1. Bellwork: Write the 2 questions and answer them in your notes
Bellwork: Write the 2 questions and answer them in your notes. Then, draw and label the parts of the nucleotide below.
1. What are the 3 components of this DNA nucleotide? 2. What is the function of DNA in the cell?

2. Genetics DNA and Genes DNA: The Molecule of Heredity
Unit Overview – pages

3. Contributors to DNA Discovery
1943 Oswald Avery: DNA carries genetic information
1952 Franklin took the first picture of DNA using X-RAY

4. Contributors to DNA Discovery
Watson & Crick proposed the structure of DNA
Nobel Prize to Watson and Crick
“FATHERS OF DNA”

5. Contributors to DNA Discovery
What event occurred allowing Watson and Crick to discover the DNA structure?

6. Section 11.1 Summary – pages 281 - 287
What is DNA?
Deoxyribonucleic Acid
determines an organism’s traits
ultimately determines the structure of proteins.
body is made up of proteins
body’s functions depend on proteins called enzymes.
Section 11.1 Summary – pages

7. Section 11.1 Summary – pages 281 - 287
The Structure of DNA
DNA is a polymer made of nucleotides.
Nucleotides have three parts:
simple sugar
phosphate group
nitrogenous base.
Section 11.1 Summary – pages

8. Section 11.1 Summary – pages 281 - 287
Nucleotide Structure:
composed of one atom of phosphorus surrounded by four oxygen atoms.
carbon ring structure that contains one or more atoms of nitrogen.
Phosphate group
Sugar (deoxyribose)
Nitrogenous base
Deoxyribose is the simple sugar in DNA
Section 11.1 Summary – pages

9. Section 11.1 Summary – pages 281 - 287
The structure of nucleotides
In DNA, there are four possible nitrogenous bases: adenine (A), guanine (G), cytosine (C), and thymine (T).
*always pair * always pair
Cytosine (C)
Adenine (A)
Thymine (T)
Guanine (G)
Section 11.1 Summary – pages

10. The structure of nucleotides
Thus, in DNA there are four possible nucleotides, each containing one of these four bases.
Nucleotides join together to form long chains.
Formed by covalent bonds
These chains are known as the Double Helix

11. Section 11.1 Summary – pages 281 - 287

12. Section 11.1 Summary – pages 281 - 287
The importance of nucleotide sequences
The sequence of nucleotides in each gene contains information for assembling the string of amino acids
Chromosome
Section 11.1 Summary – pages

13. Genes and Proteins DNA ultimately determines structure of proteins
Proteins make up the structure of an organism AND control all of the organism’s chemical reactions to keep it alive

14. Question 1 Which of the following is NOT a component of DNA?
A. simple sugars
B. phosphate groups
C. nitrogenous bases
D. proteins
The answer is D.
Section 1 Check

15. Question 2
Which of the following correctly comprises a complimentary base pair?
A. adenine – thymine
B. thymine – guanine
C. guanine – adenine
D. cytosine – thymine
The answer is A.
Section 1 Check

16. DNA and Cell Division

17. DNA to Proteins
Remember…DNA ultimately determines structure of proteins.
These proteins are what makes “us” and enables “us” to function…..
So how do we get these specific proteins?

18. Section 11.1 Summary – pages 281 - 287
Replication of DNA
Before a cell can divide by mitosis or meiosis, it must first make a copy of its chromosomes.( Interphase)
The DNA in the chromosomes is copied in a process called DNA replication.
Without DNA replication, new cells would have only half the DNA of their parents.
Section 11.1 Summary – pages

19. Section 11.2 Summary – pages 288 - 295
Cells Start Here: Transcription
Transcription results in the formation of one single-stranded RNA molecule.
takes place in the nucleus
mRNA, which is seen in here, takes the instructions from the nucleus to the cytoplasm.
Section 11.2 Summary – pages

20. Section 11.2 Summary – pages 288 - 295
What is RNA?
RNA is single stranded
The sugar is ribose
Rather than thymine, RNA contains a similar base called uracil (U).
Uracil
Hydrogen bonds
Adenine
Section 11.2 Summary – pages

21. Why RNA?
DNA provides workers with the instructions for making the proteins, and workers build the proteins.
The workers for protein synthesis are RNA molecules.

