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Lifestyle and Influence Flashcards

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1
Q

Why is water a polar molecule?

A

Water is a polar molecule because it has an unevenly distributed electric charge.

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2
Q

What charges do the atoms in a water molecule have and why?

A

The hydrogen end of the molecule becomes slightly positive whilst the oxygen end of the molecule becomes slightly negative, this is because the electrons in the molecule are more concentrated at that end.

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3
Q

How are water molecules joined?

A

The slightly positive charged end of the water molecule is attracted to the slightly negative end of the surrounding water molecules. Hydrogen bonds hold the water molecules together and this results in many of waters properties such as being a liquid at room temperature.

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4
Q

what type of molecules dissolve in water and why?

A

Polar molecules because they’re hydrophilic (water loving)

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5
Q

What type of molecules don’t dissolve in water and why?

A

Non-polar molecules dont dissolve in water because they’re hydrophobic (water-repelling)

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6
Q

Give an example of a non-polar molecule

A

Lipids are non-polar molecules because they don’t dissolve in water (fatty acid tails are hydrophobic) therefore they need to combine with proteins to form lipoproteins.

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7
Q

Why does it take a lot of energy to raise waters temperature?

A

It requires a lot of energy to increase waters temperature by 1 degrees because it takes a high quantity of energy to break the hydrogen bonds between each individual water molecule. Therefore a large input in energy only causes a small input in temperature.

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8
Q

Why does water have a high boiling point?

A

Water has a high boiling point because there are a vast array of hydrogen bonds and these all have to be broken to make the water boil (high amount of energy required)

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9
Q

Why does blood remain a liquid at room temperature?

A

TBC

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10
Q

Why is blood solvent for polar and ionic substances?

A

TBC

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11
Q

Why does blood have a high specific heat capacity?

A

TBC

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12
Q

Describe the vessels/chambers that oxygenated blood from the lungs flows through in order to get back to the blood (deoxygenated)

A

TBC

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13
Q

Describe the structure of an artery

A
  • Thick walls made up of lots of collagen and elastic fibres, the walls have to be thick enough to be able to withstand the high pressure of blood forced against them during systole.
  • Due to the thick walls of the arteries, the lumen is very narrow, this means that the pressure of the blood in them is very high
  • The arteries contain a layer of smooth muscle
  • There are no valves in the arteries
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14
Q

Describe the structure of a vein

A
  • thinner walls still made up of collagen and elastic fibres but much less of them compared an artery.
  • The lumen of a vein is much wider than that of an artery, this helps in this assist of blood flow return to the heart because more blood can be accommodated.
  • Veins contain a layer of smooth muscle
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15
Q

Describe the structure of a capillary

A

Capillaries contain a lumen surrounded by a layer of endothelium cells, the flow of blood in the capillaries is very steady and quite slow due to the friction caused by the blood moving against the walls. This friction causes the flow of blood to slow down which in turn maximises the chance of materials to be exchanged between the blood and surrounding cells.

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16
Q

Describe the flow of blood in an artery

A

Blood in an artery flows at very high pressure and the flow of blood in the arteries is assisted by the heart contracting during systole (constant contractions).
The elastic recoil of the artery wall behind the blood helps to push the blood forward through the artery, hence the need for no valves.

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17
Q

Describe the flow of blood in a vein

A

The flow of blood in a vein is under relatively low pressure and more continuous, the hearts contractions doesn’t have a direct effect on the flow of blood.
The flow of blood in veins is assisted by the contraction of the skeletal muscles during movement of limbs and breathing - the skeletal muscles contract and push blood forwards, its the valves that prevent the backward flow of blood by closing shut.

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18
Q

What muscle divides the heart?

A

The septum

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19
Q

Why is the left ventricle wall thicker than the right ventricle

A

The left ventricle wall is 3x as thick as the right side because it has to pump blood with enough force for the blood to travel around the entire body whereas the right hand side of the heart only has to pump blood to the lungs.

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20
Q

What do valves do?

A

Valves prevent the back flow of blood

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21
Q

What are the blood cycles of the heart?

A

Atrial systole
Ventricular systole
Cardiac diastole

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22
Q

Describe the process of Atrial Systole

A

Blood returns back to the heart as a result of the action f skeletal muscles during breathing and movement of limbs. Blood under low pressure flows into the atria from the great veins, as the atria continue to fill, the pressure of blood against the atrioventricular valves forces them to open and blood then flows into the ventricles. The atria then simultaneously contract which forces any remaining blood into the ventricles.

