Lifestyle Health And Risk Flashcards
1
Q
What are the most important risk factors for CVD
A
- high blood pressure
- unhealthy diet
- smoking
2
Q
3 Contributory factors to CVD
A
- stress
- sleep deprivation
- being male (difference in chromosomes)
3
Q
The most common cause of death for UK men is…
A
Cardio Vascular Disease
4
Q
What is the most common cause of death for UK women?
A
Dementia
5
Q
How do worms get oxygen to their cells?
A
- air diffuses in
- surfactant aids diffusion
6
Q
How do frogs get oxygen to their cells?
A
- tadpoles can diffuse oxygen in
- through gills ( lungs grow when they get older )
7
Q
Frogs have a ____ chamber heart
A
Three
8
Q
How do single celled organisms get oxygen to their cells
A
Diffusion
9
Q
How do fish get oxygen to their cells?
A
Through their gills
10
Q
Fish have a _______ circulatory system
A
Single
11
Q
How do crickets get oxygen to their cells?
A
Air travels through holes in their body
12
Q
Having a higher concentration gradient ________ rate of diffusion
A
Increases
13
Q
The higher the surface area…
A
The faster the rate of diffusion
14
Q
The larger the diffusion distance…
A
The slower the rate of diffusion
15
Q
If temperature increases…
A
Rate of diffusion increases
16
Q
Larger molecules =
A
Slower rate of diffusion
17
Q
Concentration gradient decreases at a decreasing rate =
A
Diffusion decreases at a decreasing rate
18
Q
The majority of cells in a _________ organism are not in contact w/ the organisms surroundings
A
multicellular
19
Q
What is needed to transport oxygen and glucose to every cell in a multicellular organism
A
A mass flow system
20
Q
Mass flow system transports substances in _______ down a __________ _____________. Enabling substances to move long distances at a ___________________________
A
- bulk
- pressure gradient
- sufficient rate
21
Q
Larger organisms have a ________________
A
Higher metabolism
22
Q
What are the requirements for a mass flow system
A
- circulatory fluid
- contracting pump to move fluid
- tubes through which fluid can circulate
23
Q
What does a circulatory system move
A
- blood
24
Q
What is the pump for a circulatory system?
A
- heart and contactable blood vessels ( arteries )
25
Digestive system moves ________________
Food and water
26
What pumps food and water around the digestive system
Muscle surround intestines
27
What materials are moved around the respiratory system
Air
28
What is the pump for the respiratory system
- intercostal muscles
- diaphragm
29
What is moved in the lymphatic system
Lymph
30
Lymph is pumped around the lymphatic system by the ____________________________
Contraction of skeletal muscle
31
Define an open circulatory system
In open circulatory systems blood is not fully contained in blood vessels
32
How do open circulatory systems work?
The heart pumps blood into the body cavity and tissues are bathed in blood
33
The blood is called __________ because it is mixed with __________
- haemolymph
- tissue fluid
34
Characteristics of a closed circulatory system
- high pressure blood
- oxygen concentration gradient is high because oxygenated and deoxygenated blood do not mix
35
Blood flow in closed circulatory systems
Heart Arteries Arterioles Capillaries Venules Valves Vein
36
Blood circulation to organs in single circulatory systems is organised in
Series
37
Circulation to organs is organised in _____________ in double circulatory systems
Parallel
38
Pulmonary circulation has high/low blood pressure?
Low
39
Systemic circulation has low/high pressure?
High
40
Why does blood pass through lungs or gills slowly?
In order to maximise the exchange of oxygen and carbon dioxide
41
Advantages of a parallel vascular system?
- high oxygen conc grad for all organs
- parallel arrangement reduces resistance
- blood speed high t.f rate of oxygen delivery high
42
How many heart chambers do amphibians have?
3
43
Oxygenated and deoxygenated blood _________ in amphibian heart
Mix
44
Describe the location of the heart
- middle of the thorax
- apex tilts to the left
45
The outer fibrous pericardium is made up of ________________
Collagen rich connective tissue
46
Outer fibrous pericardium is ______________ and protects from _______________ of the heart, trauma and infection
- inelastic
- overextension
47
How is the fluid filled cavity formed
The inner serous pericardium folds back on itself and lubricates the hearts movements
48
Where does the coronary artery carry blood to?
