Question

1. Is RNA distinguished from DNA by solubility, cellular location, 2’ OH on the sugar, or number of phosphates?

2. Is mRNA used to make proteins, make more RNA, copy DNA, or make ribozymes?

3. Do enzymes evolve to bind transition state, substrates, products, or ATP?

4. In RNA, is uracil substituted for adenine, cytosine, guanine, or thymine?

5. Are proteins synthesized by the golgi, ribosomes, the ER, or nucleus?

Answer 1

1.) RNA is distinguished from DNA on basis of 2' OH sugar
explanation : The second carbon of ribose bears a hydroxyl group while the equivaent carbon of deoxyribole bears hydrogen instead.
so RNA has one one more OH group when compared with DNA. , DNA is stable under alkaline conditions while RNA is not.
2. )mRNA helps in protein synthesis
explanation: mRNA is the only coding RNA as it bears complementary copy of deoxyribonucleotide sequence present on gene ( DNA segment) as ribonucletide sequence . It encodes chemical blueprint for protein synthesis in 5'-3' direction.
The incorporation of a particular amino acid in the correct position is wonderfully controlled and directed by a template or message which starts from a sgment of a strand of DNA.
The gene transcribes mRNA which carries the message to the site of protein synthesis. The message carried by mRNA is then translated with help of number of loaded tRNA to produce a polypeptide chain.
3.) Enzymes have evolved to bind to substrate :
Explanation : Enzymes have evolved to bind to substrate and have also improve function specifity with time to improve organism's overall fitnessin response to environmental demands. It has improved the catalytic performance of very weakly active starting points to become relevant enzymes. Enzymes are able to give many order of magitude speed up in essential reactions like respiration, photosynthesis, digestion thereby reducing activation energies and enabling reactions to proceed on time scales that can support life.
4.) IN RNA Uracil base pairs with Adenine
whereas in DNA Uracil is substituted by thymine (methylation of uracil produces thymine), It increases the stability and improves efficiency of DNA replication.
5.) Protein synthesis occurs in ribosomes
The ribosome has a groove at the junction of 2 subunits , from this grrove a tunnel extends through the arge subunit and opens into canal of endoplasmic reticulum ,The polypeptide synthesised in the groove between 2 subunits pass through the tunnel into the ER
now from ER it passes to golgi body , get packaged into vesicles and then secreted out. SO PROTEIN SYNTHESIS OCCURS IN RIBOSOMES in close association with ER and golgi body.