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23
Q

Describe the process of Ventricular Systole

A

After a slight delay atrial systole is followed by ventricular systole. The ventricles contract form the base of the heart upwards which increases the pressure in the ventricles, the pressure forces open the semi lunar valves and pushes blood up and out through the aorta and pulmonary artery. The pressure of blood against the atrioventricular valves forces them to close which creates the ‘lub’ sound.

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24
Q

Describe the process of Cardiac diastole

A

During cardiac diastole the atria and ventricles relax. The elastic recoil of the relaxing heart walls lowers the pressure in the atria and ventricles, the opposite pressure forces attracts high pressure blood from the aorta and pulmonary artery back towards the verticals which causes the semi lunar valves to close ‘dub’ sound. The low pressure in the atria helps to draw blood into the heart from the veins.

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25
What is an atheroma?
TBC
26
Describe the process of blood clotting
Blood clots are a resulting factor of a tear/damage to the endothelBlood clots are a resulting factor of a tear/damage to the endotheliuiuf larger cells) come into contact with the damaged vessel they change from their flattened disc shape into spheres with projections which makes them stick together (sticky). This causes them to stick together and to the damaged vessel causing a temporary plug. The platelets and damaged vessels release a protein called THROMBOPLASTIN. The thromboplastin reacts with the calcium and vitamin k found in the plasma of the blood to catalyse the conversion of the protein PROTHROMBIN into the enzyme THROMBIN. Thrombin then catalyses the conversion of the soluble plasma protein FIBRINOGEN into the insoluble protein fibrin. A fibrin mesh forms, this traps more platelets and red blood cells to form a clot. Once the damaged has been healed the clot is dissolved by the blood.
27
Describe the process of atherosclerosis
Atherosclerosis starts off with damage being caused to the endothelium. The endothelium damage can result from high blood pressure which puts extra strain on the layer of cells. Once the inner lining of the artery is breached, there is an INFLAMMATORY RESPONSE - WBC leave the blood vessel and move into the artery wall. These cells accumulate chemicals from the blood such as CHOLESTEROL - and a fatty acid builds up (ATHEROMA). Calcium salts and fibrous tissue also build up at the site resulting in a hard swelling called plaque on the inner wall of the artery. The build up of fibrous tissue means that the wall loses some of its elasticity (hardens). Plaques cause the lumen of the artery to become narrower - more difficult for the heart to pump blood around the body and this can lead to raised blood pressure (DANGEROUS POSITIVE FEEDBACK). The raised blood pressure makes it more likely that other plaques will form as damage to endothelial tissue in other areas becomes more likely.
28
What are the chemicals/hormones used in blood clotting and if they combine with anything, what do they combine with?
TBC
29
What is risk?
The probability of an unwanted outcome or event
30
What is probability?
Probability has a precise mathematical meaning and can be given a numerical value or percentage
31
What do we need to remember when calculating risk?
The exposure to the hazard
32
People may over estimate the risk of something happening if the risk is .....
``` Unfamiliar Dreaded Involuntary Not Natural Unfair Very small ```
33
There are many different risks which contribute to health risks, such as .......
``` Age Hereditary Physical environment Lifestyle and behaviour choices Social environment ```
34
What is correlation?
When a change in one variable is accompanied by a change in another
35
What is causation?
Causation is when one variable is responsible for a change in another variable
36
What is a null hypothesis?
They assume that for the sake of an argument that there will be no difference between an experimental group and a control group, and then rest this hypothesis using statistical analysis
37
What do scientists do to identify risk factors associated with a particular disease?
Scientists look for correlations between potential risk factors and the occurrence of the disease
38
Who identifies risk factors for CVD?
Epidemiologists are scientists who study a specific pattern in the occurrence of a disease, they look for correlations between a disease and the specific risk factors.
39
What are the two common designs for a epidemiologist to study?
Cohort study | Case-control study
40
What is a cohort study?
A cohort study is a study that follows a large group of people over time to see who develops disease and who does not. The study is a PERSPECTIVE STUDY; at the start of the study none of the participants have the disease. The researchers aim to see what happens to them in the future - during the study peoples exposure to risk factors and whether they develop a disease is recorded, this is so any correlations between risk factors and disease development can be identified.
