Microbiology Ch. 9 Study Guide

LO. 1 HEREDITY

transmission of traits from parent to offspring

LO. 1 GENETICS

Study of heredity and variations of inherited traits. And the structure of genetic material

LO.1 GENOME

The entire genetic material in an organism

LO.1 GENOME- most appear as:

chromosomes

LO. GENOME- some appear in nonchromosomal sites such as:

Mitochondria

Chloroplast

Plasmid

LO. GENOME- of cells:

DNA

LO.1 GENOME- of viruses

DNA or RNA

LO.1 GENE

Segment of DNA that codes for important products, such as proteins (products that determine traits too)

LO.1 GENOTYPE

specific genetic makeup of an individual

LO.1 PHENOTYPE

observable characteristics of an organism resulting from the genotype, and it can be affected by environment (the physical state)

LO.2 Explain how DNA is organized and packed in PROKARYOTES

Enzyme DNA gyrase coils the chromosome into a tight bundle by twisting the DNA molecules multiple times.

LO.2 Explain how DNA is organized and packed in EUKARYOTES

Histones attaches to DNA molecules, forming a nucleosome. Then multiple nucleosomes attach together forming a fiber of nucleosomes called a chromatin.

LO.2 -NUCLEOSOMES:

Histone and DNA attached together

LO.2 -CHROMATIN:

nucleosomes attached together

LO.2 CHROMOSOMES

chromatin is converted into chromosomes (only in cell division)

LO.3 Basic DNA Structure NUCLEOTIDE

Backbone + nitrogenous base (the strand)

LO.3 BACKBONE

deoxyribose sugar + phosphate groups joined by covalent bonds

LO.3 DNA arrangement:

Parallel 3’—-5’ and 5’—-3’

LO.3 a) NITROGENOUS BASE

A-adenine, T-Thymine, C-cytosine, G-Guanine

LO.3 a) NITROGENOUS BASE bonding pattern:

A-T, G-C (A-U in RNA)

LO.4 DNA replication in Prokaryote (Process begins at:)

origin of replication

LO.4 ORIGIN OF REPLICATION

start site, all chromosomes have one

LO.4 ORIGIN OF REPLICATION is ___ rich, meaning that __ energy is required to separate the two strands.

AT, less

LO.4 Step 2. ___proteins bind to origin of replication

initiator

LO.4 Prokaryotic DNA replication Step 3. (Once unwound, protein ___ breaks ___bonds between nitrogenous bases, separating each DNA strand and creating ____ “y-shaped”)

helicase, hydrogen, replication forks

LO.4 Prokaryotic DNA replication Step 4. (___ synthesis a short RNA primer so ___ can start adding nucleotides to DNA strand)

primase, DNA polymerase lll

LO.4 DNA polymerase only works in ___ direction

5’ to 3’

LO.4 Prokaryotic DNA Replication Step 5. (___ is synthesized in short fragments called ___ fragments)

lagging, Okazaki

LO.4 Prokaryotic DNA Replication Step 6. (As replication progresses ______ move until they meet at ____ site)

replication forks, termination

LO.4 Prokaryotic DNA Replication Step 7.( ____ removes the RNA nucleotides that make up the ___ and replaces them with the corresponding DNA nucleotides

DNA Polymerase lll, primer

LO.4 Prokaryotic DNA Replication Step 8. (___ seals the gap between the Okazaki fragments, completing synthesis of new DNA strand)

Ligase

LO.4 Prokaryotic DNA Replication Step 9. (___ supercoils the replicated DNA)

gyrase

LO.4 Prokaryotic DNA Replication . (Daughter cell is produced with ___DNA strand +____ DNA strand)

new, original

LO.4 SEMICONSERVATIVE

the new DNA molecule has the original strand paired with new strand

LO.5 Flow of Genetic information in cell

Transcription and Translation

LO. 6 Different types of RNA

mRna, tRNA and rRNA

LO.6 RNA is a ___ stranded molecule

single

LO.6 mRNA

carries genetic instructions from DNA to ribosome

LO.6 tRNA

matches anticodon to codons

LO.6 rRNA

makes up the core structure of ribosomes. It helps position mRNA and tRNA so proteins can be assembled.

LO.7 Major events of TRANSCRIPTION (1.Initiation) (___ binds to DNA at a ___ region “marks the starting point”)

RNA polymerase, promoter

LO.7 Major events of TRANSCRIPTION (2.Elongation) (___ reads the DNA template strand and builds an RNA strand)

RNA Polymerase

LO.7 Major events of TRANSCRIPTION (3.Termination) (___ recognizes a __sign in the DNA and releases the transcript)

RNA Polymerase, stop

LO.7 a) GENETIC CODE

role that determines which amino acid corresponds to which mRNA codon

LO.7 a) CODON (mRNA)

Three base sequence that specifies amino acids.

LO.7 a) ANTICODON

matching three-base sequence on tRNA that pairs with the codon

Lo. 7 b) TRANSLATION participants

mRNA, Ribosome, tRNA, amino acids and enzymes

LO. 7 b TRANSLATION step 1. Initiation (The ___ assembles on the mRNA at the start codon, usually ___ and initiator ___ binds)

ribosome, AUG, tRNA

LO. 7 b TRANSLATION step 2. Elongation (___ bring amino acids and the ___ joins them together in the order specified by mRNA)

tRNA, ribosome

LO. 7 b TRANSLATION step 3. Termination ( A ___ code is reached. A released factor helps release the completed ___ chain)

stop, polypeptide

LO. 7 b TRANSLATION - Termination Codons

UAA, UAG and UGA

LO.8 Major differences between prokaryotic and eukaryotic transcription

location, timing, mRNA processing, protein amount, introns

LO.8 Transcription Location in Prokaryotic:

Cytoplasm

LO.8 Transcription Location in Eukaryotes:

Nucleus

LO.8 Transcription Timing in Prokaryotic:

transcription and translation at the same time

LO.8 Transcription Timing in Eukaryotes:

first transcription and second translation

LO.8 Transcription mRNA processing in Eukaryotes:

eukaryotes add a five prime cap, a poly A tail and splice introns before sending mRNA out the nucleus.

