Organisation Flashcards
(194 cards)
1
Q
What is a cell?
A
The basic building block of a living organism
2
Q
What is a tissue?
A
A group of cells with a similar structure and function working together
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
group of organs that work together to perform a specific function
5
Q
What is the main function of the digestive system?
A
To digest food and absorb the nutrients obtained from digestion.
6
Q
What is the role of pancreas and the salivary gland in the digestive system?
A
The pancreas and the salivary gland are glands which produce digestive juices containing enzymes.
7
Q
What is the role of the stomach in the digestive system?
A
Produces hydrochloric acid - which kills any bacteria present and provides the optimum acidic pH for the protease enzyme to function.
8
Q
What is the role of the small intestine in the digestion system?
A
The small intestine is the site where soluble food molecules are absorbed into the bloodstream
9
Q
What is the role of the liver in the digestive system?
A
Produces bile (stored in the gallbladder) which emulsifies lipids and allows the lipase enzyme to work more efficiently.
10
Q
What is the role of the large intestine in the digestion system?
A
Absorbs water from undigested food and then produces faeces
11
Q
What is the role of enzymes in the digestive system?
A
Enzymes act as biological catalysts which speed up the rate of biological reactions (the breakdown of food) without being used up.
12
Q
How does the shape of an enzyme affect its function?
A
Enzymes have a specific active site which is complementary to their substrate.
13
Q
What is metabolism?
A
The sum of all the reactions in a cell or an organism
14
Q
What types of metabolic reactions do enzymes catalyse?
A
● Building larger molecules from smaller molecules
● Changing one molecule to another
● Breaking down larger molecules into smaller molecules
15
Q
What is the lock and key hypothesis of enzyme function?
A
The shape of the enzyme active site and the substrate are complementary, so can bind together to form an enzyme-substrate complex.
16
Q
How does temperature affect enzyme action?
A
Up to a certain point, increasing temperature increases enzyme action, as molecules have a higher kinetic energy. Above a certain temperature, the shape of the active site is altered and the enzyme becomes denatured, so it can no longer catalyse the reaction. The optimum temperature is around 37°.
17
Q
How does pH affect enzyme function?
A
The optimum pH for most enzymes is 7 (apart from proteases in the stomach). If the pH is too extreme, the shape of the active site may be altered and the enzyme may no longer work.
18
Q
Where are carbohydrases, proteases, and lipases produced in the body?
A
● Carbohydrases: amylase - salivary gland and pancreas; maltase - small intestine.
● Proteases: pepsin - stomach; others - pancreas and small intestine.
● Lipases: pancreas and small intestine.
19
Q
What is the role of carbohydrases in the digestive system?
A
Carbohydrases break down carbohydrates into monosaccharides and disaccharides. Amylase breaks down starch into maltose, and maltase breaks down maltose into glucose.
20
Q
What is the role of proteases in the digestive system?
A
Proteases break down proteins into amino acids.
21
Q
What is the role of lipases in the digestive system?
A
Lipases break down lipids into fatty acids and glycerol.
22
Q
How are the products of digestion used?
A
They are used to build bigger molecules such as carbohydrates and proteins. Glucose is used as a substrate in respiration.
23
Q
Where is bile made and stored in the body?
A
Bile is made by the liver and stored in the gallbladder
24
Q
What is the role of bile in the digestive system?
A
● Bile is an alkaline substance which neutralises the hydrochloric acid secreted by the stomach.
● Bile emulsifies lipids to form droplets - this increases the surface area for the lipase enzyme to work on.
25
What is the heart?
An organ that pumps blood around the body
26
What is the purpose of the circulatory system?
Carries oxygen and other useful substances to bodily tissues, and removes waste substances.
27
How does the double circulatory system work?
● One pathway carries blood from the heart to the lungs - where the gaseous exchange of oxygen and carbon dioxide takes place.
● One pathway carries blood from the heart to the tissues.
28
Where does blood pumped by the right ventricle go?
Lungs
29
Where does blood pumped by the left ventricle go?
Body tissues
30
Why is the double circulatory system important?
It makes the circulatory system more efficient - for example, oxygenated blood can be pumped around the body at a higher pressure by the left ventricle.
31
How many chambers does the heart have and what are they called?
