If a tRNA had an AGC, it could base-pair to a(n).

A. tight junctions:Tight junctions form a seal between epithelial cells, preventing leakage of substances between them and helping maintain distinct apical and basal cell surfaces. They are essential for barrier functions in epithelial tissue.

B. gap junctions:Gap junctions provide channels for communication and ion exchange between cells rather than strong attachment. While important for coordination, they are not the main structures that firmly hold epithelial cells together.

C. desmosomes:Desmosomes are anchoring junctions that strongly attach epithelial cells to each other, providing structural integrity and resistance to mechanical stress. They are vital in tissues subject to stretching.

D. both A and B:While tight junctions are involved in attachment, gap junctions serve mainly for communication rather than physical adhesion.

E. both A and C:Epithelial cells are held together primarily by tight junctions for sealing and desmosomes for strength, combining barrier function with mechanical support.

False:Pyruvic acid is converted into lactic acid only under anaerobic conditions, when oxygen is insufficient for the mitochondria to carry out aerobic respiration. When oxygen is present, pyruvic acid enters the mitochondria and is converted into acetyl CoA, which then enters the Krebs cycle for aerobic respiration. Lactic acid formation does not occur under these oxygen-rich conditions.