Nucleic Acids

Not considered a nutrient macromoleculeThey are complex compounds that determine how the cell functions and what characteristics it has.

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Nucleic AcidsThere are two types of nucleic acids:1.DNA (deoxyribonucleic acid)

Determines the heredity of the cell “double helix” 2 chains of nucleic acids

2.RNA (ribonucleic acid) Active in making proteins for the cell A single chain of nucleic acids Made from DNA (in the nucleus) and acts as a

messenger to provide information in the cell

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Structure of Nucleic AcidsNucleic acids are polymers

- a polymer is a long chain made up of repeating structural units – just like carbs/proteins/lipids

The structural unit (building block) for a nucleic acid is called a nucleotide.

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NucleotidesNucleic acids consist of nucleotides made up of:

1.Nitrogen base2.Sugar molecule3.Phosphate group

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Structure of DNA

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DNA has the following 4 nitrogen bases:1.Adenine2.Cytosine3.Guanine4.Thymine

Complementary Base Pairs

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•Two H bonds for A-T•Three H bonds for G-C

Double Helix of DNA

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Structure of RNA

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RNA has the following 4 nitrogen bases:1.Adenine2.Cytosine3.Guanine4.Uracil

Learning Check

Write the complementary base sequence for the matching strand in the following DNA section:

-G-A-G-C-T-A-T-T-C-G-A-

• • • • • • • • • • • • • • • • • • • •

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Solution NA1

Write the complementary base sequence for the matching strand in the following DNA section:

-G-A-G-C-T-A-T-T-C-G-A

• • • • • • • • • • • • • • • • • • • •-C-T-C-G-A-T-A-A-G-C-T

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DNA Replication

DNA in the chromosomes replicates itself every cell division

Maintains correct genetic informationTwo strands of DNA unwindEach strand acts like a templateNew bases pair with their

complementary baseTwo double helixes form that are copies

of original DNA11

DNA Unwinds

G- -CA- -TC- -GT- -A

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G-CA-TC-GT-A

DNA Copied with Base Pairs

Two copies of original DNA strand

G-C G-CA-T A-TC-G C-GT-A G-A

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Protein ProductionDNA “codes” for genetic information

including protein structures.DNA unwinds and an RNA strand is formed.RNA is free to travel in the cell (to

ribosomes)Ribosomes read the “code” and arrange

amino acids in the specific sequence required.

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