The correct answer is that "t<span>roponin holds the tropomyosin in place on the actin".
In excitation-contraction coupling, tropomyosin prevents the interaction between actin and myosin in resting muscles. In the event of excitation, there is release of calcium from the sarcoplasmic reticulum wherein the troponin will bind this calcium and will release tropomyosin and expose myosin enabling it to attach to actin and therefore facilitating muscle contraction.</span>
Answer:
The correct matching pairs are:
1) - B)
2)- E)
3) - A)
4) - F)
Explanation:
<u>Transferases (B)</u>: Transeferases is the class of enzyme that catalyzes reactions involving the <u>transfer of certain functional groups. (1)</u>
Example: Transaminase transfers nitrogenous groups
<u>Isomerases (E)</u>: Isomerases is the class of enzyme that catalyzes <u>isomerization reactions and intramolecular rearrangements. (2)</u>
Example: Triosephosphate isomerase interconverts aldoses and ketoses
<u>Oxidoreductases (A)</u>: Oxidoreductases is a class of enzyme that catalyzes <u>redox reactions (3) </u>which involves the simultaneous transfer of electron.
Example: Alcohol oxidoreductases acts on the alcohol functional group
<u>Ligases (F)</u>: Ligases is a class of enzyme that catalyzes reactions involving <u>chemical bond formation between two molecules. (4)</u>
Example: DNA ligase joins DNA fragments
Answer:
It is true that one-toed horse of today steadily evolved from its five-toed ancestor.
Explanation:
- Evolution is the law of nature.There is a continuous process of evolution in each biological species in nature.
- Similarly, horses had 5 toes millions of year back, but according to the theory of gradualism their use decreased and toes started fusing.
- Now, its only one toe at present but the vestigial left over provides the solid evidence for the fact that horses had 5 toes in the past.
