Biology Topic 1

?
  • Created by: Qazwsxed
  • Created on: 27-06-18 18:14
Why do mammals and other large organisms need a circulation system?
Because they are too large for diffusion to be an effective way of supplying needs and removing waste
1 of 200
In large organisms what special organs are needed?
Heart and lungs
2 of 200
What does the sa/vol ratio affect?
The ratio of the sa of an organism to its volume affects how substances enter the organism and how co2 leaves
3 of 200
Explain small organisms sa
Small organism have a large sa/vol ratio. Substances and water can enter and leave by diffusion or osmosis
4 of 200
LArge organisms have a ......... sa/vol
small
5 of 200
What is a perfect solvent for transporting substances and co2 around the body?
water
6 of 200
Explain why water is the perfect solvent in terms of water being a polar molecule
Polar molecules have uneven distractions. 1 end of water molecule is slightly positive and other slightly negative. Water is said to be dipolar
7 of 200
Explain why water is the perfect solvent in terms of water being liquid at room temperature
3 water molecules are joined to each other by H bonds formed by electrostatic attraction between polar molecules
8 of 200
Explain why water is the perfect solvent in terms of water easily dissolving molecules held together by ionic bonds
Sodium and chloride ions in common salt are pulled apart by water molecules and then surrounded by them. Water also dissolves polar molecules such as sugars and amino acids
9 of 200
Structure of artery
Relatively thick wall, smooth muscle, elastic fibres, lined with smooth layer of endothelial cells and narrow lumen
10 of 200
Functional significance of a relatively thick cell wall in artery
withstands high blood pressure
11 of 200
Functional significance of smooth muscle in artery
alters diameter of lumen to vary blood flow
12 of 200
Functional significance of elastic fibres
allows walls to stretch when blood is pumped into the artery and then recoil, smoothing blood flow
13 of 200
Functional significance of an artery being lined with a smooth layer of endothelial cells
low friction surface to ease blood flow
14 of 200
Functional significance of narrow lumen in artery
to maintain high blood pressure
15 of 200
Structure of capillaries
very thin cell wall-only 1 cell thick and 1 red blood cell thick lumen
16 of 200
Functional significance of a very thin cell wall in capillaries
Allows rapid exchange between blood and tissues
17 of 200
Structure of veins
Relatively thin wall, very little smooth muscle or elastic fibres, wide lumen, valves
18 of 200
Functional significance of a relatively thin wall in vein
blood is under low pressure so wall doesn't need to be strong
19 of 200
Functional significance of a veinhaving very little smooth muscle or elastic fibres
no pulse of blood so no stretching and recoiling
20 of 200
Functional significance of a wide lumen in vein
large volume acts as blood reservoir
21 of 200
Functional significance of valves in veins
stock back flow of blood
22 of 200
How do you work out the magnification of photographs?
image size/actual size
23 of 200
How many chambers does the heart consist of?
4
24 of 200
What are the top chambers called
atria
25 of 200
What are the lower chambers called
ventricles
26 of 200
Very simple description of the 4-chambered heart
deoxygenated blood enters the right atrium from body, its then pushed by muscles in right ventricle to lungs where its oxygenated. The oxygenated blood returns from lungs to the left atrium its then pushed into left ventricle and out along aorta
27 of 200
What is the bottom point of heart called?
Apex
28 of 200
Which ventricle of cardiac muscle is thicker and why?
Left-as theres higher pressure when pumping blood to body
29 of 200
Purpose of septum
to separate the 2 sides of heart
30 of 200
Why has the mammalian heart got 2 sides?
allow oxygenated and deoxygenated blood to be kept separate, allowing as much oxygen as possible to be carried to the cells. both sides have different amounts of muscle so that there can be higher pressure on the side pumping to the body
31 of 200
The cardiac cycle in the left side of the heart
Blood drains into left atrium from lungs along pulmonary vein*raising of BP in left atrium forces left av valve open*contraction of left atrial muscle(left atrial systole)forces more blood through valve
32 of 200
The cardiac cycle in the left side of the heart
as soon as left atrial systole (muscle contraction) is over, left av muscle starts to contract. This is left ventricular systole*This forces left av valve to close and opens valve in mouth of aorta (semilunar valve) blood then leaves left ventricle a
33 of 200
The cardiac cycle in the left side of the heart
This forces left av valve to close and opens valve in mouth of aorta (semilunar valve) blood then leaves left ventricle along the aorta
34 of 200
what are the hearts blood vessels called?
Coronary arteries and veins
35 of 200
Where can coronary be seen?
Branched over the surface of the heart
36 of 200
What do av valves do?
Stop blood flow from ventricles to atria and semilunar valves from arteries back into the heart
37 of 200
what is attached to the av valves?
Tendons (heart strings)
38 of 200
What do tendons do?
Stop valves from tuning inside out
39 of 200
In an ECG of heart beat what does it mean when graph line starts to rise?
Ventricles start to contract, ventricular pressure is greater than atrial pressure so av valve closes
40 of 200
In an ECG of heart what happens on graph when semilunar valve opens?
Pressure in ventricles is now greater than that in the aorta so the semilunar valve opens
41 of 200
Atherosclerosis definition
Atherosclerosis is the disease process that leads to coronary disease and strokes (cv disease)
42 of 200
What can block an artery?
fatty deposits (atheroma) can either block an artery directly or increase its chance of being blocked by a blood clot (thrombosis)
43 of 200
Describe the process of atherosclerosis developing
*Endothelial lining of artery is slightly damaged(endothelial dysfunction) which causes an inflammatory response and white blood cells move into artery wall. Cholesterol builds up leading to formation of atheroma. Build-up of calcium salts and fibres
44 of 200
Describe the process of atherosclerosis developing
Leads to plaque formation. The artery narrows and loses elasticity which raises blood pressure which damages endothelial lining more which increases risk of blood clotting in the artery
45 of 200
what are the 5 health effects of an atheroma?
Increased BP*aneurysm*angina*Heart attack*Stroke
46 of 200
Describe increased blood pressure as a health effect of an atheroma
Increased blood pressure can damage kidneys and retina and cause strokes
47 of 200
Describe aneurysm as a health effect of an atheroma
Aneurysm is where the increased pressure of blood caused by blockage can lead to the bursting of an artery and internal bleeding
48 of 200
Describe Angina as a health effect of an atheroma
Angina, is a chest pain often felt during exercise, Caused by reduced blood flow to heart due to narrowing of coronary arteries
49 of 200
Describe a heart attach as a health effect of an atheroma
Heart attack is when a coronary artery becomes totally blocked, usually by a clot, and part of the heart becomes starved of oxygen and dies
50 of 200
Describe a stroke as a health effect of an atheroma
Stroke is an interruption to the blood supply of the brain which can cause paralysis or even death
51 of 200
Where is it crucial that a blood clot does not form?
Blood vessels
52 of 200
Explain a very simple version of the sequence of thrombosis
platelets stick to damaged tissue, a protein thromboplastin turns into soluble prothrombin in plasma. calcium and vitamin K build up turning it into soluble thrombin the fibrinogen into fibrin to blood clot
53 of 200
What does thromboplastin do?
Trigger blood clotting
54 of 200
What will more fibrinogen result in?
Larger blood clot
55 of 200
What is more likely to happen if blood flow is slow?
Blood clot is more likely to form
56 of 200
Definition of risk
Risk is the probability of the occurrence of an unwanted event or outcome
57 of 200
When do people often overestimate the risk of something?
*When its involuntary e.g.being a passenger in an airplane *when its dreaded e.g.natural disaster *not natural (nuclear power) *unfamiliar *Unfair *very small
58 of 200
