2.3 Carbon-Based Molecules LEQ: What is the relationship between proteins and nucleic acids? Reading: 32.1, 2.3; Quiz tuesday; test next monday Activator: ruminations –“DNA neither cares nor knows. DNA just is.” Richard Dawkins. –In your group, discuss what this quote might mean Key terms – protein, nucleic acid

2.3 Carbon-Based Molecules Proteins are responsible for nearly every task that a cell performs. Monomer: amino acid –Common structure, unique R groups –left: general amino acid structure –right: serine is polar, hydrophilic

2.3 Carbon-Based Molecules –Polypeptides consist amino acids linked by peptide bonds –Information-rich.

2.3 Carbon-Based Molecules

Polypeptides differ in number and order of amino acids. –characteristic sequence; changes alter function –Amino acids interact to give a protein its shape. hydrogen bond Hemoglobin

2.3 Carbon-Based Molecules The information & function of proteins is encoded in the sequence of nucleic acids. RNA –Protein synthesis –Chemical reactions –Gene regulation…. DNA –Encodes biological information

2.3 Carbon-Based Molecules

A phosphate group nitrogen-containing molecule, called a base deoxyribose (sugar) Monomer (multi-part): nucleotide

2.3 Carbon-Based Molecules The nitrogen containing bases are the only difference in the four nucleotides.

2.3 Carbon-Based Molecules Polynucleotides (left) have a unique sequences of bases: –Hydrogen bonding –DNA is double stranded (right)

2.3 Carbon-Based Molecules Genes store the information necessary to assemble proteins. A gene is a segment of DNA that stores genetic information on a chromosome. –mutation

2.3 Carbon-Based Molecules Summary: Explain how both nucleic acids and proteins are polymers. Be sure to describe the monomers that make up the polymers.