Organisation Flashcards
(151 cards)
1
Q
What are all living things made of?
A
cells
2
Q
What is a tissue?
A
a group of specialised cells with a similar structure and function
3
Q
What are examples of tissues?
A
muscular tissue, epithelial tissue
4
Q
What are organs?
A
a group of tissues working together to produce a specific function
5
Q
What are examples of organs?
A
stomach which has muscular tissue and epithelial tissue
6
Q
What are organ systems?
A
organs that work together to produce a certain function
7
Q
What is an example of an organ system?
A
stomach is apart of the digestive system, liver and small intestine
8
Q
What is the function of the digestive system?
A
break down large insoluble food molecules into molecules that can be absorbed by cells
9
Q
What organs are included in the digestive system?
A
glands (salivary glands and pancreas), stomach, small intestine, liver, large intestine, rectum and anus
10
Q
In the digestive system, what is the role of the glands?
A
produce digestive juices containing enzymes which break down food.
11
Q
In the digestive system, what is the role of the stomach?
A
produces hydrochloric acid to kill bacteria and provide the optimum pH for the protease enzyme to work
12
Q
In the digestive system, what is the role of the small intestine?
A
where soluble molecules are absorbed into the blood
13
Q
In the digestive system, what is the role of the liver?
A
produce bile which is stored in the gall bladder, which helps digestion of lipids.
14
Q
In the digestive system, what is the role of the large intestine?
A
absorbs water from undigested food to produce faeces, this passes out of your body through the rectum and anus
15
Q
What are enzymes?
A
biological catalysts, a substance that increases the rate of reaction without being used up
16
Q
What are the qualities of enzymes?
A
- enzymes are present in many reactions so that they can be controlled
- they can both break up large molecules and join small ones
- they are protein molecules and the shape of the enzyme is vital to its function
- this is because each enzyme has its own uniquely shaped active site where the substrate binds
17
Q
What is the lock and key hypothesis?
A
the shape of the substrate is complementary to the shape of the active site, so when they bond it forms and enzyme-substrate complex.
once bound, the reaction takes place and the products are released from the surface of the enzyme
18
Q
What do enzymes require?
A
an optimum pH and temperature, because they are proteins
19
Q
What is the optimum temperature range for enzymes?
A
around 37 degrees.
20
Q
Explain what occurs in enzyme after the temperature of 37 degrees is exceeded.
A
the rate of reaction increases with an increase in temperature up to this optimum, but above this temperature it rapidly decreases and eventually the reaction stops, when the temperature becomes too hot the bonds in the structure will break, this changes the shape of the active site, so the substrate can no longer fit in, the enzyme is said to be denature and can no longer work
21
Q
What is the optimum pH for most enzymes?
A
7 but some that are produced in acidic conditions, such as the stomach, have a low optimum PH
22
Q
What will occur to enzymes if the pH is lower/higher than 7?
A
if the pH is too high or too low, the forces that hold the amino acids chains that make up the protein will be affected
this will change the shape of the active site, so the substrate can no longer fit in
the enzyme is said to be denatured and can no longer work
23
Q
What are examples of enzymes?
A
carbohydrases proteases lipases
24
Q
What do carbohydrases do?
A
convert carbohydrates into simple sugars, Example : amylase breaks down starch into maltose
25
Where are carbohydrases produced?
salivary glands, pancreas, small intestine
26
What do proteases do?
convert proteins into amino acids
27
Where are proteases made?
pepsin - produced in stomach, other forms can be found in pancreas and small intestine
28
What do lipases do?
convert lipids into fatty acids and glycerol
29
Where are lipases produced?
pancreas and small intestine
30
Where is soluble glucose, amino acids, fatty acids and glycerol used for?
build new carbohydrates, lipids and proteins, with some glucose being used in respiration
31
What are the tests you can perform to determine whether a solution is made up of carbohydrate, protein or lipid.
