4/19 ATB What material is found inside the nucleus? What material is found inside the nucleus? Today: Today: –Go over your tests – any mistakes? –Review DNA / RNA –Begin discussing the importance of DNA, and it ’ s structure

Review What makes up a chromosome? What makes up a chromosome? What is the function of DNA? What is the function of DNA? What does DNA stand for? What does DNA stand for? What is the structure of DNA? What is the structure of DNA? What is the job of enzymes? What is the job of enzymes? What are enzymes composed of? What are enzymes composed of?

4/23 ATB What is the shape of the DNA molecule? What is the shape of the DNA molecule? Today: Today: –Discuss DNA’s role in you body –What is the genetic code?

DNA, RNA and Protein Synthesis

STRUCTURE and FUNCTION of DNA Structure – Structure – –double-helix (looks like a spiral staircase) Function – Function – –carries your genetic information

DNA is the “ genetic code ” of life It controls all aspects of the cell. But how? It controls all aspects of the cell. But how?  By the different proteins that it codes for.  Different proteins have different functions –Enzymes –  control / speed up chemical reactions  EX: ATP Synthase  helps build ATP –Repair, transport, structural proteins

What is the genetic code? Set of rules by which information is transferred from… Set of rules by which information is transferred from… DNA into  RNA into  Proteins (using amino acids) DNA into  RNA into  Proteins (using amino acids) Even bacteria and viruses have a genetic code Even bacteria and viruses have a genetic code

What are Nucleic Acids? A complex macromolecule that stores information in cells in the form of a code. A complex macromolecule that stores information in cells in the form of a code. –DNA and RNA. Composed of monomers of nucleotides Composed of monomers of nucleotides

What is DNA? Deoxyribonucleic acid Deoxyribonucleic acid Contains the genetic instructions for development / functioning of living things Contains the genetic instructions for development / functioning of living things

What is a nucleotide? A monomer that consists of three parts A monomer that consists of three parts –Sugar (deoxyribose or ribose) –Phosphate –Nitrogen Base (A, C, T, G and U)

What are the Nitrogen Bases? Adenine Adenine Guanine Guanine Cytosine Cytosine Thymine (DNA only) Thymine (DNA only) Uracil (RNA only) Uracil (RNA only)

Nitrogen Bases

Nitrogen Base Pairing How do the nitrogen bases pair in DNA? How do the nitrogen bases pair in DNA? –A – T –C – G –RNA  A – U (no Thymine) What holds the nitrogen bases together? What holds the nitrogen bases together? –Hydrogen Bonds

Purines and Prymidines Which nitrogen bases are purines? Which nitrogen bases are purines? –Adenine –Guanine Which nitrogen bases are pyrimidines? Which nitrogen bases are pyrimidines? –Cytosine –Thymine –Uracil (in RNA)

Review: Name and describe the shape of DNA. Double helix A twisted ladder Double helix A twisted ladder What are the 4 nitrogen bases? What are the 4 nitrogen bases? Which nitrogen bases bond with one another? Which nitrogen bases bond with one another? Which nitrogen bases are purines? Which nitrogen bases are purines?

Why is the nucleotide sequence important? Why is the nucleotide sequence important? –All organisms have DNA –The closer the DNA resemblance, the more closely related the organisms are What is our closest relative? What is our closest relative? –Chimps –Great Apes KagyO9zS_ro KagyO9zS_ro KagyO9zS_ro KagyO9zS_ro

DNA REPLICATION DNA Replication: DNA Replication: –the process of copying DNA When do we copy our DNA? When do we copy our DNA? –During the cell cycle REVIEW: What phase of cell cycle does DNA replication occur? REVIEW: What phase of cell cycle does DNA replication occur? –Interphase

DNA REPLICATION STEP ONE: STEP ONE: –Helicase –  An enzyme that breaks hydrogen bonds between nitrogen bases “ unzipping ” the DNA

4/24 ATB Which nitrogen bases are purines? Which nitrogen bases are purines? Today: Today: –Continue with the DNA information

DNA REPLICATION Replication Fork – Replication Fork – –location where the DNA is splitting apart

Review from yesterday What are the four nitrogen bases? What are the four nitrogen bases? What is the monomer of DNA? What is the monomer of DNA? Which nitrogen bases are the purines? Which nitrogen bases are the purines? What is the enzyme that “unzips” the DNA? What is the enzyme that “unzips” the DNA? Where is the replication fork? Where is the replication fork?