Myocardium
49
Where do the subclavian arteries carry blood to
Arms
50
The ___________ arteries carry blood to the head
Carotid
51
Name the two heart valves on the right side of the heart
- aortic semilunar valve
- tricuspid valve
52
Name the two valves on the left side of the heart
-Pulmonary semilunar valve
-Biscupid valve
53
What is the scientific name for heart strings
Tendinous cords
54
What are tendinous cords used for
- inelastic
- attach valves to papillary muscles
- help valves open
- stop valves inverting
55
What is the function of the arteries?
- to transport blood away from the heart
56
Blood in arteries is __________ and _________
- oxygenated
- bright red
57
Arteries have __________ blood pressure
High
58
What is the function of the veins
To transport blood to the heart
59
Blood in veins is ___________ and _____________
- deoxygenated
- purple red
60
Veins have ____ b.p
Low
61
What is the function of capillaries
- gas exchange between blood and cells
62
Blood oxygenation in capillaries…
Changes for oxygenated to deoxygenated
63
Blood pressure in capillaries is
Low but higher than veins
64
Artery
1 - Collagen rich connective tissue
2 - Elastic tissue
3 - Smooth ( circular ) muscle
4- endothelium
5 - lumen
65
Vein
1 - Collagen rich connective tissue
2 - elastic tissue
3 - smooth ( circular ) muscle
4 - endothelium
5 - lumen
66
What is the diameter of a capillary?
8 um
67
What is the diameter of an artery
0.1 -> 20 mm
68
What is the diameter of a vein
0.1 -> 20 mm
69
Describe the wall structure of an artery
- thick muscle and elastic layer
- small lumen
70
Describe the wall structure of veins
- thin muscle and elastic layer
- large lumen
71
Describe the wall structure of capillaries
- very thin endothelium ( one cell thick )
- very small lumen ( RBC travel single file )
72
During systole arteries __________ following heart ________
- expand
- contraction
73
During diastole arteries _______________________ following heart contraction
( recoil ( = elastic recoil ))
74
Veins pass between _______________ and muscle contraction exerts a __________ on vein and propels blood forward
- skeletal muscle
- pressure
75
What is the biological significance for water being a good solvent for other polar molecules
- hydropholic molecules can be transported easily
- vital biochemical reactions can take place in aqueous cytoplasm
76
What is the biological significance of water being a bad solved for lipoprotein molecules?
- lipids can form a bilateral membrane in water
- lipids can only be transported in blood in combination w/ proteins ( hydrophobic )
77
Because water is a _______ it is a _______ molecule
- dipole
- polar
78
What is a polar molecule?
Uneven distribution of charge across the molecule
79
What is the importance of water having a high specific heat capacity ( takes a lot of energy to raise its temperature)
- water is a good temperature buffer
80
What us the importance of water having a high latent heat of vaporisation?
- organisms can cool down effectively as sweat evaporates without losing a lot of water
81
As water has _____________ organisms can survive in cold places without __________
- high latent heat of condensation
- freezing
82
What is the biological significance of water being liquid at most environmental temperatures?
- water is a useful transport medium in mass flow systems
83
Water has a higher density than ice therefore…
Ice forms at the surface of waters allowing organisms below to survive
84
Water is _____________ therefore water plants can receive light for ______________
- transmits
- photosynthesis
85
Describe waters hydrostatic properties
- water has a low compressibility so it can resist high pressure
86
What is the biological benefit of water being hydrostatic
- allowed buoyancy
- allows organisms to survive in deep oceans
87
Why is water cohesive?
- They are attracted and stick to one another ( hydrogen bonds )
88
What is the biological significance of water being cohesive?
- Water has high tensile strength so therefore it can travel in unbroken columns ( xylem vessels )
- Water has high surface tension: therefore insects can walk on water
89
What is the biological significance of water having high adhesion?
- water can be drawn into small spaces:
90
What is the cardiac cycle?
The cardiac cycle is the sequence of changes in the heart as it fills with blood and pumps it out again
91
What is atrial systole?
