However, in neither situation is it clear that amyloid deposition progresses in a smooth, time-dependent pattern. In addition, total amyloid levels exhibit substantial variability in AD subjects and dementia itself is not strongly correlated with amyloid burden. The occurrence of OO-HPC subjects reveals that amyloid deposition itself is not completely incompatible with cognitive function and suggests that a transition to dementia may be delayed or avoided. Our study adds to a body of work revealing molecular and structural heterogeneity in the development of aging and dementia and underscores the need to examine through direct observation how the processes of amyloid deposition unfold or change prior to dementia emergence. However, mitochondrion residual organelle known as mitosome is present in this parasite. Mitochondria RI-1 performs many crucial roles in various biochemical and iron-requiring biosynthetic processes; namely, heme formation, Iron-Aceclidine hydrochloride Sulfur clusters biogenesis and cellular iron regulation. Among them, Iron-Sulfur clusters biogenesis is essential for the maturation of Fe-S proteins which are biologically functional and ubiquitous components that orchestrate a wide range of biochemical machinery and efficiently regulate the metabolic cascades in living organisms for sustainable and fundamental life processes. Mitochondria assemble Fe-S clusters for their own set of mitochondrial Fe-S proteins as well as crucially involved in the biogenesis and maturation of Fe-S proteins located in the cytosol and nucleus. Despite the chemical simplicity of Fe-S clusters, Fe-S clusters biogenesis is a complex process involving three types of systems, viz, Iron Sulfur Clusters, Sulfur Utilization Factors and Nitrogen Fixation systems. The ISC system is a housekeeping system involving,30 protein components and among them 10 proteins have been conserved from bacteria to human. The majority of protozoan parasites have retained ISC system either in mitochondrion or mitochondria like organelles; mitosomes, hydrogenosomes, and mitochondria related organelles.