Term
| What did Alfred Sturtevant discover? |
|
Definition
| As an undergraduate in T.H. Morgan's lab. As physical distance on a chromosome increases, so does the probability of recombination (crossover) occurring between gene loci. |
|
|
Term
| What happens if homologues undergo two crossovers? |
|
Definition
| The parental combination is restored. |
|
|
Term
| Is the relationship between true distance on a chromosome and the recombination frequency linear? |
|
Definition
|
|
Term
| What does a three-point test cross do? |
|
Definition
| Uses 3 loci instead of 2 to construct maps. The gene in the middle allows us to see recombination events on either side. |
|
|
Term
| In any three point cross, which is the least frequent class? |
|
Definition
| The offspring with 2 crossovers |
|
|
Term
| What are three-point test crosses used for? |
|
Definition
| To determine the order of genes, then use that data from the closest 2 point crosses to determine distances. |
|
|
Term
| What is a human genome map? |
|
Definition
| Data derived from historical pedigrees. |
|
|
Term
| What is an SNP and what do they do? |
|
Definition
| Single Nucleotide Polymorphism. They are detected using molecular techniques. They have no detectable phenotype. Used in forensic analysis. |
|
|
Term
| Why is the X chromosome easier to study? |
|
Definition
| Because both sexes have it. Men are homozygous recessive because they only have 1 set of alleles on X chromosome. |
|
|
Term
| Some human genetic disorders are caused by ____? |
|
Definition
|
|
Term
| Altered proteins are encoded by a mutated ________? |
|
Definition
|
|
Term
| Because the altered protein doesn't function right, it alters the ________ as well. |
|
Definition
|
|
Term
| What was the first human disease to be a result of a mutation of a protein? |
|
Definition
|
|
Term
| What is the defect in sickle cell anemia? |
|
Definition
| The oxygen carrier molecule, hemoglobin. Leads to impaired oxygen delivery to tissue. |
|
|
Term
| Which genotype has the disease? |
|
Definition
| Homozygous. Intermittent illness and reduced life span. |
|
|
Term
| Which genotype appears normal? |
|
Definition
| Heterozygous. Some have hemoglobin with reduced function. |
|
|
Term
| Which race is effected greatest by sickle cell anemia? |
|
Definition
|
|
Term
| What confers resistance to parasite that causes malaria? |
|
Definition
|
|
Term
| Where is the mutation in sickle cell anemia? |
|
Definition
| Normal has an A where there should be a T. |
|
|
Term
| What forms the funny shape in RBC? |
|
Definition
| Tetramers form long chains when deoxygenated. This distorts the normal red blood cell shape. Sticky non-polar sites. |
|
|
Term
|
Definition
| Failure of homologues or sister chromatids to separate properly during meiosis. |
|
|
Term
|
Definition
| Gain or loss of a chromosome. |
|
|
Term
| What is monosomy aneuploidy? |
|
Definition
|
|
Term
| What is trisomy aneuploidy? |
|
Definition
|
|
Term
| Do most chromosomes survive aneuploidy? |
|
Definition
| No, but in some rare cases they do. |
|
|
Term
| On which genes can a aneuploidy cause gene death? |
|
Definition
|
|
Term
| Which defective genes can survive until adulthood? |
|
Definition
|
|
Term
|
Definition
| Trisomy on chromosome 21. |
|
|
Term
| What kind of trisomy can cause down syndrome? |
|
Definition
A full third 21st chromosome
A translocated of part of chromosome 21 |
|
|
Term
| What influences risk of down syndrome? |
|
Definition
|
|
Term
| What can determine the probability of genetic disorders in the offspring? |
|
Definition
|
|
Term
| Where does amniocentesis collect fetal cells from? |
|
Definition
| The amniotic fluid for examination |
|
|
Term
| Where does chorionic villi sampling collect cells from? |
|
Definition
| The placenta for examination |
|
|
Term
| What did Frederick Griffith study? |
|
Definition
| Streptococcus pneumoniae. The S-strain and R-strain |