22. Back to Copying DNA….
Once mRNA is in the cytoplasm… Ribosomal RNA (rRNA) binds to the mRNA and uses the instructions to assemble the amino acids in the correct order.
This starts Translation

23. Section 11.2 Summary – pages 288 - 295
Translation: From mRNA to Protein
Translation is the process of converting the information in a sequence of nitrogenous bases in mRNA into a sequence of amino acids in protein.
Translation takes place at the ribosomes in the cytoplasm.
Section 11.2 Summary – pages

24. Section 11.2 Summary – pages 288 - 295
The role of transfer RNA
Amino acid
Each tRNA molecule attaches to only one type of amino acid.
An anticodon is a sequence of three bases found on tRNA.
Chain of RNA nucleotides
Transfer RNA molecule
Anticondon
Section 11.2 Summary – pages

25. Section 11.2 Summary – pages 288 - 295
The role of transfer RNA
Ribosome
mRNA codon
Section 11.2 Summary – pages

26. Section 11.2 Summary – pages 288 - 295
The role of transfer RNA
The first codon on mRNA is AUG, which codes for the amino acid methionine.
AUG signals the start of protein synthesis.
Then the ribosome slides along the mRNA to the next codon.
Section 11.2 Summary – pages

27. Section 11.2 Summary – pages 288 - 295
The role of transfer RNA
Methionine
tRNA anticodon
Section 11.2 Summary – pages

28. Section 11.2 Summary – pages 288 - 295
The role of transfer RNA
A new tRNA molecule carrying an amino acid pairs with the second mRNA codon.
Alanine
Section 11.2 Summary – pages

29. Section 11.2 Summary – pages 288- 295
The role of transfer RNA
The amino acids are joined when a peptide bond is formed between them.
Methionine
Alanine
Peptide bond
Section 11.2 Summary – pages

30. Section 11.2 Summary – pages 288 - 295
The role of transfer RNA
A chain of amino acids is formed until the stop codon is reached on the mRNA strand.
Stop codon
Section 11.2 Summary – pages

31. Section 11.2 Summary – pages 288 - 295
The Genetic Code
The Messenger RNA Genetic Code
First Letter
Third Letter
Second Letter U C A G U
Phenylalanine (UUU)
Serine (UCU)
Tyrosine (UAU)
Cysteine (UGU) U
Phenylalanine (UUC)
Serine (UCC)
Tyrosine (UAC)
Cysteine (UGC) C
Leucine (UUA)
Serine (UCA)
Stop (UAA)
Stop (UGA) A
Leucine (UUG)
Serine (UCG)
Stop (UAG)
Tryptophan (UGG) G C
Leucine (CUU)
Proline (CCU)
Histadine (CAU)
Arginine (CGU) U
Leucine (CUC)
Proline (CCC)
Histadine (CAC)
Arginine (CGC) C
Leucine (CUA)
Proline (CCA)
Glutamine (CAA)
Arginine (CGA) A
Leucine (CUG)
Proline (CCG)
Glutamine (CAG)
Arginine (CGG) G A
Isoleucine (AUU)
Threonine (ACU)
Asparagine (AAU)
Serine (AGU) U
Isoleucine (AUC)
Threonine (ACC)
Asparagine (AAC)
Serine (AGC) C
Isoleucine (AUA)
Threonine (ACA)
Lysine (AAA)
Arginine (AGA) A
Methionine;Start (AUG)
Threonine (ACG)
Lysine (AAG)
Arginine (AGG) G G
Valine (GUU)
Alanine (GCU)
Aspartate (GAU)
Glycine (GGU) U
Valine (GUC)
Alanine (GCC)
Aspartate (GAC)
Glycine (GGC)
Glycine (GGC) C
Valine (GUA)
Alanine (GCA)
Glutamate (GAA)
Glycine (GGA) A
Valine (GUG)
Alanine (GCG)
Glutamate (GAG)
Glycine (GGG) G
Section 11.2 Summary – pages

35. DNAi Triplet code Translation

36. Question 1
What are the three chemical differences between RNA and DNA?
Answer
RNA consists of a single strand of nucleotides whereas DNA is a double strand. RNA contains ribose as its sugar and DNA contains deoxyribose as its sugar. Uracil in RNA replaces thymine in DNA as the nitrogenous base.
Section 2 Check

37. Question 2 Answer What is the role of rRNA in protein synthesis?
Ribosomal RNA binds to messenger RNA and assembles the amino acids in the order needed for the protein to be synthesized.
Section 2 Check