Benedict's test
Iodine test
Biuret test
Emulsion test
Sudan III test
32
What is Benedict's test for and what is the positive result?
test for sugars, turns brick-red
33
What is the iodine test for and what is the positive result?
starch turns blue-black
34
What is the Biuret test and what is the positive result?
protein turns purple
35
What is the emulsion test and what is the positive result?
lipids add ethanol which results in a cloudy layer if a lipid is present
36
What is the Sudan III test and what is the positive result?
lipids red layer forms on top
37
Where is bile produced?
liver
38
Where is bile stored?
gallbladder
39
Where is bile released?
small intestine
40
What are the roles of bile?
- alkaline to neutralise the hydrochloric acid which comes from the stomach - the enzymes in the small intestine have a higher optimum pH than those in the stomach
- It breaks down large drops of fat into smaller ones (emulsifies it) the larger surface area allows lipse to chemically break down the lipid into glycerol and fatty acids faster
41
What system is the heart apart of?
circulatory system
42
What does the circulatory system do?
carries oxygen and nutrients to every cell in the body and removes the waste products
43
The heart pumps blood around the body in a ...
double circulatory system, which means there are two circuits
44
What are the two circuits in the double circulatory system?
1 - deoxygenated blood flows into the right atrium and then into the right ventricle which pumps it to the lungs to undergo gaseous exchange
2 - oxygenated blood flows into the left atrium and then into the left ventricle which pumps oxygenated blood around the body
45
What does the structure of the heart involve?
- muscular walls to provide a strong heartbeat
- the muscular wall of the left ventricle is thicker because blood needs to be pumped all around the body rather than just to the lung like the right ventricle
4 chambers that separated the oxygenated blood from the deoxygenated blood
valves to make sure blood does not flow backwards
coronary arteries cover the heart to provide its own oxygenated blood supply
46
What is process in the heart?
- blood flows into the right atrium through the vena cava, and left atrium through the pulmonary vein
- the atria contract forcing the blood into the ventricles
- the ventricles then contract, pushing the blood in the right ventricle into the pulmonary artery to be taken to the lungs, and blood in the left ventricle to the aorta to be taken around the body
- as this happens, valves close to make sure the blood does not flow backwards
47
What is the natural resting heart rate?
around 70 beats per minute
48
What is the natural resting heart rate controlled by?
a group of cells found in the right atrium that act as a pacemaker
49
What does the pacemaker in the heart provide with?
provide stimulation through small electrical impulses which pass as a wave across the heart muscle, causing it to contract
50
What would happen without the stimulation provided by the pacemaker?
the heart would not pump fast enough to deliver the required amount of oxygen to the whole body
51
What can be used if the pacemaker in the heart is faulty?
an artificial pacemaker
52
What is an artificial pacemaker?
an electrical device that produces a signal causing the heart to beat at a normal speed
53
What are the three different types of blood vessel?
arteries, veins and capillaries
54
What do arteries do?
carry blood away from the heart
55
What are some qualities of arteries?
- layers of muscle in the walls make them strong
- elastic fibres allow them to stretch
- this helps the vessels withstand the high pressure created by the pumping of the heart
56
What do veins do?
carry blood towards the heart
57
What are some qualities of veins?
- the lumen (the actual tube in which blood flows through) is wide to allow the low pressure blood to flow through
- they have valves to ensure the blood flows in the right direction
58
What do capillaries do?
allow the blood to flow very close to cells to enable substances to move between them
59
What are some qualities of capillaries?
- one cell thick walls create a short diffusion pathway
- permeable walls so substances can move across them
60
How can the rate of blood flow be calculated?
volume of blood / number of minutes
61
Where are the lungs found?
thorax ( top part of body )
62
How are the lungs protected?
by the ribcage
63
What do the lungs do?
supply oxygen to your blood and remove carbon dioxide.
64
What is the gas exchange system made up of?
trachea, intercostal muscles, bronchi, bronchioles, alveoli, diaphragm
65
Explain the organs that make up the gas exchange system.
trachea - the windpipe, air moves through here
intercostal muscles - contract and relax to ventilate the lungs
bronchi - air from the trachea move into these, lead to each lung
bronchioles - bronchi split into these and air moves in
alveoli - bronchioles lead to alveoli, air sacs where gaseous exchange occurs
diaphragm - separates the lungs from the digestive organs, moves down causing inhalation
66
What are the steps of ventilation?
