Topic 2- Organisation. Flashcards
(228 cards)
1
Q
why do cells need to be organised?
A
to get the organism working.
2
Q
what are large mutlicellular organisms made up of?
A
organ systems.
3
Q
what are the basic building blocks that make up all living organisms?
A
cells.
4
Q
what do specialised cells form?
A
they form tissues, which forms organs which forms the organ systems.
5
Q
what do the large multicellular organisms have?
A
they have different systems inside them for exchanging and transporting materials.
6
Q
what can similar cells make up?
A
tissues.
7
Q
what is a tissue?
A
it is a group of similar cells that work together to carry out a function.
8
Q
an example of a tissue?
A
Epithelial tissue- a type of tissue made of epithelial cells. it covers some parts of the human body (e.g: the inside of the gut).
9
Q
what are tissues make up?
A
organs.
10
Q
what is an organ?
A
it is a group of different tissues that work together to perform a certain functions.
11
Q
an example of an organ?
A
the stomach is an organ. epithelial tissue lines the inside and outside of the stomach.
12
Q
what do organs make up?
A
organ systems.
13
Q
what is an organ system?
A
it is a group of organs working together to perform a function.
14
Q
an example an organ system?
A
the digestive system is an organ system found in humans and other mammals.
15
Q
what does the digestive system do?
A
it breaks down and absorbs food.
16
Q
it is made up of what organs?
A
- salivary glands.
- liver.
- large intestine.
- stomach.
- pancreas.
- small intestine.
17
Q
the reactions going on inside cells are controlled by what?
A
enzymes- large proteins.
18
Q
they speed up reactions inside living things by acting as what?
A
catalysts.
19
Q
what are catalysts?
A
it is a substance which increases the speed of a reaction without being changed or used up in the reaction.
20
Q
what does chemical reactions usually involve?
A
they usually involve things either being split apart or joined together.
21
Q
what does every enzyme have?
A
they each have an active site with a unique shape.
22
Q
what has to be right with the substance that is involved in the reaction?
A
the substance involved in the reaction has to fit into the active site for the enzyme to work- enzymes are really picky as they usually only catalyse one specific reaction.
23
Q
an example of an enzyme action is…
A
lock and key model.
24
Q
what do enzyme needs to have?
A
the right temperature and pH.
25
does the temperature affect the rate of a reaction involving an enzyme?
yes.
26
whats the link with temperature and rate?
a higher temperature increases the rate at first.
27
what happens when it gets too hot?
some of the bonds holding the enzyme together will break.
28
if the temperature gets too hot what does that change?
it changes the shape of the enzyme's active site, so the substrate won't fit any more- meaning the enzyme is denatured.
29
what is an optimum temperature?
all enzymes have a temperature that they work best at.
30
can pH affect the rate of reaction involving an enzyme?
yes.
31
what happens if the pH is too high or too low?
it affects the bonds holding the enzyme together.
32
what does the pH temperature change?
this changes the shape of the active site and denatures the enzymes.
33
what is optimum pH?
all enzymes have a pH that they work best at.
34
what are enzymes used in digestion produced by?
cells.
35
where are the enzymes released?
they are released into the gut to mix with food.
36
what do digestive enzymes break down?
big molecules.
37
give examples of big molecules?
starch, proteins and fats. } too big to pass through.
38
what do they do to these big molecules?
as they are too big to pass through, the digestive system break these big molecules down into smaller ones.
39
what happens after they are broken down?
the smaller, soluble molecules can now easily be absorbed into the bloodstream.
40
what are the three enzymes?
amylase, protease, lipase.
41
what are amylase?
amylase is an example of carbohydrates.
42
where are amylase made in?
- salivary glands.
- pancreas.
- small intestine.
43
where does amylase work?
mouth and small intestine.
44
where are proteases made in?
- stomach.
- pancreas.
- small intestine.
45
where do proteases work?
stomach and small intestine.
46
where are lipases made in?
- pancreas.
| - small intestine.
47
where do liapses work?
small intestine.
48
what can the products of digestion used to make?
new:
- carbohydrates.
- proteins.
- lipids.
49
what is glucose?
it is a sugar produced by digestion. some of it is used in respiration.
50
what does bile neutralise?
the stomach acid.
51
what does bile emulsifies?
fats.
52
where is bile produced?
in the liver.
