Answer:A. The release of calcium ions causes myosin and actin to attach to each other.
The contraction of skeletal muscles takes place by induction of a nerve impulse, which produces a movement and the interaction of the filaments containing proteins named as actin and myosin. This interaction of filaments is regulated by proteins called tropomyosin and troponin present on the actin filaments. The motor nerve causes the depolarization of the muscle membrane sarcolemma. This triggers the sarcoplasmic reticulum to release calcium ions. This calcium binds to troponin and thus allows the tropomyosine strand on the actin filament to displace so that the part of the actin where myosine head needs to be attached remain uncovered. Binding of the actin myosine filament results in contraction.
Hence, the release of calcium ions causes myosin and actin to attach to each other causes muscle contraction.
<span>The correct
answer is B. Bees pollinating flowers.</span>
<span>
In biology, mutualism is how two different organisms survive upon the activity
of the other. Each benefits from the mutual relationship. In the case of bees
pollinating flowers, both the bees and the flowers need something and benefit
from the interaction with the other. </span>
A seems most probable.
Oceans are also deeper and larger then Seas.
Answer:
As a new covalent connection develops between the two glucose molecules, one loses a <em>H group,</em> the other loses an<em> OH group</em>, and a <u>water molecule is freed</u>.
<h2>
Why does glucose form a polymer despite being a stable molecule?</h2>
The formation of glucose polymers (glycogen, starch, cellulose) requires the input of energy from uridine triphosphate (UTP). Any tiny molecules must be converted into bigger molecules, which is compatible with the second rule of thermodynamics. Building proteins from amino acids, nucleic acids from nucleotides, fatty acids and cholesterol from acetyl groups, and so on are examples. Energy is released when bigger molecules are broken down into smaller ones, which is compatible with the second rule of thermodynamics. Thus, glucose may be converted to CO2 and H2O, resulting in the production of ATP. While glucose is a tiny molecule and hence relatively "stable," it can exist at a potential energy level and may be used to build up (needs energy) or broken down (<em>produces</em> energy). All of these biochemical processes require the use of enzymes; otherwise, the activation energy of most reactions would require extremely long periods of time for random energy inputs to push the reactions in either direction, despite the fact that energy considerations favor spontaneous breakdown over synthesis.