|
|
Term
| The S-strain of S. Pneumoniae _______ mice. |
|
Definition
|
|
Term
| The R-strain of S. Pneumoniae ________ mice. |
|
Definition
|
|
Term
| Heat-killed S strain ________ mice |
|
Definition
|
|
Term
| Heat-killed S-Strain with live R strain _______ mice. |
|
Definition
|
|
Term
| What is the modern interpretation of the mice experiment? |
|
Definition
| The genetic material between the cells was transferred. AKA it was transformed. The information specifying virulence passed from the dead S strain cells into the live R strain cells. |
|
|
Term
| What later was discovered based off the mice experiment? |
|
Definition
| Removal of all protein from transforming material did not destroy its ability to transform the R strain cells. |
|
|
Term
| What destroyed all transforming ability? |
|
Definition
|
|
Term
| What is the transforming material? |
|
Definition
|
|
Term
|
Definition
| Viruses that infect bacteria. |
|
|
Term
| What are bacteriophages composed of? |
|
Definition
|
|
Term
| What did henry and chase want to determine? |
|
Definition
| Which molecule is the genetic material that is injected into the bacteria. |
|
|
Term
| How did henry and chase experiment? |
|
Definition
| They labeled the bacteriophage protein with 35S and bacteriophage DNA with 32P. Found that only bacteriophage DNA was used to produce more bacteriophages. |
|
|
Term
| What was the conclusion of the bacteriophage experiment? |
|
Definition
| DNA is the genetic material. |
|
|
Term
| DNA is a ______ ______ made of _______. |
|
Definition
| Nucleic acid/nucleotides. |
|
|
Term
| What is the structure of a nucleotide? |
|
Definition
- Deoxyribose
- A nitrogenous base attached to the 1' carbon
- A phosphate group attached to the 5' carbon
- An OH (hydroxyl) group on the 3' carbon
5
\
4 -O- 1
/ \
3------ 2 |
|
|
Term
| Which of the nitrogenous bases are 2 fused rings? |
|
Definition
|
|
Term
| What are the 2 groups of nitrogenous bases? |
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
| Cytosine, Thymine, and Uracil. |
|
|
Term
| What kind of bonds connect adjacent nucleotides? |
|
Definition
|
|
Term
| Where are the phosphodiester bonds formed? Between what 2 things |
|
Definition
| the phosphate group of one nucleotide and 3' - OH of the next nucleotide. |
|
|
Term
| How are chains of nucleotide oriented? |
|
Definition
|
|
Term
|
Definition
The amount of Adenine = amount of thymine
The amount of Cytosine = amount of guanine
Always an equal proportion of purines and pyrimidines |
|
|
Term
| What did Rosalind Franklin do? |
|
Definition
| Performed x-ray diffraction studies to identify the 3-D structure. Discovered that DNA is helical. Discovered that the molecule has a diameter of 2 nm and makes a complete turn of the helix every 3.4 nm. |
|
|
Term
| Who proposed the double helix structure? |
|
Definition
|
|
Term
| Did Watson and Crick perform any experiments? |
|
Definition
|
|
Term
| What does the double helix consist of? |
|
Definition
- 2 sugar-phosphate backbones
- Nitrogenous bases toward interior
- Said bases form hydrogen bonds with complementary
bases on the opposite sugar-phosphate backbone |
|
|
Term
| The two strands of nucleotides are? |
|
Definition
Antiparallel.
1 strand = 5-3
1 strand = 3-5 |
|
|
Term
| What are the 3 possible mechanisms of DNA replication that Meselon and Stahl considered? |
|
Definition
1.) Conservative
2.) Semiconservative
3.) Dispersive |
|
|
Term
| How did Meselon and Stahl perform their experiment? |
|
Definition
| Bacterial cells were grown in 15N (nitrogenous bases), which made all of their DNA incorporate 15N. Cells were switched to media containing 14N and DNA was then extracted at various times. |
|
|
Term
| Which DNA replication models were refuted? |
|
Definition
1.) Conservative
- 2 densities were not observed after round 1
2.) Dispersive
- 1st round, results consistent.
