Biology

The creation of new organic matter depends on the existence of existing organic matter.

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ecosystem

A biological community of interacting organisms and their physical environment. An ecosystem is made up of plants, animals, microorganisms, soil, rocks, minerals, water sources and the local atmosphere interacting with one another. The biotic factors and abiotic factors interact as a system and are linked to one another via nutrient cycles and energy flows. For instance, the energy from the sun is captured by plants through photosynthesis. Photosynthesis is a biological process through which plants manufacture their own food with the aid of light from the sun and from inorganic sources (e.g. carbon dioxide and water). The plants, in turn, serve as a food source for organisms incapable of producing their own food. By feeding on these plants, the energy and the nutrients flow through from one consumer to the next. Dead organic matter is then broken down by decomposers, eventually releasing materials for nutrient cycling, or for use by other living organisms.

Release factor

A cytoplasmic protein that binds to a stop codon where it appears in the A-site of the ribosome. Release factors modify the peptidyl transferase activity of the ribosome, such that a water molecule is added to the end of the completed protein. This releases the finished protein from the final tRNA, and allows the ribosome subunits and mRNA to disassociate. A release factor is a protein that allows for the termination of translation by recognizing the termination codon or stop codon in an mRNA sequence. They are named so because they release new peptides from the ribosome. The final step of translation. Chops off the protein so another one can start being made.

population

A group of individuals that belong to the same species and live in the same area A population is the number of organisms of the same species that live in a particular geographic area at the same time, with the capability of interbreeding. For interbreeding to occur, individuals must be able to mate with any other member of a population and produce fertile offspring.

tissue

A group of similar cells that perform the same function. In biology, tissue is a cellular organisational level between cells and a complete organ. A tissue is an ensemble of similar cells and their extracellular matrix from the same origin that together carry out a specific function. Organs are then formed by the functional grouping together of multiple tissues. The study of human and animal tissues is known as histology or, in connection with disease, histopathology also not forgetting to add, archeology. For plants, the discipline is called plant anatomy.

Microtubule

A hollow rod composed of tubulin proteins that makes up part of the cytoskeleton in all eukaryotic cells and is found in cilia and flagella. Microtubules are polymers of tubulin that form part of the cytoskeleton and provide structure and shape to eukaryotic cells. A microtubule can grow as long as 50 micrometres and are highly dynamic. The outer diameter of a microtubule is between 23 and 27 nm[1] while the inner diameter is between 11 and 15 nm.[2] They are formed by the polymerization of a dimer of two globular proteins, alpha and beta tubulin into protofilaments that can then associate laterally to form a hollow tube, the microtubule.[3] The most common form of a microtubule consists of 13 protofilaments in the tubular arrangement. Microtubules are very important in a number of cellular processes. They are involved in maintaining the structure of the cell and, together with microfilaments and intermediate filaments, they form the cytoskeleton. They also make up the internal structure of cilia and flagella. They provide platforms for intracellular transport and are involved in a variety of cellular processes, including the movement of secretory vesicles, organelles, and intracellular macromolecular assemblies (see entries for dynein and kinesin).[4] They are also involved in cell division (by mitosis and meiosis) and are the major constituents of mitotic spindles, which are used to pull eukaryotic chromosomes apart. Microtubules are nucleated and organized by microtubule organizing centers (MTOCs), such as the centrosome found in the center of many animal cells or the basal bodies found in cilia and flagella, or the spindle pole bodies found in most fungi. There are many proteins that bind to microtubules, including the motor proteins kinesin and dynein, microtubule-severing proteins like katanin, and other proteins important for regulating microtubule dynamics.[5] Recently an actin-like protein has been found in a gram-positive bacterium Bacillus thuringiensis, which forms a microtubule-like structure called a nanotubule, involved in plasmid segregation.[6] Other bacterial microtubules have a ring of five protofilaments.

Directionality

A key feature of all nucleic acids is that they have two distinctive ends: the 5' (5-prime) and 3' (3-prime) ends. This terminology refers to the 5' and 3' carbons on the sugar. For both DNA (shown above) and RNA, the 5' end bears a phosphate, and the 3' end a hydroxyl group. DNA is often double stranded . The complementary strand goes in the opposite direction.

DNA ligase

A linking enzyme essential for DNA replication; catalyzes the covalent bonding of the 3' end of a new DNA fragment to the 5' end of a growing chain. DNA ligase is a specific type of enzyme, a ligase, that facilitates the joining of DNA strands together by catalyzing the formation of a phosphodiester bond. It plays a role in repairing single-strand breaks in duplex DNA in living organisms, but some forms may specifically repair double-strand breaks

organism

A living thing an individual animal, plant, or single-celled life form.

vesicle

A membrane bound sac that contains materials involved in transport of the cell. In cell biology, a vesicle is a structure within or outside a cell, consisting of liquid or cytoplasm enclosed by a lipid bilayer. Vesicles form naturally during the processes of secretion (exocytosis), uptake (endocytosis) and transport of materials within the plasma membrane. Alternatively, they may be prepared artificially, in which case they are called liposomes (not to be confused with lysosomes). If there is only one phospholipid bilayer, they are called unilamellar liposome vesicles; otherwise they are called multilamellar. The membrane enclosing the vesicle is also a lamellar phase, similar to that of the plasma membrane, and intracellular vesicles can fuse with the plasma membrane to release their contents outside the cell. Vesicles can also fuse with other organelles within the cell. A vesicle released from the cell is known as an extracellular vesicle.