- the contraction of the atria which pushes blood into ventricles
92
Describe what happens during atrial systole
- as atria fills pressure increases
- AV valves open and blood flows into ventricles
- atria contract forcing blood into ventricles
93
What is ventricular systole?
- the contraction of ventricles, which pushes blood up into the arteries
94
Describe ventricular systole
- ventricles contract from the base upwards
- pressure in ventricles increase, closing AV valves (lib sound)
- semi lunar valves open and blood is pushed up and out into the arteries
95
What is diastole?
Complete relaxation of the atria and ventricles
96
Describe diastole
- Atria and ventricles recoil and relax, lowering pressure in heart chambers
- lower pressure in ventricles compared to in arteries draws in blood backward, closing semi lunar valves (dub sound)
- low pressure in atria draws blood from veins in, refilling of atria
- coronary arteries fill
97
What is SAN
- sino atrial node
- in wall of RA
- pacemaker
-generates electrical impulse to trigger atrial systole
98
What is AVN?
- atrio-ventricular node
- in wall of RA
- electrical impulse for SAN reaches AVN (delay ensures atria have fully contracted and ventricles have filled)
- AVN transmits impulse along bundle of His to Purkyne fibres, initiating ventricular systole from bottom upwards
99
The vagus nerve ___________ heart rate
Lowers
100
____________ nerve : increases heart rate
Accelerator
101
What does ECG stand for
Electrocardiogram
102
What is an ECG
- a recording of the electrical activity of the heart over time
103
P wave: atrial systole
QRS complex: ventricular systole
T wave: diastole
104
Why is the P wave smaller than the QRS complex
Atrium is a smaller muscle therefore there is less electricity
105
Why do veins have a large lumen?
To reduce resistance to blood flow back to the heart
106
Why do veins have a smooth endothelium
To reduce resistance to blood flow
107
What is atherosclerosis?
The build up of artheromortus plaque in the inner layer of the artery wall
108
What happens if the arteries supplying the heart are blocked?
Heart attack
109
What happens if the arteries supplying the brain are blocked?
Stroke
110
Describe how AS is developed
Step 1:
Endothelium damaged causing a lesion
Step 2:
Inflammatory response:
-WBC accumulates under endothelium
-foam cells die and attract more macrophages
-deposit builds up
Step 3:
Plaque formation
-build up of calcium and fibrous tissue
-artery wall loses elasticity
Step 4:
-positive feedback
-artery narrows -> HBP
-further atheroma formation
111
What is thrombosis?
A blockage of a blood vessel by a blood clot
112
A thrombus is a blood clot that…
Forms in a vessel and REMAINS there
113
An embolism is a blood clot that…
Travels to another location in the body
114
Fatty plaques can either….
-block artery directly
-increase arteries chances of being blocked by a blood clot
115
What i8s the benefit of blood clotting?
-reduces blood loss
-prevents infection
116
Clotting is triggered when platelets come into contact with…
-damaged endothelium
-collagen fibres
117
Describe the blood clotting process:
Step 1:
-endothelium damaged
-collagen fibre exposed
-platelets are activated and become irregularly shaped
-thromboplastin released from damaged tissue and platelets
Step 2:
-platelet plug formed
-platelets stick to damaged vessel wall
Step 3:
Blood clot formed - fibrin mesh traps RBCs
118
Describe the blood clotting chemical pathway
-Thromboplastin turns prothrombin to thrombin.
-Thrombin turns fibrinogen (soluble) into fibrin (insoluble)
119
What is risk?
The probability of an unwanted event or outcome
120
How is risk calculated?
By looking at past circumstances of people who have taken the same risk
121
% risk =
( Number of people with unwanted outcome/ total no. Of people taking the risk ) * 100
122
Factors that cause overestimation of risk:
-Involuntary
-Unnatural/unfamiliar
-feared
-rare
-consequences are sudden
123
Factors that cause underestimation of risk
-Undertaken voluntarily
-Natural
-Familiar
-Enjoyed
-common
-Long term consequences
124
What are risk factors?
-Variables associated with an increased risk
125
What is an example of a hereditary risk factor?
