Structure and Replication of

DNA

OBJECTIVES

Identify components of DNA, and describe how information for specifying the traits of an organism is carried in the DNA (TEKS 6A)

• Summarize the relationship between genes and DNA

• Relate DNA molecule to chromosome structure

• Describe the overall structure of the DNA molecule

• Summarize the events of DNA replication

• Learn how to extract your own DNA

MAJOR DISCOVERIES FOR DNA

GriffithGenetic information could be transferred from one bacterium to another

Avery

Nucleic acid DNA stores and transmits genetic information from one generation to the next

Hershey-Chase

Genetic material was DNA, not protein

Chargaff

A=T G =C

Franklin, Watson, & Crick

DNA’s shape is a double helix

DNA-THE BIG PICTURE

gene

video

OBJECTIVES

Identify components of DNA, and describe how information for specifying the traits of an organism is carried in the DNA (TEKS 6A)

• Summarize the relationship between genes and DNA

• Relate DNA molecule to chromosome structure

• Describe the overall structure of the DNA molecule

• Summarize the events of DNA replication

• Learn how to extract your own DNA

MACROMOLECULES-POLYMERIZATION

Macromolecules are formed by a process known as polymerization in which large compounds are built by joining smaller ones together.

The smaller units, or monomers, join together to form polymers.

~”Mono” = one~”Poly” = many

Monomers may be identical ~like the links on a metal watch band

Monomers may be different~like the beads in a multicolored necklace

TYPES OF MACROMOLECULES

Four groups of organic compounds (macromolecules) found in living things are:

~carbohydrates~lipids~nucleic acids~proteins

Sometimes these organic compounds are referred to as biomolecules

NUCLEIC ACIDS (GENETICS!!)

Nucleic acids are macromolecules/polymers containing carbon, hydrogen, oxygen, nitrogen, and phosphorus.

Nucleic acids store and transmit hereditary, or genetic, information

There are two kinds of nucleic acids: -ribonucleic acid (RNA)-deoxyribonucleic acid (DNA).

NUCLEIC ACIDS-STRUCTURE

The monomers or “building blocks” of nucleic acids are called nucleotides

Nucleotides consist of three parts:-5-carbon sugar

-phosphate group

-nitrogenous base

DNA/RNA-STRUCTURE

Four nitrogenous bases for DNANucleotide

RNA has Uracil instead of Thymine

DNA = Deoxyribonucleic AcidRNA = Ribonucleic Acid

DNA/RNA STRUCTURE• A always pairs with T

(or U if RNA)• G always pairs with

C

• Connected by a hydrogen bond

RNA Structure

OBJECTIVES

Identify components of DNA, and describe how information for specifying the traits of an organism is carried in the DNA (TEKS 6A)

• Summarize the relationship between genes and DNA

• Relate DNA molecule to chromosome structure

• Describe the overall structure of the DNA molecule

• Summarize the events of DNA replication

• Learn how to extract your own DNA

DNA REPLICATION

EduSmart video – see pages 295-299