4 - right atrium, right ventricle, left atrium, left ventricle.
32
Why is the wall of the left ventricle thicker?
The left ventricle has to pump blood at a higher pressure around the whole body.
33
What are the four main blood vessels associated with the heart?
● Aorta (left) - carries oxygenated blood from the heart to the body.
● Pulmonary vein (left) - carries oxygenated blood from the lungs to the heart.
● Vena cava (right) - carries deoxygenated blood from the body to the heart.
● Pulmonary artery (right) - carries deoxygenated blood from the heart to the lungs.
34
What is the purpose of valves in the heart?
Prevent back flow of blood
35
What is the purpose of coronary arteries?
Coronary arteries supply the heart muscle with oxygenated blood.
36
Describe the process of blood flow through the heart
● Blood enters the right atrium via the vena cava, and the left atrium via the pulmonary vein.
● The atria contract, forcing blood into the ventricles and causing valves to shut.
● After the ventricles contract, blood in the right ventricle enters the pulmonary artery (to the lungs) and blood in the left ventricle enters the aorta (to the body).
37
What is the approximate value of the natural resting heart rate?
70 beats per minute
38
How is heart rate controlled?
Heart rate is controlled by a group of cells in the right atrium which act as a pacemaker. They release waves of electrical activity which cause the heart muscle to contract.
39
How can an abnormal heart rhythm be treated?
Irregular heart rhythms can be treated using an artificial pacemaker, which sends out electrical signals to correct the heart's rhythm.
40
What are the three types of blood vessel in the body?
arteries, veins, capillaries
41
How are arteries adapted to their function?
- they have thick layers of muscle to make them strong enough to withstand the high pressure at which they carry blood
- they have strong elastic fibres to allow them to stretch and spring back
42
What is the veins function?
carry blood back to the heart
43
How are veins adapted to their function?
- the walls are not thick as blood is not carried at a low pressure
- they have a big lumen to help blood flow
- they have valves to keep blood flowing in the right direction
44
What is the capillaries function?
Enable transfer of substances between the blood and tissues
45
How are capillaries adapted to their function?
- they have permeable walls so that substances can diffuse in and out
- their walls are only one cells thick which increases the rate of diffusion by decreasing the distance over which it occurs
- capillaries are really close to every cell in the body to exchange surfaces with them
46
How would you calculate the rate of blood flow?
Volume of blood / number of minutes
47
Where are the lungs found in the body?
The lungs are located in the thorax (within the chest). They are protected by the ribcage and separated from the rest of the abdomen by the diaphragm.
48
What tissues and organs make up the gas exchange system?
trachea, intercostal muscles, bronchi, bronchioles, alveoli, diaphragm
49
How are lungs ventilated by the action of intercostal?
Intercostal muscles contract, rib cage moves upwards, diaphragm flattens and volume of the chest increases, increased volume results in decreased pressure no air is drawn into lungs down pressure gradient (the inverse occurs wen air moves out of the lungs)
50
Describe how gas exchange occurs at the alveoli
● Oxygen diffuses from the alveoli into the capillary bloodstream down its concentration gradient.
● Carbon dioxide diffuses from the capillary into the alveoli down its concentration gradient.
51
Describe how alveoli are adapted for gas exchange
● Small and arranged in clusters - larger surface area.
● Rich blood supply - maintains concentration gradient.
● Thin alveolar wall - short diffusion pathway.
52
How would you calculate the breathing rate?
Number of breaths / number of minutes
53
What substance carries the different components of blood around the body?
Plasma
54
What substance are transported by plasma?
● Red blood cells
● White blood cells
● Platelets
● Carbon dioxide
● Urea
● Products of digestion
55
What is plasma?
A yellow liquid within blood that transports substances around the body.
56
What is the purpose of red blood cells in blood?
Transport oxygen around the body
57
How are red blood cells adapted to their function?
- Biconcave discs - increases surface area to volume ratio
- No nucleus - more space for haemoglobin
58
What is the purpose of white blood cells in blood?
They form part of the immune system, which protects the body from invading pathogens.
59
How are white blood cells adapted for their function?
● Have a nucleus - contains DNA which codes for proteins
● Can produce antibodies
● Can produce antitoxins
● Can engulf and digest pathogens (phagocytosis)
60
What is the purpose of platelets in blood?
