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.
For the answer to this question i don't know yet.
Answer:
Which of the following bacteria lack a cell wall and are therefore resistant to penicillin?
B. Mycoplasmas
The protein from which hook and filaments of flagella are composed of, is
B. flagellin
A cluster of polar flagella is called
A. lophotrichous
The cooci which mostly occur in single or pairs are
B. Diplococci
Flagella move the cell by
C. spinning like a propeller
Explanation:
As mean arterial pressure increases, <u>the frequency of action potentials from the </u><u>baroreceptors</u><u> increases,</u> informing the medulla oblongata that blood pressure has indeed increased.
- Special receptors called baroreceptors monitor variations in your blood pressure.
- The aorta and carotid sinus both contain significant baroreceptors. The walls of the arteries stretch when the blood pressure in the aorta or carotid sinus rises, stimulating an increase in baroreceptor activity.
- Action potentials are more quickly fired when baroreceptors are activated, with the speed being inversely correlated with the mechanical stretch.
- The brain interprets the information that the baroreceptors send as a rise in blood pressure.
- The blood vessels, heart, and kidneys are just a few of the bodily organs that get signals from the brain to lower blood pressure.
learn more about baroreceptors here: brainly.com/question/8963123
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