..........Proteins..........
A sugar-phosphate backbone (alternating grey-dark grey) joins together nucleotides in a DNA sequence. The sugar-phosphate backbone forms the structural framework of nucleic acids, including DNA and RNA. This backbone is composed of alternating sugar and phosphate groups, and defines directionality of the molecule.The two strands run in opposite directions, one going in a 3' to 5' direction and the other going in a 5' to 3' direction. The nitrogenous bases are positioned inside the helix structure like "rungs on a ladder," due to the hydrophobic effect, and stabilized by hydrogen bonding.
Uracil is one of the four nucleobases in the nucleic acid of RNA that are represented by the letters A, G, C and U. The others are adenine, cytosine, and guanine. In RNA, uracil binds to adenine via two hydrogen bonds. In DNA, the uracil nucleobase is replaced by thymine. Uracil is a demethylated form of thymine.
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Answer:
Nebula: is an interstellar cloud of dust,hydrogen, helium and other ionized gases.
protostar: is a very young star that is still gathering mass from its parent molecural cioud.
Red Giant: is a luminous giant star of law or intermediate mass in late phase of stellar evolution.
<span>The four ribonucleoside triphos phates: adenosine triphosphate (ATP), guanosine triphosphate (GTP), cytidine triphosphate (CTP), and uridine triphosphate (UTP).</span>