Platelets are small cell fragments which aid the clotting of blood at the site of a wound.
61
Why is the function of platelets important?
Platelets aid in the process of blood clotting (conversion of fibrinogen to fibrin). As a result, red blood cells are trapped in the fibrin network, forming a clot which prevents excessive bleeding. Scab formation (after the clot has dried) prevents bacteria from entering the wound.
62
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 and this restricts the supply of oxygen to the heart, possibly leading to a heart attack or death
63
What is a stent and how does it work?
a metal mesh tube that is inserted into a blocked artery so that it remains open. The stent is inflated using a balloon, which is later removed to allow blood to flow freely.
64
What are the advantages and disadvantages of stents?
Advantages
● Insertion can be carried out without general anaesthetic
● Quick recovery time
● Lower the risk of a heart attack
Disadvantages
● Risk of postoperative infection
● Risk of blood clots
65
What are statins?
They are drugs which lower the amount of 'bad' cholestrol in blood which contributes to the development of coronary heart disease
66
What are the advantages and disadvantages of statins?
Advantages
● Reduce risk of strokes, coronary heart disease and heart attacks
● Increase level of HDL (good) cholesterol
Disadvantages
● Have to be taken continuously
● May have side effects
● Effect may not be immed
67
What is a heart bypass surgery?
A surgery where blocked coronary arteries are replaced with sections of veins taken from other parts of the body.
68
What are the consequences of leaky heart valves?
Blood flows in the wrong direction, causing the heart to become less efficient. Patients may become breathless and die as a result.
69
What types of valves can replace leaky valves?
● Mechanical - made of metal or polymers
● Biological - taken from animals (pigs, sometimes humans)
70
What are the advantages and disadvantages of mechanical valves?
Advantages
● Last for a very long time
Disadvantages
● Need to take medication to prevent blood clotting around valve
71
What are the advantages and disadvantages of biological valves?
Advantages
● Work very well - no medication required
Disadvantages
● Only lasts 12-15 years
72
What is the purpose of an artificial heart?
Artificial hearts are intended to support a patient's heart while they wait for a suitable donor heart.
73
What are the advantages and disadvantages of artificial hearts?
Advantages
● Less likely to be rejected by immune system
● Allows damaged heart to rest to help recovery
Disadvantages
● Risk of infection due to surgery
● Risk of blood clots
● Have to take blood-thinning drug
74
What is health?
A state of complete physical, mental, and social well-being
75
What is a communicable disease?
A disease that is caused by a pathogen which can be spread from person to person
76
What is a non-communicable disease?
A disease that cannot be passed from person to person
77
How can diet affect health?
● Too little food / lack of nutrition - anaemia, vitamin deficiencies.
● Too much food / too much unhealthy food - obesity, type 2 diabetes.
78
How can stress affect health?
Prolonged stress is linked to a wide range of health problems including heart diseases, cancers and mental health issues.
79
How can life situations affect health?
Many life factors such as location, gender, financial status, ethnic group and healthcare provision can impact a person's mental and physical health.
80
Give examples of how health problems can interact
● Infection with certain viruses can lead to cancer
● A compromised immune system can lead to a higher risk of infection with communicable diseases.
● Immune reactions caused by a pathogen can trigger allergic reactions.
81
What is a risk factor?
any attribute, characteristic or exposure of an individual that increases the likelihood of developing a disease or injury
82
What is a causal mechanism?
A mechanism which demonstrates how one factor biologically influences another.
83
How do diet, smoking and exercise affect the development of cardiovascular disease?
● Diet: high levels of LDL cholesterol causes arteries to become blocked, increasing blood pressure and the risk of a heart attack.
● Smoking: nicotine increases heart rate; other chemicals damage the artery lining and increase blood pressure.
● Exercise: lowers blood pressure, reducing strain on the heart.
84
How does obesity affect the development of type 2 diabetes?
● Obesity is strongly linked with the onset of type 2 diabetes - a disease in which the body stops responding to insulin.
85
How does alcohol affect liver and brain function?
● Excessive long-term alcohol use may lead to liver cirrhosis (scarring of the liver).