1. The ribcage moves up and out and the diaphragm moves down causing the volume of the chest to increase
2. increased volume results in lower pressure
3. air is drawn into the chest as air moves from areas high pressure (the environment) to low pressure (the lungs)
4. the opposite happens when exhaling
67
What are the steps in gas exchange?
1. upon inhalation, the alveoli fill with oxygen
2. the blood in the capillaries surrounding the alveoli is deoxygenated, it has lots of carbon dioxide as this is a product of respiration
3. oxygen diffuses down its concentration gradient into the capillary bloodstream, which has a low concentration of oxygen
4. carbon dioxide diffuses down its concentration gradient from the blood to the alveoli
68
How are alveoli adapted for gas exchange?
very small and arranges in clusters - creating a large surface area for diffusion to take place over
a large blood supply - maintaining a concentration gradient
walls are very thin - short diffusion pathway
69
How do you calculate breathing rate?
number of breaths / number of minutes
70
What is blood made out of?
plasma, red blood cells, white blood cells, platelets
71
What is plasma?
liquid that carries the components in the blood: red blood cells, white blood cells, platelets, glucose, amino acids, carbon dioxide, urea, hormones, proteins, antibodies, antitoxins
72
What is the role of red blood cells?
-they carry oxygen molecules from the lungs to all cells in the body
-their bioconcave disc shape provides a large surface area
- no nucleus allowing more room to carry oxygen
- contain red pigment haemoglobin, binds to oxygen and forms oxyhaemoglobin
73
What is the role of white blood cells?
- aparat of immune system
- nucleus
- produce antibodies
- engulf and digest pathogens
- produce antitoxins to neutralise toxins
74
What is the role of platelets?
- help blood clot form at site of wound
- clot dries and hardens to form a scab, new skin to grow underneath
- small fragments of cells
- no nucleus
- without them, cuts would result in excessive bleeding and bruising
75
What is coronary heart disease?
when the coronary arteries that provide blood to the heart become blocked with the build up of fatty material, this results in less blood flowing to the heart, reducing its oxygen supply
76
What may coronary heart disease lead to?
heart attack
77
What are the solutions for coronary heart disease?
stents, statins
78
What are stents?
metal mesh tubes inserted in arteries, keep the arteries open to allow blood to flow through
79
What are the advantages of stents?
they are effective in lowering the risk of a heart attack, the recovery time from surgery is quick
80
What are the disadvantages of stents?
risk of a heart attack during procedure, or risk of infection following
chance that blood clots can form near the stent called thrombosis
81
What are the statins?
drugs that decrease the levels of cholesterol, which would otherwise lead to coronary heart disease
82
What are the advantages of statins?
reduce risk of strokes, coronary heart disease, and heart attacks
they increase the levels of HDL good cholesterol
83
What are the disadvantages of statins?
need to be taken continuously
provide side effects
may not have an immediate effect
84
What are some other problems associated with the heart?
faulty valves
heart failure
extreme blood loss
85
What are faulty valves?
when a heart valve becomes stiff so cannot open or it is damaged so it leaks, blood flows in the wrong direction which means that the heart does not work as efficiently as it should
86
What are the solutions for faulty valves and what are the benefits and negatives?
- replacing with a biological valve pigs or cattle
works very well, only last 12-15 years
- replacing it with a mechanical valve
last for a long time
constant medication is needed to stop blood from clotting around the valve
87
How can heart failure be solved, and what can complicate this solution?
Heart transplant
a heart transplant requires a donor who has recently died, not always available so an artificial may be used whilst waiting
88
How can extreme blood loss be treated?
solved by giving artificial blood
89
What is artificial blood?
salt solution that can keep people alive even if they lose 2/3 of their red blood cells
90
What are the advantages and disadvantages of artificial blood?
means the patient has more time to produce new blood cells
can only be used for short periods of time then a blood transfusion has to take place
91
What is health?
a state of physical, mental and social well-being, not merely the absence of disease.
