Topic 1 Flashcards
(271 cards)
1
Q
Name the valves located between the atria and the ventricles.
A
Atrioventricular valves
2
Q
Which heart chamber has the thickest walls?
A
Left ventricle
3
Q
Name the blood vessel which carries blood from the lungs to the heart.
A
Pulmonary vein
4
Q
During which stage of the cardiac cycle does blood get pumped from the atria into the ventricles?
A
Atrial systole
5
Q
During what stage of the cardiac cycle do the semilunar valves open?
A
Ventricular systole
6
Q
If one cardiac cycle takes 0.7s, calculate the heart rate in bpm.
A
60/0.7= 85.7 bpm
7
Q
Which heart chamber pumps blood into the aorta?
A
Left ventricle
8
Q
Name the heart chamber which receives blood from the vena cava.
A
Right atrium
9
Q
During which phase of the cardiac cycle is blood pumped into the arteries?
A
Ventricular systole
10
Q
State one function of the atrioventricular valves.
A
-Open to allow blood to be pumped into the ventricles in atrial systole
-Closes to prevent the backflow of blood into the atria in ventricular systole
11
Q
Name the blood vessel which carries blood from the heart to the lungs.
A
Pulmonary artery
12
Q
What is the function of the coronary arteries?
A
To provide the cardiac muscle with an oxygenated blood supply
13
Q
Name the blood vessel which carries blood away from the left ventricle of the heart.
A
The Aorta
14
Q
During which stage of the cardiac cycle do the atrioventricular valves close?
A
Ventricular systole
15
Q
Does the aorta have thicker or thinner walls than the pulmonary artery?
A
Thicker
16
Q
Does the pulmonary artery carry oxygenated or deoxygenated blood?
A
Deoxygenated
17
Q
State the function of the semilunar valves.
A
-Open during ventricular systole so blood can be pumped into the arteries
-Close to prevent the backflow of blood into the heart from the ventricles during cardiac diastole
18
Q
Why is blood pumped at a lower pressure to the lungs than it is to the body?
A
-Right ventricle walls are thinner
-To prevent damage to delicate lung tissue
-The lungs are much closer to the heart so the blood doesn’t need to travel very far. Therefore, the blood can be under a lower pressure.
- Slow blood flow allows for efficient gas exchange
19
Q
What are the cells of the endothelium of the capillary flattened?
A
- Reduces diffusion distance for efficient gas exchange
-Provides a smooth surface to reduce friction and resistance against blood in order to transport blood faster.
20
Q
Why do capillary walls have pores?
A
Pores allow the passage of materials between the blood and the cell
21
Q
Why do arteries not need valves?
A
Blood in the arteries are under very high pressure so the blood will continue to move forward without backflow
The high content of elastic fibres continues to push the blood along due to the elastic recoil
22
Q
Which component of the artery walls allows them to stretch and recoil?
A
The elastic fibres
23
Q
Why does an artery need thick walls?
A
To withstand high blood pressures
24
Q
In which type of blood vessel is the pressure lowest?
A
Veins
25
Why do blood vessels need an **endothelial layer** which is smooth?
To reduce **friction** of blood flow against vessel walls
26
What features of an artery helps maintain high blood pressure?
- Elastic fibres
- **Narrow** lumen
- Smooth muscle
27
Why do veins need valves?
The blood in vein is at a relatively low blood pressure and this means that there can be a backflow of blood in the veins and therefore valves are needed to stop this
28
The aorta is an artery with a relatively wide lumen. Why does it need a wider lumen than other arteries?
The aorta needs a wider lumen as it is at the heart and therefore endures the highest blood pressure. The aorta also transports *all* the blood sent to the body. Therefore the lumen must be a little wider to accommodate this high pressured blood.
29
State the structural differences between an artery and a vein.
- The arteries carry oxygenated blood (besides the pulmonary artery) but veins carry deoxygenated blood (besides the pulmonary vein)
- Arteries have thicker vessel walls as the they have more smooth muscle and elastic fibres than veins
- Arteries stretch more as the accommodate blood with a higher pressure that veins
- Veins have less ability to constrict or contract due to a lower smooth muscle content than arteries
- Veins have less elastic recoils due to a lower elastic fibre content than arteries
- Veins have a **wider** lumen
- Arteries have a folded endothelium that stretches to accommodate blood, veins do not
- Veins have valves to stop backflow, arteries do not
- Veins transport blood to the heart and arteries transport blood away from the heart
- In arteries blood moves in pulses, veins have a steady blood flow
30
What is the space in the centre of the blood vessel called?
