things i fucked on the past papers x Flashcards
suggest one disadvantage of cell counts performed using the haemocytometer
time consuming. you cant distinguish dead cells from living cells
how can you minimise harm to animals during experiments
replacement
reduction
refinement
what is an advantage of an in vivo trial
allows possible side effects to be seen
describe an ethical issue that the researchers would need to consider before this trial
right to withdraw
informed consent
what does replacement mean
replace with another biological system
what does refinement mean
refine techniques
what does reduction mean
use less subjects
diabetes insipidus results from failure to recruit water channel proteins to the cell membrane. identify the cause of recruitment failure in this individual
failure to produce ADH
trypan blue is used as a vital stain to identify viable cells when viewed in a haemocytometer. a vital stain does what?
only stains dead cells
the binding of oxygen to haemoglobin is affected by small changes in temperature or pH. which of the following changes would decrease haemoglobins affinity for oxygen
increased temperature
decreased ph
what does positive control mean
a group in an experiment that receives a treatment with a known result.
treatment that is included to check that the
system can detect a positive result when it
occurs
what does negative control mean
provides results in the absence of a treatment.
used to identify exterior variables that can have an effect that were not previously accounted for
most birds have four types of cone cells. name the additional wavelength range to which these organisms are sensitive
ultraviolet
describe how protein electrophoresis is used to separate proteins
the charge separates proteins in the gel on the basis of their size shape and charge
suggest one reason why counting organisms is an appropriate indirect sampling technique
the disturbance is minimised
discuss the role of amino acid r groups in the determination of tertiary structure of proteins
tertiary structure is a folded polypeptide
the conformation is determined by the order of amino acids
there are different r groups such as basic, acidic, polar and non polar.
there are different interactions holding the shape in place such as disulphide bridges and london dispersion forces
discuss the role of amino acid r groups in influencing the location of proteins within cells
hydrophilic groups are mostly at the surface of a soluble protein, which are found in the cytoplasm
in soluble proteins, the hydrophobic groups may cluster at the centre of a protein.
membrane proteins are integral or peripheral
some integral proteins are transmembrane or channels
peripheral proteins have fewer hydrophobic r groups interacting with the phospholipids
discuss the cell membranes under the heaidng of the phospholipid bilayer as a selective barrier
the membrane has hydrophilic and hydrophobic regions
hydrophilic substances cant pass across the membrane
hydrophobic can
ozygen carbon dioxide and water can all pass through the membrane
protein channels and pumps are required to transport hydrophilic molecules across the membrane
discuss the cell membrane under the heading of types of transport proteins and their functions
channels and pumps are transmembrane proteins that can create concentration gradients
movement through channels is passive, as molecules move down a concentration gradient
transporter proteins change their conformation to transport molecules across the membrane
conformational change in active transport requires energy from the hydrolysis of ATP
describe sodium potassium pump
which pair of cell types are fused in order to produce monoclonal antibodies
b lymphocyte and myeloma
what needs to happen to p53 and retinoblastoma to increase the rate of cell division
p53 inhibited
retinoblastoma phosphorylated
name the level of protein structure describing several connected polypeptide subunits
quaternary
what are primary cell lines
they are sourced directly from normal animal tissue and are have a limited number of cell division s
which events contribute to the depolarisation of the resting potential of a neuron
- binding of a neurotransmitter to a neuron
- opening of ligand gated ion channels
- opening of voltage ligand gated ion channels
monoclonal antibodies can be produced in a laboratory using hybridomas that are prepared by fusing together b lymphocytes and myeloma cells. name the chemical used to fuse these two cell types together
PEG
explain why it is important to control pH in immunoassays
ph affects the structure of proteins because it impacts the interactions between the R groups
because of this the proteins would have a reduced affinity for binding to the substrate
state the meaning of the term monoclonal
this means the antibodies are derived from a single clone of cells
how does the binding of ATP result in the opening of the chloride ion channel
binding to the protein causes a conformational change
what is meant by epidemiology
study of outbreak
explain why an observational study can only suggest a possible link
because it does not show causation, just correlation
discuss signalling molecules and signal transduction under the heading of hydrophilic signalling molecules and signal transduction
hydrophilic signaling molecules include neurotransmitters,
and peptide hormones
the receptors are specific and are transmembrane proteins
the molecule binds to a receptor on the cell surface, causing a conformational change, bringing about a response.
this activates g proteins and proteins that regulate gene transcription
discuss signalling between cells under the heading of insulin signalling and diabetes
binding of insulin to its receptor triggers glut4 recruitment to the cell membrane of fat and muscle cells
type 1 diabetes is a reduced production of insulin
this leads to failure to recruit of glut4 so there is impaired glucose uptake
exercise increase glut4 recruitment
discuss control of the cell cycle under the heading of phases of the cell cycle and the importance of cell cycle checkpoints
lack of control of the cell cycle can result in degenerative diseases and cancer
the phases are g1, s, g2, and m
there are checkpoints at g1 g2 and m
g1 and g2 are growth phases
s phase is dna replication
size and mass of cell is assessed at the g1 checkpoint
