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Introduction to DNA and RNA Biology Standards B-4.1: Compare DNA and RNA in terms of structure, nucleotides, and base pairs. B-4.2: Summarize the relationship among DNA, genes, and chromosomes.
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Nucleic Acids Remember, there are 4 major Organic Compounds 1.Carbohydrates 2.Lipids 3.Proteins 4.Nucleic Acids
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Nucleic Acids Nucleic acids are organic molecules that serve as the blueprint for proteins These proteins give organisms their unique traits Example: hair color, eye color, blood type, height, digestive enzymes, skin color, etc.
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2 types of Nucleic Acids There are two types of nucleic acids DNA = Deoxyribonucleic acid RNA = Ribonucleic acid Both DNA and RNA are composed of small units called nucleotides Nucleotides have 3 parts: 1.Nitrogenous Base 2.Pentose Sugar 3.Phosphate Group
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All about DNA DNA is a double Helix Double = 2 strands Helix = twisted/winded DNA has 3 parts 1.Nitrogenous bases Adenine Thymine Guanine Cytosine 2.Sugar Deoxyribose 3.Phosphate Group
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All about RNA RNA is a single helix Single = 1 strand Helix = twisted/winded RNA has 3 parts 1.Nitrogenous bases Adenine Uracil Guanine Cytosine 2.Sugar Ribose 3.Phosphate group
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Let’s Compare DNA and RNA DNARNA Type of baseCytosine (C) Adenine (A) Guanine (G) Thymine (T) Cytosine (C) Adenine (A) Guanine (G) Uracil (U) Type of sugarDeoxyriboseRibose Molecule structure/shape Double HelixSingle Helix
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Complimentary Base Pairing in DNA When the nitrogenous bases of two strands of DNA chemically bond through the center of the helix, each base can bond to only one type of base Bases that bond are called complementary bases Adenine (A) will only pair with Thymine (T) Guanine (G) will only pair with Cytosine (C) When the nitrogenous bases of RNA chemically bond to a strand of DNA, each RNA base can bond with only one type of DNA base. These bases are also called complementary bases Adenine (A) will only pair with Uracil (U) Guanine (G) will only pair with Cytosine (C) **essentially, uracil replaces thymine in RNA**
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Try This… Write the complementary strand of DNA for the following 2 sequences of DNA: 1.A T G C A T G C T T A G T C C A 2.G C A T G G A A T C A C A G T T Write the complementary strand of RNA for the following 2 sequences of DNA: 1.A T G C A T G C T T A G T C C A 2.G C A T G G A A T C A C A G T T
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Chromosomes to Genes
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What do these terms mean? Chromosome – structure in the nucleus consisting of one long, tightly coiled thread of DNA DNA – composed of nucleotides, provides the blueprint for protein synthesis by the specific arrangement of nitrogenous bases Gene – a specific location on a chromosome, consisting of a segment of DNA, that codes for a particular protein. These determine the characteristics of an organism. Each chromosome consists of hundreds of genes determining the many proteins for an individual organism
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