Podcast
Questions and Answers
What are the four general characteristics of genetic materials?
What are the four general characteristics of genetic materials?
What is the central dogma of molecular genetics?
What is the central dogma of molecular genetics?
DNA makes RNA, which makes protein.
What is a mutation?
What is a mutation?
A change in the chemical composition of DNA.
What is Griffith's transformation?
What is Griffith's transformation?
Signup and view all the answers
Avery et al. proved conclusively that DNA is the transforming principle by demonstrating that DNA is the only component that retains the ability to induce transformation after removing other components like proteins and carbohydrates.
Avery et al. proved conclusively that DNA is the transforming principle by demonstrating that DNA is the only component that retains the ability to induce transformation after removing other components like proteins and carbohydrates.
Signup and view all the answers
Hershey and Chase's experiment used radioactive isotopes P32 and S35 labels to track the protein and DNA components, respectively, of bacteriophage T2 during infection.
Hershey and Chase's experiment used radioactive isotopes P32 and S35 labels to track the protein and DNA components, respectively, of bacteriophage T2 during infection.
Signup and view all the answers
Which of the following are indirect evidence to prove DNA as genetic material in eukaryotes?
Which of the following are indirect evidence to prove DNA as genetic material in eukaryotes?
Signup and view all the answers
UV light is most mutagenic at the wavelength of 260nm, and both DNA and RNA absorb UV light most strongly at 260nm, whereas proteins absorb most strongly around 280nm.
UV light is most mutagenic at the wavelength of 260nm, and both DNA and RNA absorb UV light most strongly at 260nm, whereas proteins absorb most strongly around 280nm.
Signup and view all the answers
Recombinant DNA technology is the strongest evidence that proves DNA is the genetic material.
Recombinant DNA technology is the strongest evidence that proves DNA is the genetic material.
Signup and view all the answers
RNA can act as the genetic material in viruses, such as Tobacco Mosaic Virus (TMV), where the virus's RNA carries the genetic information for replication.
RNA can act as the genetic material in viruses, such as Tobacco Mosaic Virus (TMV), where the virus's RNA carries the genetic information for replication.
Signup and view all the answers
Match the following terms related to DNA structure with their descriptions:
Match the following terms related to DNA structure with their descriptions:
Signup and view all the answers
The two strands of DNA in a double helix are parallel, meaning they run in the same direction.
The two strands of DNA in a double helix are parallel, meaning they run in the same direction.
Signup and view all the answers
Adenine (A) pairs with thymine (T), and guanine (G) pairs with cytosine (C) through hydrogen bonds, forming the bases of DNA.
Adenine (A) pairs with thymine (T), and guanine (G) pairs with cytosine (C) through hydrogen bonds, forming the bases of DNA.
Signup and view all the answers
Which of the following describes the Watson-Crick model of DNA structure?
Which of the following describes the Watson-Crick model of DNA structure?
Signup and view all the answers
The arrangement of sugars and bases along the axis in the Watson-Crick model, where hydrophobic bases are stacked inside and hydrophilic sugar-phosphate backbones are on the outside, contributes to the stability of DNA.
The arrangement of sugars and bases along the axis in the Watson-Crick model, where hydrophobic bases are stacked inside and hydrophilic sugar-phosphate backbones are on the outside, contributes to the stability of DNA.
Signup and view all the answers
How is DNA denatured?
How is DNA denatured?
Signup and view all the answers
A melting profile of DNA shows the increase in UV absorption versus temperature, and the melting temperature (Tm) is the midpoint of this profile, where 50 percent of the DNA strands are unwound.
A melting profile of DNA shows the increase in UV absorption versus temperature, and the melting temperature (Tm) is the midpoint of this profile, where 50 percent of the DNA strands are unwound.
Signup and view all the answers
What are some applications of molecular hybridization?
What are some applications of molecular hybridization?
Signup and view all the answers
Gel electrophoresis separates molecules based on their size and charge, with smaller molecules migrating faster through the gel than larger molecules.
Gel electrophoresis separates molecules based on their size and charge, with smaller molecules migrating faster through the gel than larger molecules.
Signup and view all the answers
Which of the following is NOT a mode of DNA replication?
Which of the following is NOT a mode of DNA replication?
Signup and view all the answers
The Meselson-Stahl experiment used the heavy isotope of nitrogen, N15, to demonstrate that DNA replication is semiconservative.
The Meselson-Stahl experiment used the heavy isotope of nitrogen, N15, to demonstrate that DNA replication is semiconservative.