53
where is bile stored?
in the gall blander before it is released into the small intestine.
54
is bile an alkaline or alkali?
alkaline. it neutralises hydrochloric acid from the stomach and make conditions alkaline.
55
what conditions do the enzymes in the small intestine work best in?
in the alkaline conditions.
56
what does emulsify mean?
it breaks the fats down into tiny droplets.
57
what does bile emulsified fats give?
a bigger surface area of fat for lipase to work on making digestion faster.
58
what do you need to supply the cells for respiration?
oxygen.
59
what do you need to get rid of while this happens?
carbon dioxide.
60
where does respiration and getting rid of carbon dioxide happen?
in the lungs when you breathe air in and out.
61
where does the air you breathe in goes through?
it goes through the trachea.
62
then what other parts does it pass?
passes through the bronchi, then the bronchioles and ends up in the alveoli (small air sacs).
63
what does alveoli carry out?
gas exchange.
64
what are alveoli in the lungs surrounded by?
blood capillaries.
65
where does the blood come into the lungs through?
the capillaries.
66
what does the capillaries contain?
contains lots of carbon dioxide and very little oxygen.
67
oxygen diffuses out of the air from where to where?
in the alveolus (higher concentration) into the blood (lower concentration).
68
where does carbon dioxide diffueses from to?
it diffuses out of the blood (higher concentration) into the air in the alveolus (lower concentration).
69
what happens to the blood after?
it leaves the lungs and travels around the body.
70
what is breathing rate?
it is how fast a person moves air in and out of their lungs.
71
how to calculate this?
breaths per minute = number of breaths divided by number of minutes.
72
what does the circulatory system carry?
carries food and oxygen to every cell in the body, and waste to where it can be removed.
73
humans have a what circulatory system?
double.
74
what is circulatory system made up of?
- heart.
- blood vessels.
- blood.
75
what is a double circulatory system?
it is two circuits joined together.
76
what happens in the first circuit?
the heart pumps deoxygenated blood to the lungs. the blood picks up oxygen in the lungs. oxygenated blood then returns to the heart.
77
what is deoxygenated blood?
blood without oxygen.
78
what is oxygenated blood?
blood with oxygen.
79
what happens in the second circuit?
the heart pumps oxygenated blood around all the other organs of the body. this delivers oxygen to the body cells. deoxygenated blood returns to the heart to be pumped out of the lungs again.
80
what does the heart pump around the body?
it pumps blood around the body.
81
what is the heart?
it is an organ with four chambers.
82
what are the walls of the chambers mostly made of?
muscle tissue.
83
what is the muscle tissue used to?
to pump blood around the body.
84
how does the muscle issue pump blood around the body?
blood flows into two atria from the vena cava and the pilmonary vein. the atria pumps the blood into the ventricles. the ventricles pumps the blood out of the heart. the blood then flows to the organs through arteries and returns through veins. the atria fills again and the whole cycle starts again.
85
what happens when the ventricles pumps the blood out of the heart?
blood from the right ventricle goes through the pulmonary artery to the lungs.
blood from the left ventricle goes through the aorta to the rest of the body.
86
what do the valves in the heart stop?
it stops the blood flowing backwards.
87
what does the heart need of its own?
it needs its owns supply of oxygenated blood.
88
where does the heart get its oxygenated blood from?
its from the arteries called coronary arteries. these branch off the aorta and surround the heart.
89
what is your resting heart rate controlled by?
it is controlled by a group of cells in the right atrium wall.
90
what do these cells act as?
a pacemaker- they tell the heart when to pump blood.
91
if a pacemaker doesn't work properly what does it cause?
it causes an irregular heartbeat.
92
what is an artificial pacemaker?
a small electrical device- can be used to keep the heart beating regularly.
93
what does the blood flow around the body in?
in blood vessels.
94
what are the three different types of blood vessels?
- arteries.
- capillaries
- veins.
95
what do arteries carry under pressure?
they carry blood.
96
does the arteries carry the blood away or towards the heart?
away.
97
at what pressure does the heart pump the blood out?
high pressure.
98
what are the arteries wall like?
strong and elastic. they have thick layers of muscle to make them strong.
99
what does elastic fibres allow them to do?
it allows them to stretch and spring back.
100
the walls are thick compared to the size of the hole down the middle- whats the name of that hole?
the lumen.