Glycolysis

A metabolic process that breaks down carbohydrates and sugars through a series of reactions to either pyruvic acid or lactic acid and release energy for the body in the form of ATP glucose + -lysis degradation)

Cytoskeleton

A network of fibers that holds the cell together, helps the cell to keep its shape, and aids in movement

cytoskeleton

A network of fibers that holds the cell together, helps the cell to keep its shape, and aids in movement A cytoskeleton is present in the cytoplasm of all cells, including bacteria, and archaea. It is a complex, dynamic network of interlinking protein filaments that extends from the cell nucleus to the cell membrane. The cytoskeletal systems of different organisms are composed of similar proteins. a microscopic network of protein filaments and tubules in the cytoplasm of many living cells, giving them shape and coherence.

nucleus

A part of the cell containing DNA and RNA and responsible for growth and reproduction In cell biology, the nucleus is the large, membrane-bounded organelle that contains the genetic material in the form of multiple linear DNA molecules organized into structures called chromosomes. In cell biology, the nucleus function is to act as the control center of the cell. This is because it contains the genetic material that codes for the vital functions of the cell. The nucleus is the organelle responsible for maintaining the integrity of DNA and for controlling cellular activities such as metabolism, growth, and reproduction by regulating gene expression. The nucleus is the largest cytoplasmic structure in animal cells. In mammalian cells, the average diameter is 6 µm. There are cells though that lack nuclei, such as human red blood cells. There are also certain cells that contain relatively more nuclei, e.g. osteoclasts. The cell nucleus contains all of the cell's genome, except for a small fraction of mitochondrial DNA, organized as multiple long linear DNA molecules in a complex with a large variety of proteins, such as histones, to form chromosomes. The genes within these chromosomes are structured in such a way to promote cell function. The nucleus maintains the integrity of genes and controls the activities of the cell by regulating gene expression—the nucleus is, therefore, the control center of the cell. The main structures making up the nucleus are the nuclear envelope, a double membrane that encloses the entire organelle and isolates its contents from the cellular cytoplasm, and the nuclear matrix (which includes the nuclear lamina), a network within the nucleus that adds mechanical support, much like the cytoskeleton, which supports the cell as a whole.

natural selection

A process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than other individuals because of those traits. Variation and competition lead to differential reproduction Differential reproduction is the idea that those organisms best adapted to a given environment will be most likely to survive to reproductive age and have offspring of their own. mutations lead to more fit offspring

Autophagy

A process in which lysosomes decompose damaged organelles to reuse their organic monomers meaning "self-devouring" is the natural, regulated mechanism of the cell that removes unnecessary or dysfunctional components.[3] It allows the orderly degradation and recycling of cellular components. Three forms of autophagy are commonly described: macroautophagy, microautophagy, and chaperone-mediated autophagy (CMA). In macroautophagy, expendable cytoplasmic constituents are targeted and isolated from the rest of the cell within a double-membraned vesicle known as an autophagosome,[6][7] which, in time, fuses with an available lysosome, bringing its specialty process of waste management and disposal; and eventually the contents of the vesicle (now called an autolysosome) are degraded and recycled.

prokaryotic cells

A prokaryote is a unicellular organism that lacks a membrane-bound nucleus, mitochondria, or any other membrane-bound organelle. The word prokaryote comes from the Greek πρό and κάρυον. Prokaryotes are divided into two domains, Archaea and Bacteria. Any of the group of organisms primarily characterized by the lack of true nucleus and other membrane-bound cell compartments: such as mitochondria and chloroplasts, and by the possession of a single loop of stable chromosomal DNA in the nucleiod region and cytoplasmic structures, such as plasma membrane, vacuoles, primitive cytoskeleton, and ribosomes. Membrane is composed of lipids Bacteria

