12 1 dna - bioblogadamsbiologyblog.weebly.com/uploads/2/3/0/7/23074860/...avery and dna oswald avery...

End Show

Slide

1 of 37

Copyright Pearson Prentice Hall: http://www.biologyjunction.com/powerpoints_dragonfly_book_prent.htm

12–1 DNA

End Show

12–1 DNA

Slide

2 of 37

Copyright Pearson Prentice Hall:

http://www.biologyjunction.com/powerpoints_dragonfly_boo

k_prent.htm

Griffith and Transformation


In 1928, Fredrick Griffith was trying to learn how

certain types of bacteria caused pneumonia.

He isolated two different strains of pneumonia

bacteria from mice and grew them in his lab.

End Show

12–1 DNA

Slide

3 of 37



k_prent.htm


Griffith made two observations:

(1) The disease-causing strain of bacteria grew

into smooth colonies on culture plates.

(2) The harmless strain grew into colonies with

rough edges.

End Show

12–1 DNA

Slide

4 of 37



k_prent.htm


Griffith's Experiments

Griffith set up four individual

experiments.

Experiment 1:

• Mice were injected with

the disease-causing strain of

bacteria.

• The mice developed

pneumonia and died.

End Show

12–1 DNA

Slide

5 of 37



k_prent.htm


Experiment 2:

• Mice were injected with

the harmless strain of

bacteria.

• These mice didn’t get

sick.

Harmless bacteria

(rough colonies)

Lives

End Show

12–1 DNA

Slide

6 of 37



k_prent.htm


Experiment 3:

• Griffith heated the

disease-causing

bacteria.

• He then injected the

heat-killed bacteria into

the mice.

• The mice survived.

Heat-killed disease-

causing bacteria (smooth

colonies)

Lives

End Show

12–1 DNA

Slide

7 of 37



k_prent.htm


Experiment 4:

•Griffith mixed his heat-killed, disease-causing bacteria with live, harmless bacteria and injected the mixture into the mice.

•The mice developed pneumonia and died.

Live disease-

causing bacteria

(smooth colonies)

Dies of pneumonia


causing bacteria

(smooth colonies)

Harmless bacteria

(rough colonies)

End Show

12–1 DNA

Slide

8 of 37



k_prent.htm


Griffith concluded

•the heat-killed bacteria passed their disease-causing ability to the harmless strain.

Live disease-

causing bacteria

(smooth colonies)


causing bacteria

(smooth colonies)

Harmless bacteria

(rough colonies)

Dies of pneumonia

End Show

12–1 DNA

Slide

9 of 37



k_prent.htm


Transformation

Griffith called this process transformation

because one strain of bacteria (the harmless strain)

had changed permanently into another (the

disease-causing strain).

Griffith hypothesized that a factor must contain

information that could change harmless bacteria

into disease-causing ones.

End Show

12–1 DNA

Slide

10 of 37



k_prent.htm

Avery and DNA

Avery and DNA

Oswald Avery repeated Griffith’s work to determine

which molecule was most important for

transformation.

Avery and his colleagues made an extract from the

heat-killed bacteria that they treated with enzymes.

End Show

12–1 DNA

Slide

11 of 37



k_prent.htm

Avery and DNA

The enzymes destroyed proteins, lipids,

carbohydrates, and other molecules, including the

nucleic acid RNA.

Transformation still occurred.

End Show

12–1 DNA

Slide

12 of 37



k_prent.htm

Avery and DNA

Avery and other scientists repeated the experiment

using enzymes that would break down DNA.

• When DNA was destroyed, transformation did not

occur.

• Therefore, they concluded that DNA was the

transforming factor.

End Show

12–1 DNA

Slide

13 of 37



k_prent.htm

Avery and DNA

Avery and other scientists

discovered that the nucleic

acid DNA stores and

transmits the genetic

information from one

generation of an organism to

the next.

End Show

12–1 DNA

Slide

14 of 37



k_prent.htm

The Hershey-Chase Experiment


Alfred Hershey and Martha Chase studied

viruses—nonliving particles smaller than a cell that

can infect living organisms.

