* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download DNA and RNA Chapter 12
Biochemistry wikipedia , lookup
RNA silencing wikipedia , lookup
RNA polymerase II holoenzyme wikipedia , lookup
List of types of proteins wikipedia , lookup
Promoter (genetics) wikipedia , lookup
Gel electrophoresis of nucleic acids wikipedia , lookup
Eukaryotic transcription wikipedia , lookup
Community fingerprinting wikipedia , lookup
Molecular cloning wikipedia , lookup
Epitranscriptome wikipedia , lookup
Transcriptional regulation wikipedia , lookup
Non-coding RNA wikipedia , lookup
Genetic code wikipedia , lookup
Cre-Lox recombination wikipedia , lookup
DNA supercoil wikipedia , lookup
Vectors in gene therapy wikipedia , lookup
Non-coding DNA wikipedia , lookup
Gene expression wikipedia , lookup
Silencer (genetics) wikipedia , lookup
Molecular evolution wikipedia , lookup
Artificial gene synthesis wikipedia , lookup
http://faculty.uca.edu/~johnc/mbi1440.htm DNA and RNA Chapter 12-1 http://www.wappingersschools.org/RCK/staff/teacherhp/johnson/visualvocab/mRNA.gif GENETIC MATERIAL In the middle of the 1900’s scientists were asking questions about genes. What is a gene made of? How do genes work? How do genes determine characteristics of organisms? DO PROTEINS CARRY THE GENETIC CODE? At the time most scientists believed proteins that _________ had to be the molecules that made up genes. There were so many different kinds of proteins and DNA seemed to be too monotonous . . . repeating the 4 subunits. same ___ DNA is a DOUBLE HELIX http://www.time.com/time/time100/scientist/profile/watsoncrick.html http://en.wikipedia.org/wiki/Rosalind_Franklin Then things started to take shape! X-ray experiments by Rosalind Franklin led James Watson and Francis Crick to the discovery of the structure of DNA in 1953 (GOOGLE ROSALIND FRANKLIN) For This Unit, We Are Still Inside the Cell • Where is DNA Located in Eukaryotes? Figure 12–7 Structure of DNA Section 12-1 Nucleotide Hydrogen bonds Sugar-phosphate backbone Key Adenine (A) Thymine (T) Cytosine (C) Guanine (G) NUCLEIC ACIDS like DNA are built from subunits called NUCLEOTIDES ____________________ Image by: Riedell SUGAR in DNA is ________________ deoxyribose NITROGEN BASES in DNA CAN BE ANY OF THESE FOUR _____________= A ADENINE _____________ =G GUANINE _____________ CYTOSINE = C ______________ THYMINE = T DEOXYRIBONUCLEIC ACID IT’S DOUBLE ______________ STRANDED Image from: http://www.tokyo-med.ac.jp/genet/picts/dna.jpg Backbone (sides of ladder) made of PHOSPHATES _____________ and sugars _____________ Nitrogen bases =“Steps of ladder” A Phosphate group G Deoxyribose sugar C T Purines (2 rings) Pyrimidines (1 ring) © Pearson Education Inc, publishing as Pearson Prentice Hall. All rights reserved CHARGAFF’S RULES A = T G = C _________ _________ At time no one knew why… now we know its because Adenine always bonds THYMINE across with____________ Guanine always bonds CYTOSINE across with ____________ Image from: http://evolution.berkeley.edu/evosite/evo101/images/dna_bases.gif DOUBLE HELIX Hydrogen _____________ bonds between nitrogen bases hold the two strands together. Image from: http://evolution.berkeley.edu/evosite/evo101/images/dna_bases.gif CHROMOSOMES & DNA REPLICATION 12-2 Chromosome Structure in Prokaryotes Approximately 5 million base pairs 3,000 genes Chromosome E. coli bacterium Bases on the chromosome DNA molecule in bacteria is: SINGLE ______________ CIRCULAR ______________ CYTOPLASM (NO nucleus) Found in __________ © Pearson Education Inc, publishing as Pearson Prentice Hall. All rights reserved DNA in EUKARYOTES is packaged into chromosomes http://www.paternityexperts.com/images/DNA-of-life.jpg Humans have approxim ately 3 billion base pairs (1 m long) 60,000 to 100,000 genes THINK ABOUT IT How could you get this piece of string into the container? http://www.artzooks.com/files/3966/AZ533823_320.jpg http://www.mivaroo.com/sites/toyconnection.com/ In Humans, body cells have 2 of each chromosome: One from Mom, One from Dad = diploid (2n) How many chromosomes? 46 Sperm/egg cells have 1 of each chromosome = haploid (1n) How many chromosomes? 