<prompt> Sirtuins are associated with -MemoryMetabolismVisionOlfaction  <response>: Ans. is b i.e., Metabolism o Sirtuins are a family of highly conserved NAD dependent deacetylase 5 that act as cellular sensors to detect energy availability and modulate metabolic process.o Two mammalian sirtuins are involved in controling metabolic process : SIRT-1 in nucleus and SIRT-2 in mitochondria.o They are activated by high NAD levels low cellular energy status. They, then, deacetylate a variety of proteins causing induction of catabolic processes and inhibition of anabolic processes.o SIRT-1 and SIRT-3 coordinated increase cellular energy stores and ultimately maintain cellular energy homeostasis,o Genetic variant in SIRT-1 gene is associated lower risk of cardiovascular mortality and with better cognitive functioning.o SIRT-l variants are associated with decreased basal energy expenditure and a lower lipid peroxidation rate. Therefore, it has been proposed that genetic variation in SIRT-l may determine the response rates of individuales undergoing caloric restriction and increased physical activity,o Genetic variants of SIRT-3 may be associated with increased longevity increased lifespan, but there is no evidence of such an association.o Mammals have seven sirtuins :1 SIRT-1- Intranuclear2 SIRT-2- Cytoplasmic3 SIRT-3, SIRT-4, SIRT-5- Mitochondrial4 SIRT-6- Heterochromatin-associated nuclear5 SJRT-7- Nucleolaro SIRT-1 and SIRT-3 have been studied the most in relation to phenotypes in human. 