The lumen
31
Name an artery which carries deoxygenated blood.
The pulmonary artery
32
Name the type of muscle found in artery walls
Smooth muscle
33
Name the blood vessel which delivers blood to the right atrium.
The vena cava (superior and inferior)
34
Will the CO2 concentration be higher in a coronary artery or a coronary vein?
Coronary vein
35
Calculate the volume of a section of artery which is 7cm long and 3mm is diameter.
Area= pi r squared = pi x 1.5 x 1.5
= 2.25 x pi x 70= 157.5pi mm(cubed)
36
Name the blood vessel which carries blood away from the left ventricle.
Th aorta
37
If the blood pressure in a vessel decreases form 3.1KPa to 2.5KPa, calculate the percentage decrease.
3.1 - 2.5= 0.6
0.6/3.1= 0.1935
0.1935 x 100= 19.35% decrease
38
Why do lung capillaries need very thin walls?
To make the the diffusion distance between the air and the blood small. This leads to efficient gas exchange
39
State the similarities between arteries, veins and capillaries.
-Have a smooth endothelial layer
-Have a lumen
40
If a person suffers a stroke, the blood vessels carrying oxygenated blood to which organ is blocked?
The brain
41
Is the blood in the capillary network of the lungs oxygenated or deoxygenated?
Deoxygenated at the arterial end of the capillary bed but oxygenated at the vein end of capillary bed
42
How is the low pressure blood in the veins moved back to the heart against gravity?
- The blood is pushed along by the contraction and skeletal muscles in movement
- A low pressure zone is developed in the **thorax** (chest cavity due to breathing) pulling blood back up for he heart
- Valves prevent backflow
43
Name two arteries in the body which have semilunar valves at their base.
- Aorta
- Pulmonary artery
44
Why is it important that arteries can constrict?
- For control of the blood flow eg. vasoconstriction which allows the body to maintain body heat
45
In which type of blood vessel can you feel your pulse?
Artery
46
How does the pressure of the aorta change when the left ventricle contracts?
The pressure increases rapidly
47
What is the function of the collagen coat in an artery?
-To prevent vessel from bursting
-Provide strength
-Anchors vessel to surrounding tissue
48
Name the blood vessel which delivers blood to the left atrium?
Pulmonary vein
49
What component of the artery walls allows them to constrict?
The smooth muscle
50
How does the lumen diameter of an artery change when an artery dilates?
It increases
51
What is the outer coat made out of?
Collagen fibres and connective tissue
52
How do capillaries maximise gas exchange?
-Short diffusion distances
-Pores
-Large networks to provide a large surface area
-**Narrow** lumen (1RBC in diameter) slows down blood
-Steady blood flow
53
How wide is a capillary lumen?
10 um or 1 RBC
54
To constrict blood flow, what must the smooth muscle do?
Contract
55
To dilate blood flow, what must the smooth muscle do?
Relax
56
What is the endothelial layer/endothelium?
A mono**layer** of cells
57
What does the elastic fibres in a blood vessel do?
Allows the vessel to stretch and recoil
58
What is collagen?
A tough, fibrous protein
59
Define the cardiac cycle
The repeating sequence of the action which the heart preforms from on heart beat to the next: Atrial systole, ventricular systole, cardiac diastole
60
What happens in cardiac diastole?
-The atria and ventricles relax
-The semilunar valves close caused by artery backflow
-Blood is drawn into the low pressure area in the atria
-The atria fill with blood
-The atrioventricular valves opens due to increasing pressure
-Blood moves from veins to atria and into the ventricles
61
What happens in atrial systole?
-Atria contract
-Remaining blood is pushed through atrioventricular valves
62
What happens on ventricular systole?
-Ventricles contract after slight delay
-Increasing blood pressure force the atrioventricular valves closed
-Blood is forced through the semilunar valves into arteries
63
What is the heart?
