Micro EX 2: Microbial Genetics Flashcards Preview

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Flashcards in Micro EX 2: Microbial Genetics Deck (82)
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1
Q

Define Gene

A

section of DNA that codes proteins

2
Q

Define Telomeres

A

ends of a linear chromosomes

3
Q

When telomeres are frayed and worn what does that mean?

A

linked with aging and chronic diseases

4
Q

Describe Purines & name the complementary base

A

2-ring structure; Adenine & Guanine

5
Q

Describe Pyrimidines & name the complementary base

A

1-ring structure; Thymine(DNA), Cytosine, & Uracil(RNA)

6
Q

Review: Describe the chromosomal structure in Eukaryotes vs Prokaryotes

A

Eukaryotes: linear chromosomes
Prokaryotes: 1 circular chromosome

7
Q

Describe Genome

A

-all genes in an organism
-most associated with chromosomes
-extrachromosomal genes:
~Eukaryote: Mitochondria, Chloroplasts & Plasmids in some one-celled organisms
~Prokaryote: Plasmids

8
Q

Review: What are plasmids?

A

drug-resistance genes

9
Q

What is the complementary base of Guanine?

A

Cytosine

10
Q

What is the complementary base of Thymine?

A

Adenine

11
Q

What is the complementary base of Cytosine?

A

Guanine

12
Q

What is the complementary base of Adenine?

A

DNA: Thymine; RNA: Uracil

13
Q

What is another name for DNA Synthesis?

A

DNA Replication

14
Q

Describe Genetic Code

A

-base on triplets of DNA nucleotides
~A/T/C/G
~each triplet codes for an amino acid and/or punctuation
-64 combinations
~to cover the 20 amino acids
*used to make proteins & punctuation

15
Q

Define mRNA

A

makes a complementary copy of the template strand of DNA

16
Q

Where does transcription take place in the Eukaryote & Prokaryote?

A

Eukaryote: Nucleus
Prokaryote: Cytosol

17
Q

What happens in transcription?

A

mRNA copies DNA (replicate before dividing)

18
Q

Describe translation

A
  • protein synthesis

- mRNA attaches to the ribosome & tRNA brings in raw amino acids

19
Q

Describe Codon

A

triplets of nucleotides of mRNA

20
Q

Describe Anticodon

A

triplets of nucleotides of tRNA

21
Q

Name some types of RNA

A
  • mRNA
  • tRNA
  • rRNA
  • RNA Primer
  • 5th RNA
22
Q

Which RNA goes thru both translation & transcription?

A

mRNA

23
Q

Which RNA goes thru translation only?

A

tRNA

24
Q

What is the triplet for a Start Codon?

A

AUG (Methionine)

25
Q

Which karyote has introns & exons?

A

Eukaryotes

26
Q

Which karyote does not have introns or exons?

A

Prokaryotes

27
Q

Which karyote can have simultaneous transcription & translation?

A

Prokaryote

28
Q

Why are translation & transcription separate events? Name the karyote associated with this.

A

Because the nucleus have nuclear membranes; Eukaryotes

29
Q

Describe Exons

A

expressed when needed

30
Q

Describe Introns

A

not expressed; cut out “GARBAGE”

31
Q

Describe 5th RNA

A

works as an enzyme, cut out introns splices exons together

31
Q

Define DNA Replication

A

Precursor for cell division

32
Q

Describe antiparallel concept

A

Grows 5’–> 3’

Applies to DNA molecules

33
Q

In a nucleotide what is attached to 1’?

A

Nitrogen base

34
Q

In a nucleotide what is attached to 3’?

A

Hydroxyl (OH) group

35
Q

In a nucleotide what is attached to 5’?

A

Phosphate group

37
Q

Where does DNA Replication occur in mitosis?

A

Interphase

38
Q

What is the process of DNA Replication?

A
  1. Helicase- “unzips” DNA breaking hydrogen bonds
  2. Primase/RNA Polymerase- builds RNA primer
  3. DNA Polymerase 3- puts DNA nucleotides after RNA Primer
  4. DNA Polymerase 1- replaces RNA primer with DNA nucleotides
  5. DNA Ligase- connects Okazaki fragments togerther
  6. Gyrase- super coils the strands together
39
Q

Describe the Leading Strand.

A

grows 5’ –> 3’ towards Helicase

40
Q

Describe the Lagging Strand

A

grow 5’ –> 3’ in the opposite direction of the leading strand it grows in fragments called Okazaki fragments

41
Q

Describe Regulatory Gene

A
  • can be anywhere on the chromosome

- codes for a repressor protein that can fit on the operator gene and block transcription of the structural genes

42
Q

Describe Operon

A
  • consists of the promoter gene, operator gene, & structural genes
  • these genes have to be found together on a chromosome
43
Q

What is consists of a palindrome of nucleotide bases that signals the beginning of a codon?