Golgi apparatus

A system of membranes that modifies and packages proteins for export by the cell a complex of vesicles and folded membranes within the cytoplasm of most eukaryotic cells, involved in secretion and intracellular transport. Part of the endomembrane system in the cytoplasm, the Golgi apparatus packages proteins into membrane-bound vesicles inside the cell before the vesicles are sent to their destination. The Golgi apparatus resides at the intersection of the secretory, lysosomal, and endocytic pathways. It is of particular importance in processing proteins for secretion, containing a set of glycosylation enzymes that attach various sugar monomers to proteins as the proteins move through the apparatus. The Golgi apparatus is a major collection and dispatch station of protein products received from the endoplasmic reticulum (ER). Proteins synthesized in the ER are packaged into vesicles, which then fuse with the Golgi apparatus. These cargo proteins are modified and destined for secretion via exocytosis or for use in the cell. In this respect, the Golgi can be thought of as similar to a post office: it packages and labels items which it then sends to different parts of the cell or to the extracellular space. The Golgi apparatus is also involved in lipid transport and lysosome formation.[11] The structure and function of the Golgi apparatus are intimately linked. Individual stacks have different assortments of enzymes, allowing for progressive processing of cargo proteins as they travel from the cisternae to the trans Golgi face.[5][10] Enzymatic reactions within the Golgi stacks occur exclusively near its membrane surfaces, where enzymes are anchored. This feature is in contrast to the ER, which has soluble proteins and enzymes in its lumen. Much of the enzymatic processing is post-translational modification of proteins. For example, phosphorylation of oligosaccharides on lysosomal proteins occurs in the early CGN.[5] Cis cisterna are associated with the removal of mannose residues.[5][10] Removal of mannose residues and addition of N-acetylglucosamine occur in medial cisternae.[5] Addition of galactose and sialic acid occurs in the trans cisternae.[5] Sulfation of tyrosines and carbohydrates occurs within the TGN.[5] Other general post-translational modifications of proteins include the addition of carbohydrates (glycosylation)[12] and phosphates (phosphorylation). Protein modifications may form a signal sequence that determines the final destination of the protein. For example, the Golgi apparatus adds a mannose-6-phosphate label to proteins destined for lysosomes. Another important function of the Golgi apparatus is in the formation of proteoglycans. Enzymes in the Golgi append proteins to glycosaminoglycans, thus creating proteoglycans.[13] Glycosaminoglycans are long unbranched polysaccharide molecules present in the extracellular matrix of animals.

X-ray crystallography

A technique that depends on the diffraction of an X-ray beam by the individual atoms of a crystallized molecule to study the three-dimensional structure of the molecule. X-ray crystallography (XRC) is the experimental science determining the atomic and molecular structure of a crystal, in which the crystalline structure causes a beam of incident X-rays to diffract into many specific directions. Process that was used by Watson and Crick to find DNA

membrane

A thin covering of tissue thin layer of tissue covering a structure or cavity

protein

A three dimensional polymer made of monomers of amino acids. protein chain; polypeptide chain polymer of amino acids

hydrogen bond

A type of weak chemical bond formed when the slightly positive hydrogen atom of a polar covalent bond in one molecule is attracted to the slightly negative atom of a polar covalent bond in another molecule.

bacteriophage

A virus that infects bacteria A bacteriophage, also known informally as a phage, is a virus that infects and replicates within bacteria and archaea. The term was derived from "bacteria" and the Greek φαγεῖν (phagein), "to devour". Bacteriophages are composed of proteins that encapsulate a DNA or RNA genome, and may have structures that are either simple or elaborate. Their genomes may encode as few as four genes (e.g. MS2) and as many as hundreds of genes. Phages replicate within the bacterium following the injection of their genome into its cytoplasm. Bacteriophages are among the most common and diverse entities in the biosphere.[1] Bacteriophages are ubiquitous viruses, found wherever bacteria exist. It is estimated there are more than 1031 bacteriophages on the planet, more than every other organism on Earth, including bacteria, combined.[2] One of the densest natural sources for phages and other viruses is seawater, where up to 9x108 virions per millilitre have been found in microbial mats at the surface,[3] and up to 70% of marine bacteria may be infected by phages.[4]

protobionts

Aggregates of abiotically produced molecules surrounded by a membrane. An aggregation of organic molecules, surrounded by a membrane, that abiotically coalesces into resemblances of living matter; thought to be the precursors of prokaryotic cells. Protobionts: the Simple Cell that is the Precursor to Life The lipids that form the membranes (which resemble cellular membranes), called liposomes, automatically form a bilayer in the shape of a sphere when put in water.

Ribozyme

An RNA molecule that functions as an enzyme, such as an intron that catalyzes its own removal during RNA splicing. Ribozymes (ribonucleic acid enzymes) are RNA molecules that are capable of catalyzing specific biochemical reactions, including RNA splicing in gene expression, similar to the action of protein enzymes. The 1982 discovery of ribozymes demonstrated that RNA can be both genetic material (like DNA) and a biological catalyst (like protein enzymes), and contributed to the RNA world hypothesis, which suggests that RNA may have been important in the evolution of prebiotic self-replicating systems.[1] The most common activities of natural or in vitro-evolved ribozymes are the cleavage or ligation of RNA and DNA and peptide bond formation.[2] Within the ribosome, ribozymes function as part of the large subunit ribosomal RNA to link amino acids during protein synthesis. They also participate in a variety of RNA processing reactions, including RNA splicing, viral replication, and transfer RNA biosynthesis. Examples of ribozymes include the hammerhead ribozyme, the VS ribozyme, Leadzyme and the hairpin ribozyme.