What are risks for CVD?
Poor diet, lack of exercise, smoking
59 of 200
When is risk poorly judged?
*own experience which will carry more weight than statistics *inability to assess risks well * peer pressure * idea that is something is destined to happen then it will and there is not much that can be done about it *
60 of 200
What are the 7 factors that increase risk of CVD?
high BP *genetics *inactivity *age *gender *smoking *diet
61 of 200
Info about BP and the maximum mmHg
Should not be above 140mmHg/90mmHg
62 of 200
Why is age a factor that increases risk of CVD?
Because with age elasticity and width of arteries decrease
63 of 200
why is genetics a risk factor of CVD
People can inherit tendencies to gift BP, poor cholesterol metabolism, arteries that are more easily damaged, relative hHDL : LDL levels in blood
64 of 200
Why is inactivity a risk factor of CVD
Regular vigorous exercise reduces the risk of CVD by reducing blood pressure and raising HDL (good cholesterol) levels
65 of 200
Why is gender a risk factor of CVD
Oestrogen gives women some protection from CVD before the menopause
66 of 200
Why is smoking a risk factor of CVD
Correlation and causation shown because chemicals in smoke physically damage artery linings and could also cause them to constrict
67 of 200
Why is diet a risk factor of CVD
Many correlations between dietary habits and levels of CVD e.g. lipoproteins and salt levels; some might be casual particularly for blood cholesterol levels
68 of 200
2 variables can be ..................when a change in 1 is accompanied by a change in the other
correlated
69 of 200
What does it mean to be casually linked
when the change in 1 variable os the cause of the change in the other
70 of 200
Give an example of correlation causation with smoking?
smoking causes lung cancer
71 of 200
What do epidemiologists do?
Scientists who carry out research on patterns of diseases or health risks in population to try to determine the risk factors of health
72 of 200
what are the 2 main kinds of studies
cohort studies*case-control studies
73 of 200
explain cohort studies
follow a large number of people over an extended period. subjects are monitored to see if they develop the condition, cohort then divided into groups those with and those without the condition. Subjects are interviewed to assess their risk factors.
74 of 200
explain cohort studies
correlation between risk factors and development of the condition is looked for
75 of 200
explain case-control studies
A group with the condition (cases) is compared with a group without it (control). Past histories of the 2 groups are investigated. The study will only have validity if the 2 groups are matched for other factors such as age and gender
76 of 200
Name 4 factors that make a good study
*variables should be controlled when selecting cohort or control groups to ensure validity and reliability. This is difficult because human beings are so variable *Measurement techniques or the questions on a questionnaire must be standardised
77 of 200
Name 4 factors that make a good study
*sample size is very important. For many diseases, only a low % of the population has the condition so an apparently large sample size might only contain a small number of individuals with the condition
78 of 200
Name 4 factors that make a good study
*The studied sample should be representative of the whole population to avoid bias
79 of 200
What are energy budgets
energy budgets is the balance between the amount of energy a person requires compared to the energy they take in through their diet
80 of 200
What does the energy you need in a day depend on?
your basal metabolic rate and level of activity
81 of 200
what is BMR
basal metabolic rate
82 of 200
what is BMR usually quoted as
the basic energy requirement for the day
83 of 200
What does energy budgets depend on?
gender, age, body mass
84 of 200
When will you weight stay the same?
If the energy transferred from food you eat is the same as your BMR
85 of 200
What will put you at risk of weight gain/loss
an energy imbalance
86 of 200
How do you work out body mass index
body mass(kg ). / (height m) squared
87 of 200
explain BMI values
