In order to test our hypothesis which states that sequence identity shared among orthologous proteins is not different from the sequence identity shared among paralogous proteins, we used bioinformatic databases. We found that sequence identity

Orthologs within the same Superfamily Show Higher Sequence Identity than Paralogs within the same Superfamily Abstract The purpose of this experiment is to examine the amount of relation found in proteins recognized as homologs. In order to test our hypothesis which states that sequence identity shared among orthologous proteins is not different from the sequence identity shared among paralogous proteins, we used bioinformatic databases. We found that sequence identity of human prolactin to human growth hormone was 23.9% identical, human prolactin to pig prolactin was 78.6% identical, and human prolactin to fish prolactin was 32.6% identical. In conclusion, we found that the sequence identity of orthologous protein hormones share a higher percentage of relatedness, especially those in class Mammalia. Introduction For scientist, especially those who specialize in evolution, the revolution of DNA technology has proven to be an influential factor in evolutionary research. The advancement in technology has allowed DNA to be used as a marker in the history of evolution. It is because of this technology, like bioinformatic databases, that we can compare DNA sequences of various genes between different organism and gain information about their relationships (Harvey et. al. 1995). Molecular evolution has opened a whole new field of scientific research. The purpose of this

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  • Subject: Biological Sciences
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Two-component signalling pathways in bacteria

Er Chian Kong 41004159 CMBS 309 Advanced Biochemistry Essay Two-component signalling pathways in bacteria Experiencing "life on the edge", bacteria have to respond to changes in the environment in order to survive. Facing limited resources and coupled with intense competition in almost every environment, bacteria have to accommodate any potential energy sources of nitrogen, carbon while resisting toxicity to their regulatory process and metabolism. By establishing an intra and inter species communication, bacteria can sense the multitude of extracellular signals and responds to enhance chances of survival. Bacteria change their physiological behaviour according to signals detected in their environment, typically reflected in gene expression alteration. The two-component system (TCS) is predominantly involved in many signal transduction pathways in many prokaryotes, slime molds, fungi and even plants. [1] It is a major signalling mechanism that mediates the response to various environmental stimuli in bacteria and is based on a "sensor" and "regulator" relationship. The biochemical event of the two-component signal transduction was first described by Ninfa and Magasanik [2] in 1986. Ninfa and Magasanik described in Nitrogen Regulatory (NR) protein system, which regulate gene expression in response to the available of nitrogen source in Escherichia coli. Similarities

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  • Subject: Biological Sciences
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body systems

P3 Body system Cardiovascular system The cardiovascular system is composed of the heart, blood vessels, or vasculature, and the cells and plasma that make up the blood. The blood vessels of the body represent a closed delivery system, which functions to transport blood around the body, circulating substances such as oxygen, carbon dioxide, nutrients, hormones and waste products. There are three main types of blood vessel:- • Veins - the efferent blood vessels that return blood to the heart. • Arteries - the afferent blood vessels that carry blood away from the heart. • Capillaries - narrow, thin-walled blood vessels that form networks within the tissues. Digestive system The digestive system is made up of the digestive tract a series of hollow organs joined in a long, twisting tube from the mouth to the anus and other organs that help the body break down and absorb food. Organs that make up the digestive tract are the mouth, oesophagus, stomach, small intestine, large intestine also called the colon rectum, and anus. Inside these hollow organs is a lining called the mucosa. In the mouth, stomach, and small intestine, the mucosa contains tiny glands that produce juices to help digest food. How digestive system works throughput the body Mouth:-Food enters the body via the mouth where it is chewed. This action helps to break up the food enabling it to be

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  • Level: University Degree
  • Subject: Biological Sciences
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The Use of Controls and Indicators to Find What Macromolecules are in an Unknown