- A double pump
-Made of cardiac muscle
64
Describe the order in which blood flows through the heart
1.Blood from the body travels through the superior and inferior vena cava
2.Blood enters right atrium
3.Blood flows through an atrioventricular valve
4.The right ventricle fills with blood
5.The blood exits the heart through a semilunar valve
6. Blood travels through the pulmonary artery
Blood arrives at lungs and becomes oxygenated
7.Blood travels back to the heart through the pulmonary veins (right and left)
8.Blood enters left atrium
9.Blood is pushed through an atrioventricular valve
10.Blood fills the left ventricle
11.Blood is pushed through a semilunar valve
12.Blood enters the aorta
Blood then travels to the rest of the body
65
What is the first “thump” of a heartbeat caused by?
The closing of the atrioventricular valves
66
What is the second “thump” of a heartbeat caused by?
The closing of the semilunar valves
67
In which type of blood vessels is blood pressure lowest?
Veins
68
Is diastolic or systolic pressure highest?Why?
Systolic because the blood is being forced directly whereas diastolic relies on low pressure. Ventricles are contracting
69
What effect does high blood pressure have on the artery endothelium?
High blood pressure damages the endothelium
70
What is **hypertension**?
**Hypertension** is persistently high blood pressure
71
Is blood pressure highest when blood enters the capillaries or when blood leaves the capillaries to enter the veins?
When blood enters the capillaries
72
What charge is found on the oxygen atom of water?
A negative charge. **Delta negative**
73
Is a hydrogen bond weak or strong?
Weak
74
One end of a water molecule is slightly positive and one end is slightly negative,so a water molecule is described as _______?
**Dipolar/Polar**
75
State the chemical formula of water
H2O
76
Water is a liquid at room temperature because hydrogen bonds between water molecules give it an unusually high ___________?
Boiling point
77
When hydrogen bond form between 2 water molecule, does this result is **adhesion** or **cohesion**?
**Cohesion**
78
What type of drug reduces blood pressure?
**Antihypertensive** drug
79
State lifestyle factors which can lead to high blood pressure.
-high salt diet
-high saturated fat/sugar diet
-lack of exercise
-obesity
-high stress
-smoking
-regular, excessive alcohol intake
80
Describe a hydrogen bond
A weak force of attraction between molecules/ions
81
Explain how water acts as a solvent.
The **delta positive** H attracts (delta)negative ion or molecule/part of a molecule. Bond forms between water molecule and molecule/ion. Water molecules surround the molecule/ion and dissolve it
82
Give examples of water acting as a solvent in the human body
-Water in blood dissolve oxygen, glucose etc.
-Interstitial fluid
-Tissue fluid
83
Give examples of water acting as a solvent in a plant
-Water is xylem vessels dissolves plant mineral ions
84
What is **cohesion**?
The attraction for molecules to other molecules of the same type.
85
What is **Adhesion**?
The attraction for molecules to molecules of a different type
86
Negative ions are attracted to what in water?
The slightly positive hydrogen end
87
What does hydrophilic mean?
Water-loving, can form hydrogen bonds with water
88
What does hydrophobic mean?
Water-hating, can’t form hydrogen bonds with water
89
What group of molecules are hydrophilic? Give examples
Polar group, -OH and -NH2 (amine group)
90
What group of molecules or hydrophobic? Give examples
Non-polar, lipids
91
What are lipoproteins combined of and for?
Combination of lipids and proteins in order to transport lipids around the body
92
What happens when polar ions dissolve?
The ion becomes hydrated and an ion-dipole bond is formed
93
How large is a water molecule?
Very small
94
Does water have a high or low **specific heat capacity**?
High
95
What advantages does water having a high SHC have for biological organisms?
-Maintains a steady internal temperature, avoiding rapid changes
-Bodies of water where organisms live will not change temp. rapidly
-Animals can carry out **thermoregulation**
96
Specific heat capacity is:
The amount of energy (J) needed to raise the temperature of 1g by 1°c
97
Water being a liquid at bio temp. enables **mass flow**. What is **mass flow**?
The movement of fluids down a pressure/temperature gradient (around the body)
98
Define diffusion
The free movement of molecules/ions from a region of low concentration down a concentration gradient (through a partially permeable membrane)
99
Describe a **mass transport system**
Substances are transported in the flow of a fluid with a mechanism for moving it around the body
100
What are the two main types of circulatory system?
Open and closed
101
Which organisms have open circulatory systems?
