* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download DNA Replication
Epigenetics of human development wikipedia , lookup
Mitochondrial DNA wikipedia , lookup
Polycomb Group Proteins and Cancer wikipedia , lookup
Genetic code wikipedia , lookup
Nucleic acid tertiary structure wikipedia , lookup
Epitranscriptome wikipedia , lookup
Genomic library wikipedia , lookup
Genome (book) wikipedia , lookup
History of RNA biology wikipedia , lookup
Bisulfite sequencing wikipedia , lookup
Genetic engineering wikipedia , lookup
Nutriepigenomics wikipedia , lookup
Non-coding RNA wikipedia , lookup
DNA polymerase wikipedia , lookup
United Kingdom National DNA Database wikipedia , lookup
Gel electrophoresis of nucleic acids wikipedia , lookup
Genealogical DNA test wikipedia , lookup
Designer baby wikipedia , lookup
DNA damage theory of aging wikipedia , lookup
DNA vaccination wikipedia , lookup
Site-specific recombinase technology wikipedia , lookup
Cancer epigenetics wikipedia , lookup
Molecular cloning wikipedia , lookup
Epigenomics wikipedia , lookup
Frameshift mutation wikipedia , lookup
Oncogenomics wikipedia , lookup
No-SCAR (Scarless Cas9 Assisted Recombineering) Genome Editing wikipedia , lookup
Genome editing wikipedia , lookup
Microsatellite wikipedia , lookup
Nucleic acid double helix wikipedia , lookup
Cell-free fetal DNA wikipedia , lookup
Extrachromosomal DNA wikipedia , lookup
Non-coding DNA wikipedia , lookup
DNA supercoil wikipedia , lookup
Cre-Lox recombination wikipedia , lookup
Vectors in gene therapy wikipedia , lookup
Primary transcript wikipedia , lookup
History of genetic engineering wikipedia , lookup
Therapeutic gene modulation wikipedia , lookup
Artificial gene synthesis wikipedia , lookup
Microevolution wikipedia , lookup
Helitron (biology) wikipedia , lookup
Nucleic acid analogue wikipedia , lookup
DNA Deoxyribose Nucleic Acid DNA • DNA is a double helix. • A bonds to T: C bonds to G • In man, the DNA molecule , if fully extended, would have a total length of 1.7 metres. If you unwrap all the DNA you have in all your cells, you could reach the moon ...6000 times! DNA •DNA STRUCTURE •DNA REPLICATION Components of DNA • NUCLEOTIDE – Phosphate group-phosphodiester bond – 5-Carbon sugar-deoxyribose – nucleic acid (1 of the nucleic acids) • Guanine-Purine • Cytosine-Pyrimidines • Adenine-Purine • Thymine-Pyrimidines • Held by hydrogen bonds • One end of chain with free 5’ phosphate group • Other end of chain with free 3’ hydroxyl group • Adenine, thymine form two bonds • Guanine, cytosine form three bonds COMPONENTS QuickTime™ and a mpeg4 decompressor are needed to see this picture. QuickTime™ and a Cinepak decompressor are needed to see this picture. DNA Replication • DNA is opened by enzymes (unzips) helicase • Complementary nucleotides bond with the old strands• 2 strands created: ½ is the old strand; ½ is the new strand. DNA REPLICATION • TAKES PLACE IN THE NUCLEUS • END PRODUCT IS TWO IDENTICAL STRANDS • DURING CELL DIVISION- ONE STRAND • FOR EACH CELL • Replication occurs only in 5’(P) to 3’(OH) direction(DNA IS READ 3’ to 5’) • a. Replication of leading strand, 3' to 5' strand • 1. • 2. New strand grows from 5' to 3’end Elongates towards replication fork REPLICATION ENZYMES Helicase DNA polymerase Topoisomerase RNA primer ligase QuickTime™ and a mpeg4 decompressor are needed to see this picture. QuickTime™ and a mpeg4 decompressor are needed to see this picture. From Genotype to Phenotype • Protein synthesis--converting the genetic code (in DNA) into proteins that the body uses • 3 Steps involved – Transcription – RNA splicing – Translation QuickTime™ and a mpeg4 decompressor are needed to see this picture. DNA----RNA • DNA • RNA • DOUBLE STRANDED • DEOXYRIBOSE • NUCLEIC BASES • SINGLE STRANDED • RIBOSE • NUCLEIC BASES – – – – THYMINE GUANINE ADENINE CYTOSINE – – – – URACIL GUANINE ADENINE CYTOSINE RNA Differences from DNA – Single stranded (vs. Double stranded DNA) – Contains uracil in place of thymine – Ribose