Answer:
See the explanation below, please.
Explanation:
The amino acid sequence of a protein will determine the interactions inside and with the environment (that is, it will influence the conformations that are adopted at physiological temperature: the degrees of freedom). Example: the proline amino acid (Pro) has a cyclic structure, which implies a limitation in the random movement of the polypeptide chain.
In proteins, the primary structure determines the sequence of the amino acid sequence of the polypeptide chain (amount of amino acids present and their order by means of peptide bonds).
Answer:
New cells with identical DNA are created through cell division.
Explanation:
C.18
in middle school we are told the levels are 2,8,8 but once you reach high school, you find out the third level actaully can hokd up to 18.
Crossing over (exchange of genetic information between regions of non-sister chromatids in the tetrad) occurs in the prophase I stage of meiosis.
<h3>WHAT IS MEIOSIS?</h3>
Meiosis is the process whereby a single cell produces four daughter cells that are genetically different from one another.
Meiosis is able to ensure genetic diversity in the daughter cells due to a process called Crossing over.
Crossing over is the exchange of genetic material between the non-sister chromatids of homologous chromosomes. It occurs in the prophase I stage of meiosis.
Therefore, crossing over (exchange of genetic information between regions of non-sister chromatids in the tetrad) occurs in the prophase I stage of meiosis.
Learn more about crossing over at: brainly.com/question/394891
Answer:
C The sarcomere is contracted, and the actin and myosin filaments are completely overlapped.
Explanation:
In rest, the tropomyosin inhibits the attraction strengths between myosin and actin filaments. Contraction initiates when an action potential depolarizes the inner portion of the muscle fiber. Calcium channels activate in the T tubules membrane, releasing calcium into the sarcolemma. At this point, tropomyosin is obstructing binding sites for myosin on the thin filament. When calcium binds to troponin C, troponin T alters the tropomyosin position by moving it and unblocking the binding sites. Myosin heads join the uncovered actin-binding points forming cross-bridges, and while doing so, ATP turns into ADP and inorganic phosphate, which is released. Myofilaments slide impulsed by chemical energy collected in myosin heads, producing a power stroke. The power stroke initiates when the myosin cross-bridge binds to actin. As they slide, ADP molecules are released. A new ATP links to myosin heads and breaks the bindings to the actin filament. Then ATP splits into ADP and phosphate, and the energy produced is accumulated in the myosin heads, which starts a new binding cycle to actin. Finally, Z-bands are pulled toward each other, shortening the sarcomere and the I-band, producing muscle fiber contraction.
In the sarcomere, which is the contractile unit of skeletal muscles, there are
- Thick myosin myofilaments in the central region belonging to the A band.
- Thin filaments united to the Z lines, extending in the interior of the A band until they reach the border of the H band.
- Thin actin filaments composing the I band, which belong to two sarcomeres adjacent to a Z line.
When the muscle contracts, the muscular fiber gets shorter and thicker due to the reduction in the length of the sarcomere. The H line and the I band get shorter. The Z lines get closer to the A band, meaning that they get closer to each other. A band keeps constant in length. This change is produced by movement mechanisms that involve a change in the relative position of actin and myosin filaments.
