<span>Amino acids are the basic structural unit of all proteins. A 'free' amino acid (a single amino acid) always has:
an amino group -NH2,
a carboxyl group -COOH
a hydrogen -H
a chemical group or side chain -"R".
Since the amino acids (except glycine) have 4 different groups attached to the a-carbon, they are optically active stereoisomers (recall 23.101 Organic Chemistry) although only L-isomers are found in proteins.
At a neutral pH, both the amino and the carboxyl groups are ionised, giving what is termed the zwitterionic</span>
Answer:
The given blank can be filled with cytokine storm.
Explanation:
Generally, influenza is self-restricting. Though serious cases can result in pneumonia and other issues, which can be deadly. However, such cases are very common in the elderly and in very young individuals. There are certain strains of the influenza virus, which are more dangerous to young adults in comparison to old or very young.
The strains, which influence young adults are considered to comprise a cytokine storm, that is, a positive feedback loop, which produces in between the production of cytokines and leukocytes. This cytokine storm generates an acute inflammatory reaction, which results in brisk accumulation of fluid in the lungs, resulting in pulmonary failure. The very young or very old are less vulnerable to this influence as their immune systems are less strong.
The completed sentence with the correct answer is; How does the first sentence in the paragraph help to introduce the main idea. The correct answer is B.
Answer :There was enough oxygen in the atmosphere to support a major burst of life on Earth
Explanation:
The Great Oxygen Event marks the time, approximately 2.5 billion years ago, when there was enough oxygen in the atmosphere to support a major burst of life on Earth
For the first half of the Earht's history, there was no oxygen in the atmosphere. It was inhabited only by single-celled organisms.Of those simple life forms, the cyanobacteria may have. evolved a way to take energy from sunlight, and used it to make sugars out of water and carbon dioxide. They used the same chemical process we know as photosynthesis. This released vast quantities of oxygen into the atmosphere and triggered the evolution of complex life.