- 2nd round, didn't observe 1 band. |
|
|
Term
| Which DNA replication model was accepted? |
|
Definition
| Semiconservative model. Consistent with all observations. 1 band after round 1, 2 bands after round 2. |
|
|
Term
| What would conservative replication create? |
|
Definition
| Conservative replication would leave the two original template DNA strands together in a double helix and would produce a copy composed of two new strands containing all of the new DNA base pairs. |
|
|
Term
| What would dispersive replication create? |
|
Definition
| Dispersive replication would produce two copies of the DNA, both containing distinct regions of DNA composed of either both original strands or both new strands |
|
|
Term
| What does semiconservative replication create? |
|
Definition
| Semiconservative replication would produce two copies that each contained one of the original strands and one new strand. |
|
|
Term
| What 3 things does DNA replication require? |
|
Definition
1.) Something to copy
-Parental DNA
2.) Something to do the copying
-Enzymes
3.) Building blocks to make copy
-Nucleotide triphosphates |
|
|
Term
| Where does DNA replication initiation begin? |
|
Definition
| The origin of replication |
|
|
Term
|
Definition
| When new strands of DNA are synthesized by DNA polymerase |
|
|
Term
|
Definition
| Replication is terminated differently in prokaryotes and eukaryotes. |
|
|
Term
| What does DNA polymerase do? |
|
Definition
| Matches existing DNA bases with their complementary nucleotides and links them together. |
|
|
Term
| Where are new bases added ALWAYS? |
|
Definition
| the 3' end of existing strands |
|
|
Term
| What direction does DNA polymerase synthesize in? |
|
Definition
|
|
Term
| Does DNA polymerase require a primer? |
|
Definition
|
|
Term
| The chromosome of a prokaryote is a ________ molecule of DNA. |
|
Definition
|
|
Term
| Where does the chromosome of a prokaryote begin? |
|
Definition
| Origin of replication and proceeds in both directions. |
|
|
Term
| What does DNA polymerase 1 do? |
|
Definition
| Acts on lagging strand to remove primers and replace them with DNA |
|
|
Term
| What does DNA polymerase 2 do? |
|
Definition
| Involved in DNA repair processes? |
|
|
Term
| What does DNA polymerase 3 do? |
|
Definition
|
|
Term
| What direction does prokaryotes exonuclease (DNA Pol 1,2,3) activity occur in? |
|
Definition
| 3-5. This is "proofreading" |
|
|
Term
| DNA polymerase 1 has ____ to ______ exonuclease activity also. |
|
Definition
|
|
Term
| What causes torsional strain? |
|
Definition
|
|
Term
|
Definition
| Use energy from ATP to unwind DNA |
|
|
Term
| What do single-strand-binding proteins do? |
|
Definition
| Coat strands to keep them apart. |
|
|
Term
| What prevents supercoiling? |
|
Definition
|
|
Term
| DNA _______ is used in replication. |
|
Definition
|
|
Term
| DNA replication is _____discontinuous. |
|
Definition
|
|
Term
| DNA Polymerase III can only add nucleotides to the __' end of an existing strand |
|
Definition
|
|
Term
| The leading strand of DNA is synthesized _______. Meaning the ________ direction as the replication fork. |
|
Definition
|
|
Term
| The lagging strand of DNA is synthesized _________. It creates ________ _________. |
|
Definition
| Discontinuously. Okazaki fragments. |
|
|
Term
| What are the steps of DNA replication? |
|
Definition
1.) Unzip DNA by HELICASE
2.) Add RNA primer: RNA POLYMERASE/PRIMASE
3.) Polymerize 5' -> 3' by DNA POLYMERASE 3 |
|
|
Term
| What extends the leading strand? Is it a single or multiple priming event? |
|
Definition
| DNA polymerase 3. Single. |
|
|
Term
| How does lagging DNA synthesis occur? |
|
Definition
1.) RNA primers used
2.) DNA is synthesized by DNA polymerase 3
3.) Replace RNA primers with DNA polymerase 1
4.) Seal the backbone with ligase |
|
|
Term
| Where are the enzymes for DNA replication contained within prokaryotes? |
|
Definition
|
|
Term
| What does a replisome consist of? |
|
Definition
A primosome which is composed of primase, helicase, and accessory proteins.
