Intro to DNA Protein Synthesis 02/21/2012

Goals for Today Be able to describe how DNA & RNA molecules differ from each other. Be able to describe protein synthesis (how proteins are made) Be able to describe the two major steps of protein synthesis (Transcription & Translation) be able to list the molecules & structures involved in each.

Question of the Day What do we know about the structure of DNA?

Question of the Day What do we know about the structure of DNA?

Ok…….So what is DNA good for? DNA has 2 major functions in our body: 1.Make more DNA 2.Make Protein

DNA holds the directions for protein synthesis Protein synthesis is the making of proteins A gene carries the code for making one protein

Protein Synthesis The information for making one particular protein is found on a unit of the chromosome known as a gene. There are thousands of genes on each chromosome. Everything in your body is made of AND by proteins! Ex. Enzymes are proteins!

Protein Synthesis The first step in protein synthesis involves DNA & a very similar molecule, RNA that is also made of nucleotides. Before we talk about the individual steps in making proteins, lets compare DNA & RNA

DNA vs. RNA DNA & RNA differ from each other in several important ways. See if you can fill in this chart for the DNA side of things: DNARNA Full Name Sugar in Nucleotide Nitrogen Bases # of Strands

RNA – Ribose Nucleic Acid RNA is like DNA except… - it is single stranded - it has uracil instead of thymine - it has ribose instead of deoxyribose Nitrogen Bases Sugars & Phosphates RNA DNA

Steps of Protein Synthesis The first step of Protein Synthesis is known as Transcription 1.DNA is transcribed into messenger RNA (mRNA) by an enzyme known as: RNA polymerase, which builds an RNA strand that is complimentary to the DNA strand.

Steps of Protein Synthesis If DNA is what is being transcribed, then what part of the EUKARYOTIC cell would this occur in?

Transcription RNA polymerase, which builds an RNA strand that is complimentary to the DNA strand.

Transcription – Practice! RNA polymerase, which builds an RNA strand that is complimentary to the DNA strand.

Steps of Protein Synthesis The next major process in protein synthesis is known as “translation” in this process mRNA is translated into protein. 2.Before translation can happen mRNA must move out of the nucleus ( in ______ organisms) and into the cytoplasm.

Modeling Transcription 1.Build DNA molecule 2.Build mRNA molecule

Assignment after Quiz Due Wednesday Read pages Describe the RNA molecule Describe the process of transcription & list the molecules involved (2) Describe the process of translation and list the molecules involved On what molecule is a codon found? On what molecule is an anti-codon found? What else is found on this molecule?