An orgainism is endangered when it is close to extinction...this happens when an organism is hunted down for its meat or other properties...
Answer:
mitochondria
Explanation:
In aerobic glycolysis: NADH is transferred into mitochondria via the mitochondrial shuttle, where it is oxidized to NAD in the respiratory chain, ultimately producing ATP.
(1) they keep toxic substances out of the cell;
(2) they contain receptors and channels that allow specific molecules, such as ions, nutrients, wastes, and metabolic products, that mediate cellular and extracellular activities to pass between organelles and between the cell and the outside environment;
(3) they separate vital but incompatible metabolic processes conducted within organelles.