DNA REPLICATION STEP TWO: STEP TWO: –DNA POLYMERASE –  An enzyme that bonds free floating nucleotides together to form a new DNA chain

DNA REPLICATION How long does this continue? How long does this continue? –Until the entire chain is copied…forming two new chains Why do we copy DNA? Why do we copy DNA? –So that new cells have the genetic material needed to survive

DNA Replication

REVIEW: Monomers and Polymers Define Monomer – Define Monomer – –The smallest unit that makes up a larger molecule Define Polymer Define Polymer – A large molecule formed by many smaller molecules called monomers PICTURE: PICTURE:

REVIEW Do all organisms have DNA? Do all organisms have DNA? – YES – All living things have the same genetic code What is a Protein? What is a Protein? – A large complex polymer composed of Carbon, Hydrogen Oxygen, Nitrogen and sometimes sulfur.

REVIEW Amino Acids – Amino Acids – – The monomers that make up a protein. –There are 20 common AA ’ s Peptide Bond – Peptide Bond – –Covalent bond (sharing electrons) formed between two AA ’ s

4/25 ATB What are the monomers of a protein? What type of bond connects them? What are the monomers of a protein? What type of bond connects them? Today: Today: –First WS page – “Genes and Chromosomes”, pg 13 –Discuss RNA and transcription –Quiz Friday on DNA Replication and Transcription

4/26 What are the three parts that make up a nucleotide? What are the three parts that make up a nucleotide? Today: Today: –Turn in your homework. –Discuss RNA and transcription

RNA RNA RNA –Ribonucleic acid –The 3 types of RNA function in protein synthesis The 3 types of RNA: The 3 types of RNA: –mRNA – messenger RNA –rRNA – ribosomal RNA –tRNA – transfer RNA

What are 4 differences between DNA and RNA? One strand vs. two strands One strand vs. two strands RNA has Uracil – DNA does not RNA has Uracil – DNA does not RNA contains a different sugar molecule – Ribose vs. Deoxyribose RNA contains a different sugar molecule – Ribose vs. Deoxyribose DNA is found only in the nucleus (of eukaroytic cells) DNA is found only in the nucleus (of eukaroytic cells)

Difference Between DNA & RNA

TRANSCRIPTION What is Transcription? What is Transcription? –The process by which enzymes make a RNA copy of the DNA strand Review - What are the 3 types of RNA? Review - What are the 3 types of RNA? –mRNA – messenger RNA –rRNA – ribosomal RNA –tRNA – transfer RNA

TRANSCRIPTION What is the function mRNA? What is the function mRNA? –The RNA copies the DNA using an enzyme called RNA Polymerase –RNA leaves the nucleus into the cytoplasm to the site of protein synthesis. –(Combines with rRNA and involves tRNA to complete TRANSLATION)

Transcription Summary

tRNA and rRNA What is the function rRNA? What is the function rRNA? –Helps to bond amino acids together in protein synthesis What is the function tRNA? What is the function tRNA? –tRNA brings amino acids to the ribosomal RNA so they can be assembled into proteins –Has the anticodon that matches with the codon on the mRNA

tRNA

Transcription

Transcribe the following DNA chain into RNA ATT-AGC-AGC-TAG-GGC-AGT-TAA-TCG ATT-AGC-AGC-TAG-GGC-AGT-TAA-TCG

4/27 ATB What are two difference between DNA and RNA? What are two difference between DNA and RNA? Today: Today: –Begin discussing translation –Start online translation assignment

Practice Pop Quiz -- Write you name and the period at the top of the page. 1. What is one difference between DNA and RNA? 2. What is another difference between DNA and RNA? 3. What is produced during the process of transcription? 4. What does adenine bond with? 5. What does cytosine bond with? 6. What are the three parts of a nucleotide? 7. What is the enzyme that “ unzips ” the double helix? 8. What are the building blocks of proteins? 9. What does AUG code for? 10. What does UUA code for?

TRANSLATION What is translation? What is translation? –Process by which the order of bases in mRNA codes for the order of amino acids in a protein.

tRNA and rRNA - TRANLSATION What is the function rRNA? What is the function rRNA? –Helps to bond amino acids together in protein synthesis What is the function tRNA? What is the function tRNA? –tRNA brings amino acids to the ribosomal RNA so they can be assembled into proteins –Has the anticodon that matches with the codon on the mRNA

What is a codon? Three nitrogen bases that code for an amino acid Three nitrogen bases that code for an amino acid There are “ start ” and “ stop ” codons There are “ start ” and “ stop ” codons (The code is the exact same as in humans as in a virus or a skunk) (The code is the exact same as in humans as in a virus or a skunk) –(Scientist see this as evidence that we all share a common ancestor)

–Practice:  What is UUU?  What is the start codon?  What is UGA?  What is AAA?  What is GAA?  What are the stop codons? ?

