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Chapter #7-Notes - Nucleic Acids and Protein Synthesis

I. 7-1, DNA


*1. Discuss the experiments leading to the identification of DNA as the molecule that carries the genetic code

*2. Describe the structure of DNA

*3. Explain the process of DNA replication

A. Genetic Code - The program that cells use to store the message that they pass from one generation to the next.

B. Genetic - Anything that relates to heredity

*1-C. Frederick Griffith, in 1928, while studying the way in which types of bacteria cause pneumonia, recognized the transformation principle.

-Bacterial Transformation - (Fig.7-2)

1. Smooth bacteria - with smooth appearance and did cause pneumonia, when injected into mice.

2. Rough bacteria - with rough appearance and did not cause pneumonia, when injected into mice.

- heat killed smooth bacteria did not cause disease

3). Mixture of dead smooth (heat killed) and living rough caused disease

4)The chemical, a transforming factor, had caused the rough bacteria to produce smooth bacteria. Process called "Bacterial Transformation".

*1-D. Oswald Avery, Maclyn McCarty, and Colin MacLeod, in 1944, repeated Griffith's work.

1. Provide DNA was the transforming factor

2. DNA is the nucleic acid that stores and transmits the genetic information from one generation of an organism to the next.

3. DNA carries the genetic code.

*1-E. Alfred Hershey and Martha Chase, in 1952, also demonstrated transformation with Bacteriophages.

1. Bacteriophages - viruses that infect bacteria. (fig. 7-4)

a. composed of DNA core and protein coat.

b. attach to bacteria and inject a substance (DNA) into the bacteria.

c. injected material reproduces inside of the bacteria.

d. bacteria burst, releasing hundreds of the virus.

2. Hershey and Chase "labeled the viruses' protein and DNA with radioactive isotopes.

3. By looking for the DNA inside of the bacteria, they proved it was the DNA (not the protein coat) was the carrier of the genetic code.

*2-F. The Structure of DNA

1. Nucleotide - A subunit of DNA, named for its base (A, C, G, T) (fig.7.6)

a. 3 basic parts

1. a phosphate

2. Deoxyribose - a 5-carbon sugar

3. nitrogen containing base (4)

a. purines - adenine and guanine

b. pyrimidines - cytosine and thymine

b. Form long chains (nucleotides do)

2. Rosalind Franklin - in 1950, gave clues to shape of DNA by using X-Rays. (fig.7-8)

3. Watson and Crick,in 1953, using Franklin's X-ray, developed the Double Helix (spiral ladder) model of DNA

a. two strands, twisted around each other

b. bases of each strand bonded weakly to each other.

c. Base pairing, bonding between = A-T, C-G

4. DNA Ladder Model

a. Uprights = Phosphate and Sugar (Deoxyribose)

b. Rungs = Base (adenine, cytosine, guanine, thymine)

c. Uprights bond at base (A-T, C-G)

d. Ladder is coiled = more stable

e. Each strand has all information to make the other half of the double strand


3-G. Replication of DNA

- Laser disc, Chapt #17, 25971 - Side #1

1. (Fig. 7-11, 7-12)

2. Enzymes unzips the DNA molecule, between the base pairs (base bonds are weak)

3. Enzymes cause Free Nucleotides from the nucleus to bond to the strands of the unzipped DNA molecule

4. As DNA replicates, enzymes "check" DNA strand for errors.

5. DNA now replicated (genes replicated, chromosomes replicated.)

Cooperative Starter - Groups of 3, One product, One Recorder, One resource (book). Do Study Guide, Section #1, Protein Synthesis, P#67, 68, 69.

Homework - Construct a "3-D" model of the DNA molecule

Construct a "3-D" Model of the DNA Molecule

Points Possible = 25 + 5 extra credit = 30

(use toothpicks, paper, tinker toys, legos, etc.) Ex. P#154 of textbook

1. Color Code (Label) 4 base pairs, Phosphate & Sugar = 5 Pts.

Base Pairs = 1 Pt Each (A,T,G,C) 4 pts.

Color code phosphate and sugar 1 pt.

2. Watson & Crick twisted ladder = 5 Pts.

3. Bonding of Correct Base Pairs = 4 Pts.

4. Oral Presentation = 8 Pts.


Attention Getting Sentence 1 pt.

Introduce Topic 1 pt.

Introduce Yourself 1 pt.

Body 3 pts.


Summary Sentence 1 pt.

Clincher Sentence 1 pt.

5. Creativity = 3 Pts.

Ex. Credit = Show Replication in the Model and Present in Your Oral Report = 5 Pts.

Chapter #7-1 Hour______ , Name_________________________

Quiz from Notes

1. Avery, McCarty and MacLeod, proved that _________________ was the genetic code.

Explain what happened in Griffith's experiment (#2-5).

2. Type of cell that caused disease ________________________

3. Appearance of cell that caused disease___________________

4. Name of disease caused by harmful cell __________________

5. Explain what happened to the living cells in the mixture.

6. What is a Bacteriophage? ________________________________

7. A subunit of DNA, which is named for its base. __________

The subunit for question #7 has three main parts, name them for question #8, 9, 10.

