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Powerpoint Slides 6.2 Part B
Powerpoint Slides 6.2 Part B

... How does lambda make its decision for lysis or lysogeny? ...
Molecules of Life
Molecules of Life

... Can be denatured by extreme heat (shape is changed) Can be reused over and over again “Lock & Key” ...
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... The abundance of lactose in the medium compared to glucose allows for differentiation of fermentation of one sugar against that of both sugars. Since lactose is a disaccharide (glucose and galactose) if lactose is fermented then glucose must be fermented too. Thus distinction is made between fermen ...
file
file

... natural bacterial isolates are 'mutator' clones that have high mutation rates. We consider here whether high mutation rates might play an important role in adaptive evolution. Models of large, asexual, clonal populations adapting to a new environment show that strong mutator genes (such as those tha ...
NATURE`S BIOLOGICAL BUILDING BLOCKS
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... Composed of subunits (molecules) called amino acids joined together by a peptide bond. Proteins may be structural (as in muscle tissue and connective tissue) or enzymatic. They may also function as hormones. ...
High Frequency of Recombination (Hfr)
High Frequency of Recombination (Hfr)

... Therefore, transcriptional initiation is usually the major control point. Most prokaryotic genes are regulated in units called operons (Jacob and Monod, 1960) Operon: a coordinated unit of gene expression consisting of one or more related genes and the operator and promoter sequences that regulate t ...
Evolution connection: proteins, carbohydrates, and nucleic acids
Evolution connection: proteins, carbohydrates, and nucleic acids

... Students will understand that 1) our evolutionary history has affected our genes and proteins, 2) the availability of particular carbohydrates in the environment has shaped the evolutionary history of different human populations, and 3) our evolutionary history matters in our everyday lives. ...
Transformation Lab
Transformation Lab

... Beta-galactosidase and X-gal • The beta-galactosidase gene encodes a protein that normally cleaves the disaccharide sugar lactose into galactose and glucose. However, the enzyme will also cleave many other molecules that contain structures resembling the galactoseglucose link. Researchers have deve ...
Slide 1
Slide 1

... Figure 7-56. Distribution of the gene regulatory proteins responsible for ensuring that eve is expressed in stripe 2. The distributions of these proteins were visualized by staining a developing Drosophila embryo with antibodies directed against each of the four proteins (see Figures 7-52 and 7-53) ...
12.1 Mechanisms regulating enzyme synthesis 12.1.2.2 Enzyme
12.1 Mechanisms regulating enzyme synthesis 12.1.2.2 Enzyme

...  The regulatory gene (lacI) next to the 5’ end of the operon is expressed constitutively with its own promoter.  In the absence of the inducer, the LacI protein binds the operator region of the lac operon, inhibiting RNA polymerase from binding the promoter region.  When the inducer (lactose or I ...
Presentazione standard di PowerPoint
Presentazione standard di PowerPoint

... A prototroph bacterium can grow on a minimum media, composed by inorganic minerals and containing an organic source of carbon. Glucose is the most simple source of carbon. Alternative carbon sources can be used by wild bacteria. Some mutants loose this ability. The ability of bacteria to grow on di ...
Chapter 19 - Control of Gene Expression
Chapter 19 - Control of Gene Expression

... times in certain cells of the oviduct. These cells make large quantities of the protein needed to surround the egg. In other cells of the body, there is only one copy of this gene. The Immunoglobin Genes Immunoglobins (antibodies) are proteins that are used to defend the body against foreign invader ...
Welcome to the continuation of Biol 213 Genetics!
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... Genetics News What’s in the mail? • EditBase - DNA processing program • Mystery sequence Problem Set 3 now available ...
CH18_Regulation of Gene Expression Powerpoint
CH18_Regulation of Gene Expression Powerpoint

... pathways; their synthesis is repressed by high levels of the end product • Regulation of the trp and lac operons involves negative control of genes because operons are switched off by the active form of the repressor • (12-13 from previous knowledge) ...
ara Operon
ara Operon

... • Study of biological processes (example: synthesis of proteins) • Localization and regulation of gene expression • Cell movement • Cell fate during development ...
Distinguish between these 3 root types: - mvhs
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... Secretory Protein— A protein that will be _________ from the cell. The mRNA for this protein contains a signal recognition sequence that is recognized by a signal recognition particle (SRP). The SRP brings the growing polypeptide to the receptor protein in the ___________________. ...
Feb 24
Feb 24

... Structure of Prokaryotic promoters Three DNA sequences (core regions) 1) Pribnow box at -10 (10 bp 5’ to transcription start) 5’-TATAAT-3’ determines exact start site: bound by s factor 2)” -35 region” : 5’-TTGACA-3’ : bound by s factor 3) UP element : -57: bound by a factor Other sequences also of ...
Inquiry into Life Twelfth Edition
Inquiry into Life Twelfth Edition

... Cloning a gene permits • Production of large quantities of a particular DNA sequence for detailed study • Large quantities of the gene’s product (protein or RNA) can also be obtained for ...
diauxic shift- pre-class exe
diauxic shift- pre-class exe

... performed
by
Jacques
Monod
in
the
1940’s
during
his
PhD
work.
Subsequent
work
by
 Monod
led
him
to
decipher
the
basic
mechanisms
of
gene
regulation
and
propose
the
 lac
 operon
 model
 of
 gene
 expression,
 for
 which
 he
 received
 the
 Nobel
 prize
 together
 with
Jacob
and
Lwoff
in
1965.
The
ide ...
Lac A
Lac A

... d) How can we abolish the insertion mutation in position 11? If in a position near the first insertion a deletion happens, we can restore the correct frame of aminoacids. For example in position 15 (intragenic suppressionsuppressor mutation) ...
University of York Department of Biology B. Sc Stage 1 Degree
University of York Department of Biology B. Sc Stage 1 Degree

... 6. The following table indicates whether the CAP activator protein and/or the LacI repressor protein are binding to their sites within the regulatory region of the ​lac operon of ​E. coli bacteria grown in four different growth media. a) Fill in the table indicating whether you expect Glucose and/or ...
EE150a – Genomic Signal and Information Processing
EE150a – Genomic Signal and Information Processing

... • In special cases (e.g., arrays for gene detection), designer has a lot of control over the landscape of the probes on the array • Second topic for presentations considers a combinatorial design of such arrays • [How to deal with cross-hybridization on arrays used for expression level measurements ...
IlllllllllllllIlllllllIllllllllllllllIlllllllllllllllllllllllllllllllllllll
IlllllllllllllIlllllllIllllllllllllllIlllllllllllllllllllllllllllllllllllll

... 45 apparent on SDS-PAGE and the clones cleave X-gal, forming blue colonies under the same conditions. FIG. 4 -pMYC47l, a lactose inducible plasmid For ease in construction, the lacA gene has been The lacIZYA operon was cloned into the BamHI site included on all the plasmids contining lacIZYA men of ...
The Four Groups of Biologically Important Compounds
The Four Groups of Biologically Important Compounds

... • lipids do not dissolve in water ...
PowerPoint 演示文稿 - Xiamen University
PowerPoint 演示文稿 - Xiamen University

... 7.1.6 Mechanism of CAP Action The CAP-cAMP complex stimulates transcription of the lac operon by binding to an activator site adjacent to the promoter and helping RNA polymerase to bind to the promoter. ...
< 1 ... 62 63 64 65 66 67 68 69 70 ... 93 >

Lac operon



lac operon (lactose operon) is an operon required for the transport and metabolism of lactose in Escherichia coli and many other enteric bacteria. Although glucose is the preferred carbon source for most bacteria, the lac operon allows for the effective digestion of lactose when glucose is not available. Gene regulation of the lac operon was the first genetic regulatory mechanism to be understood clearly, so it has become a foremost example of prokaryotic gene regulation. It is often discussed in introductory molecular and cellular biology classes at universities for this reason.Bacterial operons are polycistronic transcripts that are able to produce multiple proteins from one mRNA transcript. In this case, when lactose is required as a sugar source for the bacterium, the three genes of the lac operon can be expressed and their subsequent proteins translated: lacZ, lacY, and lacA. The gene product of lacZ is β-galactosidase which cleaves lactose, a disaccharide, into glucose and galactose. LacY encodes lactose permease, a protein which becomes embedded in the cytoplasmic membrane to enable transport of lactose into the cell. Finally, lacA encodes galactoside O-acetyltransferase. Layout of the lac operon.It would be wasteful to produce the enzymes when there is no lactose available or if there is a more preferable energy source available, such as glucose. The lac operon uses a two-part control mechanism to ensure that the cell expends energy producing the enzymes encoded by the lac operon only when necessary. In the absence of lactose, the lac repressor halts production of the enzymes encoded by the lac operon. In the presence of glucose, the catabolite activator protein (CAP), required for production of the enzymes, remains inactive, and EIIAGlc shuts down lactose permease to prevent transport of lactose into the cell. This dual control mechanism causes the sequential utilization of glucose and lactose in two distinct growth phases, known as diauxie.
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