used to test for lipids?
Sudan III stain solutions
45
What does Sudan III do to lipids?
It stains them
46
What would happen to the solution when Sudan III is added, if lipids are present?
The mixture will separate into 2 layers
47
What part of the lungs does air split into?
From the trachea into the bronchi, into bronchioles, into alveoli
48
What is the alveoli surrounded by?
Network of blood capillaries
49
What diffuses between the alveoli and blood?
Oxygen diffuses out of the lungs into the blood
| CO2 diffuses out of the blood into the lungs to be breathed out
50
What diffuses between body cells and the blood?
CO2 diffuses out of the cells into the blood
| Oxygen diffuses out of the blood into the cells
51
What is the circulatory system made of?
The heart, blood vessels and blood
52
What is pumped out of the right ventricle and to where?
Deoxygenated blood to the lungs
53
What is pumped out of the left ventricle and to where?
Oxygenated blood to the organs of the body (not lungs)
54
Why does the heart have valves?
To make sure that blood flows in the right direction, to stop backflow
55
What type of blood flows in through the vena cava?
Deoxygenated
56
What type of blood flows in through the pulmonary vein?
Oxygenated
57
What type of blood flows out through the pulmonary artery?
Deoxygenated
58
What type of blood flows out through the aorta?
Oxygenated
59
Where does the blood go to through the pulmonary artery?
The lungs
60
Where does the blood go from through the aorta?
The rest of the body
61
What happens when the ventricles contract?
It forces the blood into the pulmonary artery and the aorta, out of the heart
62
What supplies the heart with oxygenated blood?
The coronary arteries
63
What are pacemakers?
They are a group of cells in the right atrium that regulate the beating of the heart
64
How do pacemakers make the heart beat?
They produce a small electric impulse which spreads to the surrounding muscle cells
65
What is an artificial pacemaker and what does it do?
A small device that is implanted under the skin and has a wire going to the heart
It produces an electric current to keep the heart beating regularly
66
What are the 3 blood vessels?
Arteries
Capillaries
Veins
67
What do arteries do?
They carry oxygenated blood away from the heart to the body's cells
68
Why are the artery walls strong and elastic (muscular)?
Because the blood is pumped out at a high pressure
69
What are the walls of the artery like compared to the lumen (hole in the middle)?
They are thick compared to the size of the lumen
70
How do the arteries smooth out blood flow?
They contain elastic fibres that allow them to stretch and recoil
71
What makes arteries strong?
They contain thick layers of muscle
72
What do capillaries do?
They connect an artery to a vein and are very small
| They carry blood very close to every cell in the body to exchange substances with them
73
Why do capillaries have permeable walls?
So substances can diffuse in and out
74
Why are the walls of capillaries one cell thick?
It increases the rate of diffusion by decreasing the distance over which it occurs
75
What do the veins do?
They carried deoxygenated blood from the body's cells to the heart
76
Why don't the walls of the veins have to be that thick?
Because the blood is at low pressure
77
Why do veins have a big lumen?
To help the blood flow, despite the low pressure
78
What do valves in the do?
They make sure the blood is going the right way and to prevent backflow
79
What is the function of red blood cells?
To carry oxygen from the lungs to all the cells in the body
80
Why do red blood cells have a large surface area?
For absorbing oxygen
81
Why do red blood cells not have a nucleus?
To have more room to carry more oxygen
82
What do red blood cells contain?
Haemoglobin
83
What does haemoglobin do?
Bind to oxygen in the lungs to form oxyhaemoglobin and in body tissues, the oxyhaemoglobin splits into oxygen and haemoglobin to release oxygen to the cells
84
What is the function of white blood cells?
To protect the body from disease by fighting microbes
85
What do white blood cells do to protect the body?
Phagocytes engulf microorganisms
| Lymphocytes produce antibodies and antitoxins
86
What is the function of platelets and why?
To help the body clot - scabs - to stop blood pouring out and stop microorganisms entering
87
What is plasma and what does it do?
Its the bodily fluid that surrounds blood cells and carries them around as it flows through the blood vessels
88
What does the plasma carry?
Red and white blood cells, platelets, nutrients, hormones, antibodies, antitoxins, proteins, carbon dioxide and urea
89
What is coronary heart disease?
When the coronary arteries that supply blood to the muscle of the heart gets blocked by layers of fatty material building up
90
What happens when the coronary arteries get blocked by layers of fatty material?
The arteries become narrow, blood flow restricted and lack of oxygen to heart muscle - can cause heart attack
91
What are stents?
Tubes that are inserted insinde arteries
92
What so stents do?
They keep the arteries open, making sure blood can pass through to the heart muscles
93
Advantages of stents:
Lowers risk of heart attack
Effective for long time
Recovery from surgery is quick
94
Disadvantages of stents:
Risk of complications during surgery
Risk of infection from surgery
Risk of developing a blood clot near the stet
95
What can too much cholesterol in the blood cause?
Fatty deposits to form inside arteries
96
What are statins and what do they do?
Drugs that reduce the amount of 'bad' cholesterol in the blood - slows down rate of fatty deposits forming
97
Advantages of statins:
Reduces risks of strokes, heart attacks and coronary heart disease
They can increase the amount of beneficial cholesterol in the blood while reducing 'bad' cholesterol
98
Disadvantages of statins:
Long-term drug that must be taken regularly
Can cause negative side-effects which can be serious
The effect isn't instant, it takes time
99
Advantages of heart transplant:
It works better
| You have a better quality of life
100
Disadvantages of heart transplant:
Major surgery required
Anti-rejection drugs are needed
There is a shortage of donors
101
What are artificial hearts?
They are mechanical devices that pump blood for a person who's heart has failed
102
What is the main advantage of using artificial hearts?