41
What is a case control study?
In a case control study, a group of people with a disease are compared with a control group of individuals who do not have a disease. Information about risk factors the participants have been exposed to in the past are identified allowing factors that may have contributed to the development of a disease to be identified.
42
What are the features of a good study?
``` Clear aim Representative sample Valid and reliable results Sample size Controlling variables Risk factors of CVD ```
43
Clear aim
A well designed study has a clear aim or hypothesis, the design of the study must be appropriate to the stated hypothesis or aim to produce results that are valid and reliable - Selection bias occurs when those who participate in a study are not representative of the target population - The proportion of participants who drop out of a study should be kept to a minimum, this is important in cohort studies which follow people over a long period of time, people who drop out of studies often have common features.
44
Representative sample
A representative sample must be selected from the wider population that the studies conclusion will be applied to
45
Valid and reliable results
- Any methods used must provide valid data, the data is valid if its measuring what its intended to be measured - Any method used to collect the data must be reliable, a reliable method produces results that are repeatable and reproducible - Disease diagnosis must be clearly defined to ensure that other scientists record and measure symptoms in the same way.
46
Sample size
The sample size has to be large enough to produce results that couldn't have occurred by chance
47
Controlling variables
The potential effect of all variables that could be correlated with the disease should be considered when designing the study
48
Risk factors of CVD
``` High blood pressure Obesity Blood cholesterol Smoking Inactivity Genetic inheritance ```
49
How does age effect the risk of CVD?
The risk of developing CVD increases with age (positive correlation), partly because plaque can build up over a long period of time which can eventually lead to CVD
50
How does gender effect the risk of CVD?
Men are 3x more likely to suffer from CVD than pre-menopausal women. This may be due to the different levels of hormones, for example the hormone oestrogen is higher in women than men (typically) which increases levels of good cholesterol, the lower levels in men can lead to higher levels of bad cholesterol, increasing the risk of CVD
51
What are the situations when people will overestimate the risk of something happening?
``` Involuntary Not natural Unfamiliar Dreaded Unfair Very small ```
52
Give a weakness of a cohort study
Cohort studies take a long time to conduct and are therefore time consuming and expensive
53
Give an extended point of a case control study
Case control studies are retrospective, the control group should be representative of the population from which the sample was taken.
54
What is considered to be the most common cause of CVD?
High blood pressure
55
What does HBP increase the risk of?
HBP increases the risk of tears in the endothelium which causes atheroma's to form which can lead to atherosclerosis.
56
What is blood pressure a measure of?
Blood pressure is a measure of the hydrostatic force of blood against the walls of a blood vessel (blood pressure is higher in arteries than veins).
57
When is blood pressure in an artery at its highest?
During ventricular systole when the ventricles have contracted to force blood out of the heart through the aorta and pulmonary vein (SYSTOLIC PRESSURE)
58
When is blood pressure in an artery at its lowest?
Pressure is at its lowest when the ventricles are relaxed during cardiac diastole (DIASTOLIC PRESSURE)
59
What are the units of measuring blood pressure?
kilopascals, SYSTOLIC / DIASTOLIC
60
What are the units of measuring blood pressure in the medical practice?
Millimetres of mercury, mmHg, the numbers refer to the number of millimetres the pressure will raise a column of mercury.
61
What determines blood pressure?
- Contact between the blood and vessel wall causes friction and this impedes the flow of blood (PERIPHERAL RESISTANCE). - The arteries and capillaries offer a greater total surface area than the arteries, resisting the flow more and therefore slowing the blood down and causing blood pressure to fall - As blood is pumped from the heart, the pressure is higher, during diastole the elastic recoil of the blood vessels maintains the pressure and keeps the blood flowing - If the smooth muscles in the walls of an artery or an arteriole contract, the vessels constrict making the lumen narrower and increasing the resistance (Blood pressure is raised). - If the smooth muscles relax, the lumen is dilated, so peripheral resistance is reduced and blood pressure falls. - Any factor that causes the arteries/arterioles to constrict can lead to elevated blood pressure; such factors include natural loss of elasticity with age, high salt diet and the release of hormones such as adrenaline.
62
What causes the fluctuation of the blood pressure?