Below 20=underweight. 20-25=correct weight 25.1-30=overweight over 30=obese
88 of 200
What should the waist:hip ratio not be greater than in males and females?
males:0.9 Females:0.85
89 of 200
What does carbohydrate mean?
carbo=carbon Hydrate=water
90 of 200
what is the general formula of carbohydrates
Cx(H2O)n
91 of 200
what is the main energy source in the diet
carbohydrates
92 of 200
What are saccharides
saccharides are sugar units that make up carbohydrates
93 of 200
How many units does a disaccharide have
2
94 of 200
How many units does a monosaccharide have
1
95 of 200
how many units does a polysaccharide have
many
96 of 200
what is the general formula for glucose
C6H12O6
97 of 200
what sugar is Glucose
Hexose sugar
98 of 200
What different forms of glucose are there
alpha and beta
99 of 200
What is glucose the source of?
Glucose is the source of the most readily available energy from respiration in living things
100 of 200
Is glucose soluble?
yes
101 of 200
How does its solubility help
helps it fulfil role of energy as it can easily be carried to where ut is need
102 of 200
Why is glucose being a relatively small molecule helpful?
because its important for its movement into cells
103 of 200
When are disaccharides made
disaccharides are made when 2 monosaccharides join by losing water in a condensation reaction
104 of 200
When do 1,4 glycosidic links form
When disaccharides join at C atoms 1 and 4
105 of 200
When do disaccharides split
disaccharides are split by adding water
106 of 200
What is the reaction called where water is added
hydrolysis reaction
107 of 200
what is needed to break glycosidic bonds
water
108 of 200
what is maltose made of
a 2 alpha glucose molecule
109 of 200
what is sucrose made of
alpha glucose and fructose molecule
110 of 200
What is lactose
sugar milk
111 of 200
what is lactose made with
lactose is glucose and galactose joined with a bet a1,4 bond as glucose is in beta form
112 of 200
what does amylopectin mean
branched
113 of 200
what does amylose mean
unbranched
114 of 200
are polysaccharides amylose or amylopectin
can be both
115 of 200
what is glycogen
animal starch
116 of 200
What joins to make amylose
alpha glucose monomers join with 1,4 glycosidic bonds to make amylose
117 of 200
what is amylose
a component of starch
118 of 200
what joins to make amylose and amylopectin
alpha glucose monomers join with alpha 1,4 and alpha 1,6 glycosidic bonds to make amylopectin and amylose
119 of 200
what has glycogen got more of that amylopectin in terms of bonds
glycogen has more alpha 1,6 and is more branched
120 of 200
What is starch a mixture of
amylose and amylopectin
121 of 200
What happens when starch is broken down in digestion
the enzymes catalyse a hydrolysis reaction and monosaccharides are produced again
122 of 200
Is amylose straight or coiled
amylose is a straight chain
123 of 200
why is amylose a straight chain
due to the H Bonding
124 of 200
What bonds does amylopectin have to not allow much coiling, is it branched and what do the bonds not allow so much of?
In amylopectin, the branches (1,6 glycosidic bonds) do not allow so much coiling
125 of 200
What is glycogen like
amylopectin but more branched
126 of 200
Explain starch and its coiled shape
the coiled shape makes it more compact so it can store lots of glucose and therefore energy in a small space
127 of 200
Is starch soluble or insoluble
insoluble
128 of 200
Starch is insoluble so does not............
exert a problematic osmotic effect
129 of 200
............... Is more easily broken down than amylose
amylopectin
130 of 200
Why is amylopectin more easily broken down than amylose
due to more branches, which creates more terminal ends where breakdowns occur and gives a mixture of rapid and slower glucose and energy release
131 of 200
explain glycogen and its branches
glycogen has even more branches so can release glucose even faster, which is needed in animals
132 of 200
what bonds does amylose have
1,4
133 of 200
what bonds does amylopectin have
1,4 and 1,6
134 of 200
what are lipids
fats and oils
135 of 200
are lipids hydrophobic or hydrophilic
all lipids are hydrophobic molecules
136 of 200
what is hydrophobic
water hating/repelling
137 of 200
what are lipids used for