Mutations
126
What is an example of environmental risk factors?
-Pollution
-Access to clean water
127
What is an example of a physiological risk factor
-HBP
-Obesity
128
What is an example of demographic risk factor?
-Age
-Sex
-Religion
129
What is an example of behavioural risk factor?
-Inactivity
-Smoking
130
Correlation is a ……….. between two ……………….
-Relationship
-Variables
131
What is positive correlation
-Increase of one variable is accompanied by an increase in another
132
What is negative correlation
-increase of one variable is accompanied by a decrease in another
133
Causation is when…
A change in one variable is responsible for the change in the other
134
Causation requires ………….. experiments to see if change in one variable has ……….. effect
-controlled -predicted
135
Causation requires knowledge of …
Mechanism for how one variable affects another
136
What is epidemiology
The study of distribution of disease in human populations and the factor determining this
137
What are cohort studies
A prospective study where a group of people are followed overtime to see who develops a condition
138
Describe the method of cohort study which compares exposure to risk factor
-Population is followed overtime and then separated
-Exposure to risk factors is compared
139
Describe the method of cohort study which compares outcomes
-Population is separated into two groups
- One with risk factor one without
-Compare outcomes
140
A case control study is a ………. Study where a group of people ……………… condition is compared to a group without the condition
-Retrospective
-With the same
141
Describe a case control study
-two groups (one w/ condition and one control group)
-Look back in time
-Compare histories of exposure to risk factor
142
What are the advantages of the cohort study
-Useful for rare exposure to risk
-Can evaluate multiple disease outcomes
-Minimises recall bias - data collected regularly
-Direct measurement of disease incidence
143
What are the disadvantdges of a cohort study
-Requires more time and is more
-Large sample size
-Not useful for rare conditions (may not appear in cohort)
-Low validity due to dropouts (follow up bias)
144
What are the advantedges of a case-control study
-Requires less time and is less exspensive
-Smaller sample sizes
-Can evaluate multiple exposures to risk
-Useful for rare conditions
145
What are the disadvantdeges for a case control study
-Cannot determine disease incidence
-Not useful for rare exposures to risk
-recall bias can be substantial
-Selection bias possible in control group
146
What makes a good research study?
-validity
-bias
-reliability
147
In a reliable study results can be…
Consistently reproduced
148
How do you achieve reliability?
-Large sample size (Trend can be detected)
-Standardising methods and equipment (valid method)
149
What is validity?
Valid results answer the research question accurately
150
How do you achieve validity?
-Control variables (one independent variable)
-Method and equipment appropriate to question
151
What is Bias
The introduction of systematic error into a study by favouring one outcome or answer over others
152
What are the three types of bias
-recall
-selection
-loss to follow up
153
Selection bias is an error caused by choosing…
A group of participants that are not representive of the target population
154
what is recall bias
-Systematic error caused by inaccurate recollection of past events by study participants
155
What is loss to follow up bias
-Systematic error caused when exposure or study set up increases likelihood of participants dropping out thereby inaccurate comparison between groups
156
What types of bias does cohort study have
Loss to follow up
157
What types of bias does case control study have?
-selection
-recall
158
With increasing ages arteries become…
Less elastic and more easily damaged
-likelihood of AS increases
159
Why are men more likely to die of CVD
-women are somewhat protected by oestrogen
-men are more likely to engage in other risk factors (smoking/poor diet)
160
How does oestrogen protect against CVD
-Reduces LDL and increases HDL
-reduces inflammatory response
-> likelihood of AS decreases
-heart muscle cells have oestrogen receptors
-oestrogen binding improves mitochondrial function
-vascular endothelial cells have oestrogen receptors
-oestrogen binding causes arterial dilation
161
Blood pressure is a measure of the …………… force of blood ……….. the vessel walls
-hydrostatic
-against
162
What does blood pressure depend on
-blood flow
-peripheral resistance
163
Why is blood pressure in arteries high during systole
-blood flow increases
-peripheral resistance increases
164
Why is blood pressure low in diastole
-blood flow decreases
-peripheral resistance decreases
165
How does stress affect blood pressure
Increases
- adrenaline constricts arteries
-> peripheral resistance increases
166
-High blood pressure is in the ……….. arteries
-……………………………. In walls of carotid ………… detect increase in pressure
-……………………. Carry impulses to …………………… centre in the medulla
-……………….. impulses sent via …… nerve to ….. reducing heart rate
-> blood pressure decreases
-Carotid
-stretch receptors
-sinuses
-Sensory nerves
-Cardiovascular
-inhibitory
-vagus
-SAN
167
How does a high salt diet increase blood pressure
-osmotic effect increases blood volume
-> blood flow increases
168
How does smoking increase blood pressure?