Invertebrates
102
Describe how an open circulatory system works
The heart contracts, pumping blood into empty cavities within the organism. These cavities surround the organs allowing for gas exchange/exchange of substances. The blood is the drawn back over the gills (becoming oxygenated) before travelling into the (relaxed) heart
103
What are the differences between an open and closed circulatory system?
-OCS is under low pressure while CCS is under high pressure
-CCS has blood vessels, OCS does not
-CCS maintains higher blood pressure and therefore allows faster transport
-CCS has directed flow, OCS does not
104
What are the two main types of closed circulatory system?
Single and double
105
Fish have what type of circulatory system?
Single circulatory system
106
Describe a single circulatory system
Blood passes through the heart once. Deoxygenated blood enters the heart at low pressure and is pumped to the gills. Travelling through the gill capillaries, the blood becomes oxygenated. Blood travels from gills to the rest of the body at a low pressure before returning to the heart deoxygenated.
107
What are the advantages of a **double circulatory system**?
-Deoxygenated blood and oxygenated blood don’t mix meaning max efficiency of gas exchange
-Blood is **re-pressurised** allowing faster transport
-Allows blood to move at different pressures/speeds
-Enables fast removal of waste products
-Enables thermoregulation
-Allows us to develop higher brain function
-Creates higher metabolic rate
-Allows us to be more active
108
Why does blood travel at lower speed/pressure through the lungs?
To prevent damage and bursting of the delicate lung tissue and capillaries. The right side of the heart has less cardiac muscle
109
Why do unicellular organisms not have mass transport systems?
They have a large SA:V ratio. The diffusion distance is so small that direct diffusion with the surroundings is sufficient to maintain life
110
Why do multicellular organisms need a **mass transport system**?
They have a low SA:V ratio and therefore must have a mass transport system in order to **overcome the limitations of diffusion** and to move molecules quickly between gas exchange surfaces and cells
111
Which plasma protein is converted into **fibrin**?
Soluble **fibrinogen** by **thrombin**
112
Which of these is and enzyme, **prothrombin** or **thrombin**?
**Thrombin**
113
Is **fibrinogen** soluble or insoluble?
Soluble
114
Is **thromboplastin** a protein?
Yes, it is an enzyme and therefore a protein
115
Name the enzyme that converts **fibrinogen** into **fibrin**
Thrombin
116
Which vitamin is essential for the blood clotting process?
Vitamin K
117
Describe the role of a blood clot in coronary heart disease
The blood clot will block the coronary artery. This results in restricted blood flow and decreases/stops the oxygen supply to the cardiac muscle. This leads to anaerobic respiration which produces lactic acid/pain, the heart muscle cells die. This can lead to heart attacks
118
Describe the role of a blood clot in a stroke.
The blood clot will block the arteries leading to the brain. This results in restricted blood flow and decreases/stops the oxygen supply to the brain tissue. Causing brain cells to die. The can lead to strokes
119
What are the two enzymes used in the blood clotting process?
**Thrombin** and **Thromoplastin**
120
Is fibrin a **fibrous** or **globular** protein?
Fibrous
121
Which two blood components get trapped into he fibrin mesh to form a blood clot?
Platelets and red blood cells
122
Name the 2 plasma protein that are present in blood, which become involved in the blood clotting process
**Prothrombin** and **Fibrinogen**
123
Name the first enzyme to be produced in the blood clotting process. What releases this enzyme?
Thromboplastin. Released by platelets and damaged tissue in the presence of **collagen**
124
Give reasons why it is important for blood to be able to clot
- Stops mass blood loss
- Repairs damaged endothelium/tissue
- Prevents infection
125
Why can’t the enzyme **fibrinogen** convert **prothrombin** to **thrombin**?
The active site is the wrong shape, so fibrinogen cannot fit into it, but prothrombin can (enzyme specificity)
126
What is a blood clot known as?
**Thrombosis** or thrombus
127
What is a fibrous protein?
A long, thin protein that is insoluble in water
128
What is a globular protein?
A protein that is spherical in shape and are soluble in water. They perform metabolic roles (enzymes)
129
What is needed in addition to thromboplastin to **catalyse** the conversion of prothrombin to thrombin?
Calcium ions and vitamin K
130
What is a platelet?
