Chapter 7: Molecular Genetics Flashcards Preview

SAT 2 Biology > Chapter 7: Molecular Genetics > Flashcards

Flashcards in Chapter 7: Molecular Genetics Deck (105):
1

What did the scientist Griffith do?

griffith discovered BACTERIAL TRANSFORMATION.

2

What's bacterial transformation?

bacterial transformation is when bacteria absorbs foreign DNA from other bacteria and changes its DNA

3

How did Griffith discover bacterial transformation?

through his experiments with a bacteria that causes PNEUMONIA.

4

What did Avery, Macleod, and McCarty discover?

they discovered that the molecule that Griffith's bacteria was transferring was DNA
- in other words, they discovered that DNA is the GENETIC MATERIAL.

5

What did Hershey and Chase do?

Hershey and chase tagged the DNA and proteins of bacteriophages with radioactive isotopes P and S to determine what the genetic material is.

6

What is a bacteriophage?

viruses that kill bacteria

7

In Hershey and chase's experiment, What did the P label?

the P labeled the DNA of the bacteriophage

8

In Hershey and chase's experiment, What did the S label?

the S labeled the protein of the bacteriophage

9

What did Hershey and chase discover?

they discovered that DNA is the genetic material, because they found the phosphorous dye in the bacteria.

10

What did Rosalind Franklin do?

rosalind Franklin did x-ray crystallography of DNA

11

What did Rosalind franklin discover?

Rosalind Franklin discovered that DNA is a helix.

12

What did Watson and Crick do and achieve?

Watson and crick received the Nobel prize for correctly describing DNA as a double helix shape.

13

What did Meselson and Stahl do?

meselson and Stahl scientifically validated Watson and Crick's hypothesis that DNA replicates in a semiconservative fashion with an experiment.

14

How did Meselson and stahl cientifically validate Watson and Crick's hypothesis that DNA replicates in a semiconservative fashion?

they
1. cultured bacteria in a medium containing heavy nitrogen (15N)
2. they moved the bacteria to a medium containing light nitrogen (14N) and allowed the DNA To replicate
3. the new bacterial DNA contained one heavy strand and one light strand.

15

What's the shape of DNA?

DNA is a DOUBLE helix

16

Describe the strands in DNA.

DNA consists of two (2) COMPLEMENTARY strands running in the OPPOSITE direction.

17

DNA is a ___ made up of ____.

DNA is a POLYMER made up of monomers called NUCLEOTIDES.

18

Describe the structure of a nucleotide:

structure of a nucleotide:
1. one 5-carbon sugar
2. one phosphate
3. one nitrogenous base.

19

What're the nitrogenous bases in DNA?

nitrogenous bases in DNA:
1. adenine
2. thymine
3. cytosine
4. guanine

20

What connects the complementary nucleotides on the two strands of DNA?

HYDROGEN bonds connect the complementary nucleotides on the two strands of DNA.

21

What's the model that accurately describes DNA replication?

semiconservative model

22

What's the semiconservative model accurately describing DNA replication?

each parent strand serves as a template for the new strand.

23

What does DNA polymerase do in DNA replication?

DNA polymerase:
1. catalyzes the new DNA replicating
2. proofreads each new DNA strand, fixing errors and minimizing mutations

24

How do the parent DNA strands separate during DNA replication?

the parent DNA strands unzip at the HYDROGEN bonds.

25

What happens each time the DNA replicates?

each time the DNA replicates, some nucleotides from the ends of the chromosomes get lost

26

What protects against the loss of nucleotides at the ends of the chromosomes due to DNA replication?

TELEOMERES protects against the loss of nucleotides at the ends of the chromosomes due to DNA replication.

27

what are telomeres?

telomeres are repeating nucleotide sequences at the end of chromosomes that protect them from degrading.

28

What's the structure of RNA?

RNA is a SINGLE stranded helix!

29

What're the nitrogenous bases for RNA?

1. adenine
2. uracil
3. cytosine
4. guanine.

30

How do the nitrogenous bases differ in RNA and DNA?

in RNA, uracil replaces thymine.

31

What're the types of RNA?

