Answer:
Through simple diffusion, down the concentration gradient.
Explanation:
The phospholipids of the membrane are amphipathic with hydrophillic heads and hydrophobic tails. Other polar molecules cannot go through this hydrophobic interior. Since small uncharged lipids are non polar and hydrohobic, they are able to go through the membrane without the help of transport proteins. Therefore, the last two options can be ruled out because facilitated diffusion includes the use of a protein. Diffusion involves molecules moving down the concentration gradient so the second option can be ruled out.
Answer: The correct option is E ( Intermediate filaments are unpolarized).
Explanation:
Intermediate Filaments are usually associated with cells that can withstand mechanical stress which includes claws of animals, hair and makes up the dead remnants of the epidermal cell of the skin. Therefore without the supporting network of intermediate filaments, an epithelium remains intact but the cells are prone to damage by abrasive forces.
Intermediate filaments are so named because they are thicker than actin filaments and thinner than microtubules or muscle myosin filaments
The properties or characteristics of an intermediate filaments that explains the lack of motor proteins is as a result of its subunits which are elongated, not globular and are associated in an anti-polar manner. Therefore, the overall filament has no polarity, and therefore no motor proteins move along intermediate filaments
Answer:
Bíceps- tríceps
Explanation:
Los músculos trabajan para generar movimiento mediante la contracción de células musculares. El bíceps y el tríceps son músculos antagonistas presentes en el brazo. Cuando el brazo se acorta, el bíceps funciona como agonista (es decir, se contrae) y hace que los tendones que tiran de los huesos del antebrazo puedan doblarlo. Durante este movimento, el triceps funciona como antagonista, encontrándose en estado de relajamiento. Por otra parte, durante el estiramiento del brazo, las funciones de estos músculos se invierten, con lo cual el tríceps (agonista) se contrae y el bíceps (antagonista) se relaja.