The Use of Controls and Indicators to Find What Macromolecules are in an Unknown Name: Erin Teaching Assistants: Laura and Polina, Section # 013 Course # 4677 Day: Monday, Time: 7:00PM - 9:50PM, Room #: B2 151 Lab Performed: Monday September 15th, 2008 Introduction The objective of this lab was to discover what macro molecules were in the unknown using different substances as experimental controls. Experimental controls are samples used in a lab that have a known outcome. This outcome can show what an unknown is comprised of. A positive control shows what the outcome of the experiment should look like if the experiment were to work. A negative control shows what would happen to the substance if the experiment were to go wrong. When compared to the control, what type of macromolecules in the unknown can be discovered (Enlexica, Inc, 2008). Indicators are usually used to expose a certain substance within a substance and normally shown through a colour change. These indicators were used to create the controls and used to identify certain macro molecules in different substances. The three different indicators that were used in this lab were Lugol's iodine solution, Benedict's solution and Biuret solution (Buckley Jr., 2003). Lugol's solution, otherwise known as iodine solution is an indicator used to find starch in a substance. This solution is made of 5% iodine, 10%

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Describe the structural compartmentation of mammalian cells and the differing functions of these compartments

Describe the structural compartmentation of mammalian cells and the differing functions of these compartments All mammalian cells are eukaryotic cells. They have a true nucleus and they are normally enclosed by a plasma membrane. In a typical eukaryotic cell, one would expect to have, along with a plasma membrane and nucleus, endoplasmic reticulum, Golgi apparatus, mitochondria, cytoskeleton etc.[3] These organelles are all membrane-bound structures, each have a unique role to play in the functioning of the cell. All these organelles are specific proteins and they all interact with each other to support the cell. However cells are different from each other. Cells differ from species to species and they also differ from different organs.[5] Every cell type has its own function and its function determines the quantity of each organelle. For example, we expect to find more mitochondria in a muscle tissue cell than in a skin cell. A muscle tissue cell needs to have extra production of ATP to allow for contraction whereas the skin cell does not need to do so. This assignment will give a brief overview of the structural compartmentation and their function of a typical mammalian cell with special focus on the plasma membrane and mitochondria. Figure 1, a cartoon picture of a typical eukaryotic cell depicting all the compartments[2] Plasma membrane contains the content of the

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PoMC cell function

POMC and Human Pigmentation Proopiomelanocortin or POMC and the neuropeptides derived from it, participate in several cardinal processes that control the central nervous system and peripheral tissues. Although, POMC regulates melanocortin or MC receptors in their local activation process, its role in extracellular proteolytic processing has been largely ignored. Several research scientists have been investigating important mechanisms that have significance in controlling the bio-availability of adrenocorticotropin and hormones that stimulate cutaneous melanocyte. This has been done in the context of peptidases like neprilysin - or neutral endopeptidase or NEP, and the ACE or angiotensin - converting enzyme (König et al, 2006, Pp. 751 - 761). The skin constitutes a source, as well as a target organ for the actions of neuropeptides derived from proopiomelanocortin or POMC. These peptides are ACTH, ?-melanocyte stimulating hormone or ?-MCH, and ß-endorphin. The levels of POMC genes and corticotropin releasing hormone peptides or CRH peptides are not constant in the skin. Their levels vary due to several factors, like the physiological changes relating to hair cycles, which are at their zenith during the anagen phase; physiological changes resulting from exposure to ultraviolet radiation; cytokine releases; and the incidence of cutaneous pathology (Slominski et al, 2000, Pp.

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  • Subject: Biological Sciences
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STOICHIOMETRY REACTION

NAME : THAMARAI A/P RAJENDRAN ID NUMBER: 09ALB07214 LABORATORY 1A : ATOMIC STRUCTURE BONDING AND PERIODICITY COURSE: BIOTECHNOLOGY (Y 1 S 1) EXPERIMENT 3: STOICHIOMETRY REACTION TITLE: Stoichiometry Reaction. OBJECTIVES OF EXPERIMENT: The objective of this experiment is to decompose sodium hydrogen carbonate(sodium bicarbonate) by heating, and to accurately measure the degree of completion of the reaction by analyzing the solid sodium carbonate product. THEORY AND BACKGROUND: We need to know how much product we will get from a given amount of reactant and we also need to know how much heat a given reaction produces in order to be able to safely perform the reaction. When we measure chemical or physical quantities of starting materials or products, these are a function of the molecular transformations involved in the reaction. That is, the reaction stoichiometry (whether a molecule of compound X reacts with 1 or 2 molecules of Y) must be involved in any calculation about amounts of reactants or products. However, in the laboratory, we must be concerned with far larger quantities than the molecular scale. Similarly, going in the reverse direction, we must be able to relate the amount of heat evolved in a laboratory scale reaction to that involved when two molecules react. The scaling factor used to relate readily usable quantities to the molecular scale is called

