Zaidi Practice Questions

Question 1

The first step in translation involves the binding of a complex of the initiator tRNA, initiation factor eIF2 and GTP to which site in the ribosomal assembly?

A. A site on the small ribosomal subunit
B. P site on the small ribosomal subunit
C. E site on the small ribosomal subunit
D. A special site on the small ribosomal subunit where it interacts with large subunit

Answer 1

B. P site on the small ribosomal subunit

Question 2

Which of the following types of amino acids on a protein serve as an ER retention signal?

A. Lysine arginine rich sequence
B. Positively charged and hydrophobic sequences
C. A stretch of apolar amino acids
D. Lysine, Aspartate, Glutamate, Leucine rich sequence

Answer 2

D. Lysine, Aspartate, Glutamate, Leucine rich sequence

Question 3

This type of question will not be asked in Quiz, but a good way to test knowledge

Match the following list of RNAs with their function

A. mRNA	
B. rRNA	
C. siRNA	
D. tRNA
E. snRNA	
F. mi RNA

1. Directs degradation of selected mRNAs
2. Codes for proteins
3. Adaptor for protein synthesis
4. Splicing of RNA transcripts
5. Components of ribosome
6. Blocks translation of select mRNAs

Answer 3

A. mRNA 2. Codes for proteins

B. rRNA 5. Components of ribosome

C. siRNA 6. Blocks translation of select mRNAs

D. tRNA 3. Adaptor for protein synthesis

E. snRNA 4. Splicing of RNA transcripts

F. mi RNA 1. Directs degradation of selected mRNAs

Question 4

Fill in the blanks: this type of question will not be asked in Quiz, but a good way to test knowledge

A_____is a nucleotide sequence in DNA to which RNA polymerase binds to begin transcription.

Signal sequences that define the beginning and end of protein synthesis are contained in this molecule______.

Protein synthesis occurs on this organelle _____.

The subunit of the prokaryotic RNA polymerase that is dissociated after initiation _­­­­­­­­­­­­­­­___.

A group of proteins that interact with the eukaryotic RNA polymerase II during initiation of transcription _________.

Answer 4

promoter
mRNA
Ribosome/rough ER
Sigma factor
general transcription factors

Question 5

Use the following terms to answer the questions 1-6.

1. CCA 3’
2. transcription
3. translation
4. wobble
5. release factors
6. methionine

A. This is the term applied to describe the process of protein synthesis.
B. This is the position where the amino acid is attached to a tRNA molecule.
C. This is the term applied to describe the process of RNA synthesis.
D. This hypothesis explains why some tRNAs can bind to more than one codon.
E. These proteins recognize UAA, UAG, and UGA codons.
F. The initiation codon AUG codes for this amino acid in eukaryotes

Answer 5

3. This is the term applied to describe the process of protein synthesis.
4. This is the position where the amino acid is attached to a tRNA molecule.
5. This is the term applied to describe the process of RNA synthesis.
6. This hypothesis explains why some tRNAs can bind to more than one codon.
7. These proteins recognize UAA, UAG, and UGA codons.
8. The initiation codon AUG codes for this amino acid in eukaryotes.

Question 6

The signal recognition particle (SRP) plays an important role in the translocation of proteins across the endoplasmic reticulum membrane. The SRP has a binding site for which of the following entities. 

A. Large ribosomal subunit
B. ER signal sequence on a protein
C. SRP receptor
D. All of the above

Answer 6

D. All of the above

Question 7

Fibroblasts are isolated from healthy skin tissue and cultured in a petri dish in the absence of exogenous growth factors. What is the most likely type of signaling occurring in this culture?

A. Autocrine
B. Endocrine
C. Juxtacrine
D. Paracrine

Answer 7

A. Autocrine

Question 8

Assign the three components of G-protein-coupled receptor complexes to their functions. 

1. G-protein-coupled receptor									
2. Trimeric G-protein 					
3. Effector enzyme			

A. Specificity
B. Transducer
C. Generation of second messenger

Answer 8

B. Transducer
C. Generation of second messenger
A. Specificity

Question 9

Receptor tyrosine kinases directly mediate signal transduction by:

A. Coupling to trimeric G-proteins
B. Phosphorylation of intracellular proteins at serine or threonine residues
C. Phosphorylation of tyrosine residues and recruitment of proteins with SH2 domains
D. Phosphorylation of serine residues and recruitment of proteins with SH3 domains
E. Translocation to the nucleus and activation of gene expression

Answer 9

C. Phosphorylation of tyrosine residues and recruitment of proteins with SH2 domains

Question 10

A patient with bipolar disorder is treated with lithium, which slows the turnover of inositol phosphates in the GPCR-Gq pathway. Which of the following molecules is most directly affected by this drug?

A. Adenylate cyclase (AC)
B. Guanylate cyclase (GC)
C. Phospholipase C (PLC)
D. Protein kinase A (PKA)
E. cAMP

Answer 10

C. Phospholipase C (PLC)

Question 11

Human growth hormone propagates signals by binding two monomers of a receptor tyrosine kinase promoting dimerization. If an extracellular enzyme were to crosslink the two monomers together, what would be the expected outcome?

A. A large quantity of ions would flow into the cell.
B. A large quantity of ions would flow out of the cell.
C. Signaling would persist in the absence of hormone.
D. Signaling would be rapidly inhibited.
E. The signal would no longer be amplified.

Answer 11

C. Signaling would persist in the absence of hormone.

Question 12

A 56-year-old male was rushed to the Emergency Department due to severe chest pain which he mentioned started 4 hours ago. The attending physician ordered some laboratory tests and diagnosed him with an acute myocardial infarction. The levels of which enzyme/protein was most likely elevated in the man’s blood?

A. Aspartate aminotransferase (AST)
B. Lactate dehydrogenase -1 (LDH-1)
C. Serum glutamate oxaloacetate transaminase (SGOT)
D. Troponin (cTn-1)
E. Troponin (sTn-1)

Answer 12

D. Troponin (cTn-1)

Question 13

A couple who had a son afflicted with cystic fibrosis requests genetic testing because the mother is now pregnant with her second child. You administer a genetic test for the ΔF508 mutation responsible for 70% of all cases of cystic fibrosis. What do you tell the family based on the results shown?

A. The fetus does not carry the ΔF508 mutant allele for the cystic fibrosis gene
B. The fetus does carry the ΔF508 mutant allele for the cystic fibrosis gene
C. The fetus is heterozygous for the ΔF508 mutation
D. The fetus is homozygous for the ΔF508 mutation

Answer 13

A. The fetus does not carry the ΔF508 mutant allele for the cystic fibrosis gene

Question 14

A 30-year-old male with a family history of Alzheimer’s disease is evaluated to determine the probability of him developing the disease. What would be the best method to determine this probability?

A. cDNA library construction
B. Amplification by Polymerase chain reaction (PCR)
C. Enzyme-linked immunosorbent assay (ELISA)
D. Amplification by Polymerase Chain Reaction (PCR) followed by Southern blot hybridization
E. Western blotting

Answer 14

D. Amplification by Polymerase Chain Reaction (PCR) followed by Southern blot hybridization