RNA

RNADo Now:

1. Turn in Lab (Strawberry DNA)2. Begin working on the 10-1 review

guide – it will be your homework tonight.

RNA: Ribonucleic Acid RNA is a polymer of nucleotides, just like

DNA.

There are a few important differences though:• RNA processes information, DNA stores it.• RNA is single stranded, DNA is double stranded.• In RNA, the base uracil (U) replaces thymine (T)

… there is no T in RNA• RNA nucleotides contain the sugar ribose, not

deoxyribose (That’s where the names come from)

RNA Structure Single

stranded

A-U, G-C

Many shapes possible

RNA Functions DNA stores information (like a hard

drive or thumb drive) and never leaves the nucleus of a cell.

RNA uses that information to make proteins. Can be found anywhere in a cell.

Types of RNA There are 3 major types of RNA

molecules, each with their own structure and function.

They are mRNA, tRNA, and rRNA.

rRNA = “R”ibosome RNA Ribosomes are made

of rRNA – that’s where their name comes from.

rRNA is folded up on itself many times – making a ball-like, globular structure

mRNA = “M”essenger RNA mRNA takes messages from the DNA to the rest of the

cell.

mRNA is a copy of the instructions to make one protein.

mRNA’s structure is a straight chain of nucleotides, like a ribbon.

tRNA = “T”ransfer RNA tRNA has an unusual

“cloverleaf” structure.

tRNA is needed during the protein-building process because it carries an amino acid and TRANSFERS it to the new protein.

The “Central Dogma” of Molecular Biology

A dogma is a central belief, assumption or principle of thought.

The central dogma of how DNA controls a cell is simple:

DNA RNA Protein

The Big Idea (aka “central dogma”)

DNA mRNA ProteinTra

nscrip

tio

nTra

nslatio

nReplication

It’s Your Turn For the remainder of the period,

complete your RNA notes, then begin working on the 10-1 review.

We are DONE with 10-1, DNA. There will be a quiz tomorrow.

Coach class is tomorrow – be there if you need to be!