lipids are used to store energy and act as waterproofing and insulating agents
138 of 200
what bond joins a triglyceride
ester bond
139 of 200
What are triglycerides made of
3 fatty acids and a glycerol joined by an ester bond
140 of 200
by what reaction are ester bonds made
condensation reaction
141 of 200
explain hydrophobic/hydrophilic tails and heads in a triglyceride
hydrophobic tail, hydrophilic head
142 of 200
how do fatty acids vary
*fatty acids are of different lengths *in mixed triglycerides the 3 fatty acids are different from each other *fatty acids may be saturated or unsaturated with hydrogen
143 of 200
Explain a saturated fatty acid
no double bond between carbons
144 of 200
explain an unsaturated fatty acid
double bonds between some carbon atoms
145 of 200
explain the properties of unsaturated fatty acids
the kink in an unsaturated fatty acid makes the membrane more fluid than 1 with saturated lipids
146 of 200
Where is the kink in unsaturated fats
unsaturated fatty acids have a kink at each double bond
147 of 200
name an example of a saturated fatty acid
palmitic acid
148 of 200
name an example of an unsaturated fatty acid
oleic acid
149 of 200
what is cholesterol
cholesterol is an essential component of cell membranes where it affects their fluidity
150 of 200
Explain cholesterol in terms of solubility
Cholesterol is a water-insoluble lipid which has to be carried by proteins in complexes called lipoproteins
151 of 200
How many different types of lipids are there
2
152 of 200
What are the 2 types
LDL and HDL
153 of 200
Explain what LDL's are made from
LDL's are made from saturated fats, proteins and cholesterol
154 of 200
Explain what HDL's are made from
HDL's are made from unsaturated fats, proteins and cholesterol
155 of 200
Purpose of HDL
Transport cholesterol from body tissues to liver where it is broken down
156 of 200
Purpose of LDL
Bind to cell surface receptors which can become saturated leaving LDL's in blood
157 of 200
What is LDL associated with
Associated with formation of atherosclerosis
158 of 200
What does HDL discourage
Discourages atherosclerosis as reduces blood cholesterol levels
159 of 200
At what level should HDL's be maintained at
high
160 of 200
At what level should LDL's be maintained at
low
161 of 200
what does cholesterol help form
plaques
162 of 200
Explain the casual link between the 2 variables using rats
rats fed on a high cholesterol diet formed more plaques in the endothelium of arteries than the other control groups
163 of 200
what are the most important factors that reduce the risks of CVD
*stop smoking *maintain resting blood pressure below 140/90 mmHg *maintain a low blood cholesterol level *maintain a normal BMI/low waist to hip ratio *take regular physical exercise *moderate/no use of alcohol *reduce stress
164 of 200
What dietary strategies reduce the risk of CVD
*reduce saturated fats *more polyunsaturated fats *reduce salts (lower fluid levels in turn reduces blood pressure) *more fruit and veg (antioxidants and non-starch cabs lower blood cholesterol)
165 of 200
What dietary strategies reduce the risk of CVD
*more oily fish (linked to slight reduction in BP and risk of blood clotting) *more non-starch polysaccharides
166 of 200
What is vitamin C and what is it common in
Vitamin C is an antioxidant common in many foods such as citrus fruits
167 of 200
what are antioxidants important for
neutralising free radicals which can damage cells
168 of 200
What are antioxidants destroyed by
heat treatments
169 of 200
Why are antioxidants reducing agents
because they lose electrons
170 of 200
What will many substances do when they are reduced
change colour
171 of 200
What are these substances that change colour when reduced called
redox dyes (reduction-oxidation dyes)
172 of 200
What is DCPIP and explain its colour changes
a blue dye in its non-reduced form; goes colourless when in presence of vitamin C as it gains electrons
173 of 200
What may be done if lifestyle and diet may not be enough to prevent CVD and why
drugs may be given to control blood pressure and/or lower blood cholesterol
174 of 200
Name the 6 drugs that reduce the risk of CVD
*diuretics *calcium channel blockers *ACE inhibitors (angiotensin converting enzyme) *statins *warfarin *aspirin