smooth endoplasmic reticulum

An endomembrane system where lipids are synthesized, calcium levels are regulated, and toxic substances are broken down. The smooth endoplasmic reticulum lacks ribosomes and functions in lipid synthesis but not metabolism, the production of steroid hormones, and detoxification.[1] The smooth ER is especially abundant in mammalian liver and gonad cells. In most cells the smooth endoplasmic reticulum (abbreviated SER) is scarce. Instead there are areas where the ER is partly smooth and partly rough, this area is called the transitional ER. The transitional ER gets its name because it contains ER exit sites. These are areas where the transport vesicles that contain lipids and proteins made in the ER, detach from the ER and start moving to the Golgi apparatus. Specialized cells can have a lot of smooth endoplasmic reticulum and in these cells the smooth ER has many functions.[6] It synthesizes lipids, phospholipids,[18][19][20] and steroids. Cells which secrete these products, such as those in the testes, ovaries, and sebaceous glands have an abundance of smooth endoplasmic reticulum.[21] It also carries out the metabolism of carbohydrates, detoxification of natural metabolism products and of alcohol and drugs, attachment of receptors on cell membrane proteins, and steroid metabolism.[22] In muscle cells, it regulates calcium ion concentration. Smooth endoplasmic reticulum is found in a variety of cell types (both animal and plant), and it serves different functions in each. The smooth endoplasmic reticulum also contains the enzyme glucose-6-phosphatase, which converts glucose-6-phosphate to glucose, a step in gluconeogenesis. It is connected to the nuclear envelope and consists of tubules that are located near the cell periphery. These tubes sometimes branch forming a network that is reticular in appearance.[12] In some cells, there are dilated areas like the sacs of rough endoplasmic reticulum. The network of smooth endoplasmic reticulum allows for an increased surface area to be devoted to the action or storage of key enzymes and the products of these enzymes.

Helicase

An enzyme that untwists the double helix of DNA at the replication forks. Helicases are a class of enzymes vital to all organisms. Their main function is to unpackage an organism's genes. They are motor proteins that move directionally along a nucleic acid phosphodiester backbone, separating two annealed nucleic acid strands using energy derived from ATP hydrolysis.

mitochondria

An organelle found in large numbers in most cells, in which the biochemical processes of respiration and energy production occur. Mitochondria are structures within cells that convert the energy from food into a form that cells can use. ... Although most DNA is packaged in chromosomes within the nucleus, mitochondria also have a small amount of their own DNA. This genetic material is known as mitochondrial DNA or mtDNA. The mitochondrion, plural mitochondria is a double-membrane-bound organelle found in most eukaryotic organisms. Some cells in some multicellular organisms may, however, lack them (for example, mature mammalian red blood cells). A number of unicellular organisms, such as microsporidia, parabasalids, and diplomonads, have also reduced or transformed their mitochondria into other structures.[2] To date, only one eukaryote, Monocercomonoides, is known to have completely lost its mitochondria. Mitochondria generate most of the cell's supply of adenosine triphosphate (ATP), used as a source of chemical energy.[5] A mitochondrion is thus termed the powerhouse of the cell.

chloroplast

An organelle found in plant and algae cells where photosynthesis occurs A plastid is an organelle that is commonly found in photosynthetic plants. Plastids are of different types depending on the presence of the pigment and metabolic functions. They may be chloroplasts, chromoplasts, and leucoplasts. A chloroplast is a plastid that contains high amounts of green pigment, chlorophyll. The chlorophyll pigments may be chlorophyll a, chlorophyll b, chlorophyll c, chlorophyll d, and chrlorophyll f. Chlorophyll a is present in all chloroplasts. Other pigments that may be present (particularly in algal cells) are carotenoids and phycobilins. The chloroplast has at least three membrane systems: outer membrane, inner membrane, and thylakoid system. The thylakoids are disk-shaped structures that function as the site of photosynthesis. It is because embedded in the thylakoid membrane is the antenna complex consisting of proteins, and light-absorbing pigments, including chlorophyll (the green pigment) and carotenoids. The chlorophyll is capable of absorbing light energy for use in photosynthesis. The high amounts of chlorophyll give chloroplast a green color, making it easily recognizable from the other plastids. Chloroplasts have their own DNA and it is called chloroplast DNA or cpDNA.

Aldehyde

An organic molecule with a carbonyl group located at the end of the carbon skeleton. An aldehyde is a compound containing a functional group with the structure −CHO, consisting of a carbonyl center (a carbon double-bonded to oxygen) with the carbon atom also bonded to hydrogen and to an R group,[1] which is any generic alkyl or side chain. The group—without R—is the aldehyde group, also known as the formyl group. Aldehydes are common in organic chemistry, and many fragrances are aldehydes.

hydrophilic protein

Because the charged and polar amino acids are hydrophilic, they are usually found at the surface of a water-soluble protein, where they not only contribute to the solubility of the protein in water but also form binding sites for charged molecules.

biosphere

Biosphere encompasses all living things living in the lithosphere, atmosphere and hydrosphere. There are also artificial biospheres that have been made mainly for research and investigation, such as the Biosphere 2, which is by far the largest closed ecology system ever built by mankind.

carboxyl group

Carboxyl groups are functional groups with a carbon atom double-bonded to an oxygen atom and single bonded to a hydroxyl group. The molecular formula is COOH. Carboxyl groups missing a hydrogen atom are de-protonated and ionized. Ionized carboxyl groups act as acids, require less energy and are more stable.