Signup and view all the answers
In eukaryotes, DNA replication occurs simultaneously at multiple replication origins, with each origin forming a replication bubble.
In eukaryotes, DNA replication occurs simultaneously at multiple replication origins, with each origin forming a replication bubble.
Signup and view all the answers
The leading strand is synthesized continuously, while the lagging strand is synthesized discontinuously in Okazaki fragments.
The leading strand is synthesized continuously, while the lagging strand is synthesized discontinuously in Okazaki fragments.
Signup and view all the answers
Which enzyme is primarily responsible for DNA synthesis during replication in bacteria?
Which enzyme is primarily responsible for DNA synthesis during replication in bacteria?
Signup and view all the answers
The sliding DNA clamp is a ring-shaped structure that encircles the DNA and prevents the core enzyme from dissociating from the template during replication.
The sliding DNA clamp is a ring-shaped structure that encircles the DNA and prevents the core enzyme from dissociating from the template during replication.
Signup and view all the answers
What is a replisome?
What is a replisome?
Signup and view all the answers
What is the origin of replication in E. coli called?
What is the origin of replication in E. coli called?
Signup and view all the answers
DNA polymerase I is responsible for removing RNA primers and filling the gaps left after their removal during DNA replication in bacteria.
DNA polymerase I is responsible for removing RNA primers and filling the gaps left after their removal during DNA replication in bacteria.
Signup and view all the answers
DNA polymerase III can initiate DNA synthesis de novo, meaning it can start synthesis without a primer.
DNA polymerase III can initiate DNA synthesis de novo, meaning it can start synthesis without a primer.
Signup and view all the answers
Proofreading during DNA replication corrects errors by the 3' to 5' exonuclease activity of DNA polymerase.
Proofreading during DNA replication corrects errors by the 3' to 5' exonuclease activity of DNA polymerase.
Signup and view all the answers
What is the role of DNA gyrase during DNA replication?
What is the role of DNA gyrase during DNA replication?
Signup and view all the answers
The lagging strand is synthesized in the same direction as the leading strand.
The lagging strand is synthesized in the same direction as the leading strand.
Signup and view all the answers
DNA ligase joins Okazaki fragments together on the lagging strand.
DNA ligase joins Okazaki fragments together on the lagging strand.
Signup and view all the answers
Eukaryotic DNA replication shares many similarities with bacterial DNA replication, including the use of a single origin of replication, bidirectional replication, and the presence of leading and lagging strands.
Eukaryotic DNA replication shares many similarities with bacterial DNA replication, including the use of a single origin of replication, bidirectional replication, and the presence of leading and lagging strands.
Signup and view all the answers
Eukaryotic DNA replication occurs in the cytoplasm.
Eukaryotic DNA replication occurs in the cytoplasm.
Signup and view all the answers
Eukaryotic DNA replication origins are known as Autonomously Replicating Sequences (ARSs) and are typically 120 base pairs long.
Eukaryotic DNA replication origins are known as Autonomously Replicating Sequences (ARSs) and are typically 120 base pairs long.
Signup and view all the answers
The pre-RC, or prereplication complex, assembles at replication origins during the G1 phase of the cell cycle, marking them as potential sites for replication.
The pre-RC, or prereplication complex, assembles at replication origins during the G1 phase of the cell cycle, marking them as potential sites for replication.
Signup and view all the answers
DNA polymerase α is responsible for synthesizing both the leading and lagging strands during eukaryotic DNA replication.
DNA polymerase α is responsible for synthesizing both the leading and lagging strands during eukaryotic DNA replication.
Signup and view all the answers
Eukaryotic DNA polymerase γ is responsible for replicating mitochondrial DNA.
Eukaryotic DNA polymerase γ is responsible for replicating mitochondrial DNA.
Signup and view all the answers
Telomeres are repetitive DNA sequences found at the ends of linear eukaryotic chromosomes that help prevent chromosome degradation and fusion.
Telomeres are repetitive DNA sequences found at the ends of linear eukaryotic chromosomes that help prevent chromosome degradation and fusion.
Signup and view all the answers
The 3'-end of the telomere extends as an overhang, forming a single-stranded tail that can loop back on itself, creating a t-loop structure.
The 3'-end of the telomere extends as an overhang, forming a single-stranded tail that can loop back on itself, creating a t-loop structure.
Signup and view all the answers
Telomerase is an enzyme that extends the 3'-end of the telomere, preventing chromosome shortening during replication.
Telomerase is an enzyme that extends the 3'-end of the telomere, preventing chromosome shortening during replication.