-Nicotine constricted arteries
-Peripheral resistance increases
169
How does heavy alcohol consumption increase b.p
-Ethanol constricts arteries
-Peripheral resistance increases
170
What are some early symptoms of HBP
Headache, dizziness, vomiting
171
What are the late symptoms of HBP
CVD
172
Oedema is the ……………. Caused by an excess of ……………………….. collecting in tissues
-swelling
-tissue fluid
173
Tissue fluid is the ……………… fluid which ……………. The cells
-extracellular
-bathes
174
What are the two factors that affect the movement of tissue fluid?
-Blood pressure
-Osmotic pressure
175
If blood pressure > osmotic pressure then tissue fluid will…
Move out of blood
176
If blood pressure < osmotic pressure then tissue fluid will…
Move into blood
177
20% of tissue fluid is removed by…………………… and returned to blood at the …………
-lymphatic vessels
-vena cava
178
How does oedema form?
-high blood pressure
-more tissue fluid
-not enough t.f removed in lymph
-> swelling
179
What is blood pressure measured with?
Sphygmomanometer
180
How is blood pressure measured? (step 1)
-inflatable cuff placed around upper arm
-cuff is inflated until blood stops flowing (no sound heard)
181
How is systolic pressure measured?
-Valve opens so that air will be released from cuff
-Blood begins to flow through brachial artery
-Systolic pressure is measured when pulsing sound is heard
182
Diastolic pressure is measured when the:
-valve is opened ……
-artery is no longer …………..
-measured when there is………………. Of blood movement
-further
-compressed
-no sound
183
What is hypertension?
When the peripheral resistance of blood against artery walls is stop high
184
How do ACE inhibitors cause vasodilation?
-Angiotensin converting enzyme inhibitors stop prodcution of Angiotensin 2 (which constricts arteries)
185
How do ARBs cause vasodilation
Block angiotensin 2 receptors in arterial muscles
186
How do calcium channel blockers cause vasodilation?
-They inhibit entry of calcium ions into muscle cells so they are less able to contract
-reducing arterial walls and force of heart contraction
187
How do diuretics reduce hypertension?
Reduce water content of blood, therefore reducing blood volume
188
How do beta blockers reduce hypertension?
-They block the action of stimulant hormones (adrenaline) acting on the SAN
-> decreased heart rate
189
Reducing blood pressure by 5mmHg can decrease risk of stroke by… and ischaemic heart disease by …
-34%
-21%
190
Carbohydrates are also called…….. or ………..
-sugars
-saccharides
191
Carbohydrates contain elements…
C,H,O
192
what is the general formula for monosaccharides?
Cn(H2O)n
193
Are monosaccharides soluble or insoluble
Soluble
194
What are the two types of monosaccharides
-Pentose
-Hexose
195
What are two examples of pentose
-Deoxyribose
-Ribose
Components of DNA
196
What are 3 examples of Hexose
-glucose
-fructose
-galactose
197
What is the function of glucose?
-Major respiratory substrate
-Component of disaccharides (maltose sucrose lactose) and polysaccharides (starch, glycogen, cellulose)
198
What is the function of fructose?
-respiratory substrate
-component of sucrose
-constituent of nectar and fruit
199
What is the function of galactose?
-Respiratory substrate
-component of lactose
200
What is this molecule?
Alpha Glucose
201
What is this molecule?
Beta glucose
202
What is this molecule?
Fructose
203
What is this molecule?
Deoxyribose
204
What is this molecule?
Ribose
205
What is the general formula of a disaccharide?
Cn(H20)n-1
206
Are disaccharides insoluble or soluble?
Soluble
207
What does glucose + glucose make?
Maltose
208
What does glucose + fructose make?
Sucrose
209
What does galactose + glucose make?
Lactose
210
What type of bond does maltose have?
A (1-4) glycosidic bond
211
What type of bond does lactose have?
B (1-4) glycosidic bond
212
What type of bond does sucrose have?
A (1-2) glycosidic bond
213
What is the function of maltose?
-Respiratory substrate
-Found in germinating seeds
214
What is the function of sucrose
-respiratory substrate
-sugar transported in phloem in pants
215
What is the function of lactose
-Respiratory substrate
-Milk sugar: major carb source for sucklings in mammals
216
Polysaccharides have thousands of …………….. units
Monosaccharide
217
What is the general formula for polysaccharides?
Cx(H2O)y
218
Are polysaccharides insoluble or soluble?
Insoluble
219
Starch is made out of…
-Amylose
-Amylopectin
220
Glycogen is made out of…
Alpha glucose
221
Starch contains 30% ……….. and 70% ……………..
-Amylose
-Amylopectin
222
What is amylose?
An UNBRANCHED chain of A(1-4) glucose (200-5000) units
-forms an alpha helix - hydrogen bonds between H and OH groups
223
Amylopectin is a branched chain of…
Alpha glucose
224
It contains ………….. bonds and ……………….. bonds (which form branches)
A(1-4)
A(1-6)
225
Amylopectin is rapidly….
Hydrolysed
(Amylose digests branch endings)
226
Each branch is ………… glucose residues long
8-12
227
Glycogen is a branched chain of…
A(1-4) glucose
(5000-60,000 glucose units(
228
What is more highly branched, amylopectin or glycogen?
Glycogen
229
What digests glycogen branching endings?
Glucosidase
230
Why are carbohydrates stored as starch or glycogen rather than glucose?
-polysaccharides are insoluble
-no osmotic effect
-otherwise cells would take in too much water
231
Cellulose is an …………………. Chain of ………….. glucose
-unbranched straight
-B(1-4)
232
How do chains of cellulose align?
-Parallel to each other forming tough fibres called microfibrils
233
What are microfibrils held together by?
Hydrogen bonds
234
Why does cellulose have an alternate structure rather than a helical structure?
Consecutive B glucose residues straight in orientation
235
What is the function of glycogen?
-Major storage carb in animals and fungi
236
What type of glycosidic bond does cellulose have?
B (1-4)
237
What is the function of cellulose?
-Structural component of cell walls in plants
238
What is an example of a non reducing sugar?
Sucrose
239
What does Benedict test test for?
Reducing sugars (free alpha or B OH- group)
240
State Benedict’s test
Reducing sugar + copper sulpha -> oxidise sugar + Cu2O
Blue-> red
241
How do you adapt Benedict’s test to test for non-reducing sugars?
Use HCL to hydrolyse sugar first
242
State Benedict’s test for non-reducing sugars
-non reducing sugar + hcl -> reducing sugar
-reducing sugar + CuSO4 -> oxidised sugar + CU2O
243
What is the test for starch?
Test for amylose
Amylose + iodine -> amylose-iodine complex
yellow -> blue
244
Describe how lactose is absorbed in a person who is lactose tolerant
-Lactose is broken down by lactase into galactose and glucose
-Galactose and glucose are absorbed into the blood stream
245
Describe what happens to lactose in an intolerant person
-Lactose is not broken down
-Gut bacteria is fermented
-causing gases & acids
-leading to flatulence & abdominal pain
246
Why is lactose-free milk hard to make?
-Large amount of lactose is needed
-Lactase needs to be separated from lactose-free milk product
247
Immobilised enzymes are enzymes ………………. To a surface (e.g of ……………………………..)
-attached
-sodium alginate seeds
248
What is the benefit of immobilised enzymes
-enzymes easily separated from products
-enzymes can be easily reused
-large SA for collisions between enzyme and substrate
249
What is the difference in the way DNA and RNA are structured?
