Topic 1 and 2 extras Flashcards
Advantages of glycogen as an energy storage molecule
- large molecule/made up of many monomers allows
storage of large amounts of energy; - compact therefore large amounts can be stored in a cell;
- insoluble therefore does not have an osmotic effect/eq;
- inert so not affected by other reactions in cells;
- large molecule therefore cannot pass out of cells;
- can be hydrolysed to release large amounts of energy /
glucose when required;
Suggest how high blood pressure can result in less oxygen reaching heart muscle.
- damage to artery walls;
- ref. to blood clot;
- blood clot can block arteries;
- ref. to coronary arteries;
- lack of (oxygenated) blood flow to heart muscle;
Describe and explain the events that occur during ventricular systole in the cardiac cycle.
- ventricle (muscle) contracts;
- higher pressure in ventricles relative to atria;
- (pressure) closes atrioventricular valve;
- higher pressure in ventricles relative to the {aorta /
pulmonary artery / arteries}; - (pressure) opens the semilunar valve;
- blood forced into the {aorta / pulmonary artery /
arteries};
Percentage change
Percentage change= original - new/original
Explain the changes in blood pressure in the arteries.
(pulses)/fluctuates due to {elastic recoil/eq}
Explain why the model used to describe the structure of this cell membrane is called the fluid mosaic model.
- Fluid because phospholipids moving (within membrane);
- Causing proteins to move;
- Mosaic due to presence of proteins/eq;
Conversions
1 cubic centimetre = 1000 cubic millimetres
1 cubic decimetre = 1000 cubic centimetres
1 cubic metre = 1000 cubic decimetres
Surface area to volume ratio
divide surface area by volume
dividing the surface area by the volume of any object.
Magnification
magnification = size of image
size of real object
Percentage error
approximate value - exact value/ exact value
Percentage = Error Uncertainty / Reading x 100
Surface area and volume of shapes
Cylinder A=2πrh+2πr2 V=πr2h
Sphere V=4/3 x πr3 A=4πr2
what is meant by template?
idea that the (RNA) nucleotides attach to this strand
codes for mRNA
One advantage of DNA having two complementary strands is that
semi-conservative replication is possible
Describe differences between the processes of replication and transcription of DNA.
1
replication uses DNA nucleotides
transcription uses RNA nucleotides / eq ;
2
replication uses DNA polymerase / eq
transcription does not use DNA polymerase / uses RNA polymerase ;
3
replication reference to semi- conservative
transcription not semi-conservative / eq ;
4
replication (copies) both DNA strands / eq
transcription (copies) only {one strand / template / gene / eq} ;
5
replication makes DNA double helix / eq
transcription Makes single strand mRNA / eq ;
Recessive allele
idea that both of these alleles need to be present in order for the recessive phenotype to be expressed ;
AND
2. different form of a gene / eq ; 3. same locus /position / eq ;
4. different base sequence / eq ;
reasons why Daphnia is a suitable organism for investigating the
effect of chemicals on heart rate.
idea that you can see the { heart / internal organs / eq} ;
- Daphnia {are simple organisms / have less developed nervous system / can’t feel pain / eq} ;
- idea that there are fewer ethical concerns because it is an { invertebrate / eq} ;
- idea that they are abundant / used as fish food / eq ;
- idea that they can absorb chemicals from the surrounding solution quickly ;
suitable control method for daphnia experiment
; Examples:
• temperature ; heat shield ;
• volume of caffeine (solution) ; (use pipette to measure) stated volume e.g. 2 cm3 ;
• { age / species / source /size / gender } of Daphnia ; hatched from eggs at the same time ;
• pre-treatment / acclimatisation ; same time ;
• reduce movement of Daphnia ; use of cotton wool
strands ;
• method of measuring heart rate ; count number of
heartbeats in 30 seconds / eq ;
• {concentration / source} of caffeine ; one caffeine
tablet in 10 cm3 of water
Explain why many small animals, such as Daphnia, have a heart.
- reference to mass flow ;
- name a suitable substance transported e.g. oxygen ;
- comment on {blood pressure / fast movement of blood to cells /eq} ;
- idea of increased concentration gradient of solutes e.g. oxygen ;
- idea that diffusion alone would be too slow ;
- has high metabolic rate / eq ;
Explain why people with cystic fibrosis can have breathing difficulties.
- produces {thicker / stickier / more viscous / eq} mucus ;
- blocking { trachea / bronchi / bronchioles / airway / eq} / eq ;
- cilia are unable to move mucus out of lungs / eq ;
- idea of reduced flow of {air / oxygen } to alveoli ;
- idea of reduced concentration gradient for {oxygen / carbon dioxide} (in alveoli) ;
- idea of loss of surface area / elasticity / eq ;
- idea of reduced gaseous exchange ;
- trapped bacteria may result in more respiratory infections / eq ;
Explain either one ethical issue or one social issue relating to the use of prenatal genetic testing.
