In photosynthetic organisms, NADPH is produced by ferredoxin-NADP+ reductase in the last step of the electron chain of the light reactions of photosynthesis. It is used as reducing power for the biosynthetic reactions in the Calvin cycle to assimilate carbon dioxide.
Answer:
This should help you understand more about DNA replication
and it also has a picture.
Answer:
F1: Aa Bb Cc: 4.5 lbs
F2: Too many to list: Between 3 lbs and 6 lbs
Explanation:
F1: Aa Bb Cc, will be the genotypes and will weigh 4.5 lbs, the reason for that is because each capital letter allele adds half a pound to the base weight of 3 lbs.
F2: There are many different genotypes that can be present in the second generation, for example (AA BB CC, AA BB Cc, AA BB cc, etc.) each of which will allow the plant to grow to a certain height. The majority of phenotypes will be 4.5 lbs. There will be one who is AA BB CC, and another one person who has the code, aa bb cc.
Answer:
When a muscle cell contracts, the myosin heads each produce a single power stroke.
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, <em>tropomyosin is obstructing binding sites for myosin on the thin filament</em>. 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 liberated. Myofilaments slide impulsed by chemical energy collected in myosin heads, <u>producing a power stroke</u>. 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.
