For the answer to the question above, I think that <span>the initial titer that has been done to her may have been done too early in the infection that detectable levels of antibody were not present yet so that's why they have to repeat it.</span>
Think of respiration as ‘cellular respiration,’ which is the process by which the body extracts energy from glucose molecules. Breathing is the mechanism of the lungs that brings oxygen into the body and expels carbon dioxide
Respiration is a vital way for the cells of plants and animals to obtain and utilize energy. Without this energy, cells in the bodies of plants and animals would fail to function and will eventually break down and die. The breaking down of sugar into energy and storing it in ATP is the key to the survival of living organisms.
The formation of ATP involves two different processes, cellular respiration and fermentation. The reactions to these processes are controlled by enzymes and involve the loss and gain of electrons.
Cellular respiration takes place in the cells of organisms using metabolic reactions and processes to convert biochemical energy from the nutrients they absorbed into ATP or adenosine triphosphate and to release waste products.
The energy derived from nutrients like sugar, amino and fatty acids, an electron acceptor which can be oxygen (used by aerobic organisms) or other inorganic donors like sulfur, metal ions, methane, or hydrogen (used by anaerobic organisms) are stored in ATP and used for biosynthesis, locomotion and to transport molecules in cell membranes.
Cellular respiration can be aerobic or anaerobic. Aerobic respiration requires oxygen to generate ATP and plants and animals use this in utilizing the energy they received.
500 because of the 10% rule when moving up in food chains, for example; patch of grass-200J rabbit eats some of it but doesn’t eat all - 150J the rabbit runs around for a bit and loses energy, the fox doesn’t eat all of the rabbit - 50J ( just a rough example may not be completely right but the concept of the rule is there and the energy).
"PRODUCERS" are always found at the base of a food chain.