92
.... is one factor that can cause ill health
Disease
93
What are other factors that can cause ill health apart from disease?
diet, stress and life situations
94
What two categories does disease fall into?
communicable and non-communicable
95
What are communicable diseases?
infectious and are passed on from one person to another
96
What is an example of a communicable disease?
flu
97
What are non-communicable diseases?
not passed on from person to person
98
What is an example of a non-communicable disease?
heart disease
99
What are pathogens?
microorganisms that cause disease
100
What is a disease caused by bacteria?
salmonella
101
What is a disease caused by protist?
malaria
102
How are protist transported?
vectors
103
What is a disease caused by fungi?
athlete's foot
104
What are some examples of certain factors affecting other factors?
- immune system poor, more likely to become infected with a communicable disease
- infections by virus can trigger growth of cancers, liver cancer hepatitis virus
- infection by a pathogen trigger allergic reactions
- reduction in physical health, reducing their life expectancy can lead to mental illness, such as depression
105
How does diet affect health?
eating too little or too much food, not enough nutrients or the wrong type of food prevents you from having a good, balanced diet. this can have a big effect on mental and physical health, causing issues such as type 2 diabetes or obesity
106
How does stress affect health?
physical and mental stress places strain on our bodies, this can lead to problems such as heart disease, cancers and mental illnesses
107
How can life situations impact health?
where you live, your financial status, ethnic group, access to medical care, level of hygiene are examples of factors that may affect physical and mental health. can lead to communicable diseases such as diarrhoea and malaria, or non-communicable diseases such as heart disease
108
What are risk factors?
risk factors can either be aspects of a person's lifestyle, substances in the person's body, or environment.
109
If one factor increases as another increases, they are...
correlated
110
To prove causation scientists need to find a ...
causal mechanism, an explanation of how one influences another
111
Risk factors for cardiovascular disease could be..
- diet containing lots of LDL cholesterol resulting in arteries become blocked, increasing blood pressure
- smoking damages the walls of arteries
- exercise lowers blood pressure, reducing strain on the heart
112
What is a risk factor for type 2 diabetes?
obesity affects the body's metabolism - fat molecules are released into the blood which can affect the cells uptake of sugar
113
What is a risk factor for a flawed liver and brain function?
- alcohol causes fatty liver, which can lead to liver failure
- alcohol can damage nerve cells in the brain
114
What is a risk factor for lung disease and lung cancer?
smoking damages the cells in the lining of the lungs
115
What is a risk factor for a flawed pregnancy?
smoking and alcohol can cause many damaging effects on the unborn child
116
What is a risk factor for cancer?
carcinogens such as ionising radiation can lead to cancers
117
What is cancer?
uncontrollable growth and division, forming a tumour.
118
Do tumours always have to be cancerous?
no
119
What are the two types of cancer?
benign and malignant
120
What is a benign tumour?
growths of cells contained in one place, usually within a membrane
121
What are the qualities of a benign tumour?
- not cancerous
- grows until there is no more room
- does not invade other tissues
- if it causes pressure or damage to an organ, it can be dangerous
122
What is a malignant tumour?
grows and spreads to other tissues
123
What are the qualities of a malignant tumour?
- cancerous
- tumour may split up, resulting in cells being carried in the bloodstream or lymphatic system
- travel to and stay in another organ, potentially causing secondary tumours
- the cancer cells divide more rapidly and have a longer life span in comparison to normal cells
124
What are the lifestyle risk factors for cancer?
- smoking
- obesity
- UV light
- Viral infection
125
What are the genetic risk factors for cancer?
you can inherit certain genes which increase the likelihood of getting cancer
126
What tissues do plants consist of?
