Which of the following steps in a signaling pathway typically occurs first once a chemical messenger reaches a target cell?

Which of the following systems in absorbing oxygen and releases carbon dioxide

What is the answer for the complicated molecules that make up living things usually contain carbon. why is carbon so important in these molecules?

Neelaredoxin is a 15-kda protein that is a gene product common in anaerobic prokaryotes. it has superoxide-scavenging activity, and it is constitutively expressed. in addition, its expression is not further induced during its exposure to o2 or h2o2 (silva, g., et al. 2001. j. bacteriol. 183: 4413–4420). which of the following statements best describes neelaredoxin synthesis? a-neelaredoxin is produced at all times; levels are constant even when exposed to o2 or h2o2.b-neelaredoxin is produced at all times; exposure to o2 or h2o2 increases expression. c-neelaredoxin is produced at all times; exposure to o2 or h2o2 decreases or prevents expression. d-neelaredoxin is only produced when there is exposure to o2 or h2o2.