Nucleation phase 

Two G-actin molecules bind relatively weakly to each other, but addition of a third actin monomer to form a trimer makes the entire group more stable, acts as a nucleus for polymerization.

TLS Online TPP Program

#Id: 7753

#Section 2: General Biology

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. 

TLS Online TPP Program

#Id: 10319

#Section 2: General Biology

Fas-L on the cytotoxic T cell binds to its receptor, the Fas protein on the tumor cells, an apoptotic signaling pathway in the tumor cells becomes activated, which also leads to tumor cell death. 

TLS Online TPP Program

#Id: 8891

#Section 3: Genetics, Cellular and Molecular Biology

Kinetochores assemble on regions of chromosomal DNA marked by a centromere-specific H3 histone variant called CENP-A.

TLS Online TPP Program

#Id: 8098

#Section 2: General Biology

The surfaces of the cells that form the alveoli (small air spaces of the lung) are coated with surfactant, which decreases the alveolar surface tension. 

Lung surfactant contains 80 to 90% phospholipid by weight, and 70 to 80% of the phospholipid is phosphatidylcholine, mostly the dipalmitoyl species.

TLS Online TPP Program

#Id: 2229

#Section 3: Genetics, Cellular and Molecular Biology

The Birth of a Gene - Duplication is the most common way that new genes arise in eukaryotes.