End Show

12–1 DNA

Slide

15 of 37



k_prent.htm


Bacteriophages

A virus that infects bacteria is known as a

bacteriophage.

Bacteriophages are composed of a DNA or RNA

core and a protein coat.

End Show

12–1 DNA

Slide

16 of 37



k_prent.htm


They grew viruses in cultures

containing radioactive isotopes

of phosphorus-32 (32P) and

sulfur-35 (35S).

End Show

12–1 DNA

Slide

17 of 37



k_prent.htm


If 35S was found in the bacteria, it would mean that

the viruses’ protein had been injected into the

bacteria.

End Show

12–1 DNA

Slide

18 of 37



k_prent.htm


If 32P was found in the bacteria, then it was the DNA

that had been injected.

Bacteriophage with

phosphorus-32 in DNAPhage infects

bacteriumRadioactivity

inside bacterium

End Show

12–1 DNA

Slide

19 of 37



k_prent.htm


Nearly all the radioactivity in the bacteria

was from phosphorus (32P).

Hershey and Chase concluded that the

genetic material of the bacteriophage

was DNA, not protein.

End Show

12–1 DNA

Slide

20 of 37



k_prent.htm

The Components and Structure of DNA


DNA is made up of nucleotides.

A nucleotide is a monomer of nucleic acids made

up of:

•Deoxyribose – 5-carbon Sugar

•Phosphate Group

•Nitrogenous Base

End Show

12–1 DNA

Slide

21 of 37



k_prent.htm


There are four kinds of bases in in DNA:

• adenine

• guanine

• cytosine

• thymine

End Show

12–1 DNA

Slide

22 of 37



k_prent.htm


Chargaff's Rules

Erwin Chargaff discovered that:

• The percentages of guanine [G] and cytosine

[C] bases are almost equal in any sample of

DNA.

• The percentages of adenine [A] and thymine

[T] bases are almost equal in any sample of

DNA.

End Show

12–1 DNA

Slide

23 of 37



k_prent.htm


X-Ray Evidence

Rosalind Franklin 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 X-rays on film.

End Show

12–1 DNA

Slide

24 of 37



k_prent.htm


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

double helix, in which two strands were

wound around each other.

End Show

12–1 DNA

Slide

25 of 37



k_prent.htm

The Components and Structure of

DNA

DNA Double Helix

End Show

12–1 DNA

Slide

26 of 37



k_prent.htm

The Components and Structure of

DNA

Watson and Crick discovered that hydrogen bonds

can form only between certain base pairs—adenine

and thymine, and guanine and cytosine.

This principle is called base pairing.

End Show

12–1 DNA

Slide

27 of 37

REVIEW CONTENT



k_prent.htm

End Show

Slide

28 of 37



12–1

Avery and other scientists discovered that

a. DNA is found in a protein coat.

b. DNA stores and transmits genetic

information from one generation to the next.

c. transformation does not affect bacteria.

d. proteins transmit genetic information from

one generation to the next.

End Show

Slide

29 of 37



12–1

The Hershey-Chase experiment was based on

the fact that

a. DNA has both sulfur and phosphorus in its

structure.

b. protein has both sulfur and phosphorus in

its structure.

c. both DNA and protein have no phosphorus

or sulfur in their structure.

d. DNA has only phosphorus, while protein

has only sulfur in its structure.

End Show

Slide

30 of 37



12–1

DNA is a long molecule made of monomers

called

a. nucleotides.

b. purines.

c. pyrimidines.

d. sugars.

End Show

Slide

31 of 37



12–1

Chargaff's rules state that the number of

guanine nucleotides must equal the number of

a. cytosine nucleotides.

b. adenine nucleotides.

c. thymine nucleotides.

d. thymine plus adenine nucleotides.

End Show

Slide

32 of 37



12–1

In DNA, the following base pairs occur:

a. A with C, and G with T.

b. A with T, and C with G.

c. A with G, and C with T.

d. A with T, and C with T.

