This document discusses various techniques used to study prokaryotic genetics, including bacterial conjugation, phage transduction, transformation, cross-feeding, and complementation. It provides examples of how these techniques can be used to determine the order and function of genes in metabolic pathways. Specifically, it describes experiments using the lactose operon in E. coli to elucidate the mechanism of transcriptional gene regulation in response to environmental conditions.
Basics of Undergraduate/university fellows
Transcription is more complicated in eukaryotes than in prokaryotes because
eukaryotes possess three different classes of RNA polymerases and because of the
way in which transcripts are processed to their functional forms.
More proteins and transcription factors are involved in eukaryotic transcription.
Dna supercoiling and role of topoisomerasesYashwanth B S
supercoiling is one of the important process to condenses the huge amount of DNA to fit inside the histone and its also plays a role during the replication ,transcription etc..,these activities is carried out by an enzyme called topoisomerases.
Basics of Undergraduate/university fellows
Transcription is more complicated in eukaryotes than in prokaryotes because
eukaryotes possess three different classes of RNA polymerases and because of the
way in which transcripts are processed to their functional forms.
More proteins and transcription factors are involved in eukaryotic transcription.
Dna supercoiling and role of topoisomerasesYashwanth B S
supercoiling is one of the important process to condenses the huge amount of DNA to fit inside the histone and its also plays a role during the replication ,transcription etc..,these activities is carried out by an enzyme called topoisomerases.
An introduction to the concept of Signal transduction mechanism prevalent in lower organisms, particularly bacteria. Also forms a part in many eukaryotic systems of signal transduction, particularly in the plant world.
A ribozyme is a ribonucleic acid (RNA) enzyme that catalyses specific reactions in a similar way to that of protein enzymes; it also known as catalytic RNA, ribozymes are found in the ribosome for protein formation and play a role in other vital mechanisms such as RNA splicing, transfer RNA biosynthesis, and viral replication. Discovery of catalytic RNA contributed to the hypothesis of prebiotic RNA world i.e. how life may have originated from an “RNA World” inhabited by self-replicating ribozymes. The ribosome is indeed a ribozyme underlines the relevance of RNA catalysis in today’s protein-dominated world.
The recent discoveries of RNA interference and micro-RNA associated mechanisms of gene regulation further emphasize the central importance of RNA to understanding gene regulation and leads to design new RNA-based technologies for gene manipulation and silencing.
The discovery that riboswitches and in some cases ribozymes, including a variant of the hammerhead ribozyme are also involved in regulating gene expression explains how intimately RNA structure, function, and catalysis are involved in many aspects of biological control.
An introduction to the concept of Signal transduction mechanism prevalent in lower organisms, particularly bacteria. Also forms a part in many eukaryotic systems of signal transduction, particularly in the plant world.
A ribozyme is a ribonucleic acid (RNA) enzyme that catalyses specific reactions in a similar way to that of protein enzymes; it also known as catalytic RNA, ribozymes are found in the ribosome for protein formation and play a role in other vital mechanisms such as RNA splicing, transfer RNA biosynthesis, and viral replication. Discovery of catalytic RNA contributed to the hypothesis of prebiotic RNA world i.e. how life may have originated from an “RNA World” inhabited by self-replicating ribozymes. The ribosome is indeed a ribozyme underlines the relevance of RNA catalysis in today’s protein-dominated world.
The recent discoveries of RNA interference and micro-RNA associated mechanisms of gene regulation further emphasize the central importance of RNA to understanding gene regulation and leads to design new RNA-based technologies for gene manipulation and silencing.
The discovery that riboswitches and in some cases ribozymes, including a variant of the hammerhead ribozyme are also involved in regulating gene expression explains how intimately RNA structure, function, and catalysis are involved in many aspects of biological control.
Describe how the structure of the DNA double helix was discovered. E.pdfarchanadesignfashion
Describe how the structure of the DNA double helix was discovered. Explain how DNA
ultimately controls the functioning of cells (be specific), and how/why mutations in DNA can
disrupt proper functioning. In chapter 2 you learned that the function of DNA and RNA is
\"information storage.\" Using what you\'ve teamed in Chapter 5, describe in detail the specific
functions of DNA and RNA. Explain the process of transcription. Explain the process of
translation. Briefly describe three types of mutations and explain how certain mutations can be
unrecognizable in an organism while others may have disastrous consequences. Summarize
three ways that genetic engineering is being used in agriculture. Explain three concerns
regarding the use of GMO\'s in agriculture How has genetic engineering technology been
directly applied to human health (most agriculture applications are indirect)? Has it been
successful? How are goals used to make medicine?
Solution
1 The function of DNA? depends to a large extent on its structure. The three-dimensional
structure of DNA was first proposed by James Watson and Francis Crick in 1953. It is one of the
most famous scientific discoveries of all time.
James and Francis used evidence shared by others, particularly Rosalind Franklin and Maurice
Wilkins, to determine the shape of DNA. Rosalind worked with Maurice at King\'s College
London. She beamed X-rays through crystals of the DNA molecule and then used photographic
film to record where the scattered X-rays fell. The shadows on the film were then used to work
out where the dense molecules lie in the DNA. This technique is called X-ray diffraction. The
DNA crystals resulted in a cross shape on the X-ray film which is typical of a molecule with a
helix shape. The resulting X-ray was named Photograph 51 and Maurice shared it with James
and Francis.
In 1953 James Watson and Francis Crick published their theory that DNA must be shaped like a
double helix. A double helix resembles a twisted ladder. Each \'upright\' pole of the ladder is
formed from a backbone of alternating sugar and phosphate groups. Each DNA base? (adenine,
cytosine, guanine, thymine) is attached to the backbone and these bases form the rungs. There
are ten \'rungs\' for each complete twist in the DNA helix.
James and Francis suggested that each \'rung\' of the DNA helix was composed of a pair of
bases, joined by hydrogen bonds?. According to Erwin Chargaff’s rules, A would always form
hydrogen bonds with T, and C with G.
2 - It is not the DNA itself that controls cellular functions, it is the proteins that are coded by the
DNA. The nucleotide sequences that make up DNA are a “code” for the cell to make hundreds of
different types of proteins; it is these proteins that function to control and regulate cell growth,
division, communication with other cells and most other cellular functions. This is why DNA is
said to “carry” or “store” information in the form of nucleotide sequences.
The sequences need to be “d.
6. Manifestations of the Fertility Factor Manifestation Description Hfr The F element is integrated into the genome. When conjugation occurs, the F genes travel across the pilus, dragging the rest of the genome behind it. Eventually, the pilus breaks, so most often the entire genome is not transferred. The bacterial genome can be measured in minutes from the origin of transfer: The amount of time it takes for a particular gene to be transferred from one bacterium to another indicates how far it is from the origin of replication. F' Also called the F' episome. This is a small circular piece of DNA that contains the fertility genes and a few other genes. These other genes are transferred very efficiently from one bacterium to the next because the length of the transferred DNA is short enough that it can move across the breach before the pilus breaks. F This is a small circular piece of DNA carrying only the fertility genes.
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10. Pathways Involve Multiple Genes Both biosynthetic and catabolic pathways involve multiple enzymes and thus multiple genes
28. Elements of the Lac Operon ELEMENT PURPOSE Operator (Lac O) Binding site for repressor Promoter (Lac P) Binding site for RNA polymerase Repressor (Lac I) Gene encoding lac repressor protein Binds to DNA at operator and blocks binding of RNA polymerase at promoter Pi Promoter for LacI CAP Binding site for cAMP/CAP complex
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