23 Image from: http://evolution.berkeley.edu/evosite/evo101/images/dna_bases.gif HOW IS DNA COPIED? The structure of DNA explains how it can be copied. Each strand has all the info needed to construct matching the __________other half. If strands are separated, base-pairing rules allow _____________ you to fill in the complementary bases. Figure 12–11 DNA Replication Section 12-2 New strand Original strand DNA polymerase Growth DNA polymerase Growth Replication fork Replication fork New strand Original strand Nitrogenous bases Sites where strand separation and replication forks replication occur are called _____________ REPLICATION STEPS 1.Enzymes “unzip” molecule by breaking _______________ Hydrogen bonds that hold the strands together and unwind it. DNA polymerase joins nucleotides 2. _______________ using original strand as template and spell checks ______________for errors. opposite directions 3. Copying happens in ________ along the two strands & in __________ multiple places at once. DNA Replication • Called semi-conservative (semi= some, conserve= save) • Means half of each new DNA strand contains half of the original DNA and half of the new DNA REPLICATION ANIMATION See a video clip about DNA REPLICATION (12B) ACTIVITY • BE A DNA MOLECULE RNA and PROTEIN SYNTHESIS 12-3 What does it mean to Transcribe? To Write or Type what someone is saying (same language still) © Pearson Education Inc, publishing as Pearson Prentice Hall. All rights reserved DNA Has 2 Jobs! • We’ve talked about Replication… That’s DNA’s first Job in the Cell • What is the role of the Nulceus? • How is it the Control Center of the Cell? • This section talks about how DNA sends its control messages! • It needs a helper…… RNA- DNA’s helper and cousin NUCLEOTIDES Also made of ___________ RIBOSE instead Sugar is _______ of deoxyribose. SINGLE stranded RNA is _________ URACIL Contains _________ instead of thymine. http://images2.clinicaltools.com/images/gene/dna_versus_rna_reversed.jpg 3 KINDS OF RNA HELP WITH INFO TRANSFER FOR PROTEIN SYNTHESIS RIBOSOMAL _________________RNA (rRNA) Combines with proteins to form ribosomes TRANSFER _________________RNA (tRNA) Matches m-RNA codon to add correct amino acids during protein synthesis _________________RNA (mRNA) MESSENGER carries code from DNA to ribosomes rRNA and t-RNA images from © Pearson Education Inc, publishing as Pearson Prentice Hall. All rights reserved mRNA image from http://wps.prenhall.com/wps/media/tmp/labeling/1140654_dyn.gif Transcription- DNA gives mRNA a message to deliver • Very similar to replication- DNA unzips and new bases pair up • New bases are RNA, not DNA (mRNA in this step) • RNA has 4 bases: C, G, A and U (U replaces T) • RNA is only 1 strand, never 2 • Occurs in nucleus • Ex: CCGTAG pairs with ______ Figure 12–14 Transcription Section 12-3 Adenine (DNA and RNA) Cystosine (DNA and RNA) Guanine(DNA and RNA) Thymine (DNA only) Uracil (RNA only) RNA polymerase DNA RNA RNA POLYMERASE Enzyme called _____________________ separates strands, then uses one strand as a template to assemble an RNA copy. How does RNA POLYMERASE know where a gene starts and stops? Enzyme binds to places with specific DNA PROMOTERS sequences called _______________. RNA POLYMERASE PROMOTERS tell _________________ where to start. Signals at the end of the gene code cause transcription to _____ stop . http://images2.clinicaltools.com/images/gene/dna_versus_rna_reversed.jpg Video 3 Transcription animation See another transcription animation See a video clip about TRANSCRIPTION (12C) ACTIVITY • TRANSCRIPTION of DNA MASTER PLAN DNA stays safe in nucleus © Pearson Education Inc, publishing as Pearson Prentice Hall. All rights reserved TRANSCRIPTION (DNA→ RNA) & PROCESSING takes place in nucleus TRANSLATION (RNA→ proteins) takes place on ribosomes in cytoplasm “Blueprints” of master plan are carried to building site http://www.home-improvement-resource.com/images/architect.jpg Translation- mRNA into a Protein • Occurs at ribosome (on rough ER) • The new strand of mRNA contains a code for an amino acid (or command like STOP or Start) • Amino Acids put together make a protein chain HOW CAN JUST 4 BASES GIVE DIRECTIONS TO MAKE 20 AMINO ACIDS? Message is read in groups of 3 = _________ CODON UCGCACGGU UCG-CAC-GGU Serine - Histidine - Glycine Codons represent different amino acids KIRBY!!!!! The m-RNA Code Section 12-3 64 possible codons Some amino acids have more than one codon. AUG START= _______ STOP 3 codons for _____ ANTICODON ___________ on tRNA EACH tRNA carries only one kind of amino acid _____________ matches up with CODON ________ on mRNA Images modified from © Pearson Education Inc, publishing as Pearson Prentice Hall. All rights reserved Figure 12–18 Translation Section 12-3 Figure 12–18 Translation (continued) Section 12-3 Video 4 SEE ANOTHER Translation Animation See a video clip about PROTEIN SYNTHESIS (12D) TRANSLATION VIDEO (Choose Large video) REPLICATION DNA → DNA ____________ TRANSCRIPTION DNA → RNA ____________ RNA→ Protein TRANSLATION ___________ CENTRAL DOGMA OF BIOLOGY How is information passed? DNA → ______ RNA PROTEIN _____ → ________ Then the protein “DOES SOMETHING” that shows up as a ________ trait Mendel/flower images from: http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookTOC.html Blood cell by Riedell GENES & PROTEINS Proteins are the connection between the gene code in the DNA and how that gene is expressed. A gene that codes for an enzyme (protein) to make a pigment can control the