3-1Basic Bacteriology-Part-III-1
... transcriptions through bonding to the operator region of a regulated gene. Active repressor: When ever the repressor protein is able to bind by itself to the operator region, this repressor is said to be active ( active repressor protein). To be removed/detach from the operator region, it needs a he ...
... transcriptions through bonding to the operator region of a regulated gene. Active repressor: When ever the repressor protein is able to bind by itself to the operator region, this repressor is said to be active ( active repressor protein). To be removed/detach from the operator region, it needs a he ...
Programming Gene Expression
... arabinose-catabolizing genes as sequence-specific DNA-binding protein. The E. coli genome contains many CAP-binding sites in positions appropriate for interactions with RNA polymerase. Thus, an increase in the cAMP level inside an E. coli bacterium results in the formation of CAP-cAMP complexes that ...
... arabinose-catabolizing genes as sequence-specific DNA-binding protein. The E. coli genome contains many CAP-binding sites in positions appropriate for interactions with RNA polymerase. Thus, an increase in the cAMP level inside an E. coli bacterium results in the formation of CAP-cAMP complexes that ...
Regulation 1. Short term control
... through the various sections of the course. These include: (a) compartmentation: This was not described overtly as a control mechanism, but is implicit in the situation of β-oxidation of fatty acids (degradation) occuring inside the mitochondria and synthesis occuring in the cytoplasm. In this way, ...
... through the various sections of the course. These include: (a) compartmentation: This was not described overtly as a control mechanism, but is implicit in the situation of β-oxidation of fatty acids (degradation) occuring inside the mitochondria and synthesis occuring in the cytoplasm. In this way, ...
Gene Regulation Section 12–5 - Mrs. Brenner's Biology
... Development and Differentiation Circle the letter of each sentence that is true about hox genes. In fruit flies, a mutation affecting the hox genes ...
... Development and Differentiation Circle the letter of each sentence that is true about hox genes. In fruit flies, a mutation affecting the hox genes ...
chapt13_image
... b. Lactose present. Enzymes needed to take up and use lactose are produced only when lactose is present. ...
... b. Lactose present. Enzymes needed to take up and use lactose are produced only when lactose is present. ...
Prokaryotic Gene Expression
... Regulation of Gene Expression in Prokaryotes • Metabolic carbohydrate C-sources – Glucose – feeds directly into glycolysis – Lactose, Arabinose, Galactose – Feed indirectly into glycolysis • E. coli only uses secondary sugars once glucose is depleted • Jacques Monod demonstrated that proteins were ...
... Regulation of Gene Expression in Prokaryotes • Metabolic carbohydrate C-sources – Glucose – feeds directly into glycolysis – Lactose, Arabinose, Galactose – Feed indirectly into glycolysis • E. coli only uses secondary sugars once glucose is depleted • Jacques Monod demonstrated that proteins were ...
transcription
... Structurally Distinct from Inactive Chromatin • Heterochromatin - ~10% in eukaryotic cells, more ...
... Structurally Distinct from Inactive Chromatin • Heterochromatin - ~10% in eukaryotic cells, more ...
PowerPoint
... A particular enzyme appears in the cell only after the cell has been exposed to the enzyme’s substrate This observation became known as enzyme adaptation ...
... A particular enzyme appears in the cell only after the cell has been exposed to the enzyme’s substrate This observation became known as enzyme adaptation ...
Gene Regulation Section 12–5
... Development and Differentiation Circle the letter of each sentence that is true about hox genes. In fruit flies, a mutation affecting the hox genes ...
... Development and Differentiation Circle the letter of each sentence that is true about hox genes. In fruit flies, a mutation affecting the hox genes ...
Slide 1
... negative control of genes because operons are switched off by the active form of the repressor ...
... negative control of genes because operons are switched off by the active form of the repressor ...
Lecture 1 Introduction to Bioinformatics
... lactose is present ⇒ it binds to the protein encoded by lacI changing its shape; in this state, the protein doesn’t bind upstream from the lac operon; therefore the lac operon can be transcribed ...
... lactose is present ⇒ it binds to the protein encoded by lacI changing its shape; in this state, the protein doesn’t bind upstream from the lac operon; therefore the lac operon can be transcribed ...
F factor
... Regulation of Genes in Prokaryotes In general, prokaryotic genes are organized (and Expressed) as operons An operon consists of: Several genes that encode enzymes under the control of a single promoter ...
... Regulation of Genes in Prokaryotes In general, prokaryotic genes are organized (and Expressed) as operons An operon consists of: Several genes that encode enzymes under the control of a single promoter ...
Mader/Biology, 13/e – Chapter Outline
... 2. These three enzymes are encoded by three genes. a. One gene codes for beta-galactosidase that breaks lactose to glucose and galactose. b. A second gene codes for a permease that facilitates entry of lactose into the cell. c. A third gene codes for enzyme transacetylase, which is an accessory in l ...