101
what size are capillaries?
really small.
102
what branches into the capillaries?
arteries.
103
the capillaries carry blood close to what?
close to every cell in the body to exchange substances with them.
104
why do the capillaries have gaps in their walls?
so substances can diffuse in and out.
105
what do the capillaries supply?
they supply food and oxygen and take away waste (CO2).
106
what are capillaries’ walls like?
their walls are usually only one cell thick.
107
what does this mean?
diffusion is very fast because there is only a short distance for molecules to travel.
108
what do veins do?
they take blood back to the heart.
109
what joins together to form veins?
capillaries.
110
what pressure is the blood at in the veins?
it is at lower pressure in the veins.
111
what does having the blood at lower pressure mean?
it means the walls don't need to be as thick as artery walls.
112
what do veins have that is bigger than arteries?
veins have a bigger lumen arteries.
113
what does bigger lumen help?
this helps the blood flow despite the lower pressure.
114
what do valves help with?
this helps keep the blood flowing in the right direction.
115
what is the rate of blood flow?
it is the amount of blood that passes through a blood vessel in a given time.
116
how to calculate the rate of blood flow?
rate of blood = volume of blood divided by number of minutes.
117
what do red blood cells carry?
it carries oxygen.
118
what is the job of red blood cells?
it is to carry oxygen from the lungs to all the cells in the body.
119
what does their shape give them?
it gives them a large surface area for absorbing oxygen.
120
what do the red blood cells contain?
they contain a red substance called haemoglobin.
121
what is haemoglobin?
it is the stuff that allows red blood cells to carry oxygen.
122
what does red blood cells not have?
they don’t have a nucleus which makes more space to carry oxygen.
123
what do white blood cells defend against?
infection.
124
what system are the white blood cells part of?
the immune system.
125
why can some white blood cells change shape?
so they can take away the unwelcome microorganisms
126
what do other white blood cells produce?
they produce molecules called antibodies and antitoxins to defend again microorganisms.
127
what do white blood cells do have that red blood cells don’t?
nucleus.
128
what helps blood clot?
platelets.
129
what are platelets?
small fragments of cells. they don’t have no nucleus.
130
what does platelets stop?
- it’s stops all our blood pouring out.
| - stops any microorganisms getting in.
131
what is plasma?
it is the liquid that carries everything in blood.
132
what does it carry?
- red and white blood cells and platelets.
- food molecules (e.g: glucose + amino acids).
- waste products (e.g: carbon dioxide and urea).
- hormones.
- proteins.
133
what are cardiovascular diseases?
they are diseases of the heart or blood vessels.
134
an example of cardiovascular diseases?
coronary heart disease.
135
what is coronary heart disease?
it is a disease of the coronary arteries. it is when layers of fatty material (deposits) build up in the coronary arteries causing the arteries to narrow.
136
what do coronary arteries supply?
supply the heart muscle with blood.
137
what does coronary disease reduce?
it reduces the blood flow to the heart muscle meaning less oxygen can get to the heart muscle. results in heart attack.
138
what do stents do?
they keep coronary arteries open.
139
what are stents?
tubes that are put inside coronary arteries by surgery, keeping them open. effective for long term and recovery is quick.
140
what do stents allow?
it allows blood to reach the heart muscles and reduce the risk of a heart attack.
141
what are the risk of stents?
- heart attacks during op.
- an infection after surgery.
- can develop blood clot.
142
what do statins reduce in the blood?
cholesterol.
143
what is cholesterol?
a lipid that your body needs.
144
what can too much cholesterol do?
it can cause fatty deposits inside the arteries.
145
what are statins?
they are drugs that reduce the amount of cholesterol in the blood. this slows down the rate of fatty deposits.
146
what are the advantages of using statins?
- it can reduce risk of strokes, coronary heart disease and heart attacks.
- some suggest statin may help prevent some other diseases.
147
what are the disadvantages of using statin?
- it must be taken regularly, could forget.
- can cause unwanted side effects.
- the effect of statins isn’t instant, takes time to work.
148
what is a heart transplant?
when a heart is replaced by a donor heart.
149
what’s heart failure?
when the heart can’t pump enough blood.
150
what else can be replaced?
the lungs- if they are diseased.
151
if donor heart isn’t available what else can be fitted in?
they can fit an artificial heart.
