Lipid bylayers and Membranes
... • The term refers to the collection of mechanisms that regulate the passage of solutes such as ions and small molecules through biological membranes namely lipid bilayers that contain proteins embedded in them. • The regulation of passage through the membrane is due to selective membrane permeabilit ...
... • The term refers to the collection of mechanisms that regulate the passage of solutes such as ions and small molecules through biological membranes namely lipid bilayers that contain proteins embedded in them. • The regulation of passage through the membrane is due to selective membrane permeabilit ...
Digestion
... the pancreatic cells as proenzymes or inactive zymsgen gromules. • Trypsin is formed by removal of a hexapeptide from the trypisinogen molecule as a result of the hydrolysis of a lysineisoleucine bond. • Trypsin is an endopeptidase with optimal action at pH of about 7. • . Trypsinogen or trypsin, ha ...
... the pancreatic cells as proenzymes or inactive zymsgen gromules. • Trypsin is formed by removal of a hexapeptide from the trypisinogen molecule as a result of the hydrolysis of a lysineisoleucine bond. • Trypsin is an endopeptidase with optimal action at pH of about 7. • . Trypsinogen or trypsin, ha ...
dependent phosphotransferase system – two highly similar glucose
... suggests additional regulation by carbon catabolite repression. As described previously by the authors, both genes can be expressed in Escherichia coli under control of their own promoters. Two putative promoters are located upstream of glcA, and both were found to initiate transcription in E. coli. ...
... suggests additional regulation by carbon catabolite repression. As described previously by the authors, both genes can be expressed in Escherichia coli under control of their own promoters. Two putative promoters are located upstream of glcA, and both were found to initiate transcription in E. coli. ...
Intricacies and surprises of nuclear–mitochondrial co
... up to 20 kb. Based on these slight size differences, it remains arguable whether the pressure to reduce genome size has fuelled the general reduction of tRNA size in nematode mitochondria. Also, why was the architectural principle of the tRNA cloverleaf broken for only one tRNA (Ser AGY) in mitochon ...
... up to 20 kb. Based on these slight size differences, it remains arguable whether the pressure to reduce genome size has fuelled the general reduction of tRNA size in nematode mitochondria. Also, why was the architectural principle of the tRNA cloverleaf broken for only one tRNA (Ser AGY) in mitochon ...
Chapter 26
... • tRNA molecules contain several modified bases, such as pseudo-uridine (ψ). All four bases are modified. 3. Ribosomes • Ribosomes are composed of two ribonucleoprotein subunits. Each subunit contains rRNAs (~2/3) and proteins (~1/3). • Prokaryotic ribosome 70S = 50S (L subunit) + 30S (S subunit) • ...
... • tRNA molecules contain several modified bases, such as pseudo-uridine (ψ). All four bases are modified. 3. Ribosomes • Ribosomes are composed of two ribonucleoprotein subunits. Each subunit contains rRNAs (~2/3) and proteins (~1/3). • Prokaryotic ribosome 70S = 50S (L subunit) + 30S (S subunit) • ...
Signal Transduction in Bacterial Chemotaxis
... chemoreceptor modification on assembly and activity of the receptor-kinase complex in Escherichia coli. J. Bacteriol. 186, ...
... chemoreceptor modification on assembly and activity of the receptor-kinase complex in Escherichia coli. J. Bacteriol. 186, ...
Synapse Specificity Minireview and Long
... the synaptic neuropil was isolated from either the pre(CA3) or postsynaptic (CA1) cell bodies further substantiated a local protein synthesis source: the inhibition of potentiation by anisomycin persisted in the absence of somatic protein synthesis machinery. These results demonstrated that the site ...
... the synaptic neuropil was isolated from either the pre(CA3) or postsynaptic (CA1) cell bodies further substantiated a local protein synthesis source: the inhibition of potentiation by anisomycin persisted in the absence of somatic protein synthesis machinery. These results demonstrated that the site ...
Cytochrome P450 3A4: The Impossible Protein
... The protein P450 3A4 is one of the most abundant P450s in the liver. It is unique in that it has a particularly large binding cavity which could possible hold more than one drug at once. Although this has never been proven, the closely related bacterial P450 eryF has been shown bound to two ligands ...
... The protein P450 3A4 is one of the most abundant P450s in the liver. It is unique in that it has a particularly large binding cavity which could possible hold more than one drug at once. Although this has never been proven, the closely related bacterial P450 eryF has been shown bound to two ligands ...
Caldicellulosiruptor tāpirins bind to crystalline cellulose! ! 1 Discrete
... adhesion of cells to cellulose in F. succinogenes (11) and R. flavefaciens (18). The genus Caldicellulosiruptor employs a variety of multifunctional enzymes, both cellanchored and “free”, to deconstruct plant biomass at high temperatures (65 to 80°C, 19-21). In fact, one of the notable characteristi ...