End Show

Slide

33 of 37



12-2 Chromosomes and DNA Replication

12–2 Chromosomes and DNA Replication

End Show

Slide

34 of 37



DNA and Chromosomes

DNA and Chromosomes

In prokaryotic cells, DNA is located in the

cytoplasm.

Most prokaryotes have a single DNA molecule

containing nearly all of the cell’s genetic

information.

End Show

Slide

35 of 37



DNA and Chromosomes

Chromosome

E. Coli Bacterium

Bases on the

Chromosomes

End Show

Slide

36 of 37



DNA and Chromosomes

Many eukaryotes have 1000 times the

amount of DNA as prokaryotes.

Eukaryotic DNA is located in the cell

nucleus inside chromosomes.

The number of chromosomes varies

widely from one species to the next.

End Show

Slide

37 of 37



DNA and Chromosomes

Chromosome Structure

Eukaryotic chromosomes contain DNA and

protein, tightly packed together to form

chromatin.

Chromatin consists of DNA tightly coiled around

proteins called histones.

DNA and histone molecules form nucleosomes.

Nucleosomes pack together, forming a thick

fiber.

End Show

Slide

38 of 37



DNA

and

Chromo

somes

Eukaryotic Chromosome Structure

Chromosome

Supercoils

Nucleosome

DNA

double

helix

Histones

Coils

End Show

Slide

39 of 37



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.

Resources/Movies/vadnarep.mov

End Show

Slide

40 of 37



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 replication forks.

End Show

Slide

41 of 37



DNA Replication

Duplicating DNA

Before a cell divides, it duplicates its DNA in a

process called replication.

Replication ensures that each resulting cell will

have a complete set of DNA.

End Show

Slide

42 of 37



DNA Replication

– During DNA replication, the DNA molecule separates into two 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.

End Show

Slide

43 of 37



DNA Replication

Nitrogen Bases

Replication Fork

DNA Polymerase

Replication Fork

Original strandNew Strand

Growth

Growth

End Show

Slide

44 of 37



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.

End Show

Slide

45 of 37



DNA Replication

The principal enzyme involved in DNA

replication is DNA polymerase.

DNA polymerase joins individual

nucleotides to produce a DNA molecule

and then “proofreads” each new DNA

strand.

End Show

Slide

46 of 37



12–2

In prokaryotic cells, DNA is found in the

a. cytoplasm.

b. nucleus.

c. ribosome.

d. cell membrane.

End Show

Slide

47 of 37



12–2

The first step in DNA replication is

a. producing two new strands.

b. separating the strands.

c. producing DNA polymerase.

d. correctly pairing bases.

End Show

Slide

48 of 37



12–2

A DNA molecule separates, and the sequence

GCGAATTCG occurs in one strand. What is the

base sequence on the other strand?

a. GCGAATTCG

b. CGCTTAAGC

c. TATCCGGAT

d. GATGGCCAG

End Show

Slide

49 of 37



12–2

In addition to carrying out the replication of DNA,

the enzyme DNA polymerase also functions to

a. unzip the DNA molecule.

b. regulate the time copying occurs in the cell

cycle.

c. “proofread” the new copies to minimize the

number of mistakes.

d. wrap the new strands onto histone proteins.

End Show

Slide

50 of 37



12–2

The structure that may play a role in regulating

how genes are “read” to make a protein is the

a. coil.

b. histone.

c. nucleosome.

d. chromatin.

End Show

Slide

51 of 37



12-3 RNA and Protein Synthesis

12–3 RNA and Protein Synthesis

End Show

Slide

52 of 37


http://www.biologyjunction.com/powerpoints_dragonfly_book_prent.htm

12–3 RNA and Protein

Synthesis

Genes 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.

RNA contains coded information for making

proteins.

End Show

Slide

53 of 37



The Structure of RNA

The Structure of RNA

There are three main differences between RNA and DNA:

a. The sugar in RNA is ribose instead of

deoxyribose.

b. RNA is generally single-stranded.

c. RNA contains uracil in place of thymine.