- epidermal tissue, covers the whole plant
- palisade mesophyll tissue, found underneath the epidermal tissue
- spongy mesophyll tissue, found underneath the palisade mesophyll
- xylem, found in the roots, stems and leaves
- phloem, found in the roots stems, and leaves
- meristematic tissue, found at tips of shoots and roots
127
What are the features of the epidermal tissue?
covered with a waxy cuticle
128
What is the function of the epidermal tissue?
helps to reduce water loss by evaporation, as the waxy cuticle prevents water from moving out
129
What are the features of the palisade mesophyll tissue?
has lots of chloroplasts ( photosynthesis takes place within these structures )
130
What is the function of palisade mesophyll tissue?
having many chloroplasts means photosynthesis can happen rapidly, they are positioned at the top of the leaf so they receive lots of light
131
What are the features of the spongy mesophyll tissue?
air spaces
132
What is the function of the spongy mesophyll tissue?
allows gases to diffuse in and out of cells
133
What are the features of the xylem?
- made up of dead cells joined together, creating a continuous tube
- strengthened with a substance called lignin, but this has some holes in it along the tube called bordered pits
134
What is the function of the xylem?
- allows the movement of water and mineral ions from the roots to the stem and leaves, where it evaporates and leaves the plant, this is called transpiration stream
- lignin makes it strong and waterproof, so water will not leave except at bordered pits, allowing minerals to go to specific places in the plant
135
What are the features of the phloem?
- elongated cells with holes in the cell walls ( the end walls are now called sieve plates )
- many organelles from the cells are removed so cell sap can move through
136
What is the function of the phloem?
food substances can be moved in both directions, from the leaves where they are for use, or form storage to parts of the plant that need it, this process is called translocation
137
What are the features of the meristematic tissue?
it is able to differentiate into different types of plant cells
138
What is the function of the meristematic tissue?
the differentiation allows the plant to grow
139
The leaf is a ...
plant organ
140
What tissues does the leaf consist of?
epidermis, palisade, spongy mesophyll, xylem, phloem, guard cells (surround stomata and control the opening and closing of them, depending on the water availability)
141
What is translocation?
the movement of food substances made in the leaves up or down the phloem, for use immediately or storage
142
What is transpiration?
the loss of water of water vapour from the leaves and stems of the plant, it is a consequence of gaseous exchange, as the stomata are open so that this can occur
143
What is the process of transpiration?
- water also evaporated at the open stomata
- as water molecules are attracted to each other, when some molecules leave the plant the rest are pulled up through the xylem
- this results in more water being taken up from the soil resulting in a continuous transpiration stream through the plant
144
How can the rate of transpiration be affected?
- increase in temp
- increase in relative humidity
- increased air movement
- increase in light intensity
145
How does the increase in temperature affect the rate of transpiration?
the molecules move faster, resulting in evaporation happening at a faster rate and therefore the rate of transpiration increases,
the rate of photosynthesis increases, meaning more stomata are open for gaseous exchange, so more water evaporated and the rate of transpiration increases.
146
How does an increase in relative humidity affect the rate of transpiration?
if the relative humidity is high, then there will be a reduced concentration gradient between the concentrations of water vapour inside and outside the leaf, resulting in a slower rate of diffusion. this will decrease the rate of transpiration
147
How does an increased air movement affect the rate of transpiration?
if more air is moving away from the leaf due to it being blown away, then the concentration of water vapour surrounding the leaf will be lower. this will mean there will be a steeper concentration gradient resulting in diffusion happening faster. this will increase the rate of transpiration
148
How does an increase in light intensity affect the rate of transpiration?
this leads to an increased rate of photosynthesis, so more stomata open to allow gaseous exchange to occur, this means more water can evaporate, leading to an increased rate of transpiration
149
How can the uptake of water be measured?
potometer, which involves placing a plant in a tube of water, and measuring the distance travelled by a bubble
150
What do guard cells do?
open and close the stomata
151
What are the qualities of guard cells?
- they are kidney shaped
- they have thin outer walls and thick inner walls
- when lots of water is available to the plant, the cells fill and change shape, opening the stomata ( they are also light sensitive )
- this allows gases to be exchanged and more water to leave the plant via evaporation
- more stomata are found on the bottom of the leaf, allowing gases to be exchanged whilst minimising water loss by evaporation as the lower surface is shaded and cooler