A cell fragment
131
The fibrin forms a _______ to trap the red blood cells and platelets
Mesh
132
The enzyme thrombin _________ the ___________ of fibrinogen to fibrin
- catalyses
- conversion
133
Which forms first, a plaque or an atheroma?
Atheroma
134
Which type of blood cells move into artery walls when the endothelium is damaged?
White blood cells
135
Name the type of lipid that builds up in artery walls during atherosclerosis
Cholesterol
136
What effect does atherosclerosis have on the elasticity of artery walls?
Atherosclerosis reduces elasticity and **hardens** walls
137
If atherosclerosis cause an artery lumen diameter to decrease from 5mm to 1.2mm, calculate the percentage decrease in lumen diameter
5-1.2 = 3.8, 3.8/5=0.76, 0.76x100= 76% decrease
138
Why does atherosclerosis usually take place in arteries rather than veins?
Arteries carry blood at a much higher pressure than veins and therefore the endothelium of arteries gets damaged more
139
Which mineral ion is involved in the development of plaques in atherosclerosis?
Calcium 2+ ion
140
Why is atherosclerosis described as self-perpetuating?
An atheroma will block/narrow the lumen of an artery. This means the blood had a smaller area to pass through and this increases blood pressure. The increased blood pressure results in the damage of the endothelium and therefore leads to more atheroma
141
Which mineral ion is involved in blood clotting and atherosclerosis?
Calcium 2+ ion
142
Atherosclerosis is described as ______________ of the arteries, because there is a loss of elasticity in the artery
Hardening
143
Atherosclerosis is described as ______________ of the arteries, because there is a loss of elasticity in the artery
Hardening
144
What effect does atherosclerosis have on the lumen diameter of an artery?
It decreases it
145
What is the process of atherosclerosis?
- **Damage** - endothelium becomes damaged due to high blood pressures
- **Inflammatory response** - white blood cells move to the artery wall
- **Atheroma formation** - white blood cells accumulate chemicals from blood (cholesterol) and a fatty deposit builds up, **atheroma**
- **Plaque formation** - Calcium, salts and fibrous tissue also build up at the site, resulting in a hard swelling called a plaque. This causes the vessel to lose elasticity and harden
- **Lumen blockage** - blood causes the lumen to get narrower. This increases blood pressure and a **positive feedback** starts to bile up
146
State lifestyle dietary factors which may lead to high blood pressure
- High cholesterol in diet
- High saturated fat diet
147
Name the response triggered by damage to the artery endothelium
Inflammatory response
148
Name 3 monosaccharides
Glucose, Fructose, Galactose
149
Name 3 disaccharides
Maltose, Sucrose, Lactose
150
Name 5 polysaccharides
Starch, Cellulose, Glycogen, Amylose, Amylopectin
151
Name the bond which joins monosaccharides to form a disaccharide or polysaccharide
Glycosidic
152
Name the branched polysaccharide found in starch
Amylopectin
153
Which disaccharide is the transport sugar in plants?
Sucrose
154
If a monosaccharide contains 5 carbons atoms, how many hydrogen atoms does it contain?
10
155
If 250 monosaccharide are joined to form a polysaccharide, how many water molecules would be needed to hydrolyse the polysaccharide into monosaccharides?
249 ( there are 249 glycosidic bonds to break)
156
Name the type of glycosidic bond which joins a branch to another chain in glycogen
1,6 glycosidic bond
157
If 30% of a starch molecule is composed of amylose, what percentage of the starch molecule is composed of amylopectin?
70%
158
Why is it important for their function that starch that starch and glycogen are:
- Branched
- Insoluble in water
- Large
- Compact
- quickly hydrolysed, as enzymes can work on each branch at the same time
- The molecules can be stored in a cell without upsetting the osmotic flow in and out of the cell. Does not diffuse out of the cells
- does not diffuse out of cells
- more starch/glycogen, so glucose and energy, can be stored in a smaller space
159
State the structural differences between glucose and maltose
Maltose has two glucose molecules bonded together ( two single glucose units) with a 1,5 glycosidic bond and is a disaccharide while glucose is a monosaccharide with 6 carbon atoms and a single sugar unit
160
Write a glycosidic bond
—O—
161
Name the two monosaccharides which make up lactose
Glucose and galactose
162
Name the polysaccharide which stores energy in animal cells
Glycogen
163
State the role of glucose in the human body
Glucose is needed for respiration in every cell of the body. Immediate energy source
164
Give key features of monosaccharides which make them good for their role
They are able to for hydrogen bonds with water and therefore are soluble. The molecules are very small
165
Is amylose branched or unbranched?