End Show

Slide

54 of 37



Types of RNA

Types of RNA

There are three main types of RNA:

a. messenger RNA

b. ribosomal RNA

c. transfer RNA

End Show

Slide

55 of 37



Types of RNA

Messenger RNA (mRNA) carries copies of

instructions for assembling amino acids

into proteins.

End Show

Slide

56 of 37



Types of RNA

Ribosomes are made up of proteins and

ribosomal RNA (rRNA).

End Show

Slide

57 of 37



Types of RNA

During protein construction, transfer RNA (tRNA)

transfers each amino acid to the ribosome.

Amino acid

Transfer RNA

End Show

Slide

58 of 37

DNA

molecule

DNA strand

(template)

3

TRANSCRIPTION

Codon

mRNA

TRANSLATION

Protein

Amino acid

35

5



End Show

Slide

59 of 37



Transcription

DNA is copied in the form of

RNA

This first process is called

transcription.

The process begins at a

section of DNA called a

promoter.

End Show

Slide

60 of 37



Transcription

RNA

RNA polymerase

DNA

End Show

Slide

61 of 37



RNA Editing

Some DNA within a gene is not needed to

produce a protein. These areas are called

introns.

The DNA sequences that code for proteins are

called exons.

RNA Editing

End Show

Slide

62 of 37



The introns are

cut out of RNA

molecules.

The exons are the

spliced together

to form mRNA.

Exon IntronDNA

Pre-mRNA

mRNA

Cap Tail

RNA Editing

End Show

Slide

63 of 37



The Genetic Code

The Genetic Code

The genetic code is the “language” of mRNA

instructions.

The code is written using four “letters” (the

bases: A, U, C, and G).

End Show

Slide

64 of 37



A codon consists of three consecutive

nucleotides on mRNA that specify a

particular amino acid.

The Genetic Code

End Show

Slide

65 of 37



The Genetic Code

End Show

Slide

66 of 37

Nucleus

mRNACopyright Pearson Prentice Hall:


Translation

Translation

Translation is the decoding of an mRNA

message into a polypeptide chain (protein).

Translation takes place on ribosomes.

During translation, the cell uses information from

messenger RNA to produce proteins.

End Show

Slide

67 of 37



Translation

LysinetRNAPhenylalanine

Methionine

Ribosome

mRNAStart codon

The ribosome binds new tRNA molecules

and amino acids as it moves along the

mRNA.

End Show

Slide

68 of 37



Translation

Protein Synthesis

tRNA

Ribosome

mRNA

Lysine

Translation direction

End Show

Slide

69 of 37



Translation

The process continues until the ribosome

reaches a stop codon.

Polypeptide

Ribosome

tRNA

mRNA

End Show

Slide

70 of 37



DNA

mRNA

Protein

CodonCodon Codon

Codon Codon Codon

mRNA

Alanine Arginine Leucine

Amino acids within

a polypeptide

Single strand of DNA

GENES AND PROTIEN

End Show

Slide

71 of 37



12–3

The role of a master plan in a building is similar

to the role of which molecule?

a. messenger RNA

b. DNA

c. transfer RNA

d. ribosomal RNA

End Show

Slide

72 of 37



12–3

A base that is present in RNA but NOT in DNA is

a. thymine.

b. uracil.

c. cytosine.

d. adenine.

End Show

Slide

73 of 37



12–3

The nucleic acid responsible for bringing

individual amino acids to the ribosome is

a. transfer RNA.

b. DNA.

c. messenger RNA.

d. ribosomal RNA.

End Show

Slide

74 of 37



12–3

A region of a DNA molecule that indicates to an

enzyme where to bind to make RNA is the

a. intron.

b. exon.

c. promoter.

d. codon.

End Show

Slide

75 of 37

A codon typically carries sufficient information to

specify a(an)

a. single base pair in RNA.

b. single amino acid.

c. entire protein.

d. single base pair in DNA.