-DNA is structured into chromosomes
-RNA is structured into tRNA and mRNA
250
What elements do lipids contain?
C, O H
251
Lipids are……. In water
Insoluble
252
Lipids are ……. In organic solvents
Soluble
253
What is glycerol made out of?
-alcohol
-3 hydroxyl groups
254
What are fatty acids amde of?
-A carboxylic acid (-COOH)
-long hydrocarbon chains (14-22)§
255
What are monounsaturated fatty acids
-fatty acids that contain one C=C bond
256
What are polyunsaturated fatty acids?
-Fatty acids that contain several C=C bonds
257
How are triglycerides formed?
-3x condensation reactions to add 3 fatty acids to glycerol
258
Saturated triglycerides are…
Saturated fatty acids
259
Saturated triglycerides are …………. At room temp
Solid
(Fats)
260
Saturated triglycerides are from…
Animals
261
Unsaturated triglycerides are
Unsaturated fatty acids
262
Unsaturated triglycerides are solid/liquid at room temp
Liquid
-oils
-from plants
263
What are glycolipids made out of?
-glycerol
-2 fatty acids
-carbohydrate unit(s)
264
What is cholesterol?
-a steroid
265
Cholesterol is a component of…
Cell membranes
266
Cholesterol is a precursor for…
Hormones
267
What are waxes?
-long chain alcohols and a fatty acid linked by an ester bond
268
What are some functions of lipids
-electrical insulation
-buoyancy
-water proofing
269
What is 1 cal
-the quantity of heat energy required to raise the temp of 1g of water by 1C
270
What is 1 Kcal?
-1000 cal
4180J / 4.18 kJ
271
What is dietary reference values?
-energy and nutrient requirements for different group of healthy people in the UK
272
What is Estimated Average Requirement?
-energy/nutrient intake which meets the need of 50% of people
273
What is Lower Reference Nutrient Intake?
= energy/nutrient intake which meets needs of only 2.5% of people
= a measure of national inadequacy
274
What is higher reference nutrient intake?
=energy/nutrient intake which meets needs of 97.5%
=similar to GDA (Guidline daily amount)
275
What is 60-70% of TEE (Total energy expenditure)
Basic Metabolic Rate
276
What is 10% of TEE
-Specific Dynamic Action
277
What is 20-30% of TEE
-Physical Activity
278
Basal Metabolic Rate is…
The energy expended when completely at rest for:
-Heartbeat
-Breathing
-Body Temp
(Depends on: age, sex, mass, height, genetic factors)
279
What is specific dynamic action?
Energy expended for metabolising food including:
-eating
-digestion
-absorption
280
What is Physical Activity?
-energy expended during exercise
(Dependent on body mass, duration, intensity, type of exercise)
281
PA equation:
-time x body mass x exercise specific energy expenditure
282
What is BMI?
Body mass index
-a measure of body fat based on height and mass of adult men and women
283
What is the equation for BMI?
Body mass/ height ^2
284
What is WHR?
-a measure of abdominal fat based on waist and hip circumferences
285
What does WHR take into account?
-amount of abdominal fat
Abdominal fat correlates with risk of heart diesease
286
Where does the body get cholesterol from?
-80% from the liver
-20% from food
287
How is cholesterol transported in blood
-transported in lipoproteins because it is insoluble in water
288
What is HDL?
High density Lipoprotein
289
HDL is has …% cholesterol
20
290
HDL contains ……………. Fatty acids
Unsaturated
291
HDL contains different….
Apoproteins
292
HDL transports cholesterol to the…
Liver for breakdown
293
LDL stands for
Low density lipoprotein
294
LDL contains 40%
Cholesterol
295
LDL has……….. fatty acids and only …………. B
-saturated
-apoprotein
296
LDL transports cholesterol from the…
Liver to cells
297
How is cholesterol transported into cells?
-cells have LDL receptors on surface which bind to LDL
-LDL bound to receptor is released into the cell by endocytosis
-LDL and LDL receptors are separated at low PH
-LDL receptors are recycled back to cell surface
-LDL vesicles fuse with lysosome
-LDL is degraded and cholesterol is released
298
How does cholesterol build up in the blood?