● Increases risk of liver cancer.
● Damages brain tissue and nerve cells.
86
How does smoking affect the development of lung disease and lung cancer?
● Tar in tobacco can damage the alveoli of the lungs, leading to chronic obstructive pulmonary disease (COPD).
● Tar also damages the cells which line the lungs, leading to lung cancer.
87
How do smoking and alcohol affect unborn babies?
● Carbon monoxide from tobacco smoke reduces the amount of oxygen the foetus receives, which can lead to premature birth or stillbirth.
● Alcohol passes across the placenta and damages the developing foetus. Once born, the baby may have a number of deformities and health problems
88
How do carcinogens affect the development of cancer?
Ionising radiation is a type of carcinogen which can cause mutations in DNA, potentially leading to cancer.
89
What is cancer?
the disease caused by an uncontrolled division of abnormal cells in a part of the body.
90
What is a benign tumor?
● A tumour that is contained in one location, usually within a membrane.
● They are not cancerous and do not invade other parts of the body.
● Can grow large very quickly - may cause damage to another organ.
91
What is a malignant tumor?
● A tumour that can spread around the body via the blood and lymphatic system.
● Can invade other tissues (metastasis).
● Cells divide more rapidly and have a longer lifespan.
● Disrupts healthy tissues
92
Give examples of factors which can lead to cancer
● Genetics - certain genes increase the risk of breast and ovarian cancer
● Smoking
● Obesity
● Ionising radiation - UV light and X-rays
● Viral infections - HPV
93
How is epidermal tissue adapted for its function?
Epidermal tissue covers the entire plant. It has a waxy cuticle which helps reduce water loss from the leaf surface.
94
How is palisade mesophyll tissue adapted for its function?
Palisade mesophyll tissue contains lots of chloroplasts which allows photosynthesis to progress at a rapid rate.
95
How is spongy mesophyll tissue adapted for its function?
Spongy mesophyll tissue has lots of air spaces which allow gases (including oxygen and carbon dioxide) to diffuse in and out.
96
How is the xylem adapted for its function?
● Made up of dead cells which form a continuous hollow tube - allows the movement of water and mineral ions from the roots to the leaves.
● Strengthened by lignin - makes the vessel strong and waterproof.
● Has bordered pits - allow minerals to be transported to specific places.
97
How is the phloem adapted to its function?
Sieve plates are at the ends of the walls of the vessel cells which allow sugars to move to the cell interior
98
How is meristem tissue adapted for its function?
Made up of stem cells which can differentiate into many different cell types, allowing the plant to grow.
99
What tissues does the leaf organ contain?
The epidermis, the palisade mesophyll, the spongy mesophyll, the xylem, the phloem, guard cells.
100
What is the function of guard cells?
To open and close stomata to reduce water loss
101
How are stomata adapted for their function?
Stomata allow the control of gaseous exchange and water loss from the leaf.
● More stomata on the base of the leaf - minimises water loss as this side is cooler and shaded.
● Have guard cells
102
How are root hair cells adapted for their function?
Root hair cells allow the uptake of water and mineral ions from the soil.
● Large surface area - maximises rate of absorption.
● Contain lots of mitochondria -- release energy for active transport
103
What is transolcation?
Transport dissolved sugars from the leaves to the rest of the plant.
104
What is transpiration?
Transpiration is the evaporation of water vapour from the surface of a plant.
105
How does transpiration work?
● Water evaporates from the leaf surface via the stomata.
● Water molecules cohere together - more water is pulled up the xylem in an unbroken column.
● More water is taken up from the soil - creating a continuous transpiration stream.
106
How does temperature affect the rate of transpiration?
Increasing the temperature increases the rate of transpiration.
● Higher rate of evaporation and diffusion of water - therefore rate of transpiration is increased.
107
How does humidity affect the rate of transpiration?
Increasing relative humidity decreases the rate of transpiration.
● High relative humidity will reduce the water vapour concentration gradient. The rate of evaporation will decrease, and so will the rate of transpiration.
108
How does wind speed affect the rate of transpiration?
Increasing wind speed/air movement increases the rate of transpiration.
● Increased air movement lowers water vapour concentration outside of the leaf. This increases the water vapour concentration gradient, thereby increasing the rate of evaporation and transpiration.