2 DNA polymerase 3 molecules (one for each strand) |
|
|
Term
| How do replication forks move in prokaryotic DNA replication? |
|
Definition
| 1 direction, synthesizing both strands simultaneously. |
|
|
Term
| What does the larger size and complex packing of eukaryotic chromosomes mean? |
|
Definition
| They must be replicated from multiple origins of replication. |
|
|
Term
| Enzymes of DNA replication are more ______ than prokaryotic. |
|
Definition
|
|
Term
| Why are the ends of the chromosomes in eukaryotic organisms complicated? |
|
Definition
|
|
Term
| Because of this, with each round of DNA replication, the linear eukaryotic chromosome could become ______ but it doesn't. |
|
Definition
|
|
Term
| When the lagging strand reaches it's end, the last primer is removed, leaving one side shorter than the other. The excess is removed from the antiparallel strand which makes them even and causes a shortened template strand. |
|
Definition
|
|
Term
|
Definition
| Repeated DNA sequence on the ends of eukaryotic chromosomes. |
|
|
Term
| What does a telomere protect? |
|
Definition
| Ends of chromosomes from nucleases and maintain the integrity of linear chromosomes. |
|
|
Term
|
Definition
|
|
Term
| What keeps the leading strand from not shortening? |
|
Definition
| The RNA region in telomerase is used as a template to lengthen lagging strands so leading stand does not shorten. |
|
|
Term
| DNA polymerases have the _________ ability. |
|
Definition
|
|
Term
|
Definition
| Any agent that increases the number of mutations above background level. Radiation and chemicals. |
|
|
Term
| What is the importance of DNA repair indicated by? |
|
Definition
| The multiplicity of repair systems that have been discovered. |
|
|
Term
| What is an example of specific DNA repair? |
|
Definition
| Photorepair of thymine dimers by photolyase. |
|
|
Term
| What is an example of non specific DNA repair? |
|
Definition
| Excision repair corrects damaged or mismatched bases. They RECOGNIZE, REMOVE, RESYNTHESIZE. |
|
|
Term
| One gene = one ___________. Which is a chain of ______ _______. |
|
Definition
| polypeptide. amino acids. |
|
|
Term
| What is the central dogma of molecular biology? |
|
Definition
Information flows in one direction.
DNA -> RNA -> protein |
|
|
Term
|
Definition
| The flow of info from DNA to RNA. |
|
|
Term
|
Definition
| the flow of info from RNA to protein. |
|
|
Term
| Transcription is _______ directed synthesis of ______. |
|
Definition
|
|
Term
| What strand is used in transcription? |
|
Definition
|
|
Term
| What bases are replaced in transcription? |
|
Definition
| The Thymine in DNA is replaced by the Uracil in RNA. |
|
|
Term
| What is used to direct synthesis of polypeptides? |
|
Definition
|
|
Term
|
Definition
| Synthsis of polypeptides that takes place in the ribosomes that requires several types of RNA. |
|
|
Term
| In initiation, RNA polymerase identifies what? |
|
Definition
| Where to begin transcription |
|
|
Term
| In elongation, RNA nucleotides are added to what end of the new RNA? |
|
Definition
|
|
Term
| In termination, the RNA polymerase stops transcription when it encounters what? |
|
Definition
| Terminators in the DNA sequence |
|
|
Term
| What is the template stand? |
|
Definition
| The strand of DNA double helix used to make RNA. |
|
|
Term
| What is the coding strand? |
|
Definition
| strand of DNA that is complementary to template strand. |
|
|
Term
|
Definition
| The enzyme that synthesizes RNA from the DNA template strand. |
|
|
Term
| What are the 2 forms of RNA polymerase found in prokaryotic cells? |
|
Definition
| Core polymerase and holoenzyme |
|
|
Term
|
Definition
| Capable of RNA elongation but not initiation |
|
|
Term
|
Definition
| Composed of the core enzyme and the sigma factor which is required for transcription initiation. |
|
|
Term
| What is a transcriptional unit in prokaryotic transcription? |
|
Definition
| extends from the promoter to the terminator. |
|
|
Term
| What is the promoter composed of in prokaryotic transcription? |
|
Definition
DNA sequence for the binding of RNA polymerase.
