If cordycepin triphosphate is added to a cell-free transcription reaction, the nucleotide is added onto the growing rna chain but no more nucleotides can then be added. the added cordycepin is always found at the 3' end of an rna. examine the structure of cordycepin and explain why it ends transcription.

What is the significance of the protein-lined pits? a. protein attracts other proteins needed for atp synthesis within the cell. b. protein-lined pits are able to transport one molecule at a time down the concentration gradient within the cell. c. the polarity of proteins allows other polar molecules to attach and be transported in the cell by transport channels. d. receptors within the pits allow ligands to fuse and be transported into the cell by endocytosis.