Cellular senescence may have evolved to protect organisms against cancer. Instead of dividing out of control, the cells die. Cellular senescence appears to be regulated by several tumor suppressor genes, especially p53.what is the most appropriate reason behind this,

1) Transcription factor p53 is thought to suppress tumorigenesis by causing cell arrest and senescence in response to short telomeres, DNA damage, and viral or external signals to divide

2) This factor can stop the cell cycle, cause cellular senescence in rapidly dividing cells, instruct genes to initiate cellular apoptosis, and activate DNA repair enzymes.

3) Induction of apoptosis or cellular senescence by p53 always beneficial.

#Question id: 23751

#Unit 1. Molecules and their Interaction Relevant to Biology

#Question id: 703

#Unit 1. Molecules and their Interaction Relevant to Biology

Which of the following statements concerning protein domains is true?

#Question id: 913

#Unit 1. Molecules and their Interaction Relevant to Biology

The appropriate folding of a newly translated product is essential, and continual misfolding often leads to disease, especially in vertebrates. This misfolding, particularly in the situation of prion diseases, may be due to

#Question id: 912

#Unit 1. Molecules and their Interaction Relevant to Biology

Which of the following is correct about the native state of a protein

a. is unaffected by changes in temperature and pH.

b. corresponds to the highest Gibbs free energy state.

c. is determined by its primary amino acid sequence.

d. corresponds to the lowest entropic state.

#Question id: 911

#Unit 1. Molecules and their Interaction Relevant to Biology

The correct order for molecular chaperone–mediated protein folding is:

I – exchange of ATP for ADP on chaperone

II – chaperone undergoes conformational change, which affects protein folding

III – chaperone binds to exposed hydrophobic residues on unfolded protein

IV – folded protein is released

#Question id: 910

#Unit 1. Molecules and their Interaction Relevant to Biology

Experiments on denaturation and renaturation after the reduction and reoxidation of the —S—S— bonds in the enzyme ribonuclease (RNase) have shown that: