Answer:
The basic repeating unit of nucleic acids are known as nucleotides. A nucleotide consists of three distinct chemical groups, a 5-carbon sugar (ribose or deoxyribose), a nitrogen-rich base - (cytosine (C), guanine (G), adenine (A), thymine (T) in DNA or uracil (U) instead of T (in RNA), and phosphate.
Answer and Explanation:
In rest, attraction strengths between myosin and actin filaments are inhibited by the tropomyosin. When the muscle fiber membrane depolarizes, the action potential caused by this depolarization enters the t-tubules depolarizing the inner portion of the muscle fiber. This activates calcium channels in the T tubules membrane and releases calcium into the sarcolemma. At this point, tropomyosin is obstructing binding sites for myosin on the thin filament. When calcium binds to the troponin C, the troponin T alters the tropomyosin by moving it and then unblocks the binding sites. Myosin heads bind to the uncovered actin-binding sites forming cross-bridges, and while doing it ATP is transformed 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. Z-bands are then pulled toward each other, thus shortening the sarcomere and the I-band, and producing muscle fiber contraction.
Cholera occurs when the G protein cannot hydrolyze GTP to GDP so the G protein is always active. This causes water and salt to leak out causing diarrhea and eventually death by dehydration.
Hope this helps!
-Payshence xoxo
Yes, If there were no concentration gradient of protons across the thylakoid membrane, the ATP synthase would not be able to convert ADP to ATP.