Unbranched
166
Name the two monosaccharides which make up sucrose
Glucose and fructose
167
Which polysaccharide, glycogen or amylose can be hydrolysed faster? Why?
Glycogen because it has branched endings
168
Which polysaccharide, glycogen or amylose can be hydrolysed faster? Why?
Glycogen because it has branched endings
169
Name the two monosaccharides which make up maltose
Glucose and glucose
170
Name the two types of glycosidic bond present in glycogen
1,4 glycosidic bond and 1,6 glycosidic bond
171
Name the polysaccharide which stores energy in plant cells
Starch
172
State structural differences between amylose and glycogen
Glycogen is branched and contains 1,6 AND 1,4 glycosidic bonds and amylose ONLY has 1,4 glycosidic bonds
173
How is energy released from glucose and where in a cell does this take place?
Through aerobic respiration in the mitochondria and cytoplasm. Or anaerobic respiration in cytoplasm
174
By which process do glucose molecules enter cells when there is a higher glucose concentration outside the cell than inside the cell?
Facilitated diffusion
175
Name the type of reaction that joins two monosaccharides to form a disaccharide
Condensation
176
Is starch soluble in water ?
No
177
If an animal cell cytoplasm contains a very high level of glucose, what might happen to the cell and why?
It may take in water by osmosis and burst, as the cell membrane does not prevent cell rupture
178
Is glycogen sweet?
No
179
Does fructose contain a glycosidic bond?
No
180
Why is it important that monosaccharides like glucose are soluble in water?
So that they can be transported in liquids, blood
181
Glucose has lots of polar OH groups, which make it soluble in water . Using your knowledge of water , explain how glucose dissolves in water?
Because the OH groups are able to bond the water with hydrogen bonds and become hydrated and therefore dissolve
182
State structural differences between amylose and amylopectin
Amylopectin has branches and contains 1,6 glycosidic bonds, amylose does not
Amylose is straight chained and helixical
183
State structural differences between lactose and amylose
Lactose is made of galactose and glucose whereas Amylose has many sugar units. Lactose only contains one glycosidic bond
184
If 1100 monosaccharides are joined to form a polysaccharide, how many glycoside bonds are present in the polysaccharide?
1099
185
If 120 glucose molecules are present in a polysaccharide and 13 more are added, calculate the percentage increase in glucose molecules
13/120= 0.1083x100= 10.8%
186
What is one simple sub-unit called?
Monomer, monosaccharide
187
What are two sub units called
A dimer, disaccharide
188
What is the general formula of monosaccharides?
(CH2O)n
189
What are monosaccharides called with 6 carbon atoms?
Hexose sugars
190
What is the OH group called?
Hydroxyl group
191
What is the formula of the side chain?
CH2OH
192
What does hydrolysis mean?
Water splitting
193
In a hydrolysis reaction water is _________________?
Added to the bond
194
What type of molecule is cholesterol?
Lipid
195
Where does the cholesterol in the body come from?
- From our diet (Saturated and unsaturated fat)
- Produces in the liver from other molecules
196
State the functions of cholesterol in the body
- Used to make bile salts (for lipid digestion)
- Used to make vitamin D
- Regulates fluidity of cell membranes
- Used to make steroids
197
Explain how cholesterol is transported in the blood
Cholesterol is a lipid and therefore is insoluble. In order to carry cholesterol is the blood it must combine with a **lipoprotein** which are soluble so can be transported in the blood
198
Explain why too much saturated fat/cholesterol/LDLs in the body can increase the risk of developing CVD
- An excess of LDL is blood will overload LDL receptors, so blood cholesterol levels increase
- Saturated fats also decrease LDL receptor activity, further increasing blood cholesterol levels
- An excess of LDL leads to large fatty deposits forming in blood vessels when damaged. These deposits increase blood pressure by blocking blood flow. This also means that they may cause heart attacks or strokes
199
Explain why HDLs is the body can decrease CVD risk
HDLs bind to LDL cholesterol deposits in vessels. This reduces the affect of the LDL which in turn reduces risk of CVD
200
Explain why a high fibre diet reduces the CVD risk
Dietary fibre can’t be digested so it passes through the digestive system. It helps lower the absorption of cholesterol and increase excretion of cholesterol, reducing atherosclerosis risk
201
Explain the benefit of taking statins
Statins reduce cholesterol levels and this reduces the formation of fatty deposits
202
Explain the risks associated with taking statins
Statins can lead to side effects like muscle inflammation, muscle pains, liver damage and nausea
203
State the 3 elements that all lipids are made from
Oxygen, Carbon, Hydrogen
204
State the key role of lipids in the body
Lipids create fatty tissue which stores energy and acts as padding/protection/insulation and is used in cell membranes
205
Name the two types of monomers that triglycerides are made from
Glycerol and 3 fatty acids
206
Name the bond that links these two types of monomers in a triglyceride
Ester bond
207
Describe the structure of a fatty acid
A fatty acid is comprised of a carboxylic acid group and a hydrocarbon chain/tail
208
How many OH groups does glycerol have?