A

promoter gene

44
Q

What is a palindrome?

A

a word, that reads the same backwards or forward

45
Q

What works as a red/green light?

A

the operator gene

46
Q

If the operator gene is blocked by the repressor protein what happens?

A

nothing happens

47
Q

If the operator gene is not blocked what happens?

A

the structural genes are transcribed then translated into proteins and cells can now metabolize something

48
Q

What is the purpose of the structural genes?

A

codes for specific enzymes that helps in catabolic or anabolic reactions

49
Q

What are 2 different operons?

A

inducible operon & repressible operon

50
Q

What operons are normally on but can turned off, normally by excess product?

A

repressible operon

51
Q

What operons are normally off but can be turn on?

A

inducible operon

52
Q

What is an example of inducible operon?

A

the lac operon

53
Q

What is an example of repressible operon?

A

the trp operon

54
Q

What does trp stand for?

A

tryptophan

55
Q

Which operon are normally involved in anabolism?

A

repressible operons

56
Q

Which operon are normally involved in catabolism?

A

inducible operons

57
Q

What binds to lac repressor causes a change in the lac repressor protein,preventing it to bind to the lac operator site?

A

Allolactose (Lactose inducer)

58
Q

If there is an excess product of tryptophan what happens?

A

the trp operon stops

59
Q

In transcription of the trp operon, mRNA codes multiple polypeptides what happens in translation?

A

enzymes make tryptophan amino acids

60
Q

Define SNPS “snips”

A

single nucleotide polymorphism

61
Q

What is polymorphism?

A

many forms

62
Q

Define Point Mutation

A

one nucleotide is change

63
Q

How many base(s) does it take to make 5-6 thousand SNPs to cause a disease?

A

1 single base

64
Q

Name the 3 point mutations

A
  • silent mutation
  • missense mutation
  • nonsense mutation
65
Q

Point Mutation: changes in codons but doesnt change in amino acids

A

Silent mutation

66
Q

Point Mutation: change from an amino acid to stop codon (ends all codings)

A

Nonsense mutation

67
Q

Point Mutation: switch out 1 base code for different amino acids

A

Missense Mutation

68
Q

Define frameshift mutation

A

when the whole reading frame shifts due to an addition or deletion

69
Q

What are the 5 factors that incrases mutations?

A
  • radiation
  • heat
  • high doses of electricity
  • extreme in pH
  • some caustic chemicals
70
Q

Denature of hydrogen bonds break where?

A

between complementary bases

71
Q

What are produced from burned products & are frameshift mutagens?

A

benzopyrenes

72
Q

Describe Afla Toxins

A
  • Aspergillus mold (white powders mostly found on peanuts)

- frameshift mutagens

73
Q

What are the 3 chemical factors of a frameshift mutagen?

A
  • Benzopyrenes
  • Afla Toxins
  • Base Analogs
74
Q

Describe Base Analogs

A

imitate nitrogen bases

75
Q

Describe Conjugation

A

Is the direct transfer of DNA plasmid from one cell to another

76
Q

Give examples of genetic transfers

A

Drug resistance genes & E. coli

77
Q

Describe transformation

A

bacteria pick up pieces of DNA or plasmids from the environment and incorporate this into their genome

78
Q

Name an example of something that is similar to transformation

A

saprophytes

79
Q

Define transduction

A

Injection of foreign DNA by a bacteriophage(virus that attacks bacteria) virus into the host bacterium by recombination

80
Q

Explain Griffen’s Experiment

A
  1. he takes avirulent w/o a capsule and mixes it with a virulent capsule
  2. injects it in a mouse
  3. mouse dies
  4. because all bacteria are dead but genes are more stable & kills the mouse
81
Q

Explain the process of transduction

A
  1. phage injects in DNA
  2. phage enzyme degrade host DNA
  3. cell synthesizes new phages that incorporate phage DNA & mistakenly some host DNA
  4. transduction phage injects donor DNA
  5. Donor DNA is added into recipient’s chromosome by recombination
82
Q

Explain the steps of Conjugation

A
  1. Donor cell attaches to a recipient cell w/ its pilus. pilus draws cells together
  2. cells contact one another
  3. one strand of plasmid DNA transfer to recipient
  4. recipient synthesizes a complementary strand to become an F+ cell (restoring its complete plasmid