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What is DNA?. Nucleic acids. inheritable molecule Example: D eoxyribo n ucleic A cid = DNA OR R ibo n ucleic A cid = RNA . Nucleotides. Nucleotides bind together to form nucleic acids (eg: DNA, RNA) Three components of a Nucleotide: Nitrogen base Sugar Phosphate.
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Nucleic acids • inheritable molecule Example: Deoxyribonucleic Acid = DNA OR Ribonucleic Acid = RNA
Nucleotides Nucleotides bind together to form nucleic acids (eg: DNA, RNA) Three components of a Nucleotide: • Nitrogen base • Sugar • Phosphate
Two groups of nucleotides: 1. Purines – contain double-ring nitrogen bases Adenine (A) and Guanine (G) 2. Pyrimidines – contain single-ring nitrogen bases Thymine (T) and Cytosine (C) RNA – Uracil rather than Thymine Types of Nucleotides N Purines Pyrimidines N
SUGAR Pentose Sugar (5C) = RIBOSE DNA vs RNA Deoxyribo Ribo OH RIBOSE
Nucleotide Nucleic Acid Sugar-Phosphate backbone Stringing together DNA
Structure of DNA DNA – double helix • Two strands coiled together
Complementary Pairs Nitrogen bases of nucleotides match up and bind with each other PAIRS: Purine - Pyrimidine Adenine – Thymine Guanine – Cytosine Bind together with Hydrogen bonds • 3 H-bonds between C-G • 2 H-bonds between A-T
Function of DNA Blueprint of all living things • Directs growth and development through the production of proteins • Contains the genetic code (genes)
Protein Synthesis • Proteins are made up of 20 different amino acids linked together in certain order • The genetic code (DNA) determines how the amino acids are strung together to make different proteins • The sequence of nucleotides (eg: ATG) determines the sequence of amino acids • Three nucleotides code for one amino acid (called a codon) (eg: AUG = methionine) refer to textbook pg 194
Transcription (within the nucleus) DNA is converted to RNA (T's changed to U's) Translation (in the cytoplasm by the ribosomes) - RNA is converted to amino acids and then strung together to make proteins How Proteins are made?
Nucleotide Nucleic Acid Sugar-Phosphate backbone Review of DNA structure
Structure of DNA DNA – double helix • Two strands coiled together
DNA Replication Since cells replicate, DNA must as well
How? DNA Polymerase • Specific enzyme that splits double stranded DNA and adds complement nucleotides to each strand
DNA Replication Daughter DNA Parent DNA