Answer:
b. Infection with a hepatitis virus
Explanation:
The infection with hepatitis virus can cause sever tissue damage that leads to permanent scarring.
Answer:
Una enzima es una sustancia, generalmente una proteína, en la célula de un organismo que acelera las reacciones químicas.
Durante el pardeamiento enzimático, una enzima llamada fenolasa y otro compuesto orgánico que se encuentra en las células de la fruta llamados fenoles pasan por una reacción de oxidación cuando se exponen al oxígeno. La fenolasa regula la reacción, convirtiendo los fenoles en melanina.
Por lo general, las enzimas de la fruta están encerradas en tejido. Las enzimas están metidas en sus células, trabajando para madurar la fruta. Pero cuando esas células se descomponen, ya sea por una causa externa como si alguien muerde o corta la fruta o por causas naturales como el envejecimiento, las enzimas se liberan y entran en contacto con el oxígeno, lo que desencadena la reacción química y hace que la fruta se vuelva marrón.
-clears throat and prepares to sing- our whole universe was in a hot dense steep and nearly 14 billion years ago expansion started..........
A partial dislocation or misalignment of a joint is known as subluxation
This is when a joint slides out of position but can slide back in on its own. This is different to a luxation (or full dislocation) where the joint completely comes out and has to be put back in with human assistance.
I hope this helps! I'm happy to answer any other questions you might have :)
Answer:
In muscles contraction the correct order of the steps are: A (Nerve impulse reaches the muscle), B (Action potential travels down T-tubules), C (Calcium binds to troponin), D (Tropomyosin moves).
Explanation:
Skeletal muscle contractions are based on different physiological and biochemical phenomena that happen in every cell. These phenomena are due to stimulation produced by somatic motor neurons, which axons get in contact with muscle fibers through a neuromuscular synapse. In rest, attraction strengths between myosin and actin filaments are inhibited by the tropomyosin. When an action potential is originated in the central nervous system, it travels to the somatic motor neuron membrane: the muscle fiber, and activates the calcium channels releasing it in the neuron. Calcium makes vesicles to fuse with the membrane and release the neurotransmitter named acetylcholine (Ach) into the synaptic space in the juncture. Then, Ach binds to its receptors on the skeletal muscle fiber. This causes the ion channels to open, and positively charged sodium ions cross the membrane to get into the muscle fiber (sarcoplasm) and potassium get out. The difference in charges caused by the migration of sodium and potassium makes the muscle fiber membrane to become more positively charged (depolarized). 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, that make the calcium be released into the sarcolemma. At this point, tropomyosin is obstructing binding sites for myosin on the thin filament. When calcium binds to the troponin C, the troponin T alters the tropomyosin by moving it and then unblocks the binding sites. Myosin binds to the uncovered actin-binding sites, and while doing it 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.