The start site (+1) - the first base to be transcribed |
|
|
Term
| What happens to the transcription bubble during prokaryotic transcription elongation? |
|
Definition
| Moves down the DNA template at the rate of 50 nucleotides per second. It consists of RNA polymerase, DNA template, and a growing RNA transcript. |
|
|
Term
| What marks termination? What does termination cause? |
|
Definition
| A sequence that signals stop to polymerase. The formation of phosphodiester bonds to cease. RNA-DNA hybrid within the transcription bubble dissociates. RNA polymerase realizes the DNA and then it rewinds. |
|
|
Term
| What does a hairpin loop cause? |
|
Definition
| mRNA hairpin causes RNA polymerase to pause. |
|
|
Term
| Prokaryotic transcription is coupled to _________. |
|
Definition
|
|
Term
| mRNA begins to be ________ before transcription is finished. |
|
Definition
|
|
Term
|
Definition
| Grouping of functionally related genes. Multiple enzymes for a pathway. Can be regulated together. |
|
|
Term
| What does initiation of transcription in eukaryotes require? |
|
Definition
| A series of transcription factors. |
|
|
Term
| What must happen for euk. transcription to occur? |
|
Definition
| To get the RNA polymerase 2 enzyme to a promoter and to initiate gene expression. |
|
|
Term
| Interact with ______ _____________ to form initiation complex at promoter. |
|
Definition
|
|
Term
| Which has more defined termination sites - pro or eu? |
|
Definition
|
|
Term
| What are the modifications to the primary transcript molecule in eukaryotic mRNA? |
|
Definition
- addition of the 5' cap
+ protects from degradation, initiation of translation as well
- addition of a 3' poly-A tail
+ protects from degradation
-removal of non-coding sequences called introns |
|
|
Term
| What is responsible for removing introns and splicing exons together? |
|
Definition
|
|
Term
| What recognizes the intron-exon boundaries? |
|
Definition
| Small ribonucleoprotein particles (snRNPs) |
|
|
Term
|
Definition
| A sequence that will be translated |
|
|
Term
| How are single primary transcripts spliced into different mRNA's? |
|
Definition
| By the inclusion of different sets of exons. |
|
|
Term
| ____% of known human genetic disorders are due to altered splicing/ |
|
Definition
|
|
Term
| ____%-_____% of human genes exhibit some form of alternative splicing. |
|
Definition
|
|
Term
| What does alternative splicing explain? |
|
Definition
| How 25,000 genes of human genome can encode more than 80,000 different RNAs |
|
|
Term
|
Definition
| Carries the information from DNA that encodes proteins |
|
|
Term
|
Definition
| Structural component of the ribosome |
|
|
Term
|
Definition
| Carries amino acids to the ribosome for translation |
|
|
Term
|
Definition
| involved in processing pre-mRNA |
|
|
Term
|
Definition
| Composed of protein and RNA and involved in directing mRNA to the RER. |
|
|
Term
|
Definition
| Very small and their role is unclear yet. |
|
|
Term
| What are the 3 different RNA polymerases in eukaryotic transcription? |
|
Definition
1.) RNA polymerase I
+ transcribes RNA
2.) RNA polymerase II
+ transcribes mRNA and some snRNA
3.) RNA polymerase III
+ transcribes tRNA and some other small RNAS |
|
|
Term
| Each RNA polymerase recognizes its own _________. |
|
Definition
|
|
Term
| What happens in eukaryotic translation INITIATION? |
|
Definition
| mRNA, tRNA, and ribosome come together |
|
|
Term
| What happens in eukaryotic translation ELONGATION? |
|
Definition
| tRNAs bring amino acids to the ribosome for incorporation into the polypeptide. |
|
|
Term
| What happens in eukaryotic translation TERMINATION? |
|
Definition
| Ribosome encounters a stop codon and releases the polypeptide. |
|
|
Term
|
Definition
| A set of 3 nucleotides that specify a particular amino acid. |
|
|
Term
| What is the reading frame? |
|
Definition
| The series of nucleotides read in sets of 3. |
|
|
Term
| How many reading frames are correct for encoding the correct sequence of amino acids? |
|
Definition
|
|
Term
| WHo identified that codons that specify each amino acid? |
|
Definition
|
|
Term
| RNA molecules of only 1 nucleotide and of specific 3-base sequences were used to determine what? |
|
Definition
| The amino acid encoded by each codon. |
|
|
Term
| How many codons are there? |
|
Definition
|
|
Term
| What are the stop codons? |
|
Definition
| UAA, UGA, UAG. Terminates translation. |
|
|
Term
|
Definition
|
|
Term
| What happens with the remainder of the code? |
|
Definition
| Its degenerate meaning that some amino acids are specified by more than one codon. |
|
|
