Gene Expression and Central Dogma

Question 1

What is the central dogma of molecular biology?

Answer 1

DNA codes for RNA, which codes for proteins.

Question 2

What part of the cell is RNA produced?

Answer 2

The nucleus, then transported to the cytoplasm

Question 3

What is transfer RNA (tRNA)?

Answer 3

tRNA carries amino acids (the building blocks of proteins). There are 20 different amino acids. Each has its own specific tRNA “carrier” molecule.

Question 4

What are aminoacyl-tRNA syntheses?

Answer 4

aminoacyl-tRNA syntheses match amino acids with tRNA molecules and link them together.

Question 5

What are “anti-codons”?

Answer 5

tRNA has an “anti-codon” at its tip that recognizes a 3-nucleotide “codon” on the mRNA molecule through complementary base pairing.

Question 6

What is mRNA?

Answer 6

mRNA molecules are very long. Base-pairing within the mRNA strand folds it into complex shapes.

After being made, mRNA is processed. Introns are removed (splicing) and a protective cap and poly-A tail are added to the ends.

Each mRNA molecule contains the instructions for building a protein. Groups of 3 nucleotides (“codons”) code for specific amino acids.

Question 7

What is rRNA (ribosomal RNA)? What are ribosomes?

Answer 7

rRNA makes up the majority of the ribosome. The ribosome is the cell’s protein-building machine. Ribosomes also contain proteins that help the rRNA fold into the proper shape.

To build a protein, the ribosome reads mRNA. tRNA carries amino acids into the ribosome and rRNA links them together one at a time.