Correct approaches to protein structure prediction-:

i. Homology modeling	a) Methods is the Rosetta program, formulated by David Baker. To satisfy the program’s computational needs, a volunteer network of ∼100,000 computers, known as Rosetta@home, provides the 500,000 or so hours of processing time required to generate a structure.
ii. Structural genomics	b) which seeks to determine the X-ray structures of all representative domains, is aimed at expanding this predictive technique. The identification of structural homology is likely to provide clues as to a protein’s function even with imperfect structure prediction.
iii. Threading	c) Is a computational technique that attempts to determine the unknown structure of a protein by ascertaining whether it is consistent with a known protein structure. It does so by placing the unknown protein’s residues along the backbone of a known protein structure and then determining whether the amino acid side chains of the unknown protein are stable in that arrangement
iv. Ab initio	d) Aligns the sequence of interest with the sequence of a homologous protein or domain of known structure—compensating for amino acid substitutions, insertions, and deletions—through modeling and energy minimization calculations.

#Question id: 1529

#Unit 4. Cell Communication and Cell Signaling

Which of the following statements are true regarding to gain-of-function and loss-of-function mutations with respect to cancer.

#Question id: 1528

#Unit 4. Cell Communication and Cell Signaling

Mutation of p53 is described as a dominant-negative mutation. Which of the following statement is correct regarding to the mechanism by which this mutation causes the dominant-negative phenotype?

#Question id: 1527

#Unit 4. Cell Communication and Cell Signaling

Following are the six fundamental properties of malignant tumors. Which of these properties are amenable to study in a cell culture model of cancer?

(I) self-sufficiency in growth signals

(II) insensitivity to antigrowth signals

(III) evasion of apoptosis

(IV) limitless replicative potential

(V) sustained angiogenesis

(VI) tissue invasion and metastasis

#Question id: 1526

#Unit 4. Cell Communication and Cell Signaling

Following statements are regarding to apoptosis.

A. In the worm apoptotic pathway, CED-3 (caspase-9 in mammals) is a protease required to destroy cell components during apoptosis.

B. CED-4 (Apaf-1) was able to accelerate the autoproteolytic cleavage and activation of purified CED-9

C. Once EGL-1 causes dissociation of the CED-4/CED-9 complex, the released CED-4 dimer joins with three other CED-4 dimers to make an octamer, which then activates CED-3

D. Many apoptotic stimuli lead to damage of the outer mitochondrial membrane, causing release into the cytosol of several proteins that stimulate apoptosis. In particular, cytochrome c released from mitochondria activates Apaf-1, which in turn activates caspase-3 and 7.

Which of the following combination is incorrect?

#Question id: 1525

#Unit 4. Cell Communication and Cell Signaling

Following statements are regarding to chromatin remodelling factors SWI/SNF complexes. Which one of them is incorrect?

#Question id: 1524

#Unit 4. Cell Communication and Cell Signaling

Tumor-suppressor genes generally encode proteins that in one way or another inhibit cell proliferation. Loss-of-function mutations in one or more of these proliferation inhibitory proteins contribute to the development of many cancers. Prominent among the classes of proteins encoded by tumor-suppressor genes are:

A. Intracellular proteins that regulate or inhibit entry into the cell cycle

B. Receptors or signal transducers for secreted hormones or developmental signals that inhibit cell proliferation

C. Checkpoint pathway proteins that arrest the cell cycle if DNA is damaged

D. Proteins that promote apoptosis

Following genes belongs to the above class-

i. p53

ii. Rb

iii.TGF- β

iv. Caspase 3 and 7

which of the following match is correct?