- idea that it may result in a miscarriage / choice of an abortion ;
- {killing / eq} is {wrong / unethical / eq};
OR - idea of risk of false {positive / negative} ;
- comment on consequence e.g. healthy fetus may be aborted / parents not prepared for child with cystic fibrosis / eq ;
OR - if cystic fibrosis or some other abnormality may be found ;
- comment on possible problems with {future employment / insurance / what constitutes a serious condition} / eq ;
OR - who has right to decide if tests should be performed / eq ;
- {implications of medical costs / disagreements over next step} ;
OR - issues relating to confidentiality of {parents / child} / eq ;
- idea that {some other abnormality may be found / paternal DNA does not match / other family members have right to know results} ;
Suggest one piece of medical advice that could be given to someone who does not have high blood pressure but who is obese.
- reduce energy intake / increase activity / follow calorie controlled diet / eq ;
- idea of change in balance of energy budget ;
- lower {weight / BMI / obesity level / eq} / reduce risk of {atherosclerosis / diabetes / eq} ;
OR - statins / sterols / reduce { cholesterol
/ saturated fats / eq} in diet / eq ; - reduce blood cholesterol levels ;
- idea of reducing risk of atherosclerosis / eq ;
OR - eat more fruit / vegetable / vitamins /
moderate alcohol intake / eq ; - reference to antioxidants ;
- they protect against free radical damage / reduce damage to cells / eq ;
OR - anticoagulants / platelet inhibitory
drugs / warfarin / aspirin / eq ; - prevent blood clot formation / eq ; 12.reduces risk of blocking artery / eq
Amino acids chain
R groups bond to form secondary and tertiary structure
Explain how the dipolar nature of water is essential for living organisms.
- idea that water can form {hydrogen bonds / eq} ;
and any one from - water is a solvent / {ions / polar molecules / eq } can {dissolve / be transported / eq } in water
- reference to cohesion/adhesion
- idea of hydrogen bonds holding water together as a liquid, so that it can move in mass flow systems
- suitable ref. to specific heat capacity
- idea of distribution of thermal energy around body
- reference to high latent heat of vaporisation
During this cardiac cycle, the changes in pressure that occur in the left atrium and in the left ventricle are different.
- {pressure changes / maximum pressures} are smaller in the atrium than the ventricle / eq ;
- the atrium has less (cardiac) muscle than the ventricle ;
- the atrium does not have to push the blood as far as the ventricle has to / eq ;
- the increase in pressure happens in the atrium before the ventricle / eq ;
- idea that atrial systole has to happen before ventricular systole in order for the ventricle to fill with blood ;
- idea that increase in atrial pressure causes increase in {pressure / volume } in ventricles ;
- appropriate reference to effect of atrioventricular valve (AV) (on pressure) ;
Describe the role of each of the following in protein synthesis.
mRNA
1. idea of mRNA being a copy of the { antisense DNA strand / template DNA strand / coding DNA strand / gene / allele / part of DNA / eq } ;
2. idea that mRNA {made up of codons / codes for specific amino acids / code for amino acid sequence / eq} ;
3. idea of mRNA being taken {into the cytoplasm / to the ribosomes / out of the nucleus / eq} ;
4. used in translation ;
5. binds to ribosome ;
tRNA
6. (tRNA) {attaches to / transports / eq } (specific) amino acid / eq ;
7. idea that tRNA binds to mRNA / reference to anticodon codon interaction ;
8. idea that two tRNA bring amino acids together (for peptide bonds to be formed) ;
general formula
general formula for a monosaccharide is CnH2nOn whereas formula for disaccharide is CnH2n-2On-1
Explain why a diet consisting of a high proportion of carbohydrates could lead to obesity.
- idea of carbohydrates providing a source of energy ;
- if the {energy / carbohydrate / eq} input is greater than the {energy output / carbohydrate use / eq} (weight will be gained) / eq ;
- idea of excess carbohydrate converted to fat
*(a) Describe the structure of the mammalian heart.
- idea that there are four chambers ;
- correct reference to relative position of atria
and ventricles ; - idea of left and right sides separate / septum
; - reference to muscular nature of walls ;
- reference to cardiac muscle ;
- idea of relative thickness of ventricle (walls) ;
- correct reference to position of {atrioventricular valves / eq} ;
- correct reference to position of semilunar valves ;
10.correct reference to position of {aorta / pulmonary artery} ; - correct reference to position of {vena cava / pulmonary vein} ;
- correct reference to coronary arteries ;
xplain the importance of the heart and circulation to a large mammal
- idea that the heart has to pump blood a long way around the body of the giraffe ;
- (therefore) blood needs to be (pumped) at high pressure / eq;
- blood vessels are needed to contain the blood / reference to closed circulation / eq ;
- idea of double circulatory system ;
- capillaries needed to ensure that all parts of giraffe are close to blood supply/ eq ;
- idea of need for a circulation to {provide oxygen / remove carbon dioxide / other correct named substance} ;
- idea of {oxygen / glucose} needed as {high metabolic rate / high rate of respiration / eq} ;
- idea of diffusion not meeting the requirements of the giraffe ;
- reference to low surface area to volume ratio ;
- idea that circulatory system helps regulation of body temperature ;
Suggest why there are changes to the available energy (ATP) in the heart muscle cells following the loss of blood flow.
- idea of {less / no /eq } oxygen (available) ;
- idea of {less / no / eq} {respiratory substrate / glucose / eq} ;
- {less / no/ eq} (cellular/ aerobic) respiration / eq ;
Calculate beats per minute
60/ seconds for one cycle
