AP Biology Discussion Notes Wednesday 2/10/2015

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

Question of the Day What do you know about DNA & Proteins? –What is similar or true for both? –What is different? –How are they connected?

Be Dogmatic! Genetic Information is: Encoded in DNA; Transmitted through DNA Replication (did this!); Transcribed into RNA; this is called TRANSCRIPTION; Translated into Protein; this is called TRANSLATION

Importance GENOTYPE becomes a PHENOTYPE Gene Expression

Chapter 17

Protein Synthesis The first step in protein synthesis involves DNA & a very similar molecule, RNA that is also made of ___________. 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 the following chart for DNA

DNA vs. RNA DNARNA Full Name Sugar in Nucleotide Nitrogen Bases # of Strands Compliments/ Pairing

What is this structure called? Phosphate Group N Nitrogenous base (A, G, C, or ) Sugar ( )

RNA Nucleotide – a nucleotide is the three component parts together Phosphate Group N Nitrogenous base (A, G, C, or ) Sugar ( )

RNA – Ribonucleic 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

DNA or RNA? How could you tell, what is your evidence?

DNA or RNA? It is DNA because there are “T”s in it for Thymine

DNA…. what is 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 -making proteins Gene section of DNA that carries the code for making one protein

Protein Synthesis Gene section of DNA that carries the code for making 1 protein 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 Big Picture

Steps of Protein Synthesis The first step of Protein Synthesis is known as Transcription If you ordered a “Transcript” what would that be? Would it be the same?

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.

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

Messenger RNA - mRNA The message of mRNA is carried in “codons” A codon is a three base sequence (Ex. ) that will code for one Amino Acid (the __________ _______ /________ of ____________. Together the codons in the mRNA strand code for 1 protein (typically hundreds or thousands of Amino Acids for a single protein)

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

Transcription – Practice! How many “CODONS” would this mRNA molecule have on it?

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

Transcription Try to pick out the molecules: –RNA Polymerase – mRNA –Nucleotides –DNA 5MfSYnItYvg Real Time animation of Trancription

Lets Review What process makes an mRNA molecule? What is needed to produce it? What sets mRNA apart from DNA?

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.

Messenger RNA - mRNA DNA’s “recipes” are transcribed by the enzyme ____ ____________ to make a molecule of mRNA. mRNA is like a different language then DNA mRNA is the language that the ribosome - (protein building machine) can read.

Steps of Protein Synthesis If someone asked you to “Translate” something what would that mean, what would they be asking you to do? What “languages” are we using?

Steps of Protein Synthesis The next step of Protein Synthesis is TRANSLATION 3.Once the mRNA strand leaves the nucleus and enters the cytoplasm the mRNA Attaches to a ribosome (our cell’s protein making machine)

Steps of Protein Synthesis 3.Once the mRNA strand leaves the nucleus and enters the cytoplasm the mRNA Attaches to a ribosome (our cell’s protein making machine) 4.Next a molecule of Transfer RNA (tRNA) attaches to the mRNA strand

Anatomy of a (tRNA)

Anatomy of a Transfer “t” RNA (tRNA)

Steps of Protein Synthesis 4.Next a molecule of Transfer RNA (tRNA) attaches to the mRNA strand

Steps of Protein Synthesis 4. Next a molecule of Transfer RNA (tRNA) attaches to the mRNA strand 5. Amino acids are linked together by the ribosome to form the final protein (which is really just a long chain of amino acids)

Translation Real Time Animation Mkmb0whttps:// Mkmb0w

Protein Synthesis Lets put it all together!

Create the mRNA, tRNA and find the Amino Acid coded for on mRNA

Questions?

Protein Synthesis Story

Species of the Day 2/10 Leopard Seal –Hydrurga leptonyx

Species of the Day 2/10 Leopard Seal –Hydrurga leptonyx What do you know about the RNA of this leopard seal? (You should have a pretty good list by now, including processes that the RNA is involved in)

Species of the Day 2/10 Leopard Seal –Hydrurga leptonyx The RNA in this Seal: