Answer:
Power stroke (myosin head bends) coupled with the release of ADP and phosphate
Explanation:
Muscle contraction results from myosin heads adhering to actin and attracting it inwards. It uses ATP. Myosin adhers to actin at a binding site of its globular actin protein and adheres at another binding site for ATP (hydrolyzed ATP to ADP, Pi and energy)
ATP binding prompts myosin to detach from actin, ATP is changed to ADP and inorganic phosphate, Pi by ATPase. The energy formed at this process orientates myosin head to a “cocked” direction.
The myosin head goes in the direction of the M line, holding the actin with it in the process causing the filaments to orientate nearly 10 nm in the direction of the M line--- power stroke (force is produced), the sarcomere reduces in length and the muscle contracts.
Note: The power stroke is seen when ADP and phosphate disattaches itself from the myosin head.
At the terminal point of the power stroke, the myosin head as low-energy, followed by ADP release.
The attached image shows the cross-bridge muscle contraction cycle, which is activated by Ca2+ sticking to the actin active site. And how actin moves in relation to myosin.
B a very large molecule made of smaller molecules
Similarities: Natural Selection and Artificial Selection both result in the alteration of the gene pool. It can also change phenotypes of different species'.
Differences: Artificial Selection is when a specific trait is not wanted, and so it is not bred.
For example, humans did not like how yellow peas looked. They liked the healthy looking green better. So, they killed the yellow peas, and bred the green peas with other green pea plants, and right now it is almost completely out of our gene pool.
Natural Selection is when something naturally occurs, such as a natural disaster, famine, plague, invasive species introduction.
For example, if 10 camels lived in a desert, but one of them didn't have as good of a metabolism and stayed full longer, then that one would survive, while the others might not.
Answer:
Exercise is responsible for the increasing heart beat.
Explanation:
Exercise is responsible for the increasing heart beat because our body needs oxygen more faster during exercise. When we exercise our body needs quick energy and oxygen which can be provided by heart as well as the heart also removes carbondioxide which is produces during respiration process so the heart beat increases in order to provide energy and oxygen to the muscles.
Answer:
The bacterial DNA gets degraded at step 3 of the viral lytic cycle.
Explanation:
Viruses are organisms that are incapable of replicating on their own, hence, they require a living host which they infect and use its replicational ability to reproduce theirselves. The infection cycle of this virus is regarded as its replication cycle. Viruses employ either the LYTIC or LYSOGENIC cycle for infection.
The lytic cycle involves killing of their host cell at the end of the cycle. Generally, the cycle starts with the attachment of my the virus to the cell membrane of its host using specific receptor sites (step 1). It then penetrates the host cell as seen in step 2.
After penetration, the virus then secretes certain degrading enzymes called ENDONUCLEASES that degrades the bacterial DNA. After which the virus uses the replicational and gene expressing ability of the host to transcibe its genetic material and replicate itself. This process called SYNTHESIS occurs in step 3.
Hence, the yellow ring in the image that represents bacterial DNA disappears in step 3 (synthesis stage) because it gets degraded by viral digesting enzymes.
