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Ovomucin
Ovomucin is a glycoprotein found mainly in egg whites, as well as in the chalaza and vitelline membrane. The protein makes up around 2-4% of the protein content of egg whites; like other members of the mucin protein family, ovomucin confers gel A gel is a semi-solid that can have properties ranging from soft and weak to hard and tough. Gels are defined as a substantially dilute cross-linked system, which exhibits no flow when in the steady-state, although the liquid phase may still di ...-like properties. It is composed of two subunits, alpha-ovomucin (MUC5B) and beta-ovomucin (MUC6), of which the beta subunit is much more heavily glycosylated. External links * References Eggs Mucins Avian proteins {{biochemistry-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Egg White
Egg white is the clear liquid (also called the albumen or the glair/glaire) contained within an egg. In chickens it is formed from the layers of secretions of the anterior section of the hen's oviduct during the passage of the egg. It forms around fertilized or unfertilized egg yolks. The primary natural purpose of egg white is to protect the yolk and provide additional nutrition for the growth of the embryo (when fertilized). Egg white consists primarily of about 90% water into which about 10% proteins (including albumins, mucoproteins, and globulins) are dissolved. Unlike the yolk, which is high in lipids (fats), egg white contains almost no fat, and carbohydrate content is less than 1%. Egg whites contain about 56% of the protein in the egg. Egg white has many uses in food (e.g. meringue, mousse) as well as many other uses (e.g. in the preparation of vaccines such as those for influenza). Composition Egg white makes up around two-thirds of a chicken egg by weight. Wate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gallus Gallus
The red junglefowl (''Gallus gallus'') is a tropical bird in the family Phasianidae. It ranges across much of Southeast Asia and parts of South Asia. It was formerly known as the Bankiva or Bankiva Fowl. It is the species that gave rise to the chicken (''Gallus gallus domesticus''); the grey junglefowl, Sri Lankan junglefowl and green junglefowl have also contributed genetic material to the gene pool of the chicken. Evidence from the molecular level derived from whole-genome sequencing revealed that the chicken was domesticated from red junglefowl about 8,000 years ago, with this domestication event involving multiple maternal origins. Since then, their domestic form has spread around the world where they are kept by humans for their meat, eggs, and companionship. Taxonomy and systematics Numerous subspecies of ''Gallus gallus'' exist, including: * ''G. g. gallus'' – from India, Bangladesh, Southeast Asia * ''G. g. bankiva'' – from Java and Sumatra * ''G. g. jabouill ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glycoprotein
Glycoproteins are proteins which contain oligosaccharide chains covalently attached to amino acid side-chains. The carbohydrate is attached to the protein in a cotranslational or posttranslational modification. This process is known as glycosylation. Secreted extracellular proteins are often glycosylated. In proteins that have segments extending extracellularly, the extracellular segments are also often glycosylated. Glycoproteins are also often important integral membrane proteins, where they play a role in cell–cell interactions. It is important to distinguish endoplasmic reticulum-based glycosylation of the secretory system from reversible cytosolic-nuclear glycosylation. Glycoproteins of the cytosol and nucleus can be modified through the reversible addition of a single GlcNAc residue that is considered reciprocal to phosphorylation and the functions of these are likely to be an additional regulatory mechanism that controls phosphorylation-based signalling. In contra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chalaza
The chalaza (; from Greek "hailstone"; plural ''chalazas'' or ''chalazae'', ) is a structure inside bird eggs and plant ovules. It attaches or suspends the yolk or nucellus within the larger structure. In animals In the eggs of most birds (not of the reptiles), the chalazae are two spiral bands of tissue that suspend the yolk in the center of the white (the albumen). The function of the chalazae is to hold the yolk in place. In baking, the chalazae are sometimes removed in order to ensure a uniform texture. In plants In plant ovules, the chalaza is located opposite the micropyle opening of the integuments. It is the tissue where the integuments and nucellus are joined. Nutrients from the plant travel through vascular tissue in the funiculus and outer integument through the chalaza into the nucellus. During the development of the embryo sac inside a flowering plant ovule, the three cells at the chalazal end become the antipodal cells. Chalazogamy In most flowering plants ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vitelline Membrane
