Vocabulary Key Terms DNA replication Codon Intron Exon

Vocabulary Key Terms • • • DNA replication Codon Intron Exon Translation Central Dogma Transcription RNA • • m. RNA t. RNA Anticodon Genes Nucleotide Nitrogen base Amino Acids (AA)

Where in the cell are we looking at?

5 a. Know the general structures and functions of DNA, RNA & protein.

12— 1 The Components and Structure of DNA • What is the overall structure of the DNA molecule? • The Components and Structure of DNA • DNA is made up of ___________. • A nucleotide is a monomer of nucleic acids made up of a five-carbon sugar called ________, a phosphate group, and a nitrogenous base.

The Components and Structure of DNA • There are ______ kinds of bases in in DNA: • • adenine guanine cytosine thymine

The Components and Structure of DNA • The backbone of a DNA chain is formed by _______ and ________ groups of each nucleotide. • The nucleotides can be joined together in any order.

The Components and Structure of DNA • Chargaff's Rules – Erwin Chargaff discovered that: • The percentages of _________ [G] and ___________ [C] bases are almost equal in any sample of DNA. • The percentages of ________ [A] and _________ [T] bases are almost equal in any sample of DNA.

The Components and Structure of DNA – X-Ray Evidence • ___________ used X-ray diffraction to get information about the structure of DNA. • She aimed an X-ray beam at concentrated DNA samples and recorded the scattering pattern of the Xrays on film.

The Components and Structure of DNA • The Double Helix – Using clues from Franklin’s pattern, James Watson and Francis Crick built a model that explained how DNA carried information and could be copied. – Watson and Crick's model of DNA was a _______ in which _____ strands were wound around each other.

Who Discovered the DNA molecule? • Discovery of DNA: – ______: Proposed that DNA is made of 2 chains of nucleotides joined together by the nitrogen bases – Double Helix: DNA composed of 2 strands twisted together James Watson & Francis Crick

The Components and Structure of DNA • DNA Double Helix

The Components and Structure of DNA • Watson and Crick discovered that __________ bonds can form only between certain base pairs—adenine and thymine, and guanine and cytosine. • This principle is called ________.

From DNA to Protein • Why is DNA Important? – All of the characteristics that you have are affected by the _______ that you have in your cells. – Controls the color of your eyes, hair, or if you can digest milk. – _______ the order of the amino acids Δ’s the kind protein made.

From DNA to Protein • RNA: ___________ Acid – – a nucleic acid single stranded Sugar in RNA is ribose H Instead of Thyamine, Uracil (U) – (A)

Three Types of RNA • Help to build proteins – Messenger RNA (______): brings info from the DNA in the nucleus to the cell’s factory floor, the cytoplasm. – Ribosomal RNA (_____): clamp onto the m. RNA and use its info to assemble the amino acids in the correct order – Transfer RNA (______): transports amino acids to the ribosome to be assembled into protein

RNA Facts • RNA exists in many structural forms – m. RNA: serves as a _____ during protein synthesis – t. RNA – r. RNA

DNA vs. RNA • • • Deoxyribose sugar Adenine Guanine Cytosine _______ 2 strands • • • Ribose sugar Adenine Guanine Cytosine ______ One Strand

Proteins • Proteins are ________ composed of amino acid _______. • Different types of proteins function as enzymes and transport molecules, hormones, structural components of cells, & antibodies that fight infection.

1 d. Know the central dogma of molecular biology outlines the flow of information from transcription of ribonucleic acid (RNA) in the nucleus to translation of proteins on ribosomes in the cytoplasm.

• 12– 2 Chromosomes and DNA Replication 12 -2 Chromosomes and DNA Replication

DNA and Chromosomes • DNA and Chromosomes – In prokaryotic cells, DNA is located in the _________. – Most _________ have a single DNA molecule containing nearly all of the cell’s genetic information.

DNA and Chromosomes Chromosome E. Coli Bacterium Bases on the Chromosomes

DNA and Chromosomes • Many eukaryotes have ____ times the amount of DNA as prokaryotes. • Eukaryotic DNA is located in the cell _______ inside chromosomes. • The number of chromosomes varies widely from one species to the next.

DNA and Chromosomes – Chromosome Structure • Eukaryotic chromosomes contain DNA and protein, tightly packed together to form ________. • Chromatin consists of DNA tightly coiled around proteins called ___________. • DNA and histone molecules form nucleosomes. • Nucleosomes pack together, forming a thick fiber.

