past exam questions Flashcards
describe the process of apoptosis
apoptosis is cell suicide or cell murder. cells will commit suicide when they lack any incoming survival signal in the form of trophic factors , or when they detect extensive DNA damage in their own nucleus. the major steps in apoptosis is that the cell shrinks , then the cell turns into cell fragments. the cytoskeleton collapses and the nuclear envelope disassembles. The cell then releases apoptotic bodies.
what is the location of the nucleolus and its function
the nucleolus is found inside the nucleus of a cell. the function of the nucleolus is to produce and assemble the cells ribosomes.
With regards to the cell cycle what is G0
the G0 is the quiescent phase. This is the phase of the cell cycle when the cell is neither dividing or preparing to divide.
what effects to competitive inhibitors have on Vmax and KM
competitive inhibitors do not have an effect on Vmax or KM
give 2 examples of granulocytes
neutrophils and basophils.
what is the difference between EC50 and ED50 of a drug
EC50 is the dose required for an individual to experience 50 % of the max effect. ED50 is the dose for 50 % of the population to obtain the therapeutic effect.
what is meant by the term analytical chemistry
analytical chemistry is the study and use of instruments and methods to separate , identify and quantify matter.
name 2 analytical techniques that can be used for determining the 3-D structure of a protein or protein complex
X-ray crystallography and nuclear magnetic resonance.
provide 2 advantages of the use of size exclusion chromatography for the analysis of proteins
the advantages include good separation of large molecules from the small. can be applied without interfering with the filtration process.
outline the process of glycolysis
pyruvate is changed to acetyl CoA using three main steps. these are decarboxylation , reduction of NAD+ and the attachment of Acetyl CoA.
examples of drugs from natural sources
antimalarial drug quinine and analgesic morphine
a sequence of 3 nucleotide bases of MRNA
codon
what is the impact of deletion of the TATA box from the gene of a eukaryotic promotor
deletion of the Tata box results in loss of the corresponding cap sites.
name the two pathways of endocytosis
dynamin-dependent and dynamin-independent
4 factors which effect the choice of route of administration
bioavailability
patient compliance
cost
side affects
2 routes of administration which can by pass 1st metabolism
intravenous injection and inhalation
4 functional groups present in amoxicillin
hydroxyl
amino group
amide group
carboxylic acid
out of the cycloalkanes which is the most stable and why
cyclohexane is the most stable. it is the most stable because it can adopt the chair configuration which has no angle strain and low torsional strain
what is meant by the term pharmacophore
a pharmacophore is the ensemble of steric and electronic features that is necessary to ensure that optimal supra-molecular interactions with a specific biological target structure and to trigger its biological response
four cellular features associated with necrosis
swelling of organelles, such as the endoplasmic reticulum and mitochondria, the rupture of the plasma membrane, and the lysis of the cell. [17] These changes cause cells to be more eosinophilic, glassy, and vacuolated.
give 2 reasons why mitochondrial DNA was thought to be inherited solely from the mother
when the sperm enters the egg , the tail is left outside . this is where the mtDNA is found in the sperm.
hemidesmosomes are a type of cell junction. which structures do they anchor?
they anchor the cell wall to a cell matrix. they anchor intermediate filaments to the ECM
which part of the blastocyst develops into the i) placenta ii) develops the embryo
I) the trophoblast
ii) inner cell mass
what is a prion disease? give an example and explain how it happens.
prion disease is a transmissible , untreatable and fatal brain disease. an example of this is Creutzfeldt-jakob disease. this is caused by an abnormal isoform of cellular glycoproteins known as prion protein.
factors that effect hydrolysis
temperature
catalysis
ionic strength
structure of the reactant
primary amine + ketone =
imine
pharmacognosy
is the study of medicinal drugs derived from natural sources
name two naturally derived drugs and the plants they are derived from
analgesic morphine - opium poppy
anti malarial drug quinine - cinchoa tree
what type of reaction is Krebs cycle step 1
a condensation reaction
what are adverse reactions associated with the use of non-selective NSAIDS
perforation , ulcers and bleeding
2 types of anchoring filaments which are found between cells
adherent and desmosomes
2 types of anchoring filaments found between cell and matrix
actin cell linked matrix and hemidesmosomes
what is the function of the occluding junction.
the function of the occluding junction is to prevent lateral flow of integral membrane proteins from basal to apical . the other function is to block gaps between to prevent the flow of molecules freely and to ensure if they want to pass they will go through the cell.
examples of proteins involved in occluding junctions
occludin and Claudin
function of vitamin B1
to improve metabolism of carbohydrates
what is the disease of vitamin B1 , name a good source of vitamin B1
BeriBeri is a disease of vitamin B1 and a good source of vitamin B1 is eggs
role of vitamin B2 and the problems deficiency can cause
B2 catalyses dehydrogenation reactions and metabolises foods including liver and kidneys. deficiency can cause eye problems and skin disorders
which vitamin is part of Co-Enzyme-A
Vitamin B (panthoic acid)
list 4 physical instability of a pharmaceutical product
volatility
polymorphism
denaturation
loss or uptake of solvent
what is the isoelectric point of a protein
the isoelectric point is the point exactly in the middle of two PKA values where it equals 0
what is cytokinesis
cytokinesis is the cytoplasmic division at the end of mitosis , bringing separation into 2 daughter cells
what is isomerases function in relation to enzymes
isomerases catalyse the movement of functional groups within a molecule . an example of this is alanine
what is the function of hemidesmosomes
the function of hemidesmosomes is to anchor the ECM to the intermediate filaments
how to increase aqueous solubility for a prodrug
esterification
four functions of nucleotides
building blocks for nucleic acids
storage for chemical energy
carriers of activated metabolites for biosynthesis
metabolic regulators
what is recombinant DNA
recombinant DNA is DNA that has been made from 2 particles
briefly describe the process of producing a recombinant DNA
DNA is isolated ad purified . DNA is cleaved to get the correct length and width strands. DNA is then ligases . The DNA will then be introduced to a compatible host cell where it can be expressed and replicated . To check if there is recombinant DNA , the DNA will be screened.
