Week 9

Question 1

Gene

Answer 1

Functional unit of genetic information

Question 2

Genetic elements

Answer 2

large molecules and/or chromosomes

Question 3

genome

Answer 3

genetic information in a cell

Question 4

informational macromolecules

Answer 4

nucleic acids and proteins

Question 5

genomics

Answer 5

sequencing and molecular characterization of genomes

Question 6

genotype

Answer 6

genetic makeup containing potential properties

Question 7

phenotype

Answer 7

actual expressed properties

Question 8

nucleotides

Answer 8

nucleic acid monomers
dna and rna are polynucleotides
three components; pentose sugar, nitrogenous base, phosphate

Question 9

nucleoside

Answer 9

has pentose sugar and nitrogenase base, no phosphate

Question 10

Phoephodiester bonds

Answer 10

connect ‘3 carbon of one sugar 5’ carbon of the adjacent sugar

Question 11

Primary structure

Answer 11

sequence of nucleotides that encode genetic information

Question 12

Properties of double helix

Answer 12

double stranded, held together by hydrogen bonding between bases

two strands complementary base sequences AT GC

Strands anti parallel 5-3 3-5 forming double helix

major and minor grooves

Question 13

Positive supercoiling

Answer 13

Double helix is overwound
wound in same direction as the right handed double helix
DNA helicase mediated

Question 14

Negative supercoiling

Answer 14

double helix is underwound
wound in opposite direction of the right handed double helix
dna gyrase mediated

predominant form in nature

Question 15

Topoisomerases

Answer 15

insert and remove supercoils

Question 16

negative supercoiling

Answer 16

twisted in opposite sense relative to right handed double helix, most cells

Question 17

DNA gyrase

Answer 17

introduces supercoils into dna via double strand breaks

Question 18

positive supercoiling

Answer 18

helps prevent dna melting at high temps, ex. some archaea

Question 19

Central dogma

Answer 19

genetic information flow can be divided into three stages, dna to rna to protein

Question 20

messenger rna

Answer 20

carry info to ribosomes

Question 21

transfer rna

Answer 21

convert mrna information to amino acid sequence

Question 22

ribosomal rna

Answer 22

catalytic and structural ribosome components

Question 23

replication

Answer 23

dna is duplicated by dna polymerase

Question 24

transcription

Answer 24

information from dna is transferred to rna by rna polymerase

Question 25

translation

Answer 25

information in mrna is used to build polypeptides on ribosome

Question 26

eukaryotes info flow

Answer 26

each gene transcribes indivi into single mrna replication and transcri occurs in nucleus rnas must be exported outside nucleus for translation

Question 27

prokaryotes into flow

Answer 27

multiple genes may be transcribed in one mrna coupled transcription and translation occur producing proteins at maximal rate

Question 28

chromosome

Answer 28

main genetic element in prokaryotes most bacteria and archaea have single circular chromosome carrying all/most genes euk: 2+ linear chromosomes

Question 29

Plasmids

Answer 29

small circular or linear dna molecules replicate sep from chromosome generally beneficial not extracellular expendable

Question 30

virulence factor

Answer 30

Ability to attach or produce toxins (some bacteria have them encoded by plasmids)

Question 31

bacteriocins

Answer 31

proteins that inhibit or kill closely related species or different strains of same species (can be plasmid encoded)

Question 32

Rhizobia

Answer 32

require plasmid encoded functions to fix nitrogen

Question 33

4 types of plasmids

Answer 33

1. Resistance plasmids 2. Virulence plasmids 3. metabolic plasmids 4. conjugative plasmids

Question 34

Direction of DNA replication?

Answer 34

Always 5 to 3

Question 35

DNA polymerases

Answer 35

catalyze polymerization of deoxynucleotides can only add nucleotides to preexisting and require primer (short stretch of rna)

Question 36

DNA helicase

Answer 36

unwinds double helix

Question 37

Replisome

Answer 37

large replication complex of multiple proteins

Question 38

Primosome

Answer 38

helicase and primase sub complex within replisome

Question 39

mutations

Answer 39

change in dna sequence, proofreading to ensure high fidelity

Question 40

Wild type strain

Answer 40

a reference strain or a strain isolated from nature

Question 41

mutant

Answer 41

a strain (cell or virus) differing from parental (wild) strain

Question 42

mutation

Answer 42

stable inheritable changes in dna base sequencing single base changes more common, point mutations larger mutations are less common, insertion, deletion, inversion, duplication, translocation can be spontaneous or induced

Question 43

frame shift mutation

Answer 43

deletions or insertions of one to two base pairs dramatic changes to dna reading frame is shifted causing downstream codons to be read incorrectly

Question 44

Reversion

Answer 44

point mutations are typically reversible occurs when alteration in DNA reverses effects of prior mutation

Question 45

same site revertant

Answer 45

mutation is at the same site as original mutation

Question 46

second site revertant

Answer 46

mutation is at a different site in the dna (suppressor mutation)

Question 47

chemical mutagens (3)

Answer 47

base analogs, mistakes occur when incorporated and propagated dna modifying agents, higher freq than base analogs, faulty base pairing intercalating agents, distort dna to induce single base insert or delete

Question 48

auxotroph

Answer 48

any mutant microorganism with a nutritional requirement that is absent in the parent (wild type)

Question 49

Ames test

Answer 49

looks for inc in mutation of bacteria in presence of suspected mutagen mutagens lead to a reversion of mutants back to wild type phenotype wide variety of chemicals have been screened for toxicity and carcinogenicity

Question 50

Transformation

Answer 50

taking up naked dna from the surrounding environment

Question 51

conjugation

Answer 51

pilus mediated transfer between neighbouring cells

Question 52

transduction

Answer 52

viral transfer of genes