Genetics Study Guide Flashcards
Genetics
-study of what genes are
-how they carry information
-how information is expressed
-how genes are replicated
Gene
Segment of DNA that encodes a functional product (usually a protein)
Genome
All of the genetic material of an organism
Genomics
Molecular study of genomes
Genotype
Genes of an organism
Phenotype
Expression of the genes
DNA replication
Anabolic polymerization process that requires monomers and energy.
Transcription *
Information in DNA is copied as RNA nucleotide sequences
Translation *
Polypeptides synthesized from RNA nucleotide sequences
Central dogma of genetics
DNA →RNA →Protein
Sigma factor
Codon
Anticodon
Intron
Exon
Inducible operons
Must be activated by inducers
-ex:lactose operon
Repressible operons
Transcribed continually until deactivated by repressors.
-ex:tryptophan operon
Mutation
Any permanent change in the DNA (genetic material)
Mutagen
Agent that causes mutations
Remember: mutaGEN (prefix gen) STARTS/GENERATES a mutation
Spontaneous mutations
Occur in the absence of a mutagen.
Point mutation
(Most common) one or few base pairs affected
Frameshift mutations
Nucleotide triplets after the mutation displaced
Generalized transduction
transducing phage carriers random DNA segment from the donor to recipient
Specialized transduction
Only certain donor DNA sequences are transferred
Know the structure of DNA & RNA.
DNA: double stranded consisting of nucleotides which is composed of pentose sugar, nitrogenous base, and a phosphate group (deoxyribose sugar). DNA= A-T base pair
RNA: single stranded (ribose sugar) RNA= A-U base pair
What does it mean when DNA strands are anti parallel?
They are upside down from each other ( opposite alignments)
Ex: 2 complimentary strands of a DNA double helix which run in opposite directions alongside each other.
What does it mean when DNA replication is semi conservative?
One half of the strand is the parent strand and the other half is the daughter strand
How is DNA replicated? Where does it get its energy? Parts?
-starts at the replication fork, starts at a 5’ to 3’ strand.
Nucleotides are added as a triphosphate nucleotide and therefore it gets its nucleotide and its energy from this molecule from the breaking of a bond that will later bind to the nucleotide
What’s a leading strand vs a lagging strand?
*could be an essay question
Lagging strand: done in fragments
Leading strand: must be done continuously
What is a mutation? Name and give examples of the different types
Mutation: change in DNA (becomes permanent)
Ex: silent, missense, nonsense mutations
What causes mutations? What are mutagens?give examples of mutagens and how they damage DNA (Ex: ionizing radiation ionizes some)
Radiation, chemicals
Mutagen: anything that’s causes a mutation
Ionizing radiation: induces breaks in chromosomes
Nonionizing radiation: induces thymine dimers
How does DNA repair itself?
DNA polymerase has a repair function, it will come in and fix the DNA (editing function)
List and describe three types of horizontal transfer of genetic information
1.transformation
2.transduction
3.bacterial conjugation
describe three types of horizontal transfer of genetic information: TRANSFORMATION
-one of conclusive pieces of proof that DNA is genetic material
-transforming agent was naked DNA
-cells that take up DNA are competent which means competent=cell wall can be altered.
describe three types of horizontal transfer of genetic information: TRANSDUCTION
Generalized transduction- transducing phage carriers random DNA segment from donor to recipient.
Specialized transduction- only certain donor DNA sequences are transferred.
Involves a virus
describe three types of horizontal transfer of genetic information: BACTERIAL CONJUGATION
Involves bacterial conjunction (pillus)
Transposons are only able to transfer DNA within the cell.
TRUE OR FALSE
False
It has the ability to jump to a plasmid and can be transferred to another cell.
How is gene expression regulated?
Through operons???
What is an operon?
Control a metabolic pathway at transcription
Describe and give examples of an inducible operon
Inducible operons- must be activated by inducers
Ex:lactose operon
Repressible operon:
Transcribed continually until deactivated by repressors.
Ex: tryptophan operon
Understand the processes of DNA replication, transcription, translation, bacterial conjugation, transformation, transduction, transposons, an inducible operon such as the Lac operon and a repressible operon such as tryptophan operon. Know the participants in the process and their function.
Transcription-rna polymerase (how is it activated?)sigmafactor and promoter region
(Couldn’t hear some of it)
-need to add more on this card
Understand how bacterial transcription and translation can take place almost simultaneously. Why can’t eukaryotes do this?
mRNA has to be processed
Has to go through nuclear pore, out of the nucleus and into the cytoplasm
