Explanation:
temperature is expelled out from the body in form of sweat
Answer:
Hormones are controlled by a
(negative)
feedback system between the glands that produce this hormone and the concentration of blood calcium ions. If the level of ions is
(low)
,hormone secretion is increased. This causes resorption by cells called
which releases both calcium and phosphate ions into the blood stream.
Explanation:
Negative Feedback a the process in your body that helps to maintain Homeostasis. If some variable changes a value in your body, like your ion levels, your glands produce a hormone that causes resorption by cells. This releases both calcium and phosphate ions into the blood stream and therefore your ion levels go back to normal.
Hope this helps!
Answer:
it is located 1000 nucleotides upstream of the gene’s core promoter - true
it is located 1000 nucleotides downstream of the gene’s core promoter- true
it is in the gene’s coding region - False
Explanation:
These enhancers are located 50 or more kilobases from the promoter they controlled upstream from a promoter, downstream from a promoter within an intron, or even downstream from the <u>final exon</u> of a gene which can be thousands of bp away from the gene's core promoter and can also occur thousands of nucleotides away from the gene's core promoter needing the activity of a DNA -bending protein that binds to the enhancer changing the shape of the DNA and allow interactions between the activators and transcription factors.
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.
