Answer:
physical, chemical, nuclear
Explanation:
The best answer is D.
In active transport, molecules move against a concentration gradient from areas of lower concentration to areas of higher concentration. This happens a lot in neurons. The membrane proteins are constantly pumping ions in and out to get the membrane of the neuron ready to transmit electrical impulses.
In active transport , energy is required to move molecules across the cell membrane. Carrier proteins are needed for this e.g. proteins of the GLUT family which transport glucose molecules across the cell membrane. Carrier proteins are very specific. GLUT proteins will only move glucose molecules and not sodium or calcium. There are hundreds of types of carrier proteins.
Physical change as no new substance is created
Answer:
The 5' cap is added to the mRNA as a means of protection from being degraded by enzymes in the cellular environment. Additionally. it helps with binding to the ribosome and subsequently translating it into a protein.
Explanation:
Moreover, it's only Polymerase II that has the ability to add the 5' cap and rRNA & tRNA are not transcribed by Polymerase II, only the mRNA is.
rRNA and tRNA have stable 3-Dimensional structures that protects it from being degraded by enzymes.
Hope that answers the question, have a great day!