DNA and Chromosomes – Eukaryotic Chromosome Structure Chromosome Nucleosome DNA double helix Coils Supercoils Histones

DNA Replication • What happens during DNA replication? – DNA Replication • Each strand of the DNA double helix has all the information needed to reconstruct the other half by the mechanism of base pairing. • In most prokaryotes, DNA replication begins at a single point and continues in two directions.

DNA Replication • In eukaryotic chromosomes, DNA replication occurs at hundreds of places. Replication proceeds in both directions until each chromosome is completely copied. • The sites where separation and replication occur are called __________.

DNA Replication • Duplicating DNA – Before a cell divides, it duplicates its DNA in a process called __________. – Replication ensures that each resulting cell will have a complete set of DNA. • During DNA replication, the DNA molecule separates into ______ strands, then produces two new complementary strands following the rules of base pairing. Each strand of the double helix of DNA serves as a template for the new strand.

DNA Replication New Strand Original strand Nitrogen Bases Growth Replication Fork DNA Polymerase

DNA Replication • How Replication Occurs – DNA replication is carried out by enzymes that “unzip” a molecule of DNA. – Hydrogen bonds between base pairs are broken and the two strands of DNA unwind. • The principal enzyme involved in DNA replication is ____________. • DNA polymerase joins individual nucleotides to produce a DNA molecule and then “proofreads” each new DNA strand.

DNA Replication 1. _________ breaks up the hydrogen(H+) bonds between the nitrogen bases that holds the 2 strands together—unzips the DNA molecule 2. Free floating ________ bond to the single strands by base pairing 3. Another ________ bonds these new nucleotides into a chain

DNA Replication 4. This process continues until the entire molecule has been unzipped and replicated. 5. Each new strand formed is a _________ of the original, or parent, strands. 6. The result is the formation of two DNA molecules, each of which is _________ to the original DNA molecule.

• 12– 3 RNA and Protein Synthesis 12 -3 RNA and Protein Synthes

12– 3 RNA and Protein Synthesis • ________ are coded DNA instructions that control the production of proteins. • Genetic messages can be decoded by copying part of the nucleotide sequence from DNA into RNA. • ________ contains coded information for making proteins.

The Structure of RNA • RNA consists of a long chain of nucleotides. • Each nucleotide is made up of a ___-carbon sugar, a phosphate group, and a nitrogenous base. • There are three main differences between RNA and DNA: • The sugar in RNA is ribose instead of deoxyribose. • RNA is generally single-stranded. • RNA contains _______ in place of thymine.

Types of RNA • What are three main types of RNA? • Types of RNA – There are three main types of RNA: • _________ RNA • ribosomal RNA • ________ RNA

Types of RNA • Messenger RNA (m. RNA) carries _______ of instructions for assembling amino acids into proteins.

Ribosome Types of RNA Ribosomal RNA • Ribosomes are made up of proteins and ribosomal RNA (r. RNA).

Amino acid Types of RNA Transfer RNA • During protein construction, transfer RNA (t. RNA) transfers each amino acid to the _________.

Transcription • What is transcription? – Transcription • RNA molecules are produced by copying part of a nucleotide sequence of DNA into a complementary sequence in RNA. This process is called ___________. • Transcription requires the enzyme ______________.

Transcription – During transcription, RNA polymerase binds to DNA and separates the DNA strands. • RNA polymerase then uses one strand of DNA as a template from which nucleotides are assembled into a strand of RNA. • RNA polymerase binds only to regions of DNA known as ___________. • Promoters are signals in DNA that indicate to the enzyme where to bind to make RNA.

Transcription Steps 1. _________ unzip the molecule of DNA 2. Free RNA nucleotides pair with complementary DNA nucleotides on one of the DNA strands • • AGC TAA CCG ______ strand UCG AUU GGC _____ strand 3. When the base pairing is completed, the m. RNA molecule breaks away as the DNA strands rejoin. 4. The _______ leaves the nucleus and enters the cytoplasm

Transcription RNA polymerase DNA

RNA Editing • The DNA of eukaryotic genes contains sequences of nucleotides, called _________, that are not involved in coding for proteins. • The DNA sequences that code for proteins are called _________. • When RNA molecules are formed, introns and exons are copied from DNA.

RNA Editing Exon Intron • The ______ are cut of RNA molecules. • The _______ are the spliced together to form m. RNA. DNA Pre-m. RNA Cap Tail