Nucleic Acids and Protein

DNA Deoxyribonucleic acid Deoxyribonucleic acid Deoxyribose Deoxyribose Phosphate Phosphate Base Base Adenine Adenine Thymine Thymine Cytosine Cytosine Guanine Guanine Called a nucleotide Called a nucleotide

Function of DNA Stores Genetic info Stores Genetic info Codes for production of RNA Codes for production of RNA Makes up chromosomes Makes up chromosomes Prokaryotes Prokaryotes One single circular strand One single circular strand Eukaryotes Eukaryotes Stored in nucleus Stored in nucleus Multiple strands Multiple strands Each own chromosome Each own chromosome

Structure of DNA Double Helix (Watson/Crick 1953) Double Helix (Watson/Crick 1953) Two strands (double) Two strands (double) Twisted around central axis (helix) Twisted around central axis (helix) Think spiral stair case Think spiral stair case Rosalind Franklin Rosalind Franklin

Structure (cont) Complementary base pairing Complementary base pairing A with T A with T C with G C with G Based on number of H-bonds Based on number of H-bonds Allows DNA to replicate, and make RNA Allows DNA to replicate, and make RNA Purines/Pyrimidines Purines/Pyrimidines Purine: 2 rings, A and G Purine: 2 rings, A and G Pyrimidine: 1 ring, T and C Pyrimidine: 1 ring, T and C

Base pairing

RNA Ribonucleic acid Ribonucleic acid Ribose Ribose Phosphate Phosphate Base Base Adenine Adenine Guanine Guanine Cytosine Cytosine Uracil (very similar to thymine from DNA) Uracil (very similar to thymine from DNA)

Function of RNA Connect DNA to ribosome Connect DNA to ribosome Ribosome makes protein Ribosome makes protein Able to leave the nucleus Able to leave the nucleus Much smaller Much smaller Only one gene Only one gene Single strand Single strand

RNA base pairing (12/14) How RNA is made from DNA How RNA is made from DNA DNA serves as the template DNA serves as the template DNA Base RNA Base AdenineUracil ThymineAdenine CytosineGuanine GuanineCytosine

Codons/Anticodon Codons are 3 nucleotide sequence on mRNA Codons are 3 nucleotide sequence on mRNA Anticodon is a 3 nucleotide segment on a strand of tRNA Anticodon is a 3 nucleotide segment on a strand of tRNA Pair using comp. base pair rules Pair using comp. base pair rules 3 rd nucleotide can sometimes flex 3 rd nucleotide can sometimes flex 1 codon = 1 amino acid 1 codon = 1 amino acid

Types of RNA mRNA mRNA Carries information of DNA Carries information of DNA Linear Linear tRNA tRNA Brings amino acid to mRNA Brings amino acid to mRNA T-Shaped T-Shaped rRNA rRNA Makes up the ribosome Makes up the ribosome globular globular

DNA Replication Self Replication Self Replication Possible for 2 main reasons Possible for 2 main reasons Double Helix Double Helix One strand serves as a template One strand serves as a template Comp. Base Pairing Comp. Base Pairing Will get two identical strands Will get two identical strands Why do you need to produce identical strands? Why do you need to produce identical strands?

Steps to Replication (12/15) Formation of a replication fork Formation of a replication fork Enzyme = DNA helicase Enzyme = DNA helicase Splits 2 strands Splits 2 strands Add new bases Add new bases Enzyme = DNA polymerase Enzyme = DNA polymerase Adds bases to open strands Adds bases to open strands Checks for errors Checks for errors

Transcription Process of making RNA from DNA Process of making RNA from DNA All forms of RNA are transcribed All forms of RNA are transcribed RNA does not replicate in living things RNA does not replicate in living things Some viruses can Some viruses can Why does RNA not replicate? Why does RNA not replicate? Takes place in nucleus of eukaryotes Takes place in nucleus of eukaryotes Only one gene is transcribed Only one gene is transcribed

Process of Transcription Only one strand of DNA is transcribed Only one strand of DNA is transcribed Called the template strand (other is non-template) Called the template strand (other is non-template) Enzyme = RNA polymerase Enzyme = RNA polymerase Enzyme attaches (promoter) and separates DNA strands Enzyme attaches (promoter) and separates DNA strands Adds RNA bases Adds RNA bases Reaches a termination sequence Reaches a termination sequence Stops, RNA breaks off, DNA recoils Stops, RNA breaks off, DNA recoils

Transcription

Translation Process used to produce a polypeptide (protein) Process used to produce a polypeptide (protein) Uses all forms of RNA, ribosome, and amino acids Uses all forms of RNA, ribosome, and amino acids mRNA = message mRNA = message tRNA= transfer tRNA= transfer rRNA = ribosomal rRNA = ribosomal Takes place in the cytoplasm (where ribosomes are) Takes place in the cytoplasm (where ribosomes are)

Process of translation tRNA brings amino acids to the mRNA strand tRNA brings amino acids to the mRNA strand rRNA helps link together amino acids rRNA helps link together amino acids Protein is produced Protein is produced Function of protein Function of protein Antibodies – fight infection Antibodies – fight infection Contractile – responsible for movement Contractile – responsible for movement Enzymes – speed reactions Enzymes – speed reactions Hormones – coordinate body activities Hormones – coordinate body activities Structure – build body, tendons/ligaments Structure – build body, tendons/ligaments Storage – store amino acids (egg whites) Storage – store amino acids (egg whites) Transport – move material into/out of cell Transport – move material into/out of cell

Codons and Amino Acids

DO NOT FORGET DNA  RNA  Protein  Structure  Function DNA  RNA  Protein  Structure  Function DNA  RNA =? DNA  RNA =? RNA  Protein = ? RNA  Protein = ? DNA  DNA = ? DNA  DNA = ?