... adhesion of cells to cellulose in F. succinogenes (11) and R. flavefaciens (18). The genus Caldicellulosiruptor employs a variety of multifunctional enzymes, both cellanchored and “free”, to deconstruct plant biomass at high temperatures (65 to 80°C, 19-21). In fact, one of the notable characteristi ...
BIO 322_Rec_4part2_Spring 2013
... • In cytosol of hepatocytes, alanine amino transferase transfers the amino group of alanine to α ketoglutarate forming pyruvate and glutamate. • Glutamate goes to mitochondria releases ammonia or can undergo transamination with oxaloacetate to form aspartate, another nitrogen donor in urea synthesis ...
... • In cytosol of hepatocytes, alanine amino transferase transfers the amino group of alanine to α ketoglutarate forming pyruvate and glutamate. • Glutamate goes to mitochondria releases ammonia or can undergo transamination with oxaloacetate to form aspartate, another nitrogen donor in urea synthesis ...
Biologically Assembled Nanobiocatalysts Heejae Kim Qing Sun
... keys to achieving highly efficient synthetic enzymatic reactions. The active site must be exposed properly to incoming substrates and protected from inhibiting molecules and denaturation. Enzyme immobilization has been used to increase the overall activity and stability. The use of nanostructures suc ...
... keys to achieving highly efficient synthetic enzymatic reactions. The active site must be exposed properly to incoming substrates and protected from inhibiting molecules and denaturation. Enzyme immobilization has been used to increase the overall activity and stability. The use of nanostructures suc ...
exam1_2007 - Andrew.cmu.edu
... Asp and Lys). This is largely an enthalpic (ΔH) effect. It has very little influence on stabilizing either the folded or unfolded form of the protein, all other effects are more important. ...
... Asp and Lys). This is largely an enthalpic (ΔH) effect. It has very little influence on stabilizing either the folded or unfolded form of the protein, all other effects are more important. ...
Text - Tufts University
... Intracellular membranes compartmentalize the cell and increase the surface areas where important metabolic processes take place. Depending on the organelles, the functions of the intracellular membranes vary greatly. Some of the membrane associated proteins in the intracellular membrane function as ...
... Intracellular membranes compartmentalize the cell and increase the surface areas where important metabolic processes take place. Depending on the organelles, the functions of the intracellular membranes vary greatly. Some of the membrane associated proteins in the intracellular membrane function as ...
Astrovirus Replication: An Overview
... and other animal astroviruses correspond to coat proteins from simple, icosahedrally symmetric viruses with jelly-roll β-barrel subunits, such as Theiler’s murine encephalomyelitis virus, bean pod mottle virus, carnation mottle virus, and tomato bushy stunt virus. Structural alignments of predicted ...
... and other animal astroviruses correspond to coat proteins from simple, icosahedrally symmetric viruses with jelly-roll β-barrel subunits, such as Theiler’s murine encephalomyelitis virus, bean pod mottle virus, carnation mottle virus, and tomato bushy stunt virus. Structural alignments of predicted ...
E1. A codon contains three nucleotides. Since G and C are present
... be a down promoter mutation (i.e., a mutation in the promoter that decreases the rate of transcription), or it could be a mutation in the coding sequence that causes the protein to be degraded very rapidly. The sample in lane 4 came from an individual who is homozygous for a mutation that changed on ...
... be a down promoter mutation (i.e., a mutation in the promoter that decreases the rate of transcription), or it could be a mutation in the coding sequence that causes the protein to be degraded very rapidly. The sample in lane 4 came from an individual who is homozygous for a mutation that changed on ...
chapt 3 The Molecules of Cells
... – Coiling results in a helical structure called an alpha helix. – A certain kind of folding leads to a structure called a pleated sheet, which dominates some fibrous proteins such as those used in spider webs. – Coiling and folding are maintained by regularly spaced hydrogen bonds between hydrogen a ...
... – Coiling results in a helical structure called an alpha helix. – A certain kind of folding leads to a structure called a pleated sheet, which dominates some fibrous proteins such as those used in spider webs. – Coiling and folding are maintained by regularly spaced hydrogen bonds between hydrogen a ...
Enzymes - Hartismere
... - The substrate then reacts because it is held in such a way by the enzyme that the right atom groups are close enough to react. The active site contains R-groups that also interact with the substrate, forming temporary bonds. These bonds put strain on the bonds within the substrate which helps the ...
... - The substrate then reacts because it is held in such a way by the enzyme that the right atom groups are close enough to react. The active site contains R-groups that also interact with the substrate, forming temporary bonds. These bonds put strain on the bonds within the substrate which helps the ...