Term
| What do tRNA molecules carry? |
|
Definition
| Amino acids to the ribosome for incorporation into a polypeptide. |
|
|
Term
| What does aminoacyl-tRNA synthetases add? |
|
Definition
| amino acids to the acceptor arm of tRNA |
|
|
Term
| What does the anticodon loop contain? |
|
Definition
| 3 nucleotides complementary to mRNA codons. |
|
|
Term
| What are the different tRNA binding sites on a ribosome? |
|
Definition
- A site
- P site
- E site |
|
|
Term
|
Definition
| Binds to the tRNA carrying the next amino acid |
|
|
Term
|
Definition
| Binds to the tRNA attached to the growing peptide chain. |
|
|
Term
|
Definition
| Binds to the tRNA that carried the last amino acid (exit). |
|
|
Term
| What are the 2 primary functions of ribosomes? |
|
Definition
1.) decode the mRNA
2.) form peptide bonds |
|
|
Term
| What does peptidyl transferase do? |
|
Definition
| The enzymatic component of the ribosome which forms peptide bonds between amino acids. |
|
|
Term
| What does initiation of translation in prokaryotes require? |
|
Definition
| The formation of the initiation complex. |
|
|
Term
| What does the initiation complex include? |
|
Definition
-An initiator tRNA charged with N-formylmethionine
-A small ribosomal subunit
-mRNA strand |
|
|
Term
| THe ribosome binding sequence of mRNA is complementary to part of _______. |
|
Definition
|
|
Term
| How does initiation in eukaryotes differ from prokaryotes? |
|
Definition
- initiating amino acid is methionine
- more complicated initiation complex
- lack of an RBS - small subunit binds to the 5' cap of mRNA |
|
|
Term
| What happens in translation/tRNA elongation? |
|
Definition
| A charged tRNA binds to the A site if its anticodon is complementary to the condon at the A site. Then, the peptidyl transferase forms a peptide bond. Then the ribosome moves down the mRNA in a 5'-3' direction. |
|
|
Term
| When does elongation end? |
|
Definition
| When the ribosome encounters a stop codon. |
|
|
Term
| What are stop codons recognized by? |
|
Definition
| Release factors which release the polypeptide from the ribosome. |
|
|
Term
| Where are the 2 places that translation can occur in eukaryotes? |
|
Definition
1.) ribosomes in the cytoplasm
2.) ribosomes of the rough endoplasmic reticulum |
|
|
Term
| What do signal sequences bind to? |
|
Definition
| the signal recognition particle. |
|
|
Term
| The signal sequence and the SRP are recognized by what? |
|
Definition
| Rough endoplasmic reticulum receptor proteins. |
|
|
Term
| What holds the ribosome to the rough endoplasmic reticulum? |
|
Definition
|
|
Term
| Do prokaryotes have introns? |
|
Definition
| No, but some genes possess them. |
|
|
Term
| How many genes can be transcribed into a single mRNA molecule in prokaryotes? |
|
Definition
|
|
Term
| How many genes can be transcribed into a single mRNA molecule in eukaryotes? |
|
Definition
| One one genes per mRNA molecule |
|
|
Term
| Are translation and transcription separate or coupled in prokaryotes? |
|
Definition
|
|
Term
| Where does transcription occur in eukaryotes? |
|
Definition
|
|
Term
| Where does translation occur in eukaryotes? |
|
Definition
|
|
Term
| Where does initiation of translation begin in both eu and pro? |
|
Definition
|
|
Term
| What precedes the AUG codon in pro? |
|
Definition
| Special sequence that binds the ribosome |
|
|
Term
| What preceded the AUG codon in eu? |
|
Definition
| 5' cap that binds to the ribosome |
|
|
Term
| IS there modification of mRNA after transcription in pro? |
|
Definition
| No. Translation begins after transcription ends. Coupled. |
|
|
Term
| IS there modification of mRNA after transcription in eu? |
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Definition
| Happens while mRNA is in the nucleus. Introns are removed, exons spliced together, a 5' cap is added, and a poly a tail is added. |
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Term
| What do point mutations alter? |
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Definition
|
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Term
| What is a base substitution? |
|
Definition
| Substitutes base for another. Also called missense mutation |
|
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Term
| What is a nonsense mutation? |
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Definition
|
|
Term
| What is a frameshift mutation? |
|
Definition
| Caused by insertion or deletion of a single base |
|
|
Term
| What is a chromosomal mutation? |
|
Definition
| Change chromosomal structure |
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Term
|