explain the significance of primary , secondary and tertiary structure of proteins
primary stricture is a linear structure . The second structure is not able to be made without the primary structure as it is a spontaneously folded into a regular and defined shape based on the primary structure . the tertiary structure is a 3-D structure of a polypeptide , this is a folded compact secondary structure.
explain the principle of mass spectrometry and why it is useful for determining the size of a protein or protein complex
mass spectrometry is an analytical techniques that separate ionised particles such as atoms , molecules and clusters by using the differences in the ratios of their charge and their masses which can help to find their molecular weight. this can be used to determine the size of proteins and seperate them based on size.
explain the principle of size exclusion chromatography and how it can be used to separate proteins
Size exclusion chromatography (SEC) separates molecules based on their size by filtration through a gel. The gel consists of spherical beads containing pores of a specific size distribution. Separation occurs when molecules of different sizes are included or excluded from the pores within the matrix.
what is vmax with regards of enzyme activity
vmax is the reaction rate when the enzyme is fully saturated by substrate
what is KM with regards of enzyme activity
KM is the concentration of the substrate which permits the enzyme to achieve half of Vmax
ester + ? = carboxylic acid
amine + ? = amide
water
explain the difference between inter and intra molecular H bonding . how do they affect boiling point and aqueous solubility of compounds
intermolecular bonding occurs between molecules of the same atom
intramolecular bonding occurs between 2 molecules .
they increase boiling point
Log P , Ptrue and Papparent
PTrue - ratio of concentration of unionised particles in a mixture of two immiscible liquids .
Pappsrent - ratio of concentrations of ionised particles in a mixture of two immiscible liquids
LogP - A measure of the preference of a compound to dissolve in either water or an organic solvent (such as octanol) when uncharged.
3 amino acids that would have an overall i) neutral nett ii) positive charge iii) negative charge
I) gly-gly-gly
ii) gly-lys-gly
iii) gly-asp-gly
what interactions are involved when a substrate interacts with the active site of an enzyme
H-bonds , van Der Waals , ionic when substrate interacts with the active site of an enzyme.
allosteric
change in shape and activity of a protein
agonist
a drug or endogenous compound that when binds to a receptor causes a biological response .
antagonist
a drug or endogenous compound that when binds to a receptor does not cause a biological response .
suggest 2 possible mechanisms by which enzymes can catalyse biological reactions
provide a catalyst
provide a nucleotide
describe the mode of action of penicillin antibiotics against bacteria
penicillin kills bacteria through binding of the B-lactam ring to the DD-transpeptidase inhibiting its cross linking activity and preventing new cell wall formation .
what are the three issues associated with penicillin antibiotics and how can they be counteracted
sensitivity to stomach acid - add acyl side chain to make it electron withdrawing .
sensitivity to B-lactam- use stearic shields
limited range of activity - vary R side group till effective .
why is penicillin V active when administered orally but penicillin G is not
penicillin V is active orally because it is much more stable compared to penicillin g which is too unstable to work orally .
what is mean by the term rotamer
conformational isomer can be drawn rotated , staggered or eclipsed. it is not quiet free rotation due to torsional strain .
what is meant by anti, gauche , staggered and eclipsed
anti is a staggered conformation which is the most stable due its substituents being the farthest apart (180)
Gauche is staggered conformation in which substituents are directly L or R of each other ( more than 0 less than 120)
staggered - newman projections , rotation around the c-c bonds . atoms are far away so it requires less energy (very stable)
eclipsed - newman projections. rotation around the c-c bond , relatively unstable due to torsional strain.
what is torsional energy and torsional strain
torsional energy is the energy required to rotate ethane about the c-c bond.
torsional strain is the resistance to bond twisting / rotating
name the 2 conformations and which is most stable
the boat and the chair .
the chair is the most stable as it lacks torsional strain or angle strain .
what would happen if cyclohexane contained substituent groups - how would this affect the stability
this would increase the stability
what happens when cyclohexane flips between 2 chair conformations
substituents move from equatorial to axial and vice versa. when substituents are in equatorial position , it is much more stable as when axial it is less crowded and less repulsive actions
name the alternative naming system of geometric isomers
E-Z system , if the alkane is tri or tetra substituted system based on prioritisation of the molecular weight of the atoms. Z is if the highest molecular weight are on the same side .
enantiomer
chiral compounds whose molecules are non super imposable mirror images of each other
diastereoisomer
stereoisomer whose molecules are not mirror images of each other
apoptosis
apoptosis is the programmed cell death - it is vital process that eliminates unwanted cells; an internally programmed series of events.
>cell shrinkage
> membranes remain intact
> cell is phagocyted so no inflammatory response
> DNA fragmented into nucleosome sized fragments
necrosis
necrosis occurs after irreversible cell injury ; changes produced by enzymatic digestion of dead cellular elements.
> cellular swelling
> membranes rupture
> random DNA fragmentation
> cell contents are released eliciting an inflammatory response
examples : frost bite , gangrene
