http faculty uca edujohncmbi 1440 htm DNA and

http: //faculty. uca. edu/~johnc/mbi 1440. htm DNA and RNA Chapter 12 -1 http: //www. wappingersschools. org/RCK/staff/teacherhp/johnson/visualvocab/m. RNA. 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 100/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?

Section 12 -1 Figure 12– 7 Structure of DNA 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/evo 101/images/dna_bases. gif

DOUBLE HELIX Hydrogen _______ bonds between nitrogen bases hold the two strands together. Image from: http: //evolution. berkeley. edu/evosite/evo 101/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/AZ 533823_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 (2 n) How many chromosomes? 46

Sperm/egg cells have 1 of each chromosome = haploid (1 n) How many chromosomes? 23

Image from: http: //evolution. berkeley. edu/evosite/evo 101/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 Replication fork Nitrogenous bases Replication fork New strand Original strand 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 (12 B)

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: //images 2. clinicaltools. com/images/gene/dna_versus_rna_reversed. jpg

3 KINDS OF RNA HELP WITH INFO TRANSFER FOR PROTEIN SYNTHESIS RIBOSOMAL _________RNA (r. RNA) Combines with proteins to form ribosomes TRANSFER _________RNA (t. RNA) Matches m-RNA codon to add correct amino acids during protein synthesis _________RNA (m. RNA) MESSENGER carries code from DNA to ribosomes r. RNA and t-RNA images from © Pearson Education Inc, publishing as Pearson Prentice Hall. All rights reserved m. RNA image from http: //wps. prenhall. com/wps/media/tmp/labeling/1140654_dyn. gif

Transcription- DNA gives m. RNA a message to deliver • Very similar to replication- DNA unzips and new bases pair up • New bases are RNA, not DNA (m. RNA 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 _ _ _

Section 12 -3 Figure 12– 14 Transcription Adenine (DNA and RNA) Cystosine (DNA and RNA) Guanine(DNA and RNA) Thymine (DNA only) Uracil (RNA only) RNA polymerase RNA DNA 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: //images 2. clinicaltools. com/images/gene/dna_versus_rna_reversed. jpg

Video 3 Transcription animation See another transcription animation See a video clip about TRANSCRIPTION (12 C)

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- m. RNA into a Protein • Occurs at ribosome (on rough ER) • The new strand of m. RNA 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? CODON Message is read in groups of 3 = _____ 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 t. RNA EACH t. RNA carries only one kind of amino acid _______ matches up with CODON ____ on m. RNA Images modified from © Pearson Education Inc, publishing as Pearson Prentice Hall. All rights reserved

Section 12 -3 Figure 12– 18 Translation

Section 12 -3 Figure 12– 18 Translation (continued)

Video 4 SEE ANOTHER Translation Animation See a video clip about PROTEIN SYNTHESIS (12 D) 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/Bio. Book. TOC. 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 m. RNA Carry instructions also called which functions to r. RNA Combine with proteins from to to make up DNA Ribosomes Transfer RNA also called which functions to t. RNA 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 One or a few Mutations involving ________ = _________ 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 neutral Most mutations are ______ meaning they have little or no effect on gene ______. function defective proteins Mutations that cause ________ HARMFUL are usually ______ 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 natural selection for ______ to act upon MORE ON THIS 2 nd SEMESTER!

POLYPLOIDY Condition in which an organism has extra sets of chromosomes POLYPLOIDY = ________ LETHAL _____ in humans, but beneficial in some ______. plants 3 N or tetraploid (___) 4 N Triploid (___) plants are often ________ larger and stronger than diploid plants.