38. Question 3
Which regions of the mRNA travel to the ribosome; introns, exons, or both?
Answer
Only exons, which contain coding information, travel to the ribosome. Introns, noncoding nucleotide sequences, do not travel to the ribosome.
Section 2 Check

39. Question 4 Answer What is an anticodon, and what does it represent?
An anticodon is a sequence of three nucleotides on the tRNA molecule that binds to a codon of the mRNA strand.
Section 2 Check

40. Question 4
What is the product of replication; of transcription; of translation?
Answer
Two DNA molecules; one mRNA molecule; a protein
Section 2 Check

41. 11.3 Section Objectives – page 296
1. Why is this exact base sequence important?
2. What may be the result of “wrong” base sequencing?
11.3 Section Objectives – page 296

42. 11.3 Section Summary 6.3 – pages 296 - 301
Mutations
Organisms have evolved many ways to protect their DNA from changes.
In spite of these mechanisms, however, changes in the DNA occasionally do occur.
A mutation is any change in a DNA sequence.
Mutations can be caused by errors in replication, transcription, cell division, or by external agents.
11.3 Section Summary 6.3 – pages

43. 11.3 Section Summary 6.3 – pages 296 - 301
Mutations in reproductive cells
Mutations can occur in the reproductive cells.
This then becomes part of the genetic makeup of the offspring.
If the change makes a protein nonfunctional, the embryo may not survive.
11.3 Section Summary 6.3 – pages

44. 11.3 Section Summary 6.3 – pages 296 - 301
Mutations in body cells
What happens if powerful radiation, such as gamma radiation, hits the DNA of a nonreproductive cell, a cell of the body such as in skin, muscle, or bone?
If the body cell’s DNA is changed, this mutation would not be passed on to offspring.
The mutation may cause problems for the individual.
11.3 Section Summary 6.3 – pages

45. 11.3 Section Summary 6.3 – pages 296 - 301
The effects of point mutations
A point mutation is a change in a single base pair in DNA.
A change in a single nitrogenous base can change the entire structure of a protein because a change in a single amino acid can affect the shape of the protein.
11.3 Section Summary 6.3 – pages

46. 11.3 Section Summary 6.3 – pages 296 - 301
The effects of point mutations
mRNA
Normal
Protein
Stop
Replace G with A
Point mutation
mRNA
Protein
Stop
11.3 Section Summary 6.3 – pages

47. 11.3 Section Summary 6.3 – pages 296 - 301
Frameshift mutations
A frameshift mutation is a mutation in which a single base is added or deleted from DNA.
A frameshift mutation shifts the reading of codons by one base.
This mutation would cause nearly every amino acid in the protein after the deletion to be changed.
11.3 Section Summary 6.3 – pages

48. 11.3 Section Summary 6.3 – pages 296 - 301
Frameshift mutations
Deletion of U
Frameshift mutation
mRNA
Protein
11.3 Section Summary 6.3 – pages

49. 11.3 Section Summary 6.3 – pages 296 - 301
Chromosomal Alterations
Chromosomal mutations are structural changes in chromosomes.
When a part of a chromosome is left out, a deletion occurs
A B C D E F G H
A B C E F G H
Deletion
11.3 Section Summary 6.3 – pages

50. 11.3 Section Summary 6.3 – pages 296 - 301
Chromosomal Alterations
When part of a chromatid breaks off and attaches to its sister chromatid, an insertion occurs.
The result is a duplication of genes on the same chromosome.
A B C D E F G H
A B C B C D E F G H
Insertion
11.3 Section Summary 6.3 – pages

51. 11.3 Section Summary 6.3 – pages 296 - 301
Chromosomal Alterations
When part of a chromosome breaks off and reattaches backwards, an inversion occurs.
A B C D E F G H
A D C B E F G H
Inversion
11.3 Section Summary 6.3 – pages

52. 11.3 Section Summary 6.3 – pages 296 - 301
Chromosomal Alterations
When part of one chromosome breaks off and is added to a different chromosome, a translocation occurs. A B C D E F G H W X A B C D E F G H W X Y Z Y Z
Translocation
11.3 Section Summary 6.3 – pages

53. 11.3 Section Summary 6.3 – pages 296 - 301
Causes of Mutations
A mutagen is any agent that can cause a change in DNA.
Mutagens include radiation, chemicals, and even high temperatures.
Forms of radiation, such as X rays, cosmic rays, ultraviolet light, and nuclear radiation, are dangerous mutagens because the energy they contain can damage or break apart DNA.
11.3 Section Summary 6.3 – pages

