Chapters 13.1-13.2

What does RNA stand for?

It stands for ribonucleic acid.

How many strands does RNA have?

It is single-stranded.

What sugar does RNA have?

It has the sugar ribose.

What are the nitrogenous bases of RNA?

Adenine, guanine, cytosine, and URACIL.

How many strands does DNA have?

It is double-stranded.

What sugar does DNA have?

It has the sugar deoxyribose.

What are the nitrogenous bases of DNA?

Adenine, guanine, cytosine, and THYMINE.

Do both DNA and RNA have nucleotides?

Yes, they both have nucleotides.

What is an amino acid?

It is a monomer of protein determined by three nucleotide bases.

What is a protein?

It is a chain of amino acids.

What are proteins the chemical triggers for?

They are the chemical triggers for many cell functions.

What do proteins determine?

Proteins determine traits.

What is a gene?

It is a segment of DNA that specifies the amino acid sequence of a protein.

What is the role of RNA?

Its role is to serve as a temporary copy of DNA that translates the genetic code into a protein.

What are the 3 types of RNA?

Messenger RNA (mRNA), ribosomal RNA (rRNA), and transfer RNA (tRNA).

What does mRNA do?

It brings the instructions for polypeptide/protein synthesis from the nucleus to ribosomes in the cytoplasm.

What does rRNA do?

It forms an important part of both subunits of the ribosome.

What does tRNA do?

It carries amino acids to the ribosome and matches them to the coded mRNA message.

Where does transcription take place?

It takes place in the nucleus.

What happens during transcription?

During this, DNA is copied into RNA (mRNA). mRNA then leaves the nucleus and moves onto a ribosome in the cytoplasm.

What do ribosomes (rRNA) use to make proteins?

They use mRNA, tRNA, and amino acids to make proteins.

How does transcription work?

It works thanks to an enzyme called RNA polymerase, which looks for a region on the DNA known as a promoter. There, it binds and begins transcription.

What are introns?

They are parts of RNA that are removed.

What are exons?

They are the expressed (remaining) genes after the introns are removed.

What is the genetic code of mRNA based on?

It is based on the 4 bases of mRNA (A, C, G, U).

What are the "words" of the genetic code of mRNA?

They are 3 RNA sequences called codons.

How many nucleotide bases code for 1 amino acid?

3 nucleotide bases code for 1 amino acid.

A group of 20+ amino acids creates what?

It creates a polypeptide chain (protein).

Where does the information that translation uses to produce proteins come from?

The information used by translation comes from the mRNA.

Describe the transition from transcription to translation.

After transcription is finished in the nucleus, mRNA moves to the cytoplasm and the ribosomes. There, translation begins; tRNA "reads" the mRNA and attaches complementary amino acids.

What attach the amino acids together during translation, forming a polypeptide chain?

Ribosomes attach amino acids together during translation.

The polypeptide chain produced by translation keeps growing until?

It keeps growing until a STOP codon is reached.

What is the start codon for the majority of polypeptide chains?

Methionine (AUG, met), is the start codon.

How many different STOP codons are there?

There are 3 different STOP codons.

Define what an anticodon is.

It is the 3 unpaired bases that each tRNA molecule possesses. It matches with the mRNA codon.

Why is mRNA like a conveyor belt?

It is like a conveyor belt because it adds amino acids as it slides through the ribosome, creating a chain of amino acids (that eventually becomes polypeptide).

What happens after the ribosome forming the polypeptide reaches a STOP codon on the mRNA molecule?

After the ribosome reaches a STOP codon, it releases the polypeptide (protein) that it was working on as well as the mRNA.

What is the Central Dogma of Molecular Biology?

DNA to RNA to protein.

What is gene expression?

It is the process of proteins putting genetic information into action in living cells.