Vacuole

Cell organelle that stores materials such as water, salts, proteins, and carbohydrates The function and significance of vacuoles varies greatly according to the type of cell in which they are present, having much greater prominence in the cells of plants, fungi and certain protists than those of animals and bacteria. In general, the functions of the vacuole include: (pic) Vacuoles also play a major role in autophagy, maintaining a balance between biogenesis (production) and degradation (or turnover), of many substances and cell structures in certain organisms. They also aid in the lysis and recycling of misfolded proteins that have begun to build up within the cell. Thomas Boller[6] and others proposed that the vacuole participates in the destruction of invading bacteria and Robert B. Mellor proposed organ-specific forms have a role in 'housing' symbiotic bacteria. In protists,[7] vacuoles have the additional function of storing food which has been absorbed by the organism and assisting in the digestive and waste management process for the cell.[8]

community

Community, also called biological community, in biology, an interacting group of various species in a common location. For example, a forest of trees and undergrowth plants, inhabited by animals and rooted in soil containing bacteria and fungi, constitutes a biological community.

differential reproduction

Differential reproduction is the idea that those organisms best adapted to a given environment will be most likely to survive to reproductive age and have offspring of their own.

secondary structure

Either an alpha helix or beta pleated sheet. Protein secondary structure is the three dimensional form of local segments of proteins. The two most common secondary structural elements are alpha helices and beta sheets, though beta turns and omega loops occur as well.

Amylase

Enzyme in saliva that breaks the chemical bonds in starches Amylase is an enzyme that catalyses the hydrolysis of starch into sugars. Amylase is present in the saliva of humans and some other mammals, where it begins the chemical process of digestion.

Topoisomerase

Enzyme that functions in DNA replication, helping to relieve strain in the double helix ahead of the replication fork. corrects "overwinding" ahead of replication forks by breaking, swiveling, and rejoining DNA strands Topoisomerases are enzymes that participate in the overwinding or underwinding of DNA. The winding problem of DNA arises due to the intertwined nature of its double-helical structure. During DNA replication and transcription, DNA becomes overwound ahead of a replication fork.

Nucleolus

Found inside the nucleus and produces ribosomes the largest structure in the nucleus of eukaryotic cells.[1] It is best known as the site of ribosome biogenesis. Nucleoli also participate in the formation of signal recognition particles and play a role in the cell's response to stress.[2] Nucleoli are made of proteins, DNA and RNA and form around specific chromosomal regions called nucleolar organizing regions. Malfunction of nucleoli can be the cause of several human conditions called "nucleolopathies"[3] and the nucleolus is being investigated as a target for cancer chemotherapy.

Amino acid structure

H, NH2, COOH bonded to a central carbon and then a variable R group

hydrophobic protein

Hydrophobic amino acids are those with side-chains that do not like to reside in an aqueous (i.e. water) environment. For this reason, one generally finds these amino acids buried within the hydrophobic core of the protein, or within the lipid portion of the membrane.

Denaturation

In proteins, a process in which a protein unravels and loses its native conformation, thereby becoming biologically inactive. In DNA, the separation of the two strands of the double helix. Denaturation is a process in which proteins or nucleic acids lose the quaternary structure, tertiary structure, and secondary structure which is present in their native state, by application of some external stress or compound such as a strong acid or base, a concentrated inorganic salt, an organic solvent (e.g., alcohol or chloroform), radiation or heat. If proteins in a living cell are denatured, this results in disruption of cell activity and possibly cell death. Protein denaturation is also a consequence of cell death. Denatured proteins can exhibit a wide range of characteristics, from conformational change and loss of solubility to aggregation due to the exposure of hydrophobic groups. Denatured proteins lose their 3D structure and therefore cannot function.

ganglion cells

In the retina, the specialized neurons that connect to the bipolar cells; the bundled axons of the ganglion cells form the optic nerve. Ganglion cells are the projection neurons of the vertebrate retina, conveying information from other retinal neurons to the rest of the brain. Their perikarya are the largest of any retinal neurons and are located along the inner margin of the retina, in the ganglion cell layer. A ganglion is a nerve cell cluster[1] or a group of nerve cell bodies located in the autonomic nervous system and sensory system, mostly outside the central nervous system except certain nuclei.[2][3] Ganglia house the cell bodies of afferent nerves (input nerve fibers) and efferent nerves (output/motor nerve fibers). A pseudoganglion looks like a ganglion, but only has nerve fibers and has no nerve cell bodies. Ganglia are primarily made up of somata and dendritic structures which are bundled or connected. Ganglia often interconnect with other ganglia to form a complex system of ganglia known as a plexus. Ganglia provide relay points and intermediary connections between different neurological structures in the body, such as the peripheral and central nervous systems.