152
what can an artificial heart be used for?
it can be used to keep a person alive until donor heart available or help the person recover to rest and heal their heart.
153
can artificial hearts be permanent?
they can be permanent so sonar heart not needed.
154
what is an advantage of artificial hearts?
they are made of plastics or metals so less likely to attack immune system than donor heart.
155
what are disadvantages of artificial hearts?
- surgery to fit it can lead to bleeding and infection.
- don’t work as well as healthy natural ones.
- blood doesn't flow through smoothly in artificial- cause clots and strokes.
- has to take drugs to thin blood- can bleed more if an accident had happened.
156
what can the valves in the heart be damaged by?
heart attacks, infection or old age.
157
the valves being damaged what can that cause?
can cause the valves to stiffen so it won't open properly.
158
why does the valve become leaky?
as the blood flows in both directions.
159
what does it mean when the valve becomes leaky?
the blood doesn't flow around the body as well as normal.
160
what can damaged valves be replaced by?
- biological valves- from humans or other mammals.
| - mechanical valves- man-made.
161
what is less risky replacing valve or heart transplant?
replacing a valve- but still risks of blood clots.
162
what is health?
it is a state of physical and mental wellbeing.
163
what can diseases be responsible for causing?
ill health.
164
what can diseases be?.
communicable or non-communicable.
165
what is communicable disease?
- these can spread between people or between animals and people.
- they are caused by bacteria, viruses, parasites or fungi.
- examples... measles and malaria.
166
what is non-communicable disease?
- cannot spread between people or between animals and people.
- example... coronary heart disease.
167
can a disease cause other physical and mental health issues?
yes.
168
what are pathogens?
a microorganism that can cause disease.
169
what does the immune system help fight off?
pathogens.
170
what can the immune system cause if there is a problem?
makes people more likely to suffer from communicable diseases.
171
what can an immune system reaction caused by pathogen lead to?
it can lead to an allergic reaction (skin rash) or symptoms of asthma for asthma sufferers.
172
what do virus infect?
the cells in the body and this could lead to some types of cancer.
173
can physical health problems lead to mental health problems?
yes.
174
what are the other factors that can affect your health?
- poor diet.
- constantly under stress.
- life situation- able to have access to medicine.
175
can risk factors increase your chance of getting a disease?
yes.
176
what can risk factors be?
- part of person's lifestyle (how much exercise is done).
- substances in the environment (air pollution).
- substances in the body (asbestos fibres in lung can cause cancer).
177
what can lifestyle factors have different effects on?
- locally.
- nationally.
- globally.
178
what can cause how common a disease is locally?
your individual choices.
179
what can cause disease nationally?
obesity and type 2 diabetes more common poorer areas. as they are more likely to smoke, have a poor diet and not exercise.
180
what can cause diseases globally?
non-communicable disease more common in developed countries. as they generally earn more and can buy high-fat food.
181
what risk factors can cause disease directly?
- smoking- cause cardiovascular disease, lung disease and lung cancer- damage walls of arteries and lining of lungs.
- obesity- cause type 2 diabetes, body less sensitive to insulin.
- too much alcohol- damage brain and liver.
- exposure to substances/ radiation- cause cancer. (carcinogens- things that cause cancer).
182
can a risk factors always cause a disease directly?
no- lack of exercise and high fat diet are risk factors for cardiovascular disease but doesn't directly cause it. high cholesterol levels can cause it.
183
what is the human cost of non-communicable disease?
shorter lifespan.
184
is the cost of research and treating non-communicable disease huge?
yes.
185
what can affect a country's economy?
a reduction in employment.
186
what is cancer cause by?
uncontrolled cell growth and division.
187
what leads to uncontrolled cell growth and division?
changes in the cell. this results in a tumour (a mass of cells).
188
what can tumours be?
benign or malignant.
189
what are benign tumours?
there are masses of abnormal cells.
- they stay in one place (usually within a membrane).
- don't invade other parts.
- it isn't normally dangerous or cancerous.
190
what are malignant tumours?
spread to other parts.
- can break off and travel in bloodstream.
- get into healthy tissues and form secondary tumours.
- they are dangers and can be fatal.
- they are cancers.
191
what can risk factors increase the chance of?
the can increase the chance of some cancers.
192
what can be lifestyle factors for cancers?
- smoking.
