Answer:
C: Lipid A
Explanation:
Lipid A is a component of the endotoxin (also called the lipopolysaccharide) present in Gram-negative bacteria. The LPS has 3 component namely;
- the O-antigen: they are antigenic determinants and are the outer carbohydrate chains
- the core polysaccharide: forms the centre core of the LPS
- The Lipid A: forms the innermost part of the LPS and triggers acute inflammatory responses (e.g endotoxic shock) when released.
Upon detection of an endotoxin which forms the component of the outer membrane of a Gram negative organism (in exception to the Gram-positive bacteria called <em>Listeria monocytogenes</em>), the innate immune defense system (e.g macrophages and T-helper cells) are alerted to initiate elimination strategies towards the invading organism. Lipid A binds to the CD14/MD2 receptor on macrophages and monocytes which activates the nuclear factor kappa- light chain enhancer (NF-κβ). The activation of NF-κβ protein triggers the production of inflammatory cytokines which includes Interleukin-1 (IL-1), IL-12, IL-18 as well as the Tumor necrosis factor- alpha (TNF-α).
Inflammatory responses are as a result of the release of these cytokines which sometimes leads to shock and death of the host
<span>DNA polymerase is instrumental in DNA elongation as it catalyzes the addition of deoxyribonucleoside triphosphates to the 3 prime end hydroxyl group of the DNA chain. DNA polymerase binds on the origin of replication, and forms a pre-replication complex with other proteins. The replication complex unwinds DNA during replication</span>
Heartwood. In contrast to sapwood, a term for the dead, clogged xylem cells near the center of a tree. Heartwood is the tree's main column of support.
The moon does not create its own light, but the sun reflects light of the moon so depending on where the sun sits (which it is always moving) causes the different phases or appearances to the moons shape