Signup and view all the answers
Homologous recombination is a reciprocal genetic exchange between two DNA molecules, resulting in the creation of new combinations of genetic material.
Homologous recombination is a reciprocal genetic exchange between two DNA molecules, resulting in the creation of new combinations of genetic material.
Signup and view all the answers
Gene conversion is a nonreciprocal exchange of genetic information between two DNA molecules, where one molecule inherits a copy of a gene from the other molecule.
Gene conversion is a nonreciprocal exchange of genetic information between two DNA molecules, where one molecule inherits a copy of a gene from the other molecule.
Signup and view all the answers
The genetic code is a triplet code, meaning that each amino acid is encoded by a sequence of three nucleotides.
The genetic code is a triplet code, meaning that each amino acid is encoded by a sequence of three nucleotides.
Signup and view all the answers
The genetic code is unambiguous, meaning that each codon specifies only one amino acid.
The genetic code is unambiguous, meaning that each codon specifies only one amino acid.
Signup and view all the answers
The genetic code is degenerate, meaning that multiple codons can specify the same amino acid.
The genetic code is degenerate, meaning that multiple codons can specify the same amino acid.
Signup and view all the answers
The wobble hypothesis explains the flexibility in base pairing at the third position of the codon, allowing a single tRNA to recognize multiple codons.
The wobble hypothesis explains the flexibility in base pairing at the third position of the codon, allowing a single tRNA to recognize multiple codons.
Signup and view all the answers
AUG is the initiator codon, specifying methionine, while UAG, UAA, and UGA are termination codons.
AUG is the initiator codon, specifying methionine, while UAG, UAA, and UGA are termination codons.
Signup and view all the answers
A nonsense mutation occurs when a codon is changed to a termination codon, resulting in the premature termination of protein synthesis.
A nonsense mutation occurs when a codon is changed to a termination codon, resulting in the premature termination of protein synthesis.
Signup and view all the answers
Overlapping genes occur when a single mRNA molecule can be translated into multiple proteins by using different reading frames.
Overlapping genes occur when a single mRNA molecule can be translated into multiple proteins by using different reading frames.
Signup and view all the answers
Transcription is the process of copying the genetic information from DNA to RNA, acting as the first step in gene expression.
Transcription is the process of copying the genetic information from DNA to RNA, acting as the first step in gene expression.
Signup and view all the answers
RNA polymerase is the enzyme responsible for synthesizing RNA from a DNA template, requiring a primer to initiate synthesis.
RNA polymerase is the enzyme responsible for synthesizing RNA from a DNA template, requiring a primer to initiate synthesis.
Signup and view all the answers
Promoters are DNA sequences that signal the location of genes and serve as binding sites for RNA polymerase, initiating transcription.
Promoters are DNA sequences that signal the location of genes and serve as binding sites for RNA polymerase, initiating transcription.
Signup and view all the answers
The sigma subunit (σ subunit) of RNA polymerase recognizes specific promoter sequences, initiating transcription in bacteria.
The sigma subunit (σ subunit) of RNA polymerase recognizes specific promoter sequences, initiating transcription in bacteria.
Signup and view all the answers
Transcription in prokaryotes is typically polycistronic, meaning that a single mRNA molecule can encode multiple proteins.
Transcription in prokaryotes is typically polycistronic, meaning that a single mRNA molecule can encode multiple proteins.
Signup and view all the answers
Transcription in eukaryotes is typically monocistronic, meaning that each mRNA molecule encodes only one protein.
Transcription in eukaryotes is typically monocistronic, meaning that each mRNA molecule encodes only one protein.
Signup and view all the answers
RNA splicing is a process that removes introns, noncoding sequences within a eukaryotic pre-mRNA, to produce a mature mRNA.
RNA splicing is a process that removes introns, noncoding sequences within a eukaryotic pre-mRNA, to produce a mature mRNA.
Signup and view all the answers
RNA editing refers to the process of altering the nucleotide sequence of a pre-mRNA prior to translation, resulting in changes to the protein product.
RNA editing refers to the process of altering the nucleotide sequence of a pre-mRNA prior to translation, resulting in changes to the protein product.
Signup and view all the answers
Study Notes
Genetics 244 Summaries CHP 10, 11, 13
-
Chapter 10: DNA Structure and Analysis
- Explains general characteristics of genetic material
- Outlines historical studies proving DNA as genetic material in prokaryotes and eukaryotes
- Discusses RNA as genetic material in viruses
- Describes chemical composition of nucleic acids
- Explains structures of DNA and RNA, highlighting differences
- Details various analyses of nucleic acids
-
Four General Characteristics of Genetic Material
- Replication (mitosis, meiosis)
- Storage of information (genome repository)
- Expression of stored information (DNA→RNA→Protein)
- Variation by mutation (chemical changes in DNA)
-
Historical Timeline of DNA as Genetic Material in Prokaryotes
- 1927: Griffith's transformation of bacteria
- 1944: Avery et al.
