PRACTICE QUESTIONS Flashcards
1. A colonic biopsy specimen from a 72-year old man with diarrhoea was being examined microscopically. Which of the following is the Pathologist unlikely to see in the specimen? A. Endothelial cells B. Epithelial cells C. Osteoblasts D. Ganglion cells E. Smooth muscle cells
C
what is a form of programmed cell death?
apoptosis
what is an increased in the number of cells?
hyperplasia
what is an increase in organ dimensions with no change in cell numbers?
hypertrophy
what is an altered state of maturation?
dysplasia
Scientists in the department of Genetics at Ninewells Hospital are analysing transcripts within bone marrow cells from patients attending the Haematology department. Which of the following best describes the material the analysis is being performed on? Genomic DNA Amino acids Histones Protein RNA Mitochondrial DNA Chromosomes
RNA
Which of the following statements is true about events during human embryonic development?
A. Implantation is complete 5 days after fertilization.
B. The development of the heart begins in Week 10
C. Cranial folding forms the foregut
D. Lateral folding forms the umbilical cord
E. The size of the head, relative to the body increases with gestational age
C
A 20-year old male university student visits his general practitioner with a sore throat. A throat swab is sent for microbiological analysis and Streptococcus pyogenes (S. pyogenes) is identified. Which of the following statements is true about S. pyogenes?
A. It is rod shaped B. It is a Gram negative organism C. It is a type of protozoa D. It causes haemolysis in cultures E. It is usually penicillin resistant
D
what is tagging of microbes by antibodies
opsonisation
what is movement of a cell along a chemical gradient
chemotaxis
what is engulfing of a pathogen by a macrophage
phagocytosis
what is the functional inactivation of a lymphocyte following antigen encounter
anergy
what is a change in the type of antibody produced
class switch
what is production of plasma cells from B lymphocytes
differentiation
Which of the following statements is incorrect about animal cell membranes?
A. The phospholipid head is hydrophilic.
B. The phospholipids tail is hydrophobic.
C. The cell wall outside the membrane offers protection.
D. Cholesterol contributes to the stability of the membrane.
E. Integral proteins are embedded in the lipid bilayer.
F. Carbohydrate chains are often bound to membrane protein.
C
what is a drug that binds to a receptor to mediate an effect by the activation of that receptor.
agonist
what is the mechanism of action of a drug
pharmacodynamics
what is the absorption, distribution, metabolism and excretion of a drug, or its metabolite.
pharmacokinetics
what is the strength of association between a receptor and ligand
affinity
what is the dose, or concentration, of drug needed to produce a given effect.
potency
Phosphoglucomutase catalyses the conversion of Glucose-6-phosphate to Glucose-1-phosphate. Which of the following statements is true about this reaction?
- Glucose-6-phosphate is a substrate
- The forward reaction results in glycogen breakdown
- Glucose-6-phosphate is an enzyme
- This is an exergonic reaction
1
Which of the following are close anatomical relations of the left kidney?
A. Tail of pancreas B. 2nd part of duodenum C. Ascending colon D. Descending colon E. Spleen F. Left adrenal gland
A
D
E
F
Which of the following statements about imaging are correct?
A. CT involves high dose ionising radiation.
B. There are no absolute contraindications to MRI.
C. There are no absolute contraindications to ultrasound.
D. Modern CT scan images can be viewed without loss of quality in all anatomical planes.
E. A plain radiograph of the abdomen is a good way to assess for free intra peritoneal gas.
F. Iodine based contrast is routinely used in contrast enhanced MRI.
A
C
D
A chemical change for which the associated enthalpy change is positive:
a) cannot occur spontaneously
b) may occur spontaneously if coupled to a reaction in which the enthalpy change is negative and of greater magnitude
c) raises the temperature of the surroundings
d) will inevitably occur spontaneously
B
a chemical reaction for which the associated free energy change is large and negative:
a) cannot occur spontaneously
b) is likely to be irreversible in the cell
c) will inevitably occur spontaneously
d) will occur very rapidly
B
which one of the following statements about ATP is correct?
a) atp can diffuse through cell membranes
b) atp is considered a low energy phosphate compound
c) atp is present at high concentrations in the cell
d) hydrolysis of atp is a strong exergonic reaction
C
which of the following statements best describes how a reaction is likely to behave if it has a large, negative value for G?
a) the reaction will be at equilibrium
b) the reaction is likely to happen to a small extent, with only a small amount of product formed
c) the reaction will happen to a moderate extent, with about as much product being formed as reactant being left
d) the reaction is likely to happen to a large extent, with large amounts of product formed
D - enthalpy change is large and negative, equilibrium lies to the right suggesting spontaneous reaction that favours the formation of products
At Keq the value of the change in free energy for a chemical reaction is:
a) zero
b) greater or less than zero but remains at a stable value
c) does not change with respect to energy transfer from coupled reactions
d) The point at which the concentration of reactants and products are equal.
A - DG Keq is the equilibrium constant, determined from ([C].[D])/[A].[B]). It represents the concentrations of products:reactants at which there is no net free energy transfer.
What is a polar molecule?
a) a molecule with no charge
b) a molecule with opposite charges at opposite ends
c) a molecule with identical charges at opposite ends
d) molecule with an unequal number of protons and electrons
B
How do water molecules arrange around ions?
a) the more negative atoms attach to positive ions
b) the more positive atoms attach to negative ions
c) water forms a hydration shell
d) all of these answers are true
D
Which is TRUE regarding the structure of hydrogen bonds?
a) Hydrogen bonds can only arise from the covalent interaction between oxygen and hydrogen atoms.
b) It is only the hydrogen atoms of a water molecule which interact with polar molecules
c) Hydrogen bonds involve a linear arrangement of one hydrogen atom between two electronegative atoms
d) Hydrogen bonds are angled at 104.3o
C
Which one of the following statements about amino acids is correct?
a) Amino acids are classified according to the structures and properties of their side chains.
b) Amino acids are uncharged at neutral pH.
c) Amino acids in proteins are mainly in the D-configuration.
d) Twenty four amino acids are commonly used in protein synthesis.
A
All amino acids contain an alpha carbon bonded to the following structures:
a) an amino group (-NH2), a carboxyl group (-COOH), a hydrogen (-H), a side chain (-R)
b) an amide group (-CONH2), a carboxyl group (-COOH), a hydrogen (-H), a side chain (-R)
c) an amino group (-NH2), a carboxyl group (-COOH), a hydroxyl group (-OH), a side chain (-R)
d) an amide group (-CONH2), a hydrogen (-H), a side chain (-R)
A
Which of the following statements is true about a peptide bond (RCONHR’)?
a) It is non planar.
b) It is capable of forming a hydrogen bond.
c) Electron resonance between amino and carbonyl groups creates a partial double bond
d) The cis configuration is favoured over the trans configuration.
C
During the formation of the peptide bond which of the following takes place?
a) The α-amino group of one amino acid acts as a nucleophile to displace the hydroxyl group of another amino acid forming a peptide bond.
b) Hydrogen atom is lost from its carboxyl group of one amino acid and a hydroxyl group is lost from its amino group of another amino acid
c) Hydroxyl group is lost from its carboxyl group of one amino acid and a hydroxyl group is lost from its amino group of another amino acid
d) Hydrogen atom is lost from its carboxyl group of one amino acid and a hydrogen atom is lost from its amino group of another amino acid
A