color of a flower. A gene that codes for an enzyme (protein) adds carbohydrates to glycoproteins to produce your blood type. Enzymes catalyze and regulate chemical reactions so proteins build and operate all cell components. Concept Map Section 12-3 can be also called which functions to from also called to which functions to to make up also called which functions to Concept Map Section 12-3 RNA can be Messenger RNA also called Ribosomal RNA which functions to mRNA Carry instructions also called which functions to rRNA Combine with proteins from to to make up DNA Ribosome Ribosomes Transfer RNA also called which functions to tRNA Bring amino acids to ribosome MUTATIONS 12-4 REMEMBER! _______________ MUTATIONS are changes in the genetic material. Mutations can happen when cells make mistakes _____________ in copying their own DNA radiation or be caused by _______________ or chemicals in the enviroment. ___________ KINDS OF MUTATIONS Mutations that produce changes in a single GENE MUTATIONS gene = ______________________ Mutations that produce changes in whole chromosomes = CHROMOSOMAL MUTATIONS _____________________ GENE MUTATIONS Mutations involving ________________ One or a few ____________ = __________________ nucleotides Point mutation because they occur at a single point in the DNA sequence. TYPES OF POINT MUTATIONS: _____________________ substitutions deletions _____________________ insertions _____________________ SUBSTITUTION Changes one base for another ATTCGAGCT ATTCTAGCT How many amino acids get changed? SICKLE CELL ANEMIA CAUSE: (autosomal recessive) A changed to T (glu to val) gene on chromosome #11 that codes for part of hemoglobin protein (carries oxygen in blood) DELETION Piece of DNA code is lost ATTCGAGCT ATTCAGCT How many amino acids get changed? INSERTION Extra piece of DNA is added ATTCGAGCT ATTCGCAGCT How many amino acids get changed? GENE MUTATIONS Substitutions usually affect no more than a Amino acid single ____________, but deletions and insertions can have a more dramatic effect. IMAGE FROM BIOLOGY by Miller and Levine; Prentice Hall Publishing©2006 FRAME SHIFT MUTATIONS Change multiple bases in code thefatcatatetherat the fat cat ate the rat ____________________ INSERTION thefatcataatetherat the fat cat aat eth era t DELETION thefatcatatetherat the fat ata tet her at FRAME SHIFTS Frame shift mutations change every Amino acid ___________ in the ___________ protein that follows the shift. Frame shifts can alter a protein so function much it is unable to _____________ Location of the shift is important! AT BEGINNING the fat cat ate the rat the fac ata tet her at AT END the fat cat ate the rat the fat cat ate thr at BEGINNING MUTATIONS AT _____________OF GENE DAMAGE __________ OF THE CODE! MORE CHROMOSOMAL MUTATIONS Mutations involving changes in the Number structure _____________ or ______________ of whole chromosomes TYPES OF CHROMOSOMAL MUTATIONS: _____________________ deletions See a Video duplications _____________________ inversions _____________________ translocations _____________________ (deletions & duplications See a Video (inversions & translocations DELETION Piece of chromosome is lost ________________________________________ Image from: http://www.biology-online.org/2/8_mutations.htm Duchenne Muscular Dystrophy CAUSE: (X linked recessive) DELETION in gene that codes for a muscle protein DUPLICATION Piece of DNA is copied too many times ________________________________________________ Image from: http://www.biology-online.org/2/8_mutations.htm HUNTINGTON’S • Degenerative brain disorder • Symptoms appear age 30-40 • Lose ability to walk, think, talk, reason • Cause = ADDITION of extra CAG repeats INVERSION Segment flips and reads backwards Image from: http://www.biology-online.org/2/8_mutations.htm TRANSLOCATION Segment breaks off and joins a different non-homologous chromosome Image from: http://www.biology-online.org/2/8_mutations.htm MUTATIONS Most mutations are ____________ neutral meaning they have little or no effect on gene ____________. function defective proteins Mutations that cause ________________ are usually ____________ HARMFUL Harmful mutations are associated with many genetic disorders and can cause ________________ ____________ cancer MUTATIONS Mutations are also a source of Genetic variability _________________ and can be beneficial _____________ Can help an organism _________________ Survive and reproduce variation Provide _________ in population for ____________ natural selection to act upon MORE ON THIS 2nd SEMESTER! POLYPLOIDY Condition in which an organism has extra sets of chromosomes POLYPLOIDY = _______________ LETHAL __________ in humans, but beneficial in some ___________. plants 3N or tetraploid (___) 4N Triploid (___) plants are often ________________ larger and stronger than diploid plants.