Central Dogma Date: 4/1/2013 Pd: 1 By: Clesi Crochet, LexiGocken, Joelle Chowaiki, Tanguy Deriot, Rob Levine
Chapter 12 vocab 12.1 • Transformation: the process in which one strain of bacteria is changed by a gene or genes from another strain of bacteria. • Bacteriophage: virus that infects bacteria • Nucleotide: monomer of nucleic acids made of a 5 carbon sugar a phosphate group and a nitrogenous base • Base paring: principle that bonds in DNA can form only between adenine and thymine and between guanine and cytosine.
Chapter 12 vocab 12.2 • Chromatin: granular material visible within the nucleus consists of DNA tightly coiled around proteins • Histones: proteins in the molecule around witch DNA is tightly coiled in chromatin • Replication: copying process by which a cell duplicates its DNA • DNA polymerase: enzyme evolved in DNA replication that joins individual nucleotides to produce DNA molecules.
Chapter 12 vocab • 12.3 • Gene: sequence of DNA that codes for a protein and thus determines a trait. • Messenger RNA: molecule that carries copies of instructions for the assembly of amino acids into proteins from DNA to the rest of the cell. • Ribosomal RNA: type of RNA that makes up the major part of the ribosomes. • Transfer RNA: type of RNA molecule that transfers amino acids to ribosomes during protein syntheses. • Transcription: proses in which part of the nucleotide sequence of DNA is copied into a complementary sequence in RNA. • RNA polymerase: enzymes similar to DNA polymerase that binds to DNA and separates the DNA strands during transcription.
Chapter 12 vocab • 12.3 • Promoter: region of DNA that indicates to an enzyme where to bind and make RNA. • Intron: sequence of DNA that is not involved in coding for a protein. • Exon: expressed sequence of DNA codes for protein. • Codon: three nucleotide sequence on mRNA that codes for a single amino acid. • Translation: decoding od an mRNA message into a polypeptide chain. • Anticodon: group of three bases on a tRNA molecule that are complementary to an mRNA codon.
Chapter 12 vocab • 12.4 • Mutation: change in a DNA sequence that effects genetic info. • Point mutation: gene mutation involving changes in one or a few nucleotides. • Frameshiftmutation: mutation that shifts the “reading” frame of the genetic message by inserting or deleting a nucleotide. • Polyploidy: condition in which an organism has an extra set of chromosomes.
Chapter 12 vocab • 12.5 • Operon: group of genes that operate together • Operator: region od chromosomes in an operon to which the repressor binds when the operon is turned off. • Differentiation: the process in which cells become specialized in structure and function. • Hox gene: series of genes that controls the of differentiation cells in tissue in an embryo.
DNA • Base pairs: A(adenine)=T(thymine) C(cytosine)=G(guanine) • Nucleotide=phosphate+sugar+base
DNA replication • 5 steps of DNA rep: 1) Enzyme initiates(starts) replication and untwists the helix 2) DNA unzips 3) Free nucleotides attach(the nucleotides bind the unzipped DNA strands). 4) Enzymes check for errors. 5) Enzymes twist the new strands (creating the double helix) results in 2 identical copies.
RNA notes • RNA= Ribonucleic Acid • RNA structure: composed of nuclotides uracil replaces thymine single stranded only 1 gene
3 types of RNA • Messenger RNA (mRNA) • Facts: -usues DNA as template - single strandes - U replaces T - largest RNA molecule • Function: mRNA is used to carry the genetic code from the nucleus to the ribosomes
3 types of RNA • Transfer RNA (tRNA) • Facts: -on one end of the tRNA a specific amino acid detaches. - on the other end is a sequence of 3 base pairs called anticodons, that complement the codon on the mRNA • Function: tRNA bonds to amino acids and is used in the syntheses of proteins
3 types of RNA • Ribosomal RNA (rRNA) • Facts: -the small subunit of a ribosomes that contains an rRNA strand(1542 nucleotides long) - the larger subunit contains 2 strands of rRNA(one 2904 nucleotides in lenth and the other starnd is 120 in thengt). • Function: component of ribosomes
RNA Transcription • Transcription: the process of building an mRNA copy of a DNA sequence • DNA replication vs. RNA transcription -RNA is single stranded -U replaces T in RNA -RNA transcription only happens in small sections(one gene) -DNA replication copies the whole strand
6 Steps of Transcription • Enzymes untwist the DNA and starts transcription • Enzyme unzips DNA(transcription bubble) • Free RNA nucleotides base pair with DNA - A=U / C=G 4. RNA nucleotides bond together at the backbone 5. New single strand RNA detaches from DNA template 6. Enzymes close(rezips) and twists DNA
3 Steps of Translation • Initiation • Ribosomes attaches to the mRNA • Start codon is always AUG • Elongation • tRNA anticodon matches with codon on mRNA • Peptide bonds are formed between amino acids • Amino acids released from tRNA • Ribosome moves down the mRNA and continues adding amino acids • Termination • Ribosome reaches one of the three stop codons • mRNA and protein are released
Mutations • Mutations: a change in a base sequence of DNA • What causes mutations? -Mistakes in replication(spontaneous) -mistakes in base pairs -environmental factors(mutagens) -high energy radiation -chemicals -high temperature Mutagens: any agent that causes a changes to the DNA sequence
Types of Mutations • Point Mutations • Frameshift Mutations • Deletions • Insertions • Inversions • Translocations
Quiz • What is transcription? • What is translation and where does it occur? • Where do we store our genetic information? • What is DNA polymerase used in? • What is a mutation? • What makes up a nucleotide? • What is the function of mRNA? • What are3 the differences between RNA and DNA? • What are the 6 steps transcription? • Outline the central dogma pathway.
Quiz answers • The process of building an mRNA copy of a DNA sequence • The decoding of an mRNA message into a polypeptide chain • The nucleus • Used in DNA replication • Change in a DNA sequence that effects genetic information • Sugar, phosphate, and a nitrogen base • To carry the genetic code from the nucleus to the ribosomes • RNA: single stranded nucleic acid that contains the sugar ribose\DNA: nucleic acid that contains the sugar deoxyribose • A. Enzymes untwist the DNA and starts transcription B. Enzyme unzips DNA(transcription bubble) C. Free RNA nucleotides base pair with DNA - A=U / C=G D. RNA nucleotides bond together at the backbone E. New single strand RNA detaches from DNA template • Enzymes close(rezips) and twists DNA 10. See picture in book.