LO.8 EXONS

parts in DNA that codes for proteins (kept in mRNA)

LO.8 INTRONS

parts of DNA that donut code for proteins and gets cut before sending mRNA out of nucleus.

LO.9 Explain function of OPERON

regulates to be active only when their products are required

LO.10 INDUCIBLE OPERON

operon is turned ON :catabolic operons- enzymes needed to metabolize a nutrients are produced when needed (of, turned on when needed)

LO. 10 Ex. LACTOSE OPERON INDUCIBLE

in the absence of lactose is off, in the presence of lactose it gets turned on

LO.10 REGULATOR

gene that codes for repressor (creates repressor)

Lo.10 CONTORL LOCUS

region in DNA, composes of promoter and operator

LO. 10 STRUCTURAL LOCUS

made of three genes each coding for an enzyme needed to catabolize molecule

LO.10 In lac operon Ex. B-GALACTOSE

hydrolyzed lactose

LO. 10 In Lac operon ex PERMEASE

brings lactose across cell membrane

LO. 11 REPRESSIBLE OPERON function

Normally on, will be turned off when product of the pathway is no longer required

LO. 11 COREPRESSOR (molecule that binds to the __making the ___ bind to ___ blocking___

repressor, repressor, operator, RNA Polymerase

LO. 11 Arginine Operon on Ex. 1. (___ is repressed when arginine builds up and serving as a ___ activates the repressor protein)

operon, corepressor

LO. 11 Arginine Operon on Ex. 2. (the activated repressor binds to the ___ and blocking ___ and further ___ of genes for arginine synthesis )

operator, RNA Polymerase, transcription

LO.12 Genetic control by RNA in Prokaryotes:

Riboswitch

LO. 12 Genetic control by RNA in Eukaryotes:

RNA Interference

LO. 12 RIBOSWITCH

short nucleotide segment of mRNA that regulates translation of the same mRNA it is part of (if riboswithc is attached to binding sequence, its blocking)

LO. RNA INTERFERENCE

noncoding RNa molecules (microRNA, antisenseRNA and smal interfering RNA) regulates gene expression

LO.13 Define MUTATION

change in phenotype due to a change in genotype

LO. 13 WILD TYPE

nonmutated characteristic

LO.13 MUTANT STRAIN

organism that has a mutation

LO.13 a) Cause of mutation SPONTANEOUS MUTATION

random change in the DNA due to error in replication that occur without known cause

LO.13 a) Cause of mutation INDUCED MUTATION

exposure to known mutagens, physical (radiation) or chemical agents that retract with DNA in a disruptive manner.

LO. 13 a) Types of Mutation POINT MUTATION

substitution of a single nucleotide base

LO. 13 a) Types of Mutation MISSENSE MUTATION

causes change in a single amino acid

LO. 13 a) Types of Mutation NONSENSE MUTATION

changes a normal codon into a stop codon

LO. 13 a) Types of Mutation SILENT MUTATION

alters a base but does not change the amino acid

LO. 13 a) Types of Mutation BACK MUTATION

when a mutated base gene reverse to its original base composition

LO. 13 a) Types of Mutation FRAMESHIFT MUTATION

when the reading frame of the mRNA is altered

LO.13 b) Repair Mechanisms for Mutations DNA POLYMERASE

proofreads nucleotides during DNA replication

LO.13 b) Repair Mechanisms for Mutations MISMATCH REPAIR

locates and repairs mismatched nitrogen bases that were not repaired by DNA polymerase

LO.13 b) Repair Mechanisms for Mutations LIGHT REPAIR

for UV light damage

LO.13 b) Repair Mechanisms for Mutations EXCISION REPAIR

locates and repairs incorrect sequence by removing a segment of the DNA and then adding the correct nucleotides

The Ames Test

Checks whiter a chemical can cause mutations

LO.13 c) Positive effects of Mutation (Organism with beneficial mutations can ___, ___ and , these mutations are the basis of change in ___)

adapt, survive, reproduce, populations

LO.13 c) Negative effects of Mutation

harmful or fatal

LO.14 GENETIC RECOMBINATION (when an organism ___ and ___ ___ that oginirated in another ___)

acquires, expresses genes, organism

LO.14 GENETIC RECOMBINATION three means for bacteria:

conjugation,transformation and transduction

LO.15 CONJUGATION (Transfer of ___ or ___ fragments, from a ___ cell to a ___ cell via ___ contact)

plasmid, chromosomal, donor, recipient, direct

LO. 15 in CONJUGATION (___cell is converted into __ cell)

F-, F+

LO.15 Fertility Factor:

F+ Factor (donor)

LO.15 What do bacteria need for gene transferring in direct contact?

pilus

LO. 15 HIGH FREQUENCY OF RECOMBINATION (Hfr)

donors fertility plasmid is integrated into the bacterial chromosome (but F- cell doesnt change to F+ cell)