RNA

Its principal role is to act as a messenger carrying instructions from DNA for controlling the synthesis of proteins, although in some viruses RNA rather than DNA carries the genetic information. Ribonucleic acid (RNA) is a polymeric molecule essential in various biological roles in coding, decoding, regulation and expression of genes. RNA and DNA are nucleic acids, and, along with lipids, proteins and carbohydrates, constitute the four major macromolecules essential for all known forms of life. Like DNA, RNA is assembled as a chain of nucleotides, but unlike DNA it is more often found in nature as a single-strand folded onto itself, rather than a paired double-strand. Cellular organisms use messenger RNA (mRNA) to convey genetic information (using the nitrogenous bases of guanine, uracil, adenine, and cytosine, denoted by the letters G, U, A, and C) that directs synthesis of specific proteins. Many viruses encode their genetic information using an RNA genome. Some RNA molecules play an active role within cells by catalyzing biological reactions, controlling gene expression, or sensing and communicating responses to cellular signals. One of these active processes is protein synthesis, a universal function in which RNA molecules direct the synthesis of proteins on ribosomes. This process uses transfer RNA (tRNA) molecules to deliver amino acids to the ribosome, where ribosomal RNA (rRNA) then links amino acids together to form coded proteins. The chemical structure of RNA is very similar to that of DNA, but differs in three primary ways: Unlike double-stranded DNA, RNA is a single-stranded molecule[1] in many of its biological roles and consists of much shorter chains of nucleotides.[2] However, a single RNA molecule can, by complementary base pairing, form intrastrand double helixes, as in tRNA. While the sugar-phosphate "backbone" of DNA contains deoxyribose, RNA contains ribose instead. Ribose has a hydroxyl group attached to the pentose ring in the 2' position, whereas deoxyribose does not. The hydroxyl groups in the ribose backbone make RNA more chemically labile than DNA by lowering the activation energy of hydrolysis. The complementary base to adenine in DNA is thymine, whereas in RNA, it is uracil, which is an unmethylated form of thymine. Like DNA, most biologically active RNAs, including mRNA, tRNA, rRNA, snRNAs, and other non-coding RNAs, contain self-complementary sequences that allow parts of the RNA to fold[5] and pair with itself to form double helices. Analysis of these RNAs has revealed that they are highly structured. Unlike DNA, their structures do not consist of long double helices, but rather collections of short helices packed together into structures akin to proteins. In this fashion, RNAs can achieve chemical catalysis (like enzymes).[6] For instance, determination of the structure of the ribosome—an RNA-protein complex that catalyzes peptide bond formation—revealed that its active site is composed entirely of RNA.

multicellular

Multicellular organisms are organisms that consist of more than one cell, in contrast to unicellular organisms

Nicotinamide adenine dinucleotide

Nicotinamide adenine dinucleotide (NAD) is a cofactor that is central to metabolism. Found in all living cells, NAD is called a dinucleotide because it consists of two nucleotides joined through their phosphate groups. One nucleotide contains an adenine nucleobase and the other nicotinamide. NAD exists in two forms: an oxidized and reduced form, abbreviated as NAD+ and NADH respectively. In metabolism, nicotinamide adenine dinucleotide is involved in redox reactions, carrying electrons from one reaction to another. The cofactor is, therefore, found in two forms in cells: NAD+ is an oxidizing agent - it accepts electrons from other molecules and becomes reduced. This reaction forms NADH, which can then be used as a reducing agent to donate electrons. These electron transfer reactions are the main function of NAD. However, it is also used in other cellular processes, most notably a substrate of enzymes that add or remove chemical groups from proteins, in posttranslational modifications. Because of the importance of these functions, the enzymes involved in NAD metabolism are targets for drug discovery.

Adenosine Triphosphate (ATP)

One of the principal chemical compounds that living things use to store and release energy A nucleotide is an organic compound made up of three subunits: a nucleobase, a five-carbon sugar, and a phosphate group. The sugar component may either be ribose or deoxyribose. A nucleotide is, thus, a nucleoside with a phosphate group. Depending on the number of phosphate groups attached to the sugar moiety, a nucleotide may be called nucleoside monophosphate (if with only one phosphate group), nucleoside diphosphate (with two phosphate groups), or nucleoside triphosphate (when with three phosphate groups). Depending on the pentose sugar component, a nucleoside may be a ribonucleoside or a deoxyribonucleoside. A ribonucleoside is a nucleoside with a ribose sugar component. Based on the nucleobase component, the ribonucleoside may be adenosine, guanosine, cytidine, uridine, or 5-methyluridine. A deoxyribonucleoside is a nucleoside with a deoxyribose sugar. Similarly, depending on the nucleobase component, a deoxyribonucleoside may be deoxyadenosine, deoxyguanosine, deoxycytidine, thymidine, or deoxyuridine. Also, depending on the nucleobase component, the nucleosides may be grouped into either the "double-ringed" purine or the "single-ringed" pyrimidine. Adenosine triphosphate (ATP) is a nucleoside phosphate comprised of a ribonucleoside and three phosphate groups. It means it has a ribose as its sugar and three phosphate groups attached. Its structure is comprised of a purine base, particularly adenine that is bound at the 9' nitrogen atom to the 1' carbon atom of ribose sugar, and a three phosphate groups. The removal of one or two phosphate groups yields adenosine monophosphate or adenosine diphosphate, respectively. Cellular respiration is a series of metabolic processes wherein the biochemical energy is harvested from organic substance (e.g. glucose) and stored in energy-carriers like ATP. Glycolysis is the initial stage in cellular respiration that is involved in the cellular degradation of the simple sugar, glucose to pyruvate in order to yield high-energy molecules such as ATP and NADH. The most common and well-known type of glycolysis is the Embden-Meyerhof-Parnas pathway, which was first describe by Gustav Embden, Otto Meyerhof, and Jakub Karol Parnas. Other alternative pathways are exemplified by the Entner-Doudoroff pathway and the pentose phosphate pathway. The Krebs cycle is a stage of cellular respiration following glycolysis and is characterized by its decarboxylation of pyruvate. It involves a cyclic series of enzymatic reactions through which pyruvate -- converted into Acetyl Coenzyme A -- is completely oxidized to CO2. Along with this, hydrogen ion is removed from the carbon molecules, transferring the hydrogen atoms and electrons to electron-carrier molecules (e.g. NADHand FADH2), and metabolic energy to high energy bonds (e.g. ATP). CO2 from the complete oxidation of pyruvate is removed from the cell into the blood. The electron and hydrogen carriers, NADH and FADH 2 , donate these electrons to the electron transport chain to generate ATP via oxidative phosphorylation, the final metabolic pathway of cellular respiration. In eukaryotes the Krebs Cycle occurs in the matrix of the mitochondrion whereas in prokaryotes, it occurs in the cytoplasm.

