Past Paper Error revision Flashcards
What is the name of the drug that can manage type 2 diabetes
Monitor blood glucose concentration with drugs metformin
Explain why glucose is required for the contraction of skeletal muscle
Glucose is required to provide energy for the muscle to contract.
ATP is needed for breaking cross bridges between myosin and actin
ATP hydrolysed to ADP and Pi, to reset myosin head
Outline the importance of photosynthetic pigments in photosynthesis
Pigments absorb light which excite electrons to higher energy level.
Accessory pigments pass energy to reaction centres
Primary pigments lose electrons, pass electrons to electron transport chain for light independent reaction
Give three properties of cellulose that make it suitable as the basis of plant cell walls
High Tensile Strength
Insoluble
Flexible
RQ of 1
RQ of 0.9
RQ of 0.7
These RQ value suggests what type of diet
RQ 1 = carbohydrates
RQ 0.9 = protein
RQ = 0.7 = lipids
Outline the processes involved in the generation of ATP through Chemiosomosis
ATP produced in both photosynthesis and respiration is synthesised primarily by a process called chemiosmosis.
Chemiosmosis involves the diffusion of H+ from high concentration to low concentration through a partially permeable membrane.
The movement of protons as they flow down their concentration gradient releases energy that is used in the attachment of an inorganic phosphate (Pi) to ADP forming ATP
What happens when the heart rate is too slow
The level of carbonic acid in the blood becomes higher than normal.
Accelerator nerve sends action potentials to the SAN to increase the contraction rate of the heart muscle.
Chemoreceptors detect the pH of the blood is normal, so heart rate can return to normal.
Adrenaline from adrenal medulla can cause cardiac muscle to contract more - endocrine system.
Describe two ways in which the structure of mitochondrial membranes is related to the function of a mitochondrion
Site for chemiosmosis - ATP Synthesis
Allow formation of proton gradient
The endosymbiosis theory suggests that mitochondria may have evolved from bacteria that were taken inside other cells.
Give two structural features of mitochondria that support this theory
70s ribosomes
Double membrane
What are the monosaccharides, disaccharides and polysaccharide
Mono - glucose, fructose, galactose
Disaccharide - sucrose, lactose, maltose
Polysaccharide - starch, cellulose, glycogen
How to ensure experiment is repeatable
Rinse the equipment
Mitosis is involved in growth and repair of tissues.
State two other roles of mitosis in multicellular organisms
- Asexual reproduction
- Development of body plan
- Production of new stem cells
What is selective breeding and why is it important to maintain
Selective breeding is where we obtain the best characteristics of an animal/plant and breed them together to produce the best offspring - with desirable characteristics.
It is important to increase genetic variation.
it promotes source of useful allele
Prevents a dwindling gene pool
Prevent inbreeding –> genetic disorders
How can genetic diversity be measured
Genetic polymorphism
Explain why a genetic bottleneck can lead to low genetic diversity
caused by natural disasters
Affects future generation
Many alleles lost when population dropped
new population descended from few survivors
What is genetic drift
It can be due to random mutation or selection pressure
It causes a large impact due to new allele formed
1 allele has proportionally higher effect on small population
alleles will be lost from population
What three conditions needed for speciation to occur
Mutation ,Time, natural selection
Define the term DNA sequencing
Working out the sequence of nucleotides
Explain how DNA sequencing allows the sequence of amino acids in polypeptides to be predicted
Sequence of bases codes for amino acids. Each triplet codes for one amino acid.
What type of bond does collagen have
peptide bond
The use of electrons as a source of radiation in the electron microscope allows high radiation to be achieved because electrons
Have a very short wavelength
Why is the Pacinian corpuscle described as a transducer?
Converts mechanical energy into another form of energy - electrical
What would you expect to happen to the speed of the impulse if the diameter of the axon of the sensory neurone was increased?
Speed will increase as less resistance to the flow of ions in the cytoplasm
Explain why it is important for the leaf tissue sampled to be thin?
Single few layers
Light can pass through
