The structure of a typical antibody molecule
Antibodies are the secreted form of the B-cell receptor. An antibody is identical to the B-cell receptor of the cell that secretes it except for a small portion of the C-terminus of the heavy-chain constant region. In the case of the B-cell receptor the C-terminus is a hydrophobic membrane-anchoring sequence, and in the case of antibody it is a hydrophilic sequence that allows secretion. Since they are soluble, and secreted in large quantities, antibodies are easily obtainable and easily studied. For this reason, most of what we know about the B-cell receptor comes from the study of antibodies.
Antibody molecules are roughly Y-shaped molecules consisting of three equal-sized portions, loosely connected by a flexible tether. Three schematic representations of antibody structure, which has been determined by X-ray crystallography, are shown in Fig. 3.1. The aim of this part of the chapter is to explain how this structure is formed and how it allows antibody molecules to carry out their dual tasks—binding on the one hand to a wide variety of antigens, and on the other hand to a limited number of effector molecules and cells. As we will see, each of these tasks is carried out by separable parts of the molecule. The two arms of the Y end in regions that vary between different antibody molecules, the V regions. These are involved in antigen binding, whereas the stem of the Y, or the C region, is far less variable and is the part that interacts with effector cells and molecules.
Answer:
When making yogurt the tart flavor get in the end is more likely because the bacteria have carried out a type of respiration named lactic acid fermentation (option C).
Explanation:
The process of obtaining yogurt from whole milk involves the association of the bacterial species Streptococcus and Lactobacillus. In order to carry out the lactic acid fermentation that produces yogurt, the bacteria act in a different way:
- Streptococcus is in charge of removing the oxygen from the milk product.
- Lactobacillus promotes the conversion of lactose sugar into lactic acid.
This fermentation process leads to the conversion of milk into a coagulated and tart flavor product.
Other options are not correct because:
<em> A. </em><u><em>Photosynthesis
</em></u><em>: is the process that occurs in plants to obtain chemical energy from sunlight.</em>
<em> B. </em><u><em>Alcoholic fermentation</em></u><em>: in this chemical process alcohol is obtained from the fermentation of a sugar.</em>
<em> D. </em><u><em>Aerobic cellular respiration</em></u><em>: does not involve fermentation, but the series of processes that convert glucose into energy.</em>
For any terrestrial planet in the solar system, the core would be the densest layer, and the crust would be the least dense layer.
The most appropriate answer is C ! in atomic bomb there is uncontrolled nuclear chain reaction !!