- obesity.
- viral infection.
- UV exposure- sun produces this, can increase chance of skin cancer.
193
what can be the genetic factor for cancers?
can have inherit faulty genes.
194
why are more people likely to survive cancer?
- improved treatments.
- doctors diagnose them earlier.
- more people being tested for cancer.
- more now know about risk factors of cancers.
195
what are plant cells organised into?
tissues and organs.
196
what do the organs in the plant work together to make?
the organ system.
197
what are the plant organs?
- stems.
- roots.
- leaves.
198
what are plant organs made of?
tissues.
199
what are the plant tissues?
- epidermal tissue- covers the whole plant.
- palisade mesophyll - part of the leaf where photsynthesis happens.
- spongy mesophyll- part of the leaf that has big air spaces. allows gases to diffuse in and out of the cells.
- xylem+phloem- transport things (water, mineral ions and food).
- meristem tissue- found at the growing tips of shoots and roots.
200
what happens in the leaf?
photosynthesis and gas exchange.
201
whats are the tissues in the leaf?
- upper epidermis- it is transparent, allows light to through the palisade layer.
- palisade layer- lots of chloroplasts, near the top to get more light.
- spongy mesophyll- air spaces to increase rate of diffusion of gases.
- lower epidermis.
- stomata- let gases diffuses in and out, opened or closed in response of environment. controlled by guard cells.
- xylem and phloem- bring water and nutrients to the leaf, take away glucose produced by photosynthesis. support the leaf.
202
what do phloem tubes transport?
food. transport both directions.
203
what are phloem tubes made of?
elongated living cells.
204
what do phloem tubes have between the cells?
end walls. they have pores (small holes) to allow cell sp to flow through.
205
what is cell sap?
it is a liquid that's made up of the substances being transported and water.
206
what do plants make in their leaves?
food substances (dissolved sugars).
207
why do phloem transport these food substances?
for immediate use or storage.
208
what is the process called?
translocation.
209
what do xylem tubes take up?
water.
210
what are xylem tubes made of?
dead cells.
211
what are the cells like in a xylem tube?
the cells are joined together with a hole down the middle. there are no end walls. the cells are strengthened with a material called ligin.
212
where does the xylem tubes carry water and mineral ions from and to?
from the roots to the stem and leaves.
213
what is the movement of water from the roots through the xylem and out of the leaves called?
the transpiration stream.
214
what is transpiration?
it is the loss of water from the plant.
215
what is transpiration caused by?
by evaporation and diffusion of water from a plant's surface (mainly the leaves).`
216
how does it happen?
1) water evaporates from leave and diffuses into the air.
2) it creates a little shortage in the lead. more water is drawn up from the rest of the plant through the xylem tubes to replace it.
3) meaning more water comes from the roots.
217
what is the constant stream of water through the plan t called?
transpiration stream.
218
what are the four main things that affect transpiration rate?
- air flow.
- temperature.
- humidity.
- light intensity.
219
what happens within the air flow?
the more windy it is, the faster transpiration happens. this means that water vapour around leaf is swept away. there's a higher concentration of water vapour inside the leaf compared to outside so water will diffuse out of the leaf quickly.
220
what happens with the temperature of the environment?
the warmer it is, the faster transpiration happens. because the water particles have more energy so they evaporate and diffuse out of the stomata faster.
221
what happens within humidity?
the drier the air around the lead, the faster transpiration happens. if the air is humid, there's a lot of water already in it. this means there isn't much difference within the outside and inside of the leaf. so diffusion won't happen very fast.
222
what happens with the light intensity?
the brighter the light, the greater the transpiration rate. photosynthesis can't happen in the dark so stomata begin to close as it gets darker. when stomata is closed, very little water can escape.
223
what does guard cells control?
gas exchange and water loss.
224
what is the stomata surrounded by?
guard cells.
225
why does the guard cells change shape?
to control the size of the stomata.
226
what happens with the guard cells when there is lots of water?
the guard cells fill with it and get fat meaning the stomata opens so gases can be exchanged for photosynthesis.
227
what happens with the guard cells when there is a shortage of water?
the guard cells loses water and becomes floppy making the stomata close. this helps stop too much water vapour escaping.
228
where is there more stomata and why?
normally on the bottoms of leaves than on tops. because the lower surface is cooler so less water gets lost.