3
209
What name is given to a long chain made only of C and H atoms?
Hydrocarbon chain
210
What is the name given to a COOH group?
A carboxylic acid group
211
Which group on a glycerol molecule does a fatty acid bond to?
OH group
212
Explain how a triglyceride forms
A glycerol molecule and 3 fatty acids bond together in a condensation reaction resulting is the release of a water molecule and a triglyceride bonded with and ester bond. Using an enzyme
213
State the differences between an unsaturated fatty acid and a saturated fatty acid
- Saturated fatty acids have no double carbon bonds whereas unsaturated fatty acids do
- Unsaturated fatty acids have ‘kinks’ in the chain whereas saturated fatty acids are long straight chains
- Saturated fatty acids can be stored compactly and have strong intermolecular bonds between chains whereas unsaturated fatty acids can’t be compactly stored, leading to weak intermolecular bonds
- Saturated fatty acids have the full complement of H atoms but unsaturated fatty acids do not
214
Explain why saturated fats have a higher melting point than unsaturated fats.
Saturated fats have long straight chains that can be stored compactly together. This leads to strong intermolecular bonds between molecules whereas unsaturated fats have weak intermolecular bonds due to their bent shape. Therefore saturated fats have a higher melting point as they have stronger intermolecular bonds that need to be overcome
215
How many ester bonds are found in a triglyceride?
3
216
What is a condensation reaction?
A reaction between two or more molecules that results in a bond being formed and a release/loss of water molecule/s as one of the products
217
Which type of chemical reaction takes place when a triglyceride breaks down into fatty acids and glycerol?
A hydrolysis reaction
218
If 4 triglyceride molecules are broken down, how many water molecules will be released?
3x4=12 12 bonds
219
What is an **essential** fatty acid?
A fatty acid that is needed for the function of our body but can’t be formed by the body so must be obtained in the diet
220
Is an enzyme needed to break down a triglyceride into its monomers?
Yes
221
What would happen to the pH in a flask when the triglycerides in the flask are hydrolysed?
The pH would decrease as the hydrolysis of a triglyceride would lead to the release of fatty acids. These acids would lower the pH
222
Are unsaturated fats usually solid or liquid at room temperature?
Liquid (or soft solids)
223
A fatty acid has one double bond. Is is necessarily an unsaturated fatty acid?
No the double bond could be the C=O double bond carboxyl group
224
What does an ester bond look like?
O
=
O-C
225
Define polysaccharide
Many sugar monomer joined together by glycosidic bonds formed in a condensation reaction
226
What type of glucose is starch made from?
Alpha glucose
227
What type of glucose is glycogen made from?
Alpha glucose
228
What type of glucose is cellulose made from?
Beta glucose
229
What is cellulose used for?
Plant cell walls
230
What is glycogen used for?
Storage of glucose in animals
231
What do starch used for?
Storage of glucose in plants
232
What are lipids soluble in?