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Effect of temperature on membrane permeability

Effect of temperature on membrane permeability Aim This investigation aims to determine what effect an increase in the surrounding temperature has on the plasma membrane of a typical plant cell structure. Hypothesis An increase in temperature will damage and denature the plasma membrane, which would cause the substances contained within the cytoplasm to leak out of the membrane. The investigation carried out was to see the "effect of temperature on membrane permeability". Different temperatures were used, ranging from room temperature to 87°C. Three test tubes were used to give a range of results. They were placed in a colorimeter, from which a percentage was recorded showing how much light had passed through. Figure 1 shows the results obtained from the investigation. A mean has also been calculated and included in the results. Temperature (°C) Test tube 1 (%) Test tube 2 (%) Test tube 3 (%) Mean (%) 23 98 96 96 96.67 45 95 93 91 93.00 53 74 73 73 73.33 65 54 45 34 44.33 87 Figure 1: A table showing the results obtained. From the above results it can be seen that as the temperature increases, the permeability of beetroot membrane increases. This shows that the plasma membrane must be denatured. In the cells of a beetroot plant, a substance called anthocyanin is contained within the plasma membrane. It is anthocyanin which gives the beetroot

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Are CD46, CD55 and CD59 good targets for the treatment of malignant disease?

BM301 Fundamental Immunology | Essay Fundamental Immunology: Are CD46 - CD55 - CD59 good targets for the treatment of malignant disease? Are CD46 - CD55 - CD59 good targets for the treatment of malignant disease? Clusters of differentiation which is often abbreviated to CDxx (xx representing a number specific to each CD molecule), is a naming system developed in 1982 to recognise surface molecules present on white blood cells that were recognised by monoclonal antibodies (Fiebig et al., 1984). They can perform a number of functions such as acting as receptors or ligands and are usually involved in cell signalling, causing a cascade in certain immune responses. There are now over 250 proteins that are classified as CD molecules (Zola et al., 2005). This essay will look at three clusters of differentiation - CD46, CD55 and CD59 - known membrane proteins that protect against native complement damage (Xu et al, 2008) and conclude whether or not they are good targets in the treatment of malignant disease. CD46 (Membrane Cofactor Protein) is a type I membrane protein which acts as a complement receptor. It is a cofactor for the proteolysis of C3, so cells displaying CD46 will be protected from attack by the native complement system (Assem et al., 2005). CD55, which is also known as Decay Accelerating Factor is also a membrane protein with a similar function to CD46. CD55 causes

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  • Subject: Biological Sciences
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Discuss the role of CaMKII (calcium/calmodulin-dependent kinase II) autophosphorylation in learning and memory

Institute of Psychiatry MSc Neuroscience 2007 - 2008 FULL TIME STUDENT ESSAY Module 2: Essay Question No: 10 TITLE Discuss the role of CaMKII (calcium/calmodulin-dependent kinase II) autophosphorylation in learning and memory. WORD COUNT: 3043 MARKER'S COMMENTS: CANDIDATE NUMBER: K22563 PAGE NUMBER: 15 Discuss the role of CaMKII (calcium/calmodulin-dependent kinase II) autophosphorylation in learning and memory. In my essay, I will be discussing the mechanism of CaMKII autophosphorylation and how this process brings about LTP, which contributes to learning and memory. Furthermore I will talk about how the autophosphorylated kinase interacts with the postsynaptic receptors, which underlies the mechanisms of neuronal plasticity. Neural tissues contain many protein kinases and phosphatases and of these protein kinases, calcium-calmodulin dependent protein kinase II (CaMKII) plays an important role in learning and memory. CaMKII is a Ca2+-activated enzyme and makes up 1-2% of the total protein. The kinase is abundantly found in synapses and is one of the main proteins of the postsynaptic density in the vertebrate central nervous system. In mammals, there are more than 30 isoforms of CaMKII consisting of 4 genes, which are ?,?,? and ? and have molecular weights ranging from 52-83kDa. The main isoforms in the brain are ? and ?(Colbran et al, 2004). The ?-isoform is

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  • Subject: Biological Sciences
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