Eukaryotic cells

Organisms such as animals, plants, fungi, and protists are examples of eukaryotes because their cells are organized into compartmentalized structures called organelles, the nucleus in particular. The presence of a distinct nucleus encased within membranes differentiates the eukaryotes from the prokaryotes. The eukaryotes are also known for having cytoplasmic organelles apart from nucleus, such as mitochondria, chloroplasts and Golgi bodies. Eukaryotes often have unique flagella made of microtubules in a 9+2 arrangement.

Polysaccharide

Polysaccharides are polymeric carbohydrate molecules composed of long chains of monosaccharide units bound together by glycosidic linkages, and on hydrolysis by amylase enzymes give the constituent monosaccharides or oligosaccharides. They range in structure from linear to highly branched.

polysaccharides

Polysaccharides are polymeric carbohydrate molecules composed of long chains of monosaccharide units bound together by glycosidic linkages, and on hydrolysis by amylase enzymes give the constituent monosaccharides or oligosaccharides. They range in structure from linear to highly branched. a carbohydrate (e.g. starch, cellulose, or glycogen) whose molecules consist of a number of sugar molecules bonded together.

Protein primary structure

Protein primary structure is the linear sequence of amino acids in a peptide or protein. By convention, the primary structure of a protein is reported starting from the amino-terminal end to the carboxyl-terminal end. Protein biosynthesis is most commonly performed by ribosomes in cells

Protein quaternary structure

Protein quaternary structure is the number and arrangement of multiple folded protein subunits in a multi-subunit complex. It includes organisations from simple dimers to large homooligomers and complexes with defined or variable numbers of subunits.

tertiary structure

Protein tertiary structure is the three dimensional shape of a protein. The tertiary structure will have a single polypeptide chain "backbone" with one or more protein secondary structures, the protein domains. Amino acid side chains may interact and bond in a number of ways

Protein makes up all biological life. It is a key component of DNA, chromosomes, cytoskeletons, etc.

Proteins are made up of hundreds or thousands of smaller units called amino acids, which are attached to one another in long chains. There are 20 different types of amino acids that can be combined to make a protein. The sequence of amino acids determines each protein's unique 3-dimensional structure and its specific function. It is also estimated that human body has the ability to generate 2 million different types of proteins, coded by only 20,000-25,000 of our genes. The sum of proteins in biological organisms exceeds 10 million, despite this, I do not think anyone has done any proper research on this.

s strain bacteria

Strain of Streptococcus pneumoniae that causes pneumonia (it would be SO BAD to be infected by this one) S bacteria formed colonies that were rounded and smooth (hence the abbreviation "S"). The smooth appearance was due to a polysaccharide, or sugar-based, coat produced by the bacteria. This coat protected the S bacteria from the mouse immune system, making them virulent (capable of causing disease).

R strain bacteria

Strain of Streptococcus pneumoniae that does not cause pneumonia (you'll be R RIGHT if infected by this one) When grown in a petri dish, the R bacteria formed colonies, or clumps of related bacteria, that had well-defined edges and a rough appearance (hence the abbreviation "R"). The R bacteria were nonvirulent, meaning that they did not cause sickness when injected into a mouse.

disulfide bond

Strong chemical side bond that joins the sulfur atoms of two neighboring cysteine amino acids to create one cystine, which joins together two polypeptide strands like rungs on a ladder. A disulfide bond, also called an S-S bond, or disulfide bridge, is a covalent bond derived from two thiol groups. In biochemistry, the terminology R-S-S-R connectivity is commonly used to describe the overall linkages. The most common way of creating this bond is by the oxidation of sulfhydryl groups.

