my RNA sucks!

RNA

Learning Objectives

▪ Contrast RNA and DNA.
▪ Explain the process of transcription.

Open Ended

Review: What are the nucleotides in DNA made of?

Comparing RNA and DNA

▪The sugar in RNA is ribose instead of deoxyribose.
▪RNA is generally single-stranded, not double-stranded.
▪RNA contains uracil in place of thymine.

The Role of RNA

The roles played by DNA and RNA molecules in directing protein
production are like the two types of plans builders use:
▪ A master plan
▪ A blueprint

Types of RNA

The three main types of RNA are:

Messenger RNA

Ribosomal RNA

Transfer RNA

Messenger RNA

▪ An mRNA molecule is a copy of the portion of DNA that will be

used to make a protein.

▪ After being made in the nucleus, mRNA travels to the

cytoplasm, the site of protein synthesis.

Ribosomal RNA

▪ Protein synthesis occurs on ribosomes, which are made up of

two subunits.

▪ These subunits consist of several molecules of ribosomal RNA

(rRNA) and as many as 80 different proteins.

Transfer RNA

During protein synthesis, transfer RNA molecules (tRNA)
carry amino acids from the cytoplasm to the mRNA.

RNA Synthesis: Transcription

In transcription, segments of DNA serve as templates to
produce complementary mRNA molecules.

RNA Synthesis: Promoters

RNA polymerase binds only to regions of DNA that have specific
base sequences. These regions are called promoters.

RNA Synthesis: RNA Editing

New RNA molecules sometimes require a bit of editing
before they are ready to be read.

Introns

Exons

Cap

Tail

Multiple Choice

How does RNA differ from DNA?

• RNA contains uracil and deoxyribose

• RNA contains ribose and thymine

• RNA contains uracil and ribose

• RNA contains adenine and ribose