1. mRNA
2. tRNA
3. rRNA

32

What's mRNA?

mRNA is the copy of DNA that goes to the ribosomes to make proteins.

33

What's tRNA?

tRNA carries specific amino acid molecules to mRNA at the ribosome to help form a protein during translation.

34

What's rRNA?

rRNA makes up a ribosome, along with proteins

35

What's the structure of a ribosome?

each ribosome is made up of one small subunit and one large subunit made up of rRNA and proteins.

36

What're the steps of replicating DNA?

steps of replicating DNA:
1. transcription
2. RNA processing
3. translation

37

What's transcription?

transcription is when mRNA is made or copied from the DNA

38

What's a ribosome made up of?

rRNA and proteins.

39

convert these bases from DNA to RNA:
1. Adenine

URACIL

40

convert these bases from DNA to RNA:
1. Thymine

ADENINE

41

convert these bases from DNA to RNA:
1. Cytosine

GUANINE

42

convert these bases from DNA to RNA:
1. Guanine.

CYTOSINE.

43

What're the specific steps of transcription?

specific steps of transcription:
1. RNA polymerase binds to one strand of DNA at the PROMOTER region
2. RNA polymerase pries apart the two DNA strands
3. RNA polymerase adds RNA nucleotides complementary to the parent strand.
4. the RNA polymerase reaches a STOP codon, ending transcription.

44

What does RNA polymerase do during transcription?

RNA polymerase:
1. RNA polymerase binds to one strand of DNA at the PROMOTER region
2. RNA polymerase pries apart the two DNA strands
3. RNA polymerase adds RNA nucleotides complementary to the parent strand.
4. the RNA polymerase reaches a STOP codon, ending transcription.

45

What ends the transcription when DNA replicates?

a STOP CODON on the DNA strand ends the transcription of RNA.

46

What're the specific steps of RNA processing?

specific steps of RNA processing:
1. enzymes called snRNPs edit the initial mRNA transcipt
2. the enzymes remove the introns
3. the enzymes splice together the exons to form the final mRNA transciprt

47

What do snRNPs do in the replicating of DNA?

snRNPs are enzymes that EDIT and SPLICE the INITIAL mRNA transcript!

48

What are the introns in an initial mRNA transcript?

the introns are the NONCODING regions of the mRNA

49

What are the exons in an initial mRNA transcript?

the exons are the CODING regions of the mRNA

50

What's longer: the initial mRNA transcript or the final mRNA transcript?

the INITIAL mRNA transcript is longer because of RNA PROCESSING!

51

What's translation?

translation is when ribosomes use the mRNA sequence as a transcript to make proteins.

52

Where do the amino acids for making the proteins come from?

tRNA molecules bring them to the ribosomes in groups of three unique amino acids.

53

______ can code for the same amino acid.

several unique CODON SEQUENCES can code for the same amino acid
- for example, UUU and UUC both make phenylalanine, even though the amino acid sequence is different.

54

Where does transcription occur?

transcription occurs in the NUCLEUS

55

How are genes regulated in PROKARYOTES?

they're regulated using OPERONS.

56

What're operons?

operons are a group of genes controlled by one single switch.

57

Where does RNA processing occur?

RNA processing occurs in the NUCLEUS

58

What're the types of operons?

1. the inducible operon
2. the repressible operon

59

do eukaryotes like humans have operons?

NO, only PROKARYOTES have operons!

60

What's the inducible operon?

the inducible operon is normally turned off unless something induces or triggers it to turn on.

61

What's an example of an inducible operon?

the lac (lactose) operon is an example of an inducible operon.

62

Where does translation occur?

translation occurs in the CYTOOPLASM at the RIBOSOMES.

63

What's the repressible operon?

the repressible operon is always turned on unless something turns it off temporarily.

64

What're the important parts of an operon?

important parts of an operon:
1. the promoter
2. RNA polymerase
3. operator
4. TATA box

65

What's the promoter part of the operon?

the promoter is where RNA polymerase binds onto the operon

66

What's the operator part of the operon?

the operator is where the REPRESSOR binds to TURN OFF the lac or inducible operon.