The contraction and relaxation of the heart
63
What is a sign of high blood pressure?
An oedema
64
What is an oedema?
Oedema is a build up of fluid in the tissues which causes swelling - oedemas can also be associated with kidney or liver disease with restricted body movement
65
How is an oedema formed?
At the atrial end of a capillary, the pressure of blood is under high pressure - this forces fluids and small molecules out through the tiny gaps between the cells in the capillary all into intercellular space (forming tissue fluid). Blood cells and larger plasma proteins stay inside the capillary because their large size prevents them from passing though the gaps between the cells. The tissue fluid drains to a network of lymph capillaries which returns the fluid to the body via a lymph vessel which empties into the vena cava.
66
What can increase CVD?
Dietary factors - the type and quantity of high energy food that we eat can either increase or decrease our risk of developing certain diseases such as CVD
67
Where do we get our energy from?
carbohydrates, lipids and proteins are constituents of our food that contain energy.
68
What is a monosaccharides
monosaccharides are simple sugars (single sugar units)
69
What are disaccharides?
Disaccharides are double-sugars formed when two monosaccharides combine in a condensation reaction
70
How are polymers made?
made by linking identical or similar subunits called monomers together
71
Why are lipids not polymers?
Lipids aren't polymers because they aren't chains of monomers
72
How many carbon atoms do monosaccharides have?
Between 3 and 7
73
What is the formula of a monosaccharide?
(CH2O)n, n = number of carbons
74
Monosaccharide - Glucose
Glucose is the main sugar used by all cells in respiration. Starch and glycogen are polymers made up of glucose subunits joined together, when starch or glycogen is digested, glucose is produced. This can be absorbed and transported in the blood stream to cells, this is known as å glucose
75
What is maltose made of?
Maltose is made up of two å glucose molecules, the two å glucose molecules join in a condensation reaction to make maltose, the bond between the two å glucose molecules is called a glycosidic bond. When two glucose monosaccharides join the link will be between the first and forth carbon, therefore its called a 1,4-glycosidic bond.
76
What molecule is also made in addition to maltose?
Water (H2O)
77
What is maltose?
A disaccharide
78
Alpha glucose + Alpha glucose = ?
Maltose
79
Alpha glucose + Fructose = ?
Sucrose
80
Alpha glucose + Galactose = ?
Lactose
81
Practice drawing the above^
Practice drawing the above^
82
What is a hydrolysis reaction?
When water is added
83
What molecule is required for a hydrolysis reaction to take place?
Water
84
What is starch?
Starch is a polysaccharide made of many glucose molecules arranged in two different structures.
85
What are the starch polymers?
Amylose | Amylopectin
86
Describe amylose
Amylose is a starch polymer with 1,4-glycosidic bonds between adjacent glucose molecules. Amylose is a unbranched polymer that contains only 1,4-glycosidic bonds. The position of the bonds cases the molecule to coil which makes it more compact. This makes it a good storage molecule because you can fit more into a small space. An amylose molecule is made up of 200-500 glucose molecules, these molecules can only be removed by enzymes working from each end of the amylose molecule.
87
Describe amylopectin
Amylopectin is a starch polymer also with 1,4-glycosidic bonds between adjacent molecules, they also have 1,6-glycosidic bonds which hold side branches onto the main chain. Amylopectin is a branched polymer that contains 1,4-glycosidic bonds and 1,6-glycosidic bonds. The side branches allow enzymes to get to the glycosidic bonds easily. This means that the sugar molecules can be broken off readily by enzymes when energy is needed.
88
Where is starch found?
Starch is the major carbohydrate storage molecule in plants
89
What is a disaccharide?
Disaccharides are two single sugar units which join together in a condensation reaction to form a disaccharide
90
What is the bond between a disaccharide called?
Glycosidic bond
91
What is a polysaccharide?
Polysaccharides are polymers made up from simple sugar monomers joined by glycosidic bonds into long chains
92
What is glycogen?
Glycogen is a polymer composed of glucose molecules, it has many side branches meaning it can be rapidly hydrolysed, giving easy access to stored energy.
93
Where is glycogen stored in humans?
The liver and muscles
94
What is cellulose?
Cellulose is a dietary fibre (also called a non-starch polysaccharide.
95
Why are glycogen and starch polymers?
Because they're made up of glucose subunits
96
How is alpha glucose produced?
When starch or glycogen are digested
97
Name 2 structural differences between starch and cellulose
Starch contains alpha glucose whilst cellulose contains beta glucose starch is linked by alpha glycosidic bonds and cellulose is linked by beta glycosidic bonds Starch may contain branched chains, whilst cellulose doesn't.

Biology (4 decks)

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