Exam #3 Chapter 19

Question 1

mRNA Messenger RNA

Answer 1

A class of RNA molecules which carries a copy of the sequence of nucleic acid bases from the DNA to the ribosomes, where these sequences are translated into a series of linked amino acids to form proteins. It is typically a short lived species and is turned over quickly.

Question 2

Nucleic Acid

Answer 2

Biopolymers consisting of nitrogenous bases which are linked to ribose or deoxyribose linked by phosphodiester bonds.

Question 3

Anomer

Answer 3

A chiral center which is not initially present in a molecule and which is created by intramolecular bonding

Question 4

rRNA ribosomal ribonucleic acid

Answer 4

The series of RNAs combine with proteins to form ribosomes. Ribosomes are the site of protein synthesis.

Question 5

snRNA small nuclear ribonucleic acid

Answer 5

This is a series of RNA molecules ranging in size from about 100 to 300 nucleotides long. Some combine with protiens to form complexes, splicesomes, which remove introns from eukaryotic mRNA.

Question 6

Tm

Answer 6

The temperature at which a particular molecular transistion is 50% completed. This term is usually found with membrane fluidity measurments and nucleic acid melting measurements.

Question 7

tRNA transfer ribonucleic acid

Answer 7

This is a series of RNA molecules composed of 75-95 nucleotides, which are charged with an amino acid by the appropriate tRNA synthetase enzyme and which carry that activated amino acid to the ribosome. Once there, the tRNA binds to the mRNA via the anti-codon loop and transfers the activated amino acid to the growing polypeptide chain.