-excess saturated fat from diet increase in ldl
-LDL receptors on cell surface saturated:
-not all cholesterol taken into cells
-more cholesterol in blood stream
(Saturated fats may also increase LDL receptor activity)
299
Why does high cholesterol increase CVD risk?
-LDL can build up in artery walls leading to atheroma formation
300
How can blood cholesterol level be lowered?
-increase unsaturated fat in diet: increase in HDL
-HDL can reduce cholesterol in atheroma
-HDL takes cholesterol to liver for breakdown
-may also increase LDL receptor activity
301
How do we keep our cholesterol in the healthy range?
HDL:LDL balance important
302
What is a monogenic disorder?
Disease cause by mutations in a single gene
303
What is a polygenic disorder
-disease caused by mutations in several genes
304
What is a multifactorial disorder
-disease caused by a combination of mutations in several genes and environmental factors
305
Genetic mutations in several different genes can…
Predispose an individual to CHD but environmental factor also contribute to CHD development
306
What is familial hypercholestrolaemia
0Genetic disorder characterised by high LDL levels
307
What can hypercholesterolaemia be caused by?
-Mutations in APOB gene
-dominant
-prevents ldl from binding to LDLR
-mutations in LDL receptor gene
-dominant
-LDLR levels reduce
Mutations in LDL RAP1 gene
-recessive
-LDLRAP1 protein assists LDLR function
Mutations in PCKS9 gene
-dominant
-PCKS9 required for LDLR synthesis
308
What is apolipoprotein gene cluster?
-mutations in apoa1 gene
-familial HDL defiance
-dominant
-leads to low HDL levels
-mutations in APOE gene
-apoe & 9 allele
-co-dominant
-leads to low HDL levels
309
What is the effect of the apolipoprotein gene cluster?
-cholesterol not removed from blood
-increased risk of AS
310
What is hypertrophic cardiomyopathy?
-left ventricle myocardium and septum thickened
-1 in 500 have HCM mostly undiagnosed
311
What is the effect of hypertrophic cardiomyopathy?
-heart pumps blood to body less effectively
-electrical activity of heart affected - arithymia
-cardiac arrest
312
What are free radicals?
-highly reactive molecules with unpaired electrons
313
What are examples of free radicals?
-superoxide anion
-peroxide
-hydroxyl
314
How are free radicals produced?
-uv light
-metabolism
-ionizing radiation
-smoking
315
Free radicals are ……….. agents:
Oxidising
- they take electrons from other molecules thereby oxidising and damaging them
316
How do free radicals cause CVD
-they oxidise LDL
-oxLDL causes inflammation - e.g more macrophages recruited
-oxLDL causes foam cell formation
-> artheroscleoris
317
What are antioxidants?
-molecules that prevent oxidation of other molecules by providing electrons to pair up with unpaired electrons of free radicals
318
Vitamin C has various functions…
Within the body, including antioxidant properties
319
How does caffeine affect neurotransmitter action?
-decreases adenosine : less alert and sleepy
-increases serotonin: more relaxed and tired
-increases noradrenaline: increases heart rate -> more oxygen to brain
320
How can blood cholesterol be kept in a healthy range?
-healthy life-style
-healthy diet
-statins
321
What are statins?
-decrease cholesterol synthesis
-increase LDL receptors synthesis
-increase LDL removal from blood
322
How do u prevent blood clots?
Using anticoagulant drugs
-they affect synthesis of clotting factors (warfarin)
323
What do platelet inhibitory drugs do?
-reduce stickiness of platelets
Aspirin
324
What is the energy store in plants?
- starch
325
What is the energy store is animals?
- glycogen
326
What is the main energy store in animals?
- lipids
327
How does the structure of glycogen allow it to be an energy store?
- polysaccharide of glucose
- to provide glucose for respirate
- A(1-6) bonds for rapid hydrolysis
- compact to allow large amount to be stored
328
Describe the reaction that joins two a-glucose molecules?
- involving OH groups on both molecules
329
Why is amylopectin and glycogen a good energy store
- compact
- highly branched so rapidly hydrolysed
- insoluble so no osmotic affect
- too large to diffuse across cell surface