109
How does light intensity affect the rate of transpiration?
Increasing the light intensity increases the rate of transpiration.
● The rate of photosynthesis increases, so more stomata open. This allows the rate of evaporation to increase, increasing the rate of transpiration.
110
What is a multicellular?
Organisms that are made of multiple cells
111
What is an organelle?
A sub-cellular structure that carries out a specific function within a cell
112
What are some examples of human tissues?
Muscular tissue and nervous tissue
113
What are some examples of human organs?
Stomach and heart
114
What are some example of organ systems?
Digestive system and immune system
115
What are some examples of plant tissues?
Epidermal tissue and palisade mesophyll
116
What are some examples of plant organs?
Roots and stem
117
What is an abnormal cell?
When cell growth and division not under normal control processes
118
What is a malignant tumour?
Lump of cells that have developed the ability to travel to other parts of the body
119
What is a secondary tumour?
A lump of cells formed from a cell transported from a primary tumour
120
What is a carcinogen?
A cancer-causing substance
121
What is an ionising radiation?
Type of radiation that can cause mutations in DNA
122
What is the genetic risk factor?
Specific genes which increase the risk of certain health problems
123
What is the lifestyle risk factor?
Specific actions which increase the risk of certain health problems
124
What is radiotherapy?
A treatment for cancer using radiation
125
What is chemotherapy?
A treatment for cancer using drugs
126
What is epidemiology?
The study of the distribution of mental or physical disorders in a population
127
What is blood?
Connective tissue made of plasma, red blood cells, white blood cells and platelets
128
What are platelets?
Particles in the blood needed for blood clotting
129
What is cardiovascular disease?
A disease of the heart and blood vessels
130
What is coronary heart disease?
The clogging of the vessels that surround the heart muscle
131
What is stent?
A wire mesh tube used to keep arteries open, can sometimes only be a temporary solution
132
What is a faulty valve?
A heart valve which is damaged
133
What is a biological valve?
A replacement heart valve made with the valves and tissues derived from animals or human donors
134
What is mechanical heart?
A non-biological replacement heart valve
135
What is donor heart?
A heart that comes from a deceased donor
136
What is an artificial heart?
A mechanical pump implanted in place of a diseased or damaged heart
137
What is the left ventricle of the heart?
Pumps oxygenated blood to the body through the aorta
138
What is the right ventricle of the heart?
Pumps deoxygenated blood to the lungs through the pulmonary artery
139
What is an atria?
Upper chambers of the heart that receive blood, the right atrium receives blood from the vena cava and the left atrium receives blood from the pulmonary vein
140
What is an aorta?
The largest artery in the body, carries oxygenated blood to the body from the left ventricle
141
What is a vena cava?
The largest vein in the body, carries deoxygenated blood from the body back to the heart, specifically to the right atrium
142
What is pulmonary artery?
Carries deoxygenated blood from the heart to the lungs
143
What is a pulmonary vein?
Carries oxygenated blood from the lungs to the heart
144
What are coronary arteries?
Blood vessels that supply the muscle of the heart
145
What is a trachea?
Allows air to pass to and from lungs
146
What are bronchi?
Two short branches at the lower end of the trachea that carry air into the lungs
147
What is an alveoli?
Tiny sacs of lung tissue where gaseous exchange takes place with the blood
148
What is a capillary network?
An interconnecting network of capillaries surrounding the alveoli
149
What are arteries?
Blood vessels with thick walls, a narrow lumen and elastic fibres, they carry blood away from the heart
150
What are veins?
Blood vessels with valves to prevent the back-flow of blood, thin walls and a large lumen, they carry blood back to the heart
151
What are capillaries?
Smallest and thinnest blood vessels where the exchange of molecules takes place, they consist of a single layer of cells
152
What is the blood flow rate?
The volume of blood passing through a blood vessel per unit of time
153
What is a pacemaker?
The natural resting heart rate is controlled by a group of cells in the right atrium that act as a pacemaker
154
What is an artificial pacemaker?
Electrical devices used to correct irregularities in the heart rate
155
What is a double circulatory system?
The human circulatory system is a double system that has a circuit linking the heart and lungs and a circuit that links the heart to the rest of the body
156
What is a water bath?