67

What's the TATA box?

the TATA box HELPS RNA polymerase BIND to the promoter.

68

What causes mutations?

1. chance- they may occur spontaneously at random
2. mutagens

69

What're mutagens?

toxic chemicals and radiation that causes MUTATIONS.

70

What're the types of gene mutations?

types of gene mutations:
1. point mutations
2. insertions
3. deletions

71

What's a point mutation?

a point mutation is only ONE (1) nitrogenous base and its complement change.

72

example of a point mutation?

DNA: AGC -> TGC
RNA: UGC -> AGC

73

What's insertion and deletion?

insertion and deletion is when ONE (1) single nitrogenous base pair is inserted into or deleted from the sequence.

74

What do insertions and deletions cause?

they cause a FRAMESHIFT

75

what's a frameshift?

a frameshift is when the reading frame of a nucleotide sequence is shifted.

76

What're chromosome mutations?

chromosome mutations are when the number or structure of chromosomes CHANGES.

77

How can you view chromosome mutations?

with a MICROSCOPE.

78

Where is polyploidy common?

polyploidy is common in PLANTS

79

What does polyploidy in plants cause?

polyploidy in plants causes unusually LARGE and COLORFUL flowers!

80

What causes sickle cell anemia?

a POINT mutation causes sickle cell anemia!

81

Where does the point mutation that causes sickle cel anemia occur?

it occurs in the gene that codes for HEMOGLOBIN.

82

What's sickle cell anemia?

sickle cell anemia is lack of oxygen causes red blood cells to sickle become damaged.

83

What conditions does nondisjunction cause?

nondisjunction causes
1. aneuploidy
2. polyploidy

84

What are aneuploidy and polyploidy caused by?

aneuploidy and polyploidy are caused by NONDISJUNCTION!

85

What's the GENOME?

the genome is the GENETIC MATERIAL

86

How many base pairs of DNA does the human genome contain?

the human genome contains THREE (3) BILLION base pairs of DNA.

87

How many genes does the human genome contain?

the human genome contains TWENTY-THOUSAND (20,000) genes.

88

How much of our DNA codes for proteins?

THREE (3) percent of our DNA codes for proteins.

89

Most of our DNA are what?

most of our DNA consists of REPETITIVE sequences that get repeated millions of times.

90

What are pseudogenes?

pseudogenes are former genes that have accumulated mutations over a long period of time.

91

What's RECOMBINANT DNA?

recombinant DNA means taking DNA from two (2) sources and combining them in one cell.

92

What branch of science uses recombinant DNA?

GENETIC ENGINEERING or biotechnology uses recombinant DNA.

93

What're some important areas of study in genetic engineering?

1. gene therapy
2. cleaning up the environment. (environmental cleanup).

94

What're restriction enzymes?

restriction enzymes CUT DNA at specific locations.

95

What're the pieces of DNA that result from restriction enzymes cutting them called?

RESTRICTION FRAGMENTS are the pieces of DNA that result from restriction enzymes cutting them.

96

How much of our DNA doesn't code for proteins?

NINETY-SEVEN (97) percent of our DNA doesn't code for proteins.

97

What does gel electrophoresis do?

electrophoresis separates large molecules of DNA based on how fast they move through an agar gel in an electric field.

98

What type of DNA molecules move FASTER through the agar gel in gel electrophoresis?

SMALLER DNA molecules move FASTER through the agar gel in gel electrophoresis
- (well no duh because they weigh less)

99

How do you prepare the DNA for gel electrophoresis?

to prepare the DNA for gel electrophoresis, you have to use restriction enzymes to cut the DNA into small enough pieces that can move through the gel.

100

What's polymerase chain reaction (PCR)?

polymerase chain reaction is a technique used to RAPIDLY copy DNA

101

How fast is polymerase chain reaction (PCR)?

BILLIONS of DNA can be produced in a FEW HOURS.

102

What kind of sugar does DNA contain?

DNA contains deoxyribose

103

What kind of sugar does RNA contain?

RNA contains ribose.

104

When does DNA replication occur?

during the "S" Synthesis phase of interphase

105

Which process requires DNA polymerase?

the "S" Synthesis phase of interphase