Definition
|
|
Term
|
Definition
| Part of chromosome is copied |
|
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Term
|
Definition
| Part of a chromosome is in reverse order |
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Term
|
Definition
| Part of chromosome is moved to new location. |
|
|
Term
| What is control of gene expression often controlled by? |
|
Definition
| Controlling transcription initiation |
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|
Term
| Regulatory proteins bind to DNA may _____ or ______ transcription. |
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Definition
|
|
Term
| When do prokaryotes regulate gene expression? |
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Definition
| IN response to their environment |
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|
Term
| When do eukaryotes regulate gene expression? |
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Definition
| To maintain homeostasis in the organism |
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|
Term
| Gene expression is often controlled by what? |
|
Definition
| Regulatory proteins binding to specific DNA sequences |
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|
Term
| Where do regulatory proteins gain access to the bases of DNA? |
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Definition
|
|
Term
| What do regulatory proteins possess? |
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Definition
|
|
Term
| How do motifs in regulatory proteins help bind to DNA? |
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Definition
1.) Helix-turn-helix motif
2.) Leucine zipper motif |
|
|
Term
| In prokaryotes, what are the 2 types of control of transcription of initiation? |
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Definition
|
|
Term
| What is positive control of transcription initiation? |
|
Definition
| Increases transcription when activators bind to DNA |
|
|
Term
| What is negative control of transcription initiation? |
|
Definition
| Reduces transcription when repressors bind to DNA regulatory regions called operators. |
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|
Term
| Genes that are involved in the same metabolic pathway are organized in what? PRO |
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Definition
| Operons. All genes in operons are regulated together. |
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|
Term
| When are operons induced and repressed? PRO |
|
Definition
Induced - when the metabolic pathway is needed
Repressed - when the metabolic pathway is not needed |
|
|
Term
| What does the lac operon contain? |
|
Definition
| Genes for the use of lactose as an energy source. |
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|
Term
| When is the lac operon active? PRO |
|
Definition
| When lactose is available |
|
|
Term
| What are the 3 enzymes that are in lac operons that help metabolize lactose? PRO |
|
Definition
1.) beta-galactosidase
2.) permease
3.) transacetylase |
|
|
Term
| How is the lac operon negatively regulated? PRO |
|
Definition
| lac repressor binds to the operator to block transcription. in the presence of lactose, an inducer molecule binds to the repressor protein. the repressor can no longer bind to the operator, so transcription proceeds. |
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|
Term
| When lac operon is normally repressed, inducer _______ repressor. PRO |
|
Definition
|
|
Term
| So, when lactose is present the repressor is _______ so transcription and translation of these enzymes occurs so it can be digested. PRO |
|
Definition
|
|
Term
| What does a trp operon do? PRO |
|
Definition
| encodes genes for the biosynthesis of tryptophan. |
|
|
Term
| When the cell contains sufficient amounts of tryptophan, the operon is ______ _______. PRO |
|
Definition
|
|
Term
| Tryptophan _________ repressor, which ______ ______ operon. PRO |
|
Definition
|
|
Term
| What negatively regulates the trp operon? PRO |
|
Definition
|
|
Term
| How is trp negatively regulated? PRO |
|
Definition
| trp repressor binds to operator to block transcription, binding of repressor to the operator requires a COREPRESSOR which is tryptophan. Low levels of tryptophan prevent the repressor from binding to the operator. |
|
|
Term
| What controls the expression of eukaryotic genes? |
|
Definition
|
|
Term
| What are general transcription factors? |
|
Definition
| required for transcription initiation. required for proper binding of RNA polymerase II to the DNA. |
|
|
Term
| What are specific transcription factors? |
|