12–3

End Show

Slide

76 of 37



12-4 Mutations12–4 Mutations

End Show

Slide

77 of 37



Kinds of Mutations

Mutations are changes in the genetic

material.

Kinds of Mutations

Mutations that produce changes in a single

gene are known as gene mutations.

Mutations that produce changes in whole

chromosomes are known as chromosomal

mutations.

End Show

Slide

78 of 37



Kinds of Mutations

Gene Mutations

Gene mutations involving a change in one or

a few nucleotides are known as point

mutations because they occur at a single

point in the DNA sequence.

Point mutations include substitutions,

insertions, and deletions.

Resources/Movies/vapointm.mov

End Show

Slide

79 of 37



Kinds of Mutations

Substitutions

usually affect

no more than a

single amino

acid.

End Show

Slide

80 of 37



Kinds of Mutations

The effects of insertions or deletions are

more dramatic.

The addition or deletion of a nucleotide

causes a shift in the grouping of codons.

Changes like these are called frameshift

mutations.

End Show

Slide

81 of 37



Kinds of Mutations

In an insertion, an

extra base is

inserted into a

base sequence.

End Show

Slide

82 of 37



Kinds of Mutations

In a deletion, the loss of a single base is

deleted and the reading frame is shifted.

End Show

Slide

83 of 37



Kinds of Mutations

Chromosomal Mutations

Chromosomal mutations involve changes in the

number or structure of chromosomes.

Chromosomal mutations include deletions,

duplications, inversions, and translocations.

End Show

Slide

84 of 37



Kinds of Mutations

Deletions involve the loss of all or part of a

chromosome.

End Show

Slide

85 of 37



Kinds of Mutations

Duplications produce extra copies of parts of

a chromosome.

Resources/Movies/vaduplic.mov

End Show

Slide

86 of 37



Kinds of Mutations

Inversions reverse the direction of parts of

chromosomes.

End Show

Slide

87 of 37



Kinds of Mutations

Translocations occurs when part of one

chromosome breaks off and attaches to another.

Resources/Movies/vatransl.mov

End Show

Slide

88 of 37



Significance of Mutations

Significance of Mutations

Many mutations have little or no effect on gene

expression.

Some mutations are the cause of genetic

disorders.

Polyploidy is the condition in which an

organism has extra sets of chromosomes.

End Show

Slide

89 of 37



12–4

A mutation in which all or part of a chromosome

is lost is called a(an)

a. duplication.

b. deletion.

c. inversion.

d. point mutation.

End Show

Slide

90 of 37



12–4

A mutation that affects every amino acid

following an insertion or deletion is called a(an)

a. frameshift mutation.

b. point mutation.

c. chromosomal mutation.

d. inversion.

End Show

Slide

91 of 37



12–4

A mutation in which a segment of a chromosome

is repeated is called a(an)

a. deletion.

b. inversion.

c. duplication.

d. point mutation.

End Show

Slide

92 of 37



12–4

The type of point mutation that usually affects

only a single amino acid is called

a. a deletion.

b. a frameshift mutation.

c. an insertion.

d. a substitution.

End Show

Slide

93 of 37



12–4

When two different chromosomes exchange

some of their material, the mutation is called

a(an)

a. inversion.

b. deletion.

c. substitution.

d. translocation.

End Show

Slide

94 of 37



12-5 Gene Regulation

• 12-5 Gene Regulation

Fruit fly chromosome

Fruit fly embryo

Adult fruit fly

Mouse chromosomes

Mouse embryo

Adult mouse

End Show

Slide

95 of 37



Gene Regulation: An

Example

• Gene Regulation: An Example

a. E. coli provides an example of how gene

expression can be regulated.

b. An operon is a group of genes that operate

together.

c. In E. coli, these genes must be turned on so

the bacterium can use lactose as food.

d. Therefore, they are called the lac operon.

End Show

Slide

96 of 37



Gene Regulation: An

Example

–How are lac genes turned off and on?