The vitelline membrane or vitelline envelope is a structure surrounding the outer surface of the plasma membrane of an ovum (the oolemma) or, in some animals (e.g., birds), the extracellular yolk and the oolemma. It is composed mostly of protein fibers, with protein receptors needed for sperm binding which, in turn, are bound to sperm plasma membrane receptors. The species-specificity between these receptors contributes to prevention of breeding between different species. It is called zona pellucida in mammals. Between the vitelline membrane and zona pellucida is a fluid-filled perivitelline space. As soon as the spermatozoon fuses with the ovum, signal transduction occurs, resulting in an increase of cytoplasmic calcium ions. This itself triggers the cortical reaction, which results in depositing several substances onto the vitelline membrane through exocytosis of the cortical granules, transforming it into a hard layer called the “fertilization membrane”, which serves as a b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mucin
Mucins () are a family of high molecular weight, heavily glycosylated proteins (glycoconjugates) produced by epithelial tissues in most animals. Mucins' key characteristic is their ability to form gels; therefore they are a key component in most gel-like secretions, serving functions from lubrication to cell signalling to forming chemical barriers. They often take an inhibitory role. Some mucins are associated with controlling mineralization, including nacre formation in mollusks, calcification in echinoderms and bone formation in vertebrates. They bind to pathogens as part of the immune system. Overexpression of the mucin proteins, especially MUC1, is associated with many types of cancer. Although some mucins are membrane-bound due to the presence of a hydrophobic membrane-spanning domain that favors retention in the plasma membrane, most mucins are secreted as principal components of mucus by mucous membranes or are secreted to become a component of saliva. Genes Human mucins ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein Family
A protein family is a group of evolutionarily related proteins. In many cases, a protein family has a corresponding gene family, in which each gene encodes a corresponding protein with a 1:1 relationship. The term "protein family" should not be confused with family as it is used in taxonomy. Proteins in a family descend from a common ancestor and typically have similar three-dimensional structures, functions, and significant sequence similarity. The most important of these is sequence similarity (usually amino-acid sequence), since it is the strictest indicator of homology and therefore the clearest indicator of common ancestry. A fairly well developed framework exists for evaluating the significance of similarity between a group of sequences using sequence alignment methods. Proteins that do not share a common ancestor are very unlikely to show statistically significant sequence similarity, making sequence alignment a powerful tool for identifying the members of protein famil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eggs
Humans and human ancestors have scavenged and eaten animal eggs for millions of years. Humans in Southeast Asia had domesticated chickens and harvested their eggs for food by 1,500 BCE. The most widely consumed eggs are those of fowl, especially chickens. Eggs of other birds, including ostriches and other ratites, are eaten regularly but much less commonly than those of chickens. People may also eat the eggs of reptiles, amphibians, and fish. Fish eggs consumed as food are known as roe or caviar. Bird and reptile eggs consist of a protective eggshell, albumen ( egg white), and vitellus ( egg yolk), contained within various thin membranes. Egg yolks and whole eggs store significant amounts of protein and choline, and are widely used in cookery. Due to their protein content, the United States Department of Agriculture formerly categorized eggs as ''Meats'' within the Food Guide Pyramid (now MyPlate). Despite the nutritional value of eggs, there are some potential healt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mucins
Mucins () are a family of high molecular weight, heavily glycosylated proteins (glycoconjugates) produced by epithelial tissues in most animals. Mucins' key characteristic is their ability to form gels; therefore they are a key component in most gel-like secretions, serving functions from lubrication to cell signalling to forming chemical barriers. They often take an inhibitory role. Some mucins are associated with controlling mineralization, including nacre formation in mollusks, calcification in echinoderms and bone formation in vertebrates. They bind to pathogens as part of the immune system. Overexpression of the mucin proteins, especially MUC1, is associated with many types of cancer. Although some mucins are membrane-bound due to the presence of a hydrophobic membrane-spanning domain that favors retention in the plasma membrane, most mucins are secreted as principal components of mucus by mucous membranes or are secreted to become a component of saliva. Genes Human muc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
