Table of Contents : DNA, RNA, and Protein Synthesis Chapter 10 Table of Contents Section 1 Discovery of DNA
Section 2 DNA Structure
Section 3 DNA Replication
Section 4 Protein Synthesis Objectives : Section 1 Discovery of DNA Chapter 10 Objectives Relate how Griffith’s bacterial experiments showed that a hereditary factor was involved in transformation.
Summarize how Avery’s experiments led his group to conclude that DNA is responsible for transformation in bacteria.
Describe how Hershey and Chase’s experiment led to the conclusion that DNA, not protein, is the hereditary molecule in viruses. Griffith’s Experiments : Section 1 Discovery of DNA Chapter 10 Griffith’s Experiments Griffith’s experiments showed that hereditary material can pass from one bacterial cell to another.
The transfer of genetic material from one cell to another cell or from one organism to another organism is called transformation. Griffith’s Discovery of Transformation : Chapter 10 Griffith’s Discovery of Transformation Section 1 Discovery of DNA Slide 5: Chapter 10 Click below to watch the Visual Concept. Visual Concept Transformation Section 1 Discovery of DNA Avery’s Experiments : Section 1 Discovery of DNA Chapter 10 Avery’s Experiments Avery’s work showed that DNA is the hereditary material that transfers information between bacterial cells. Hershey-Chase Experiment : Section 1 Discovery of DNA Chapter 10 Hershey-Chase Experiment Hershey and Chase confirmed that DNA, and not protein, is the hereditary material. The Hershey-Chase Experiment : Chapter 10 The Hershey-Chase Experiment Section 1 Discovery of DNA Slide 9: Chapter 10 Click below to watch the Visual Concept. Visual Concept Hershey and Chase’s Experiments Section 1 Discovery of DNA Slide 10: Section 2 DNA Structure Chapter 10 Objectives Evaluate the contributions of Franklin and Wilkins in helping Watson and Crick discover DNA’s double helix structure.
Describe the three parts of a nucleotide.
Summarize the role of covalent and hydrogen bonds in the structure of DNA.
Relate the role of the base-pairing rules to the structure of DNA. DNA Structure : DNA Structure By the 1950’s most biologists accepted DNA as the hereditary material.
They still laced an understanding of the basic structure of DNA.
Watson and Crick changed this by building a model of DNA.
In 1962 they received a Nobel prize for their work in DNA. Slide 12: Section 2 DNA Structure Chapter 10 DNA Double Helix Watson and Crick created a model of DNA by using Franklin’s and Wilkins’s DNA diffraction X-rays. Franklin’s and Wilkins’s DNA diffraction X-rays. : Franklin’s and Wilkins’s DNA diffraction X-rays. Slide 14: Section 2 DNA Structure Chapter 10 DNA Double Helix DNA is made of two nucleotide strands that wrap around each other in the shape of a double helix. Slide 15: Section 2 DNA Structure Chapter 10 DNA Double Helix, continued A DNA nucleotide is made of a 5-carbon deoxyribose sugar, a phosphate group, and one of four nitrogenous bases: adenine (A), guanine (G), cytosine (C), or thymine (T). DNA Nucleotide : DNA Nucleotide Slide 17: Section 2 DNA Structure Chapter 10 DNA Nucleotides Bonds Hold DNA Together
Nucleotides along each DNA strand are linked by covalent bonds.
Complementary nitrogenous bases are bonded by hydrogen bonds. Purines and Pyrimidines : Purines and Pyrimidines The sugar and phosphate bases are identical in all DNA nucleotides.
The bases can vary.
Bases that have a double ring of carbon and nitrogen atoms, such as adenine and guanine are called purines.
Nitrogenous bases that have a single ring of carbon and nitrogen atoms, such as cytosine and thymine, are called pyrimidines. Slide 20: Section 2 DNA Structure Chapter 10 Complementary Bases Hydrogen bonding between the complementary base pairs, G-C and A-T, holds the two strands of a DNA molecule together.
This is called the base-pairing rule and was formulated by Chargaff.