175 of 200
What is aspirin an example of
platelet inhibitory drugs
176 of 200
What is warfarin an example of
anticoagulants
177 of 200
name 3 antihypertensive drugs
*diuretics *calcium channel blockers *ACE
178 of 200
What does ACE stand for
angiotensin converting enzyme
179 of 200
What do diuretics do
increase volume of urine, lowers blood volume and blood pressure
180 of 200
What is the risk/side effect of diuretics
very occasional dizziness *nausea *muscle cramps
181 of 200
What do calcium channel blockers do
disrupts calcium ion movement through calcium channels in the cell membrane, reducing muscle contractions so increases diameter of arteries reduces force of heart beat and frequency, lowering BP
182 of 200
What is the risk/side effect of calcium channel blockers
headaches *dizziness *swollen ankles *constipation *lushing in face
183 of 200
What does ACE inhibitors do
blocks the production of ACE, reducing arterial constriction and lowering BP
184 of 200
WHta is ten risk/side effect of ACE inhibitors
*cough *dizziness *abnormal heart rhythm *impaired kidney function
185 of 200
What do statins do
inhibit an enzyme in the liver that produces LDL cholesterol
186 of 200
What are the risk/side effects of statins
*tiredness *disturbed sleep *nausea *diarrhoea *headache *muscle weakness
187 of 200
What do anticoagulants do
reduce risk of clot formation
188 of 200
What are the risk/side effects of anticoagulants
Risk of uncontrollable bleeding, dosage control is essential
189 of 200
What do platelet inhibitory drugs do
Make platelets less sticky
190 of 200
rosk/side effects of platelet inhibitory drugs
aspirin irritates stomach lining ands can cause stomach bleeding *clopidogrel with aspirin increases risk
191 of 200
compare the ethical issues of using daphnia and humans in the daphnia heart rate experiment
daphnia= have simple nervous system humans=complex nervous system *daphnia=no need for dissection as transparent and can see heart beating human=needs dissection *D=abundant in nature H=cannot kill for *D=bred for fish food H=experiment
192 of 200
compare the ethical issues of using daphnia and humans in the daphnia heart rate experiment
*D=no loss of genetic variation *D=cannot give consent H=can give consent
193 of 200
Why is daphnia used for this experiment
*abundant *easily obtained *transparent-so heart can be seen *simple nervous system so ethically less of an issue that a mammal
194 of 200
what are some limitations of this daphnia experiment
*they are not human
195 of 200
Explain the step in the experiment and method
*immobilise the daphnia-use strands of cotton wool in a small dish of the experimental solution to trap the daphnia
196 of 200
Explain the step in the experiment and method
*control other variables e.g.water temperature, daphnia size-difficult to maintain constant temperature but should be monitored with thermometer in water, daphnia of similar size etc. should all be used for all experiments
197 of 200
Explain the step in the experiment and method
*accurate measurement of HR-dots are put on piece of paper in S shape to avoid putting dot on top of another or repeatedly press a button on a calculator *repeatability-ensure that variables other than caffeine conc are controlled
198 of 200
What are the variables considered to be in the daphnia experiment
*temperature *age, size, sex of daphnia *aspects of pretreatment such as type of water, length of time out of natural habitat
199 of 200
What are the safety measures that should be taken during the experiment
*do not mix water an electricity *don't forget to wash your hands after handling daphnia
200 of 200

Other cards in this set

Card 2

Front

In large organisms what special organs are needed?

Back

Heart and lungs

Card 3

Front

What does the sa/vol ratio affect?

Back

Preview of the front of card 3

Card 4

Front

Explain small organisms sa

Back

Preview of the front of card 4

Card 5

Front

LArge organisms have a ......... sa/vol

Back

Preview of the front of card 5
View more cards

Comments

No comments have yet been made

Similar Biology resources:

Biology
See all Biology resources »See all Topic 1 resources »