End Show

Slide

97 of 37



Gene Regulation: An

Example

–The lac genes are turned off by repressors and turned on by the presence of lactose.

End Show

Slide

98 of 37



Gene Regulation: An Example

–On one side of the operon's three genes are two regulatory regions.

a. In the promoter (P) region, RNA polymerase

binds and then begins transcription.

End Show

Slide

99 of 37




a. The other region is the operator (O).

End Show

Slide

100 of 37




–When the lac repressor binds to the O region,

transcription is not possible.

End Show

Slide

101 of 37




• When lactose is added, sugar binds to the

repressor proteins.

End Show

Slide

102 of 37




• The repressor protein changes shape and

falls off the operator and transcription is

made possible.

End Show

Slide

103 of 37




• Many genes are regulated by repressor

proteins.

• Some genes use proteins that speed

transcription.

• Sometimes regulation occurs at the level

of protein synthesis.

End Show

Slide

104 of 37



Eukaryotic Gene Regulation

–How are most eukaryotic genes controlled?

End Show

Slide

105 of 37




• Eukaryotic Gene Regulation

–Operons are generally not found in

eukaryotes.

–Most eukaryotic genes are controlled

individually and have regulatory sequences that

are much more complex than those of the lac

operon.

End Show

Slide

106 of 37




• Many eukaryotic genes have a sequence

called the TATA box.

Promoter

sequences

Upstream

enhancer

TATA

box Introns

Exons

Direction of transcription

End Show

Slide

107 of 37




• The TATA box seems to help position

RNA polymerase.

Promoter

sequences

Upstream

enhancer

TATA

boxIntrons

Exons


End Show

Slide

108 of 37




• Eukaryotic promoters are usually found

just before the TATA box, and consist of

short DNA sequences.

Promoter

sequences

Upstream

enhancer

TATA

boxIntrons

Exons


End Show

Slide

109 of 37




• Genes are regulated in a variety of ways

by enhancer sequences.

• Many proteins can bind to different

enhancer sequences.

• Some DNA-binding proteins enhance

transcription by:

a. opening up tightly packed chromatin

b. helping to attract RNA polymerase

c. blocking access to genes.

End Show

Slide

110 of 37



Development and

Differentiation

• Development and Differentiation

a. As cells grow and divide, they undergo

differentiation, meaning they become

specialized in structure and function.

b. Hox genes control the differentiation of cells

and tissues in the embryo.

End Show

Slide

111 of 37



Development and

Differentiation

• Careful control of expression in hox

genes is essential for normal

development.

• All hox genes are descended from the

genes of common ancestors.

End Show

Slide

112 of 37



Development and

Differentiation

• Hox Genes

Fruit fly chromosome

Fruit fly embryo

Adult fruit fly

Mouse chromosomes

Mouse embryo

Adult mouse

End Show

Slide

113 of 37



12–5

–Which sequence shows the typical organization

of a single gene site on a DNA strand?

a. start codon, regulatory site, promoter, stop

codon

b. regulatory site, promoter, start codon, stop

codon

c. start codon, promoter, regulatory site, stop

codon

d. promoter, regulatory site, start codon, stop

codon

End Show

Slide

114 of 37



12–5

– A group of genes that operates together is

a(an)

a. promoter.

b. operon.

c. operator.

d. intron.

End Show

Slide

115 of 37



12–5

– Repressors function to

a. turn genes off.

b. produce lactose.

c. turn genes on.

d. slow cell division.

End Show

Slide

116 of 37



12–5

–Which of the following is unique to the

regulation of eukaryotic genes?

a. promoter sequences

b. TATA box

c. different start codons

d. regulatory proteins

End Show

Slide

117 of 37



12–5

–Organs and tissues that develop in various

parts of embryos are controlled by

a. regulation sites.

b. RNA polymerase.

c. hox genes.

d. DNA polymerase.

12 1 dna - bioblogadamsbiologyblog.weebly.com/uploads/2/3/0/7/23074860/...avery and dna oswald avery...

Documents