They're less likely to be rejected by the body's immune system than a donor heart - body doesn't recognise as foreign
103
What are disadvantages of using artificial hearts?
Surgery can lead to bleeding and infection
They don't work as well as real ones
Parts could wear out or the electric motor could fail
Blood doesn't flow as smoothly, can lead to blood clots and strokes - have to take drugs to thin their blood to make sure this doesn't happen - these drugs can cause problems with can cause problems with bleeding if hurt
104
What can cause valves to be damaged or weakened?
Heart attacks, infection or old age
105
What does valve damage cause?
It won't open properly
May become leaky allowing blood to flow in both direction - blood doesn't circulate effectively - cells won't have enough oxygen
106
How can severe valve damage be treated?
By replacing the valve - biological and mechanical
107
What does artificial blood do?
Replaces lost volume of blood
108
When is artificial blood used?
When someone loses a lot of blood
109
How does artificial blood help a patient?
It may keep them alive long enough for them to produce new blood cells
110
What does the patient need if they can't create red blood cells quickly enough?
A blood transfusion
111
Communicable diseases are ...
spread from person to person or between animals and people
112
Non-communicable diseases ...
cannot be spread between people or animals and people
113
Factors that affect health and diseases:
Good balanced died or not
Amount of stress
Life situation
Any other diseases
114
What diseases can smoking cause and how?
Cardiovascular disease, lung disease, lung cancer
| Damages walls of arteries and cells in lung's lining
115
What diseases can drinking too much alcohol cause and how?
Liver disease and brain function
| Damage nerve cells - causes brain to lose volume
116
What is cancer?
An uncontrollable growth and division that is because of of changes that occur to the cells that results in the formation of a tumour
117
What is a benign tumour?
When the tumour grows until there's no more room - stays in one place rather than invading other tissue
118
What is a malignant tunour?
When the tumour grows and spreads to neighbouring healthy tissues. Cells can break off and travel to other parts of the body via the blood. These malignant cells then invade healthy tissues elsewhere in the body to form secondary tumours
119
What are some risk factors of developing cancer?
Smoking, obesity, UV radiation, Viral infection
| Genetics
120
What tissues make up plant leaves?
Epidermal Tissue
Palisade Mesophyll Tissue
Spongy Mesophyll Tissue
121
What tissues make up plant stems?
Xylem & Phloem
| Meristem Tissue
122
What does the epidermal tissues do?
They cover the leaf with a waxy cuticle that reduces water loss by evaporation and act as a barrier to disease causing organisms
123
Why is the upper epidermis transparent?
So that light can pass through to the palisade layer
124
What is the job of the palisade layer and what are it's adaptations for this job?
To carry out photosynthesis
It's near the top of the leaf, cells shaped so easily packed together and have lots of chlorophyll - absorb max amount of sunlight
125
Why does spongy mesophyll cells have air gaps between them?
So CO2 can enter and O2 can leave the leaf easily
126
What are some adaptations of spongy mesophyll tissue?
The calls have a more rigid shape, have air gaps between the cells and contain a lot of chlorophyll to carry out photosynthesis
127
What do guard cells do and how?
Control the opening and closing of the stomata by changing the water content
When full, the stomata open. When empty, the stomata close
128
What is the stomata?
Small holes on the underside of the leaf
129
What does the stomata do?
Allows gas and water vapour to enter and exit the leaf
130
What are phloem tubes made of?
Living elongated cells
131
Why do phloem cells have small pores in the end of the walls?
To allow cell sap to flow through
132
What do phloem tubes do?
They transport food substances (dissolved sugars) from where they are produced in the leaves to the rest of the plant for storage
133
What way does transport go in the phloem tubes?
Both directions
134
What are xylem tubes made of?
Dead cells, joined together, end to end, with no end walls between them, and a hole down the middle
135
What do xylem tubes do?
They carry mineral ions and water from the roots to the stem and leaves
136
What is the movement of water through the xylem called?
The transpiration stream
137
What is transpiration caused by?
The evaporation and diffusion of water from a plant's surface
138
What does evaporation at the leaves cause?
A slight shortage of water in the leaf, so more water is drawn from the rest of the plant, e.g. roots, to replace it
139
Why is there a constant transpiration stream of water through the plant?
Because as water evaporates, more water is drawn up from the roots
140
Why does the water escape through the stomata?
Because of diffusion - there is more water inside the plant than in the air outside
141
How many guard cells is each stomata surrounded by?
2
142
Why does the stomata close at night?
It's sensitive to light and close to save water at night, without losing out on photosynthesis
143
How come less water is lost on the underside of the plant than if the stomata were on the top of the leaf?
The lower surface of a leaf is shaded and cooler
144
4 factors that affect transpiration rate:
Light Intensity
Temperature
Air Flow
Humidity
145
Relationship between light and the transpiration rate:
The brighter the light, the faster transpiration occurs
146
Relationship between temperature and the transpiration rate:
The warmer it is, the faster transpiration occurs
147
Relationship between air flow and the transpiration rate:
The better the air flow, the greater the transpiration rate
148
Relationship between humidity and the transpiration rate:
The drier the air around the leaf, the faster transpiration occurs
149
How does more light cause an increase in transpiration?
The stomata are triggered to open in light - more water leaves through the stomata
150
How does a higher temperature cause an increase in transpiration?
When warm, particles have more energy to evaporate and diffuse out of the stomata
151
How does a good air flow cause an increase in transpiration?
Water vapour around the leaf is swept away - low concentration of water outside - diffusion happens quickly
152
How does a bad air flow cause an decrease in transpiration?
Water vapour surrounds the leaf - high concentration of water outside - diffusion very slow
153
How does a a humid atmosphere cause an decrease in transpiration?
There is a lot of water outside the leaf - not much of a concentration gradient - less diffusion