- 1952: Hershey-Chase
-
Griffith's Experiment
- Used strains of Diplococcus pneumoniae (some virulent, others avirulent, differing in polysaccharide capsules).
- Injected live avirulent cells plus killed virulent cells into mice- mice died.
- Blood contained live virulent bacteria.
- Concluded a transforming principle.
-
Avery, MacLeod, and McCarty Experiment
- Repeated Griffith's experiment, removing proteins and polysaccharides.
- The transforming activity remained.
- Treated with enzymes- removing RNA, proteins, still active.
- Treating with DNase destroyed transforming activity.
- Concluded DNA was the transforming principle.
-
Hershey-Chase Experiment
- Used bacteriophage T2 to infect E. coli
- Radioactively labeled bacteriophage protein (S35) and DNA (P32).
- Phage DNA entered the bacterial cells directing phage reproduction; protein remained outside and did not.
- Indicated that DNA was the genetic material.
-
Indirect and direct evidence for DNA as genetic material in eukaryotes
- Indirect: Distribution of DNA in nucleus and genetic material functions in nucleus
- Indirect: Mutagenesis (UV light absorption in nucleic acids);
- Direct: Recombinant DNA Studies
-
Chapter 11: DNA Replication and Recombination
- Explains various DNA replication modes (semi-conservative, conservative, dispersive)
- Details the Meselson-Stahl experiment which proves semi-conservative replication by using isotopes (15N, 14N).
- Discusses replication modes (bidirectional) and initiation in prokaryotes (e.g. E. coli)
-
Enzymes involved in DNA synthesis in microorganisms
- Explains the function of DNA polymerase I (DNA synthesis and removal of RNA primers)
- Details the requirement of dNTP's, template DNA and a primer for reaction.
- Describes the polymerization process; 5'-3' direction.
-
DNA Polymerase II, III, IV, and V
- DNA polymerase III is responsible for DNA synthesis during replication
- DNA polymerase I removes RNA primers and fills in gaps
- DNA polymerase II, IV, and V are believed to be involved in DNA repair.
- Explains the core enzyme of DNA polymeras III holoenzyme which plays a role in DNA replication
- Explains the replisome which is an enzyme complex responsible for replication synthesis.
-
A Model for DNA Synthesis (Prokaryotes)
- Outlines the steps involved in the bacterial DNA synthetic process. The mechanisms enabling the unwinding and opening of the DNA helix, the synthesis of RNA primers, and the filling of the gaps.
- Details the process required for the replication of the DNA strands
- Explains proofreading by DNA polymerases.
- Details Unwinding of DNA helix
- Discusses Origin of Replication in E. coli
- Defines replicons and replication forks
-
Chapter 13: The Genetic Code and Transcription
- Introduces characteristics of the genetic code:
- Triplet code
- Unambiguous, degenerate
- Commaless, nonoverlapping
- Early work on deciphering the code:
- Importance of synthetic mRNAs (Nirenberg and Matthaei experiments)
- Mixed copolymers experiments
- Introduces the wobble hypothesis and its implications for degeneracy.
- Discusses initiation, termination, and suppression factors in translation; and their mechanisms
- Introduces characteristics of the genetic code:
-
DNA Replication in eukaryotes
- Differences in eukaryotic DNA replication mechanisms in comparison to bacterial cells:
- Site of replication (within nucleus)
- Origins of replication (multiple)
- Replication forks (many)
- Types of DNA polymerase
- Size of Okazaki fragments
- Rates of DNA synthesis
- Initiation at Multiple Replication Origins (ARS sequences)
- Introduces various eukaryotic DNA polymerases: Pol a, δ, ɛ, γ
- Describes Processing Eukaryotic RNA (5' capping, 3' polyadenylation, splicing removal of introns)
- Discusses the problem of replicating the ends of linear chromosomes (telomeres and telomerase)
- Differences in eukaryotic DNA replication mechanisms in comparison to bacterial cells:
-
RNA editing
- Definition and types (substitutions and deletions)
-
Additional Information
- Covers characteristics of RNA sequence
- Includes processes of the transcription of RNA on DNA template in both eukaryotes and prokaryotes
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