Organic solvents (ethanol)
233
What is energy input?
the energy you put into your body e.g food
234
What is energy output?
the energy that your body uses up e.g. BMR and exercise
235
What happens in the body is energy input is regularly higher than energy output?
energy imbalance, energy stored as fat and body will gain weight - become obese
236
What happens in the body if energy output is regularly higher than energy input?
energy imbalance, body will lose weight - become underweight
236
What does **energy balance** mean?
where energy input in equal to energy output
237
List the consequences of excessive weight gain
- become obese, lose mobility
- increase risk of atherosclerosis and therefore heart attack or stroke (CVD)
- increase risk of type II diabetes
- increase heart rate and blood pressure (Hypertension)
238
List the consequences of excessive weight loss
- malnourishment, gallstones, tiredness, dehydration, irritability, depression
- reduced cognitive ability, reduced muscle/tissue mass, decreased mobility/stamina. difficulty staying warm
- death
239
Why does being overweight increase the risk of developing CVD?
- higher blood pressure and heart rate
- more fatty deposits are restricting blood flow and oxygen supply
- damaged endothelium
- atherosclerosis
- blood vessels harden and narrow
- Risk of blood clot increases
- puts extra strain on the heart
- increased risk of heart attack
240
Name the 2 obesity indicators
- BMI
- waist to hip ratio
241
State the units for BMI
kgm*-2*
242
What is the formula for calculating BMI?
weight, kg / height*2*, m*2*
243
Calculate BMI for a person with a body mass of 55kg and a height of 1.50m
55/1.5*2* = 55/2.25 = 24.44kgm*-2*
243
Who is BMI unsuitable for?
- people over 60
- certain ethnic groups
- Children
- Athletes
- those with long term health conditions
243
How can someone reduce their BMI?
- eat less saturated fats
- eat the cholesterol
- more polysaturated fat
-reduce stress
- increase antioxidants
- have an energy imbalance towards energy output
- reduce salt intake
- reduce alcohol intake
- stop smoking
- longer/more intense exercise/ increase activity. this increases muscle mass and metabolic rate. muscles use more energy than fat
243
Define calorie
one calorie is the quantity of heat energy required to raise the temperature of 1cm*3* of water by 1*c
244
What does BMR mean?
basal metabolic rate- the amount of energy needed for essential processes
244
How do you calculate waist to hip ratio
Waist circumference / hip circumference
244
define multifactorial
developing the disease relies on multiple factors all combined/contributing to the risk
244
1 calorie = ______ J
4.18
244
What does DRV mean?
dietary reference values- estimate requirements
244
What is the lowest boundary for overweight?
25
244
What is the maximum waist to hip value for men?
0.9
245
How do calcium channel blockers work?
calcium enters muscle tissue through calcium channels in order to allow the muscle to contract. CC blockers will block the channels resulting in to contraction from the smooth muscle and therefore lower bp
245
What is the maximum waist to hip value for women?
0.85
246
What is the main side effect of antihypertensives?
dizziness
246
What class of drugs are used to reduce blood pressure
Antihypertensives
246
How do ACE inhibitors work?
Angiotensin converting enzyme inhibitors prevent the production of the angiotensin II hormone from angiotensin I. This hormone is responsible for vasoconstriction so inhibiting it will prevent vasoconstriction and lower bp
247
How do diuretics work?
diuretics decreases water retention and increases the volume of urine. this helps to remove excess fluids and salts, leading to a decrease in the blood plasma volume. reducing bp
248
What is the main drug for reducing cholesterol?
Statins
249
How do statins work?
Statins inhibit the enzyme(HMG-CoA) involved in the production of LDL cholesterol in liver, reducing cholesterol
250
What are the main side effects of statins?
tiredness, disturbed sleep
251
What are the two types of drug used to reduce blood clots?
- Anticoagulants
- Platelet inhibitory drugs
252
How does warfarin work?
Warfarin is an anticoagulant that interferes with the production of vitamin K and therefore it affects the blood clotting process
253
How does aspirin work?
aspirin is a platelet inhibitory drug that reduces the 'stickiness' of the platelets, reducing blood clot formation
254
What is the side effect of drugs that reduce blood clotting?
Serious bleeding
255
Explain how antioxidants reduce the risk of developing CVD
In the body there are particles called **free radicals**. antioxidants neutralise these free radicals by donating an electron. this stops the radicals from damaging cells
256
Define **free radicals**
an atom in a molecule which has a free unpaired electron
257
Explain **free radicals**
these are made in the body as a product of reactions and are found in the environment
they will cause damage to cell components and are very reactive
258
Define antioxidants
compounds that protect against free radical damage
