Answer:
- Calcium binds to troponin C
- Troponin T moves tropomyosin and unblocks the binding sites
- Myosin heads join to the actin forming cross-bridges
- ATP turns into ADP and inorganic phosphate and releases energy
- The energy is used to impulse myofilaments slide producing a power stroke
- ADP is released and a new ATP joins the myosin heads and breaks the bindings to the actin filament
- ATP splits into ADP and phosphate, and the energy produced is accumulated in the myosin heads, starting a new cycle
- Z-bands are pulled toward each other, shortening the sarcomere and the I-band, producing muscle fiber contraction.
Explanation:
In rest, the tropomyosin inhibits the attraction strengths between myosin and actin filaments. Contraction initiates when an action potential depolarizes the inner portion of the muscle fiber. Calcium channels activate in the T tubules membrane, releasing <u>calcium into the sarcolemma.</u> At this point, tropomyosin is obstructing binding sites for myosin on the thin filament. When calcium binds to troponin C, troponin T alters the tropomyosin position by moving it and unblocking the binding sites. Myosin heads join to the uncovered actin-binding points forming cross-bridges, and while doing so, ATP turns 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. Finally, Z-bands are pulled toward each other, shortening the sarcomere and the I-band, producing muscle fiber contraction.
B Since protons and electrons have to be the same amount!
The structure of the eukaryotic cell is as follows: It is seperates into many different "compartments" or what we call organelles. Each organelle carries out a different function. The different organelles include: mitochondria, nucleus, endoplasmic reticulum, ribosomes, golgi apparatus, vesicles, peroxisomes, etc.
The structure is enforced by intertwining fibers known as microtubules and microfilaments. The membrane is composed of millions of phospholipids that are amphiphilic (comprised of a hyprophilic phosphate head as well as a hydrophobic fatty tail) that seperate the cells internal environment with the outside space. Spread throughout and across the membrane are thousands of different proteins that allow certain molecules to pass in and out of the cell as well as to bind different ligands to stimulate cellular responses.
Mitosis and meiosis are both stimulated by different factors. Meiosis by fertilization of an egg cell from a sperm cell while mitosis can be signaled by a variety of hormones, protein concentration within the cell, size, etc. Regardless, each process requires the chromosomes in the nucleus to disperse into their loose forms which allows the genes to be copied by a variety of enzymes and ensure that every cell division will yield two genetically identical cells. After the newly copied chromosomes are formed, they condense once again and a large array of microtubules (as mentioned earlier) help bind to these chromosomes and pull them in opposite directions towards the poles of the single cell preparing to divide into two daughter cells. Eventually, the formation of two completely new cells occurs (known as cytokinesis) and the process is complete.
C) Folded mountain with waves, twists, and turns
Answer:
When the body does not convert enough glucose, blood sugar levels remain high. Insulin helps the cells absorb glucose, reducing blood sugar and providing the cells with glucose for energy. When blood sugar levels are too low, the pancreas releases glucagon.
Explanation:
Hope this helps! :)