... 2. These three enzymes are encoded by three genes. a. One gene codes for beta-galactosidase that breaks lactose to glucose and galactose. b. A second gene codes for a permease that facilitates entry of lactose into the cell. c. A third gene codes for enzyme transacetylase, which is an accessory in l ...
Where do pumpkins come from?
... • Small snippets of RNA that are made in the nucleus and move to the dicer complex and also recognize specific base sequences in mRNA to cut it up. • In humans, there are almost 2,000 distinct microRNAs, which collectively regulate somewhere between 30 and 80 percent of human genes. ...
... • Small snippets of RNA that are made in the nucleus and move to the dicer complex and also recognize specific base sequences in mRNA to cut it up. • In humans, there are almost 2,000 distinct microRNAs, which collectively regulate somewhere between 30 and 80 percent of human genes. ...
ppt
... When lactose is present, E. coli produce three enzymes involved in lactose metabolism. Lactose is broken into glucose and galactose, and galactose is modified into glucose, too. Glucose is then metabolized in aerobic respiration pathways to harvest energy (ATP). When lactose is absent, E. coli does ...
... When lactose is present, E. coli produce three enzymes involved in lactose metabolism. Lactose is broken into glucose and galactose, and galactose is modified into glucose, too. Glucose is then metabolized in aerobic respiration pathways to harvest energy (ATP). When lactose is absent, E. coli does ...
Module 3 Questions Section 1. Essay and Short Answers. Use
... a It diminishes the transcription of the related gene structure. b Interaction with another molecule causes a conformational change in the repressor's active site. C It represses the production of lactose or tryptophan. D It induces the production of lactose or tryptophan. 42 Which gene in an operon ...
... a It diminishes the transcription of the related gene structure. b Interaction with another molecule causes a conformational change in the repressor's active site. C It represses the production of lactose or tryptophan. D It induces the production of lactose or tryptophan. 42 Which gene in an operon ...
11GeneExpr
... D. RNAi involves binding of a small RNA to a target gene to inactivate it. 11. In the RNAi regulatory pathway, the DICER enzyme cleaves: A. RNA polymerase into non-functional pieces. B. single-stranded DNA into repetitive sequences. C. double-stranded RNA into short strands. D. mRNAs of genes to be ...
... D. RNAi involves binding of a small RNA to a target gene to inactivate it. 11. In the RNAi regulatory pathway, the DICER enzyme cleaves: A. RNA polymerase into non-functional pieces. B. single-stranded DNA into repetitive sequences. C. double-stranded RNA into short strands. D. mRNAs of genes to be ...
Chapter 11 Regulation of Gene Expression
... altered patterns of gene expression. If these altered patterns of gene expression produce a selective advantage (or at least do not produce a major disadvantage), they may be maintained and even contribute to evolution of new species. The three-spined stickleback (Figure 11.1) provides an example of ...
... altered patterns of gene expression. If these altered patterns of gene expression produce a selective advantage (or at least do not produce a major disadvantage), they may be maintained and even contribute to evolution of new species. The three-spined stickleback (Figure 11.1) provides an example of ...
Chapter Outline
... genes. 8. Further Control of the lac Operon a. Since E. coli prefers to break down glucose, how does E. coli know how to turn on when glucose is absent? b. When glucose is absent, cyclic AMP (cAMP) accumulates; cAMP has only one phosphate group and attaches to ribose at two locations. i. CAP is a ca ...
... genes. 8. Further Control of the lac Operon a. Since E. coli prefers to break down glucose, how does E. coli know how to turn on when glucose is absent? b. When glucose is absent, cyclic AMP (cAMP) accumulates; cAMP has only one phosphate group and attaches to ribose at two locations. i. CAP is a ca ...
A Symbolic and Graphical Gene Regulation Model of the lac Operon
... creation of these molecules dependent on the amount of lactose present in the cell. More specifically, the lac operon consists of four genes (Fig. 1): the lacI gene, the lacZ gene, the lacY gene, and the lacA gene. The lacZ, lacY and lacA genes are adjacent to one another on the operon. They are pre ...
... creation of these molecules dependent on the amount of lactose present in the cell. More specifically, the lac operon consists of four genes (Fig. 1): the lacI gene, the lacZ gene, the lacY gene, and the lacA gene. The lacZ, lacY and lacA genes are adjacent to one another on the operon. They are pre ...
Gene Regulation
... Lactose binds to repressor, causing shape change; repressor falls off DNA, allows unhindered transcription by RNA polymerase. Translation of mRNA results in enzymes needed to use lactose. ...
... Lactose binds to repressor, causing shape change; repressor falls off DNA, allows unhindered transcription by RNA polymerase. Translation of mRNA results in enzymes needed to use lactose. ...
Genetics of Viruses & Bacteria
... Beneficial for recombination; not necessary for survival R plasmid allows bacteria to be antibiotic resistant ...
... Beneficial for recombination; not necessary for survival R plasmid allows bacteria to be antibiotic resistant ...
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.