The bases ALWAYS join to a sugar molecule! Slide 21: Section 3 DNA Replication Chapter 10 Objectives Summarize the process of DNA replication.
Identify the role of enzymes in the replication of DNA.
Describe how complementary base pairing guides DNA replication.
Compare the number of replication forks in prokaryotic and eukaryotic cells during DNA replication.
Describe how errors are corrected during DNA replication. Slide 22: Section 3 DNA Replication Chapter 10 How DNA Replication Occurs DNA replication is the process by which DNA is copied in a cell before a cell divides.
Steps of DNA Replication
Replication begins with the separation of the DNA strands by helicases.
Then, DNA polymerases form new strands by adding complementary nucleotides to each of the original strands. DNA Replication : Chapter 10 DNA Replication Section 3 DNA Replication Slide 24: Section 3 DNA Replication Chapter 10 How DNA Replication Occurs, continued Each new DNA molecule is made of one strand of nucleotides from the original DNA molecule and one new strand. This is called semi-conservative replication. DNA replication
http://www.youtube.com/watch?v=teV62zrm2P0&NR=1 Slide 25: Chapter 10 Replication Forks Increase the Speed of Replication Section 3 DNA Replication Slide 26: Section 3 DNA Replication Chapter 10 DNA Errors in Replication Changes in DNA are called mutations.
DNA proofreading and repair prevent many replication errors. Slide 27: Section 3 DNA Replication Chapter 10 DNA Errors in Replication, continued DNA Replication and Cancer
Unrepaired mutations that affect genes that control cell division can cause diseases such as cancer. Slide 28: Section 4 Protein Synthesis Chapter 10 Objectives Outline the flow of genetic information in cells from DNA to protein.
Compare the structure of RNA with that of DNA.
Describe the importance of the genetic code.
Compare the role of mRNA, rRNA, and tRNA in translation.
Identify the importance of learning about the human genome. Slide 29: Section 4 Protein Synthesis Chapter 10 Flow of Genetic Information The flow of genetic information can be symbolized as DNA RNA protein. Slide 30: Section 4 Protein Synthesis Chapter 10 RNA Structure and Function RNA has the sugar ribose instead of deoxyribose and uracil in place of thymine.
RNA is single stranded and is shorter than DNA. Slide 31: Chapter 10 Click below to watch the Visual Concept. Visual Concept Comparing DNA and RNA Section 4 Protein Synthesis Slide 32: Section 4 Protein Synthesis Chapter 10 RNA Structure and Function, continued Types of RNA
Cells have three major types of RNA:
messenger RNA (mRNA)
ribosomal RNA (rRNA)
transfer RNA (tRNA) Slide 33: Section 4 Protein Synthesis Chapter 10 RNA Structure and Function, continued mRNA carries the genetic “message” from the nucleus to the cytosol.
rRNA is the major component of ribosomes.
tRNA carries specific amino acids, helping to form polypeptides. Slide 34: Chapter 10 Click below to watch the Visual Concept. Visual Concept Types of RNA Section 4 Protein Synthesis Slide 35: Section 4 Protein Synthesis Chapter 10 Transcription During transcription, DNA acts as a template for directing the synthesis of RNA. Transcription : Chapter 10 Transcription Section 4 Protein Synthesis Slide 37: Section 4 Protein Synthesis Chapter 10 Genetic Code The nearly universal genetic code identifies the specific amino acids coded for by each three-nucleotide mRNA codon. Slide 39: Section 4 Protein Synthesis Chapter 10 Translation Steps of Translation
During translation, amino acids are assembled from information encoded in mRNA.
As the mRNA codons move through the ribosome, tRNAs add specific amino acids to the growing polypeptide chain.
The process continues until a stop codon is reached and the newly made protein is released. Translation: Assembling Proteins : Chapter 10 Translation: Assembling Proteins Section 4 Protein Synthesis Slide 41: Section 4 Protein Synthesis Chapter 10 The Human Genome The entire gene sequence of the human genome, the complete genetic content, is now known.
To learn where and when human cells use each of the proteins coded for in the approximately 30,000 genes in the human genome will take much more analysis.