Answer: D. Reduce kcal en 250
Explicación: Una persona ha llegado a un estancamiento cuando no nota cambios significativos o experimenta estancamiento en su esfuerzo por alcanzar un objetivo. En el contexto del ejercicio y la pérdida de grasa, el cliente estaba haciendo más de 5 horas de ejercicio a la semana, al principio hubo cambios visibles, pero después de un tiempo, se dio cuenta de que no había cambios, esto indica un estancamiento, para combatir esto, considerando que el cliente desea perder peso, se recomienda disminuir la ingesta diaria de calorías en 250. Esto representa una reducción en la ingesta diaria de grasas, tras lo cual el cliente podrá evaluar si hay algún cambio notable.
The benefit of reduced gametophytes in seed plants is that they obtain nutrients from the sporophytes. Gametophytes are tiny and can develop from spores that are kept within the parental sporophyte's sporangia. This setup shields the growing gametophyte from environmental stress, allowing it to absorb nutrients from the sporophyte.
Answer: Transcription and translation enable tRNA and rRNA molecules to produce a diverse range of polypeptides.
Explanation:
DNA comprises the genetic instructions for protein synthesis, and this data is transmitted to mRNA during transcription. This initial phase of gene expression entails copying a portion of DNA into RNA (mainly mRNA) facilitated by the enzyme RNA polymerase.
Both DNA and RNA are types of nucleic acids that utilize nucleotide base pairs as a complementary code. During transcription, an RNA polymerase reads a DNA sequence, generating a corresponding, antiparallel RNA strand termed a primary transcript.
A notable variation exists among genes, leading to numerous distinct mRNA molecules. However, ribosomes, made up of rRNA, play a crucial role during translation. This phase occurs in the cytoplasm or ER, where proteins are synthesized after the DNA-to-RNA transcription within the cell's nucleus. This entire process is recognized as gene expression.
Among the three forms of RNA, tRNA is the smallest, consisting of only 75 to 95 nucleotides, and functions to transport specific amino acids to the developing polypeptide chain. It can be concluded that mRNA enhances the variety of polypeptide structures by carrying essential information regarding their synthesis.
Answer:
- Calcium attaches to troponin C
- Troponin T shifts tropomyosin to reveal the binding sites
- Myosin heads connect to actin, forming cross-bridges
- ATP is converted to ADP and inorganic phosphate and releases energy
- This energy drives the sliding of myofilaments, resulting in a power stroke
- ADP detaches and a fresh ATP binds to the myosin heads, breaking the bond with the actin filament
- ATP is then split into ADP and phosphate, storing energy in the myosin heads, thus beginning another cycle
- Z-bands are drawn together, which shortens the sarcomere and the I-band, leading to muscle contraction.
Explanation:
At rest, tropomyosin blocks the attraction between actin and myosin filaments. Contraction starts when an action potential depolarizes the interior of the muscle fiber. Calcium channels in the T tubules open, leading to the release of calcium into the sarcolemma. At this moment, tropomyosin obstructs the myosin binding sites on actin. Upon binding of calcium to troponin C, troponin T modifies the position of tropomyosin, exposing the binding sites. Myosin heads attach to the exposed actin sites forming cross-bridges, while ATP is converted into ADP and inorganic phosphate, which is then released. The sliding of myofilaments is driven by the chemical energy stored in myosin heads, resulting in a power stroke. The power stroke starts as the myosin cross-bridge binds to actin. During the slide, ADP is released. A new ATP connects to myosin heads, terminating the bond with the actin filament. Then ATP is split into ADP and phosphate, and the energy generated is stored in the myosin heads, which initiates a new cycle of binding to actin. In the end, Z-bands pull together, which shortens the sarcomere and the I-band, causing muscle fiber contracture.