A green glow
... brain, thus giving an indication on cerebral development. GFP is also used to visualize something even smaller than cells: proteins. Several techniques have been developed to study their function. One such technique is used to find out where and when a particular protein is produced – in the brain, ...
... brain, thus giving an indication on cerebral development. GFP is also used to visualize something even smaller than cells: proteins. Several techniques have been developed to study their function. One such technique is used to find out where and when a particular protein is produced – in the brain, ...
Going from where to why—interpretable
... subcellular localization that addresses these issues. Due to its simple architecture, YLoc can identify the relevant features of a protein sequence contributing to its subcellular localization, e.g. localization signals or motifs relevant to protein sorting. We present several example applications w ...
... subcellular localization that addresses these issues. Due to its simple architecture, YLoc can identify the relevant features of a protein sequence contributing to its subcellular localization, e.g. localization signals or motifs relevant to protein sorting. We present several example applications w ...
lecture4
... tRNA is present for each of the 20 amino acids used in protein synthesis. (Some amino acids employ the services of two or three different tRNAs, so most cells contain as many as 32 different kinds of tRNA.) The amino acid is attached to the appropriate tRNA by an activating enzyme (one of 20 aminoac ...
... tRNA is present for each of the 20 amino acids used in protein synthesis. (Some amino acids employ the services of two or three different tRNAs, so most cells contain as many as 32 different kinds of tRNA.) The amino acid is attached to the appropriate tRNA by an activating enzyme (one of 20 aminoac ...
24.9 Synthesis of Amino Acids
... Overview, Metabolism Catabolic pathways • degrade large molecules. • form small molecules that enter the citric acid cycle and electron transport to produce energy. Anabolic pathways • use small molecules and energy. • synthesize larger molecules in the cell. In the overall view of metabolism, ther ...
... Overview, Metabolism Catabolic pathways • degrade large molecules. • form small molecules that enter the citric acid cycle and electron transport to produce energy. Anabolic pathways • use small molecules and energy. • synthesize larger molecules in the cell. In the overall view of metabolism, ther ...
Protein
Proteins (/ˈproʊˌtiːnz/ or /ˈproʊti.ɨnz/) are large biomolecules, or macromolecules, consisting of one or more long chains of amino acid residues. Proteins perform a vast array of functions within living organisms, including catalyzing metabolic reactions, DNA replication, responding to stimuli, and transporting molecules from one location to another. Proteins differ from one another primarily in their sequence of amino acids, which is dictated by the nucleotide sequence of their genes, and which usually results in protein folding into a specific three-dimensional structure that determines its activity.A linear chain of amino acid residues is called a polypeptide. A protein contains at least one long polypeptide. Short polypeptides, containing less than about 20-30 residues, are rarely considered to be proteins and are commonly called peptides, or sometimes oligopeptides. The individual amino acid residues are bonded together by peptide bonds and adjacent amino acid residues. The sequence of amino acid residues in a protein is defined by the sequence of a gene, which is encoded in the genetic code. In general, the genetic code specifies 20 standard amino acids; however, in certain organisms the genetic code can include selenocysteine and—in certain archaea—pyrrolysine. Shortly after or even during synthesis, the residues in a protein are often chemically modified by posttranslational modification, which alters the physical and chemical properties, folding, stability, activity, and ultimately, the function of the proteins. Sometimes proteins have non-peptide groups attached, which can be called prosthetic groups or cofactors. Proteins can also work together to achieve a particular function, and they often associate to form stable protein complexes.Once formed, proteins only exist for a certain period of time and are then degraded and recycled by the cell's machinery through the process of protein turnover. A protein's lifespan is measured in terms of its half-life and covers a wide range. They can exist for minutes or years with an average lifespan of 1–2 days in mammalian cells. Abnormal and or misfolded proteins are degraded more rapidly either due to being targeted for destruction or due to being unstable.Like other biological macromolecules such as polysaccharides and nucleic acids, proteins are essential parts of organisms and participate in virtually every process within cells. Many proteins are enzymes that catalyze biochemical reactions and are vital to metabolism. Proteins also have structural or mechanical functions, such as actin and myosin in muscle and the proteins in the cytoskeleton, which form a system of scaffolding that maintains cell shape. Other proteins are important in cell signaling, immune responses, cell adhesion, and the cell cycle. Proteins are also necessary in animals' diets, since animals cannot synthesize all the amino acids they need and must obtain essential amino acids from food. Through the process of digestion, animals break down ingested protein into free amino acids that are then used in metabolism.Proteins may be purified from other cellular components using a variety of techniques such as ultracentrifugation, precipitation, electrophoresis, and chromatography; the advent of genetic engineering has made possible a number of methods to facilitate purification. Methods commonly used to study protein structure and function include immunohistochemistry, site-directed mutagenesis, X-ray crystallography, nuclear magnetic resonance and mass spectrometry.