54. 11.3 Section Summary 6.3 – pages 296 - 301
Causes of Mutations
The breaking and reforming of a double-stranded DNA molecule can result in deletions.
Chemical mutagens include dioxins, asbestos, benzene, and formaldehyde, substances that are commonly found in buildings and in the environment.
Chemical mutagens usually cause substitution mutations.
11.3 Section Summary 6.3 – pages

55. 11.3 Section Summary 6.3 – pages 296 - 301
Repairing DNA
Repair mechanisms that fix mutations in cells have evolved.
Enzymes proofread the DNA and replace incorrect nucleotides with correct nucleotides.
These repair mechanisms work extremely well, but they are not perfect.
The greater the exposure to a mutagen such as UV light, the more likely is the chance that a mistake will not be corrected.
11.3 Section Summary 6.3 – pages

56. Question 1 Any change in DNA sequences is called a _______.
A. replication
B. mutation
C. transcription
D. translation
The answer is B.
Section 3 Check

57. Question 2
Which is more serious, a point mutation or a frameshift mutation? Why?
Answer
A frameshift mutation is more serious than a point mutation because it disrupts more codons than a point mutation.
Section 3 Check

58. Question 3
Why are chromosomal mutations rarely passed on to the next generation?
Answer
Few chromosomal changes are passed on to the next generation because the zygote usually dies. If the zygote survives, it is often sterile and incapable of producing offspring.
Section 3 Check

59. Question 4
How does DNA control the structures and functions of a cell?
Answer
DNA determines the structure of proteins. Some proteins become important cell structures. Other proteins, such as enzymes, control chemical reactions that perform key life functions.
Chapter Assessment

60. Question 5
The process through which the order of bases in messenger RNA codes for the order of amino acids in a protein is:
A. transcription
B. translation
C. replication
D. point mutation
The answer is B.
Chapter Assessment

61. Question 6
Why would scientists use nucleotide sequences to identify bodies of crime victims?
Answer
In comparing nucleotide sequences in the DNA of a crime victim with nucleotide sequences from a possible close relative of the crime victim, scientists can determine if the two are related.
Chapter Assessment

62. Question 7
What happens when a stop codon is reached during translation?
Answer
When a stop codon is reached, translation ends and the amino acid strand is released from the ribosome.
Chapter Assessment

63. Question 8
A ________ bond forms between adjacent amino acids during translation.
A. nucleotide
B. phosphate
C. hydrogen
D. peptide
The answer is D.
Chapter Assessment

64. Question 9 Answer Why is DNA replication important to cell division?
Without DNA replication, new cells would have only half the DNA of their parents. Species could not survive and individuals could not grow or reproduce successfully.
Chapter Assessment

65. Question 10 Answer What is the role of mRNA in protein synthesis?
The messenger RNA acts as a genetic message, providing the complete information, in sequences of codons, for the building of a protein.
Chapter Assessment

66. Question 11 The DNA sequences of a parrot _________.
A. are more similar to those of a clam than a robin
B. are more similar to a fern than a dog
C. are exactly the same as those of a human
D. contain exactly the same nucleotides as those of a beetle
The answer is D.
Chapter Assessment

67. Mutate your name! Name: R A C H E L R O ‘ C O N N O R Insertion:
Copy the chart below in your notes
Write your name in the first box so that there are 3 bases per codon
Draw a box around each codon
Do each of the mutations by filling in the rest of the chart
Put a box around each codon after the mutation
Name:
R A C H E L R O ‘ C O N N O R
Insertion:
(Add a base to the sequence)
Deletion:
(Delete a base)
Substitution:
(Take out a base a replace it with another)

68. Name: Insertion: Deletion: Substitution:
(Add a base to the sequence)
R A C H E L R B O ‘ C O N N O R
Deletion:
(Delete a base)
Substitution:
(Take out a base a replace it with another)

69. A DNA sequence reads: THE CAT ATE THE BIG RAT What type of mutation would change the sequence to: THE CAT ATA ETH EBI GRA T

70. Original DNA sequence: THE BIG RAT ATE THE CAT Mutated sequence: THE BIG FAT ATE THE CAT

71. Original DNA sequence: THE FAT BAT ATE THE RAT Mutated sequence: THE FAT BAT AT THE RAT