Answer:
have curved protofilaments at their plus ends
Explanation:
Microtubules are polymers of tubulin proteins that function as the cytoskeleton of eukaryotic cells. Microtubules are dynamic structures that can grow and shrink at a rapid rate. During this process, tubulin subunits can associate and dissociate at the plus end of the protofilament. Tubulin subunits bind to two GTP molecules, one of which is hydrolyzed to GDP after assembly. When microtubules are unstable, protofilaments curl outwards because GDP-bound tubulin has a weak affinity (thereby curving it) and disassemble. The dynamic stability of microtubules is regulated by a feedback loop: when microtubules shrink, free tubulin concentration increases and microtubules start to grow. As microtubules grow, free tubulin concentration decreases and the rate of GTP-tubulin addition also decreases.
Answer:
irritate people's breathing, ling cancer, asthma
Explanation:
Particulate matter in the air decreases life expectancy according to many researchers. Pollutants such as ozone irritate people's breathing, trigger asthma symptoms and cause lung and heart diseases. Exposure to environmental tobacco smoke causes many severe respiratory health problems such as asthma and lung cancer.
Answer:
By changing a gene's instructions for making a protein, a mutation can cause the protein to malfunction or to be missing entirely. When a mutation alters a protein that plays a critical role in the body, it can disrupt normal development or cause a medical condition.
The answer is option a hope it helps
Answer:
Acceleration is the distance an object travels within a specific unit of time, whereas speed is the rate at which the acceleration or direction of an object is changing.
Explanation: