DNA

Traits A physical feature, or characteristic, a living thing can pass on to its young. Ex. Blood type, Eye color, Hair color, Facial features, and your body build…

Genes Coded info that determines traits. A region of DNA that controls a hereditary characteristic.

Chromosomes carries the genes that control traits.

DNA Deoxyribo Nucleic acid

Structure of DNA Double Helix

What are the building blocks? Nucleotides – joined by strong covalent bonds Nucleotides composed of: Phosphate group Deoxyribose – 5 carbon sugar One of four Nitrogenous bases Adenine Thymine Guanine Cytosine

Base Pairing Rules Adenine = Thymine Guanine = Cytosine

Functions of DNA Replication – DNA makes DNA Transcription – DNA makes RNA Translation – RNA makes Proteins

DNA Replication The helix unwinds DNA unzips - nucleotides separate as hydrogen bonds break Free nucleotides base pair with both nucleotide chains 2 identical DNA molecules result

DNA Replication                               

Leading Strand – continuous replication Lagging strand – discontinuous replication

figure 11-07b.jpg

Semi Conservative Replication   Each old DNA strand gets a new strand

DNA vs. RNA

DNA VS. RNA Deoxyribose Sugar Ribose 2 Strands 1 A, T, C, G Bases A, U, C, G

Transcription DNA unwinds and unzips. RNA nucleotides base pair with the DNA master strand Uracil bonds with Adenine Cytosine with Guanine. RNA strand separates and moves to the cytoplasm DNA zips back up

Reverse Transcription HIV – retrovirus Makes DNA replica of its own RNA Viral DNA joins normal DNA of host Directs production of new virus particles

RetroTranscription.jpg‎ (

3 Types of RNA mRNA – messenger RNA tRNA – transfer RNA rRNA – ribosomal RNA

mRNA Messenger RNA – single strand coded from the DNA master strand. Contains a three base sequence – codon Codon – codes for a specific amino acid

tRNA Transfer RNA – contains sequence of three bases – anticodon anticodon – which carry a specific amino acid to the mRNA

rRNA Ribosomal RNA – located in the ribosomes

Translation The mRNA attaches to a ribosome. mRNA contains codons (3 nucleotides that code for 1 amino acid) The tRNA contain three opposite letters called the anticodon. tRNA carries an amino acid at the other end. Anti codons base pair with codons Amino Acids covalently bonded to each other tRNA is released to get more Amino Acids

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Phenylalanine Phenylalanine Leucine Leucine Tyrosine Tyrosine UUU UUC UUA UUG Phenylalanine Phenylalanine Leucine Leucine UAU UAC Tyrosine Tyrosine UAA UAG None (stop signal) None (stop signal) CUU CUC CUA CUG Leucine Leucine Leucine Leucine CAU CAC Histidine Histidine CAA CAG Glutamine Glutamine AUU AUC AUA AUG Isoleucine Isoleucine Isoleucine Methioninie (start codon) AAU AAC Asparagine Asparagine AAA AAG Lysine Lysine GUU GUC GUA GUG Valine Valine Valine Valine GAU GAC GAA GAG Aspartic Acid Aspartic Acid Aspartic Acid Aspartic Acid UCU UCC UCA UCG Serine Serine Serine Serine UGU UGC Cysteine Cysteine UGA None (stop signal) UGG Tryptophan CCU CCC CCA CCG Proline Proline Proline Proline CGU CGC CGA CGG Arginine Arginine Arginine Arginine ACU ACC ACA ACG Threonine Threonine Threonine Threonine AGU AGC Serine Serine AGA AGG Arginine Arginine GCU GCC GCA GCG Alanine Alanine Alanine Alanine GGU GGC GGA GGG Gylcine Gylcine Gylcine Gylcine

Central Dogma DNA --------------------RNA ------------------Protein transcription translation