TLS Online TPP Program

#Question id: 4165


Which is true about proofreading activity during the synthesis of aminoacyl-tRNAs?

#SCPH01 Biochemistry
  1. Proofreading is accomplished as an amino acid enters the active site of the enzyme. Incorrect amino acids are rejected before any reaction occurs.

  2. Proofreading occurs just after aminoacyl-adenylate formation.

  3. A separate cytosolic proofreading enzyme catalyzes the hydrolysis of incorrect aminoacyl-tRNAs.

  4. No proofreading activity is necessary due to the high level of specificity of all aminoacyl-tRNA synthetases.

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TLS Online TPP Program

#Question id: 7764

#SCPH01 Biochemistry

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.

TLS Online TPP Program

#Question id: 7764

#I Life Science/ Life Sciences Group – I-V

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.

TLS Online TPP Program

#Question id: 7764

#SCPH06 I Botany

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.

TLS Online TPP Program

#Question id: 7764

#SCPH28 | Zoology

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.

TLS Online TPP Program

#Question id: 7765

#SCPH01 Biochemistry

The enzyme complex or gene that maintains telomere integrity is________, which acts as an antisenescence complex. Mice and humans with its deficiencies age prematurely (Mitchell et al. 1999). Overexpressing or reactivating it in senescent cells extends longevity in mice without increasing cancer,

TLS Online TPP Program

#Question id: 7765

#I Life Science/ Life Sciences Group – I-V

The enzyme complex or gene that maintains telomere integrity is________, which acts as an antisenescence complex. Mice and humans with its deficiencies age prematurely (Mitchell et al. 1999). Overexpressing or reactivating it in senescent cells extends longevity in mice without increasing cancer,