Answer:
The correct answer is 3: "<em>High levels of Ca2+ are expected to be found </em><em>within the sarcoplasmic reticulum</em>".
Explanation:
Muscular contraction is a highly regulated process that depends on free calcium concentration in the cytoplasm. Amounts of cytoplasmic calcium are regulated by <u>sarcoplasmic reticulum</u> that functions as a storage of the ion.
When a nerve impulse reaches the membrane of a muscle fiber, through acetylcholine release, the membrane depolarizes producing the entrance of calcium from <u>extracellular space</u>. The impulse is transmitted along the membrane to the sarcoplasmic reticulum, from where calcium is released. At this point, <em>tropomyosin is obstructing binding sites for myosin on the thin filament</em>. The calcium channel in the sarcoplasmic reticulum controls the ion release, that activates and regulates muscle contraction, by increasing its cytoplasmic levels. When <em>calcium binds to the troponin C</em>, <em>the troponin T alters the tropomyosin by moving it and then unblocks the binding sites,</em> making possible the formation of <em>cross-bridges between actin and myosin filaments.</em> When myosin binds to the uncovered actin-binding sites, ATP is transformed into ADP and inorganic phosphate.
Z-bands are then pulled toward each other, thus shortening the sarcomere and the I-band, and producing muscle fiber contraction.
ATP has more energy potential. It is like a very strong, charged battery. The most energy is stored in the 2nd and 3rd phosphates. If one is released, it becomes ADP. That is like a weak battery.
B) An increase in the overall temperature of the Earth
B is the answer because global climate change is the increase of the overall temperature of the planet.
hope that helps :)
Answer:
a. transcription/RNA processing
: pre-mRNA, snRNA
b. translation
: mRNA, rRNA,
c. not used in protein synthesis: RNA primers
Explanation:
pre-mRNA, mRNA, rRNA, RNA primers, snRNA
a. transcription/RNA processing
: pre-mRNA, snRNA
b. translation
: mRNA, rRNA,
c. not used in protein synthesis: RNA primers
The pre mRNA the product after transcription from the DNA is processed eg by addition of poly A tail, splicing etc before undergoing the process of translation, the snRNA also help in performing this function. In translation, the mRNA is trnslated to proteiin in the ribosomes which is also made up of rRNA and proteins. RNA primers is not needed in any of these two, only i DNA replication as the DNA polymerase is uable to begin the synthesis of adding nucleotides to a DNA strand.
Answer:
- There are many craters on the moon
- Spherical rocky body
- The moon has great basins
- Many great dark plains
H o H o Hope this helped!
Merry Christmas!
