DNA and RNA each contain four nitrogenous bases. They have 5 not 4.
Answer:
the nervous system uses electrical impulses to send signals through neurons, whereas the hormonal system uses chemical messengers transported into blood plasma to target cells.
Explanation:
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Answer:
The chance of a normal couple having a child with down syndrome is 1 to 600 births.
Explanation:
Down syndrome is a genetic flaw that occurs when the fetus is being formed.
A human cell considered normal has 46 chromosomes, divided into 23 pairs. For some unknown reason, an error may occur at the beginning of embryonic development and an extra chromosome is created, which binds to par 21. The result is cells with 47 chromosomes. This causes the said syndrome.
It is important to know that this failure happens at random. It is nobody's responsibility. It has not been proven to date that lifestyle, actions during pregnancy, smoking, drinking, medicines, environmental factors or kinship between the couple can influence this occurrence. She is not contagious either. The likelihood of a normal couple having a child with the syndrome is approximately 1 to 600 births.
Answer:
(B) They may have binding sites for regulatory molecules that are separate from active sites.
(C) They generally have more than one subunit.
(E) They interconvert between a more active form and a less active form.
Explanation:
Allosteric enzymes are the regulatory enzymes that have a specific site for binding of modulator or effector molecule. The activity of these enzymes is altered by the noncovalent binding of modulators at the allosteric site. The binding of the modulator brings about a conformational change in the allosteric enzymes.
The relatively inactive conformation of these enzymes is called T state while the active conformation is the R state. Most of the allosteric enzymes have multiple subunits and deviate from Michaelis–Menten kinetics and exhibit a sigmoid saturation curve of V0 vs. [S].