4/30 ATB What amino acid cooresponds with the following codons? AUG – GGA – AAG – UGA What amino acid cooresponds with the following codons? AUG – GGA – AAG – UGA Today: Today: –Finish online assignment –Finish discussing translation –Take home quiz.

Codon Chart

Transcription Transcription – class.unl.edu/biochem/gp2/m_biology/animation/gene/gene_a2.htm l class.unl.edu/biochem/gp2/m_biology/animation/gene/gene_a2.htm lhttp://www- class.unl.edu/biochem/gp2/m_biology/animation/gene/gene_a2.htm l Translation Translation – class.unl.edu/biochem/gp2/m_biology/animati on/gene/gene_a3.html class.unl.edu/biochem/gp2/m_biology/animati on/gene/gene_a3.htmlhttp://www- class.unl.edu/biochem/gp2/m_biology/animati on/gene/gene_a3.html

Protein Synthesis, Translation (1) Protein Synthesis, Translation (1) Q_tAkY Q_tAkY Q_tAkY Q_tAkY

Transcription animations – class.unl.edu/biochem/gp2/m_biology/animation/ge ne/gene_a2.html class.unl.edu/biochem/gp2/m_biology/animation/ge ne/gene_a2.htmlhttp://www- class.unl.edu/biochem/gp2/m_biology/animation/ge ne/gene_a2.html – molgenetics/transcription.swf molgenetics/transcription.swfhttp:// molgenetics/transcription.swf

Translation – Step by Step

Translation Summary

Translation Animations ching/genetics/animations/translation.htm ching/genetics/animations/translation.htm

Transcription and Translation

4-29 ATB What type of bond holds the amino acids together? What type of bond holds the amino acids together? Today: Today: –Online assignment

5-2 ATB What is the job of an enzyme? What is the job of an enzyme? Today: Today: –How did the keystone bio test go?

5-3 ATB What makes up the backbone of DNA? What is the product of translation? What is the product of transcription? What makes up the backbone of DNA? What is the product of translation? What is the product of transcription? Today: Today: –Discuss mutations –Test / RS -- FRIDAY

5-4 ATB What is worse a point mutation or frameshift mutation? Why? What is worse a point mutation or frameshift mutation? Why? Today: Today: –REVIEW! –DNA Practice Quiz –TEST / RS MONDAY

Mutations – page 324 Mutation – Mutation – –random error or change in a DNA sequence that may affect the whole chromosome or just one gene –What can cause a mutation?  Copying errors by the polymerase, UV radiation, chemicals, viruses Are mutations always bad? Are mutations always bad? –No. Beneficial mutations can lead to evolutionary change

Mutations Point Mutation – Point Mutation – –a change to a single base pair in DNA –(This error can change the ENTIRE MEANING of the DNA sequence)  EXAMPLE: –THE CAT ATE THE RAT –THE CAT ATE THE MAT

Mutations Frameshift Mutation – Frameshift Mutation – –a mutation in which a single base is added or deleted from the DNA sequence  This would cause every ____codon___ to be different after that addition / deletion.

Substitution – Substitution – –when one nucleotide replaces another Insertion Mutation – Insertion Mutation – –one or more nucleotide are added to a gene (can lead to a frame-shift mutation)

Mutations What are chromosomal mutations? What are chromosomal mutations? –Mutation affecting gene distribution to gametes during meiosis

Most common mutations: (see page 326)  Deletions – –chromosomes part lost  Insertions – –chromosome part breaks off and rejoins its sister chromatid

Most common mutations: (see page 326)  Inversions – –when a part of the chromosome breaks off and is reinserted backwards  Translocations – –when a part breaks off and joins a different chromosome

The End

5-5 ATB What is the job of the tRNA? What is the job of the tRNA? Today: Today: –Review for the test! –Finish the assignment from yesterday –Start working on the review sheet –Tomorrow: Book assignment. –TEST / Study guide ---- MONDAY

5-9 ATB TEST  ANY QUESTIONS? TEST  ANY QUESTIONS? Turn in Review Sheet!!! Turn in Review Sheet!!! Turn in DNA  Translation assignment Turn in DNA  Translation assignment

Mutations MiniLab – page 327 – Complete Analysis Questions #1-3 and turn in MiniLab – page 327 – Complete Analysis Questions #1-3 and turn in

Mutations Nondisjunction – failure of homologous chromosomes to separate properly during meiosis Nondisjunction – failure of homologous chromosomes to separate properly during meiosis –Trisomy – when gamete (sex cell) has an extra chromosome  So in humans, there would be ____47 chromosomes____  If the extra chromosome is #21 in humans = ___downs syndrome_______

Mutations –Monosomy –absence of a chromosome – most do not survive  Females can be missing the ___X___ chromosome and survive  WHY? ____B/C the other X chromosome can make up the difference_____

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