8. ____________________________

9. ____________________________

10. ___________________________

11. Name one of the two purines. ___________________________

12. Adenine can only bond with which nucleotide?____________

II. 7-2, RNA

*1. List the similarities and differences between DNA and RNA.

*2. Explain the process of transcription

*3. Discuss the role of Messenger RNA

*1-A. The Structure of RNA

1. RNA is made up of a long chain of nucleotides

2. RNA, Ribose replaces Deoxyribose,

3. RNA is single stranded.

4. In RNA, Uracil replaces Thymine (A-U, C-G).

*2-B. Transcription: RNA Synthesis

1. DNA does not leave the nucleus, but we know proteins are made on the ribosomes.

2. RNA is found in the nucleus, cytoplasm and on ribosomes

3. RNA is the messenger from the nucleus to the cytoplasm, (mRNA)

-Transcription - The process by which a molecule of DNA is copied into a complementary strand of RNA.

- Laser Disc - Side 1, chapt. #17, 25971

1)DNA unzips because of RNA polymerase

2)RNA nucleotides match up (bond) to one DNA strand (polymerase).

3)When RNA is complete, it detaches from the DNA.

4)The DNA strands rejoin

5)The RNA strand was determined by the DNA strand

6)DNA has Start and Stop Signals that are recognized by the RNA polymerase

6)RNA strand is called mRNA (process is called transcription)

7)mRNA leaves the nucleus to the ribosomes

Cooperative Starter - RNA, P#70, Study Guide. One Resource person (Book, Notes), One Recorder, One Product. Groups of 2. During Hour.

Homework - The Role of DNA, Teachers Resource Book. P#131-133.

7-3, Protein Synthesis


List some functions of proteins in cells

Describe translation.

Explain the term "codon".

Identify the three main types of RNA

A. Proteins are organic molecules composed of twenty amino acids. The order of the amino acids and shape of the protein molecule itself, determine the protein type.

B. Each cell has thousands of different proteins, each with its own specific job.

C. Proteins can be specific structures (plasma membrane, chromosomes and organelles), enzymes or antibodies in the blood.

D. Genes and Proteins

1. Genes (because of its DNA) are responsible for making proteins, or part of proteins (polypeptides)

E. DNA Code

1. The sequence of base pairs from the top to the bottom of the DNA ladder determines the protein.

2. The sequence of base pairs is the code.

a)proteins are composed of amino acids.

b)The order of the amino acids determine the protein

c)Their are only 4 bases

d)To be able to get 20 amino acids, there must be a sequence of 3 bases. So, three bases in a row do act as the code for amino acids.

e)Three bases in a row are called "CODONS"

F. Translation (Protein Synthesis) Laser Disc - Side #1, chapt. #17, 22695

1)DNA code is translated into mRNA

2)mRNA moves to cytoplasm and then to the ribosomes

3)tRNA carries amino acids to the mRNA

a)tRNA looks like a cloverleaf

b)tRNA picks up amino acid and takes it to the mRNA

c)tRNA anticodon links to mRNA (mRna and tRNA carry the same codon, or three letter message)

d)Amino Acids link together (as tRNA brings it to mRNA)

e)process repeats itself, tRNA is released from mRNA after amino acids link, forming the new protein

f)last three letters of the mRNA code (UAG,UAA,UGA) no amino acids can match these codons, so protein is complete

g)mRNA breaks down

Quiz Name_________________________

1.__________________________A phosphate, sugar and base are the three parts of a ?

2.__________________________Proteins are organic molecules composed of about (?) amino acids.

3.__________________________These structures, located on chromosomes, are responsible for making proteins.

4.__________________________The sequence of base pairs from the top to the bottom, determine the type of protein.

5.__________________________Three bases grouped together are called a ?

6.__________________________Organelle where proteins are made.

7.__________________________Process where mRNA is made.

8.__________________________Name one difference between RNA and DNA.

9.__________________________In making a RNA molecule, adenine of DNA links with ?

10._________________________UUACCGAAUGUA, contains how many codons.

Quiz Genetics, Chapter #7 Name_____________________

1._________________If the DNA code for the amino acid arginine is GCA, the mRNA code is ___?

2._________________If the DNA code for the amino acid cysteine is ACA, the tRNA anticodon is ___?

3._________________If the DNA code for the amino acid valine is CAA and for the amino acid glycine is CCT, then the correct mRNA sequence is ___.

4._________________The number of bases in a row in a gene which codes a protein composed of 300 amino acids is ___.

5._________________The transforming principle was later discovered to be a ___?


a)DNA, b)mRNA, c)tRNA, d)mRNA and tRNA, e)replication, f)sugar, g)uracil, h)base, i)thymine, j)phosphate

6._____Carries amino acids to ribosomes

7._____Composed of two chains of nucleotides

8._____Contains thymine

9._____Contains ribose

10_____Involved in translation

11_____Made during transcription

12 @ 13______The uprights of a DNA molecule are made up of these

14_____DNA makes an exact copy of itself during this process

15_____During replication of DNA, Adenine pairs with ___?

16_____During production of mRNA, adenine pairs with ___?

17_____The rungs of a DNA molecule are made up of this

18_____Contains deoxyribose

19_____A gene is composed of this organic material

20_____The weakest bond in a DNA molecule is between the ____ pairs