In immunology two types of immune response are described depending on whether there is prior contact with the antigen.
• At this first contact, only lymphocytes with receptors specific to the antigen in question are stimulated and lead to the production of antibodies capable of neutralizing it. The lymphocytes capable of recognizing a specific antigen are very few and the production of antibodies - of low intensity and limited duration - is detectable only after a period of latency of several days. This is called the primary response. The specificity of the resulting seropositivity, however, makes it possible to detect contamination (seroconversion).
• Upon re-contact with an antigen that has already triggered a primary response, specific antibody production is found to increase rapidly after a short latency period. The secretion of IgG then reaches levels much higher than those observed during the primary response, while that of IgM is of the same order. This early and intense response, called secondary response, most often results in the destruction of infectious agents before any clinical sign.
• Many centuries before the discovery of microbes, it was noted that people who developed a contagious disease without death were then specifically immunized against the disease, without being protected against others.
• The ability to react appropriately to an already received stimulus supposes the existence of a memory. The immune memory is based on the existence of memory B and T lymphocytes, resulting from the clonal expansion due to the first contact with the antigen. Their lifespan is significantly higher than that of other lymphocytes and their high reactivity gives its rapid and intense character to the secondary response.
<h2>Cellular respiration </h2>
Explanation:
- Cellular respiration is defined as a ATP generating process in which organic molecule is oxidized and inorganic molecule is final electron acceptor
- Pain experienced in leg muscles is the result of formation of lactic acid in muscle cells
- Under low oxygen, NADH cannot be reoxidized to NAD+ but NAD+ is required as an electron acceptor to continue glycolysis
- In lactic acid fermentation pyruvate is the final electron acceptor and converted in lactate
- Reaction catalyzed by lactate dehydrogenase
- The pain in her chest is caused from the lack of oxygen she received while running so her chest starts to heavily breathe so that the lungs can receive as much oxygen possible
The correct answer is option A, that is, saturated.
The mentioned lipid is not a phospholipid, as it does not comprise a phosphate group at the terminal of the chain, and is not a triglyceride due to the absence of glycerol moiety.
Each carbon combined with the hydrogens forms the maximum number of possible C-H bonds, thus, there are no multiple bonds between the carbons. Hence, it can be concluded that the lipid is saturated.
Independent variable: Temperature
Levels: Room temperature
Freezing point 0C
Boiling point 100C
Dependent variable: breaking point of rubber bands measured in certain amount of temperature