sugar (instead of deoxyribose) 4 Types of RNA preMRNA---transcribes the message from the DNA(rough blueprint) – mRNA (messenger RNA)-carries message to to ribosome(final blueprint) – rRNA (ribosomal RNA)--makes up the ribosome(forman that assembles parts of protein in a specific order) – tRNA(transfer RNA)--carries amino acids to ribosomes tRNA • Anticodon of MRNA • Wobble to take in all possible aa combinations of 3 nitrogen bases • Carries specific aa on 3’ on of strand DNA TRANSCRIPTION DNA- GIVES CODE TO preRNA or hnRNA PROCESSING QuickTime™ and a mpeg4 decompressor are needed to see this picture. QuickTime™ and a mpeg4 decompressor are needed to see this picture. RIBOSOME STRUCTURE A site - attracts Trna P site - forms peptide bonds between aa of protein E site - where Trns leave ribosome and aa chain elongates 5’ end with initiator sequence attaches to small subunit Large subunit goes over small at the A site. Attracts 1st Trna with aa Met DNA TRANSLATION tRNA translates mRNA into proteins SUMMARY Comparison of DNA and RNA • RNA is single stranded • RNA has uracil instead of thymine • A-U • DNA is double stranded • DNA has thymine instead of uracil • A-T Understanding DNA • Inheritance/ Genetic Counseling • Cell function/protein synthesis • Embryonic development/gene regulation • Evolution/ phylogenetic relationships • Medicine/genetic diseases • Genetic engineering/ recombinant DNA Changes in Chromosomes • Mutation--a change in the sequence of DNA nucleotides (nitrogen bases) – Causes a change in the protein formed – Causes a change in organisms’ phenotype (trait) • Effects of mutations? – Some have little or no effect – A few are beneficial – Most are harmful or lethal (fatal) Chromosomal Mutations • Deletion mutation--piece of chromosome breaks off and is lost; the new DNA strands are also missing a piece • Duplication--piece of chromosome breaks off and is inserted on homologous chromosome • Translocation--piece of chromosome breaks off and attaches to a different, non-homologous chromosome • Inversion--piece of chromosome breaks off, turns around and reattaches in opposite direction Mutations Illustrated Gene mutations • Frameshift mutation--deletion or addition of single (or few) nucleotides alters the amino acid sequence of the protein • Point (Substitution) mutation--wrong base is added in a position--new DNA chains will show the change Point Mutations QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. MUTATIONS Frameshift Mutations Expansions are responsible for many genetic diseases: • Muscular Dystrophy (CTG repeats) • Huntington’s (CAG repeats) • Fragile X (CCG repeats) Replication Errors and Mutations • Inheritance of mutations – Harmful mutations • Individuals may not live to reproductive age • Individuals may not develop/adapt as well – Advantageous mutations • Help survival of organism and are passed down if mutation occurred in cells that produce gametes Genes and cancer • Cancer is uncontrolled, abnormal cell division – Apoptosis--programmed cell death, which is necessary for normal functioning • Cause of cancer? – Genes that control production of new cells don’t turn off Genetic causes of cancer • Oncogenes--cause cell to become cancerous • Genes become oncogenes in 3 ways – Mutation can occur in a growth-factor gene, causing rapid, uncontrolled cell growth – Error in DNA replication, producing multiple copies of a single-growth factor gene – Change in gene’s location--falls under the control of a different promoter is transcribed more often (producing more growth-factor) Tumor suppression • Humans have tumor-suppressor genes which are natural “anti-oncogenes” – If tumor suppressor gene is mutated, uncontrolled growth/reproduction occurs • Retinoblastoma--inheritable cancer in eyes caused by changes in tumor-suppressor gene on chromosome 13 – Can also occur when mutations occur in an individual (not always inherited) • Identifying location of these genes can increase identification and treatment of cancer