Question

cell Bio Practice Questions!

1a. What is the function of kinases, for example PKA (protein kinase A)?

		to dephosphorilate proteins
		to hydrolyse ATP and absorb energy
		to phosphorylate proteins
		to degrade proteins

1b.

If a nucleic acid contains the bases A-A-G-G-C, it would have to be a molecule of_________________.

		tRNA only
		DNA
		DNA or RNA
		rRNA only

1c.

1. Transcytosis is the process of ________________?

   		combining a vesicle with a lysosome and degrading or releasing the contents
   		recycling the contents of the endosome back to the surface of the cell
   		transporting a vesicle from one side of a cell to the other and releasing the contents by exocytosis
   		storing the contents of the lysosome

Answer 1

1) a- phosphorylate protein.

Kinase are the enzymes which leads to phosphorylate the protein. The ATP acts as a donor molecule in this reaction. The phosphoryl group is added to the protein.

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1- b) DNA or RNA.

We can not dustinguish the DNA from RNA by A, G and C nitrogenous bases. Because they are differ only by T and U. The T is found in DNA and U is found in RNA. That's why the given sequence can be DNA or RNA.

---t

1) c- transporting a vesicle from one side of a cell to the other and releasing the contents by exocytosis.

Transcytosis is the process in which the molecukes are taken from one side of cell by endocytosis and released to the other side of cell by exocytosis.

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