Definition
| Increase transcription in certain cell types or in response to signals |
|
|
Term
| General transcription factors bind to the ________ region on the gene. |
|
Definition
|
|
Term
| RNA polymerase II then binds to the promoter to begin _______ at the _____ ______. |
|
Definition
| transcription. start site. (+1) |
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|
Term
|
Definition
| DNA sequences to which specific transcription factors (activators) bind to increase the rate of transcription. |
|
|
Term
| What are coactivators and mediators? |
|
Definition
| Also required for the fan of transcription factors. They bind to transcription factors and bind to other parts of the transcription apparatus. |
|
|
Term
| What are the 3 of transcription complex? |
|
Definition
1.) nearly every eukaryotic gene represents a unique case
2.) great flexibility to respond to many signals
3.) virtually all genes that are transcribed by RNA polymerase II need the same suite of general factors assemble initiation complex. |
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|
Term
| What is the structure of chromatin in eukaryotes? |
|
Definition
| Directly related to the control of gene expression. DNA wound around histone proteins form nucleosomes. Nucleosomes may block access to promoter. Histones can be modified to result in greater condensation. |
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|
Term
|
Definition
|
|
Term
| Methylation of DNA or histone proteins is associated with what? |
|
Definition
| Control of gene expression |
|
|
Term
| Clusters of methylated cytosine nucleotides bind to a protein that _____________ activators from binding to DNA. |
|
Definition
|
|
Term
| What are associated with inactive regions of chromatin? |
|
Definition
| Methylated histone proteins |
|
|
Term
| Acteylation of histones signals what? |
|
Definition
| Actively transcribed regions of DNA |
|
|
Term
| What 4 things control gene expression after transcription? |
|
Definition
- RNA interference (miRNA and siRNA)
- alternative splicing
- RNA editing
- mRNA degradation |
|
|
Term
| Where does production of micro RNA begin? End? |
|
Definition
| The nucleus. Ends in the cytoplasm with a ~22 nt RNA that functions to repress gene expression |
|
|
Term
| What induces silencing complex (RISC)? |
|
Definition
|
|
Term
| What is RISC targeted to repress? |
|
Definition
| The expression of genes based on sequence complementary to the miRNA. |
|
|
Term
| How does small interfering RNA work? |
|
Definition
| Similarly to RISC and miRNA |
|
|
Term
| What does biogenesis of both miRNA and siRNA involve? |
|
Definition
| Cleavage by dicer and incorporation into a RISC complex |
|
|
Term
| What is the target of miRNA? |
|
Definition
| Repress genes different from their origin |
|
|
Term
| What is the target of siRNA? |
|
Definition
| Repress genes they were derived from |
|
|
Term
| In alternative splicing, introns are spliced out of ____-_____ to produce the mature _______. |
|
Definition
|
|
Term
| What is tissue specific alternative splicing? |
|
Definition
| Same gene makes calcitonin in the thyroid and calcitonin-gene related peptide in the hypothalamus. Determined by tissue specific factors that regulate the processing of primary transcript. |
|
|
Term
| What does RNA editing create? |
|
Definition
| Mature mRNA that are not truly encoded by the genome. |
|
|
Term
| What does RNA editing involve? |
|
Definition
| Chemical modification of a base to change its base-pairing properties. |
|
|
Term
| What are the two isoforms of apolipoprotein? |
|
Definition
- One for is produced by editing mRNA to create stop codon
- This RNA editing is tissue specific. |
|
|
Term
| What does mature mRNA half-lives depend on? |
|
Definition
| The gene and location (tissue) of expression. |
|
|
Term
| What can the amount of polypeptide produced from a particular gene be influenced by? |
|
Definition
| The half-life of the mRNA molecules. |
|
|
Term
| What are the steps of regulation? |
|
Definition
1.) Initiation of transcription
2.) RNA splicing (exon inclusion)
3.) Movement of mRNA from nucleus to ribosomes
4.) Protection/degradation of mRNA
5.) Regulation of translation
6.) Post-translational modification EX: phosphorylation influences enzyme activity. |
|
|
Term
|
Definition
| Proteases for nonspecific protein digestion. |
|
|
Term
| What are proteins marked with so they are eaten by lysosome? |
|
Definition
|
|
Term
| Where does degradation of proteins marked with ubiquitin occurs at ________? |
|
Definition
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