A container of water heated to a given temperature for control purposes
157
What is a spotting tile?
Equipment used to observe the colour changes of small quantities of reacting mixtures
158
What is a qualitative reagent?
A substance used in chemical analysis to test for the presence of specific molecules
159
What is a qualitative?
Relates to measuring the quality of something rather than its quantity
160
What is a positive result?
A result that shows the presence of a specific substance
161
What is a negative result?
A result that does not show the presence of a specific substance
162
What is the digestive system?
A body system that breaks down large insoluble food molecules into smaller useful soluble molecules via enzymes, chemicals and mechanical action
163
What is the mouth?
Where food is taken into the body and digestion starts, the mouth contains digestive saliva and can also mechanically digest food via teeth and the tongue
164
What are salivary glands?
Glands in the mouth which release saliva and digestive enzymes such as amylase which breaks down starch
165
What is the oesophagus?
A tube that uses repeated muscular contraction to move food from the mouth to the stomach
166
What is the peristalsis?
The involuntary constriction and relaxation of the muscles of the oesophagus or intestine, creating wave-like movements that push food contents along
167
What is bile?
Emulsifies fat and neutralises stomach acid to help create alkaline conditions in the small intestine, for optimal intestinal enzyme activity
168
What is emulsification?
Allowing fat and water to mix, produces fat droplets with an increased surface area that makes them easier to break down
169
What is gallbladder?
Stores bile produced by the liver
170
What is the bile duct?
Carries bile from the liver and gallbladder and empties it into the duodenum
171
What is the pancreas?
A gland which produces digestive enzymes such as amylase, protease and lipase that can be released into the small intestine
172
What is the pancreatic duct?
Conducts pancreatic juices containing enzymes from the pancreas to the duodenum
173
What is the duodenum?
The first section of the small intestine, receives digestive enzymes from the pancreas and bile from the gall bladder
174
What is the small intestine?
The site of digestion completion where small soluble molecules are absorbed into the bloodstream
175
What is the ileum?
The last portion of the small intestine, the walls of the ileum can produces enzymes such as amylase, protease and lipase to aid digestion
176
What is the villi?
Small finger-like projections on the walls of the small intestine, increases surface area for absorption of soluble food molecules
177
What are the large intestine?
Where water is absorbed from food into the bloodstream
178
What is the appendix?
A small pouch-like sac of tissue at the end of the large intestine
179
What is the rectum?
Where faeces is stored before excretion
180
What is the anus?
Where faeces leave the body
181
What are epidermal tissues?
Tissue that covers and protects the plant
182
What are waxy cuticle?
A layer on the surface of the leaf which protects the plant and reduces water loss, thicker on the upper surface
183
What is the palisade mesophyll?
Photosynthetic tissue below the epidermis in a leaf, palisade cells contain high concentrations of chlorophyll and high quantities of chloroplasts for photosynthesis
184
What is the spongy mesophyll?
Layer of tissue found beneath the palisade mesophyll that is packed loosely for efficient gas exchange of carbon dioxide and oxygen
185
What is a xylem?
Non-living vascular tissue that carries water and dissolved minerals from the roots of a plant to its leaves, the xylem is hollow and nearby cells are lignified or dead so water can move continuously
186
What are shoots?
The aerial portion of a plant body consisting of stems, leaves and flowers
187
What is the roots?
Underground plant organs that absorb water and minerals
188
What is the stomata?
Small openings on the underside of a leaf through which oxygen, carbon dioxide and water can move
189
What are guard cells?
Pairs of cells that surround the stomata and control their opening and closing to optimise gas exchange and reduce water loss
190
What are root hairs cells?
Cells that absorb water and mineral ions from the soil, via diffusion, osmosis or active transport using structures with a large surface area
191
What factors affecting transpiration?
Changing temperature, humidity, air movement and light intensity
192
What is the effect of factors affecting transpiration?
Light, wind and heat will increase the rate of transpiration, humidity will decrease the rate of transpiration
193
What is the rate of transpiration?
The rate of water loss from a plant
194
What is a potometer?
A device used for measuring the rate of water uptake of a plant due to photosynthesis and transpiration, a bubble of water will move along the potometer to indicate the rate of transpiration
