Answer: Eating excessive quantities of such molecules could deregulate this process, increasing methylation and repressing the expression of genes that should normally be expressed.
Explanation:
DNA methylation is one of the epigenetic mechanisms involved in the regulation of gene expression, because it is a process by which methyl groups are added to DNA.
Methylation then modifies the function of DNA when it is found in the promoter gene, it is essential for normal development and is associated with a number of key processes, including genomic imprinting, inactivation of the X chromosome, repression of repeating elements, aging, and carcinogenesis. Usually, <u>it acts to suppress gene transcription.</u>
For example, folic acid is essential for the rapid cell division that occurs during early fetal development and it also plays an important role in methylation and thus in gene regulation. <u>The metabolism of these vitamins is aimed at achieving adequate levels of DNA methylation, necessary for the cellular processes</u>. Eating excessive quantities of such molecules could deregulate this process, <u>increasing methylation and repressing the expression of genes that should normally be expressed</u>.
For body cells to function properly, the following conditions need to be balanced:
1. BLOOD SUGAR
2. BODY WATER
3. BODY TEMPERATURE.
These three factors have to be in the right proportion for the cells and the body as a whole to function properly and to maintain homeostasis.
Blood sugar is the source of energy in the cell and it is required by all cell for carrying out the normal biochemical reactions in the body. The biochemical reactions in the body use water as a medium of reaction, thus the water balance in the body must be maintained. The body temperature also need to be kept at the normal level or else the normal biochemical reaction of the body will not be able to take place, due to the fact that incorrect temperatures deactivate the enzymes that mediate biochemical reactions.
The amount of available resources in the ecosystem must change at a predictable rate.
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.
