Some elements exist naturally as molecules. For example, hydrogen and oxygen exist as two-atom molecules.

TLS Online TPP Program

#Id: 8345

#Unit 2. Cellular Organization

TLS Online TPP Program

#Id: 2339

#Unit 3. Fundamental Processes

Amino acid starvation leads to the binding of uncharged tRNAs to the ribosomal A site; this triggers a sequence of events that begins with the binding of an enzyme called stringent factor (RelA protein) to the ribosome. 

TLS Online TPP Program

#Id: 8452

#Unit 1. Molecules and their Interaction Relevant to Biology

If the α helix lies parallel to the direction of the major groove, the straight α helix can contact 4–6 bp before the bases curve out of the plane of the amino acids in the α helix.

TLS Online TPP Program

#Id: 2309

#Unit 3. Fundamental Processes

Comparisons of the sequences of several bacterial sigma factors suggested conserved regions in E. coli s70  that interact directly with promoters DNA-binding regions of the sigma factor fold into independent domains in the protein regions 1.2, 2.3– 2.4, 3.0, and 4.1–4.2.

TLS Online TPP Program

#Id: 5922

#Unit 3. Fundamental Processes

The 5’–3’ exonuclease activity removes the RNA primer while simultaneously replacing it with a DNA sequence extended from the 3’–OH end of the next Okazaki fragment.