Nurturing Life Sciences
#Id: 7933
Signal sequences
contain one or more positively charged amino acids adjacent to a continuous stretch of 6–12 hydrophobic residues (known as the hydrophobic core)
#Id: 7754
#XL - Q Biochemistry
#Id: 7753
Electron affinity: The enthalpy change that results from adding an electron to a gaseous atom.
Electron affinity is becoming less negative (less exothermic) and less likely to gain an electron.
#Id: 7751
Ranks the following in increasing atomic radius
S, Mg, Al
S: 16-10 +6
Mg: 12-10 = +2
Al: 13-10 +3
So: S < AlMg
#Id: 7750
The greater the effective nuclear charge the more tightly an electron is held in by the nucleus because there is less electron shield between the valence electrons and the nucleus, and so, the smaller the radius.
#Id: 7749
#Id: 7748
Zeff=Z –S
Chlorine would have a Z value of 17 (the atomic number of Chlorine). Continuing to use Chlorine as an example, the 10 inner electrons (S) would screen out the positive charge of ten protons. Therefore there would be and effective nuclear charge of 17-10 or +7.