Peptide bond

The chemical bond that forms between the carboxyl group of one amino acid and the amino group of another amino acid This is what allows protein chains to form

endomembrane system

The endomembrane system is composed of the different membranes that are suspended in the cytoplasm within a eukaryotic cell. These membranes divide the cell into functional and structural compartments, or organelles. In eukaryotes the organelles of the endomembrane system include: the nuclear membrane, the endoplasmic reticulum, the Golgi apparatus, lysosomes, vesicles, endosomes, and plasma (cell) membrane among others. The system is defined more accurately as the set of membranes that form a single functional and developmental unit, either being connected directly, or exchanging material through vesicle transport.[1] Importantly, the endomembrane system does not include the membranes of chloroplasts or mitochondria, but might have evolved from the latter (see below: Evolution). The nuclear membrane contains a lipid bilayer that encompass the contents of the nucleus.[2] The endoplasmic reticulum (ER) is a synthesis and transport organelle that branches into the cytoplasm in plant and animal cells.[3] The Golgi apparatus is a series of multiple compartments where molecules are packaged for delivery to other cell components or for secretion from the cell.[4] Vacuoles, which are found in both plant and animal cells (though much bigger in plant cells), are responsible for maintaining the shape and structure of the cell as well as storing waste products.[5] A vesicle is a relatively small, membrane-enclosed sac that stores or transports substances.[6] The cell membrane is a protective barrier that regulates what enters and leaves the cell.[7] There is also an organelle known as the Spitzenkörper that is only found in fungi, and is connected with hyphal tip growth.[8] In prokaryotes endomembranes are rare, although in many photosynthetic bacteria the plasma membrane is highly folded and most of the cell cytoplasm is filled with layers of light-gathering membrane.[9] These light-gathering membranes may even form enclosed structures called chlorosomes in green sulfur bacteria.[10] The organelles of the endomembrane system are related through direct contact or by the transfer of membrane segments as vesicles. Despite these relationships, the various membranes are not identical in structure and function. The thickness, molecular composition, and metabolic behavior of a membrane are not fixed, they may be modified several times during the membrane's life. One unifying characteristic the membranes share is a lipid bilayer, with proteins attached to either side or traversing them.[11]

hydroxyl group

The hydroxyl group is a functional group consisting of a hydrogen atom covalently bonded to an oxygen atom. The hydroxyl group is denoted by -OH in chemical structures and has a valence charge of -1. The hydroxyl radical is very reactive, so it quickly reacts with other chemical species.

supernatant

The liquid on top of material deposited by settling or centrifugation. denoting the liquid lying above a solid residue after crystallization, precipitation, centrifugation, or other process.

photoablation

The procedure using ultraviolet radiation from a laser to remove tissue. Photoablation is the use of light or lasers to destroy tissues. The excimer laser of deep ultra-violet light is mainly used in Photoablation. The wavelength of laser used in photoablation is approximately 200 nm.

Supervenience

There is a necessary connection between the mental and physical a relation between properties at different levels in which there can be no change in a higher-level property without a corresponding change in a lower-level property In philosophy, supervenience refers to a relation between sets of properties or sets of facts. X is said to supervene on Y if and only if some difference in Y is necessary for any difference in X to be possible

emergent property

a characteristic of a system that does not appear in any of the system's component parts An emergent property is a property which a collection or complex system has, but which the individual members do not have. A failure to realize that a property is emergent, or supervenient, leads to the fallacy of division.

Miller-Urey experiment

a chemical experiment that simulated the conditions thought at the time to be present on the early Earth, and tested the chemical origin of life under those conditions. The experiment supported Alexander Oparin's and J. B. S. Haldane's hypothesis that putative conditions on the primitive Earth favoured chemical reactions that synthesized more complex organic compounds from simpler inorganic precursors After Miller's death in 2007, scientists examining sealed vials preserved from the original experiments were able to show that there were actually well over 20 different amino acids produced in Miller's original experiments. That is considerably more than what Miller originally reported, and more than the 20 that naturally occur in life.[7] More recent evidence suggests that Earth's original atmosphere might have had a composition different from the gas used in the Miller experiment, but prebiotic experiments continue to produce racemic mixtures of simple to complex compounds under varying conditions

nucleic acid

a complex organic substance present in living cells, especially DNA or RNA, whose molecules consist of many nucleotides linked in a long chain. Nucleic acids are the biopolymers, or small biomolecules, essential to all known forms of life. The term nucleic acid is the overall name for DNA and RNA. They are composed of nucleotides, which are the monomers made of three components: a 5-carbon sugar, a phosphate group and a nitrogenous base.

Amoeba

a kind of single-celled organism in kingdom Protista able to move by itself one common sarcodine with an unusual adaptation for movement and getting nutrients A type of protist characterized by great flexibility and the presence of pseudopodia. a single-celled animal that catches food and moves about by extending fingerlike projections of protoplasm. Amoebas are either free-living in damp environments or parasitic.

polymerization

a large molecule composed of a chain of smaller, chemically related subunits (called monomers); for example, proteins are polymers of amino acids and nucleic acids are polymers of nucleotides. In polymer chemistry, polymerization is a process of reacting monomer molecules together in a chemical reaction to form polymer chains or three-dimensional networks. There are many forms of polymerization and different systems exist to categorize them Polymerization is the act or process wherein monomeric molecules join together to form a polymer or a 3D network. In biochemistry, polymerization occurs through a chemical reaction that ends up in creating a polymer as monomers link through chemical bonds.

coacervate

a mass of droplets of colloidal substances, such as lipids, amino acids, and sugars, that are held together by electrostatic attraction a mass of colloidal substances held together by electrostatic attraction Coacervates are organic-rich droplets formed via liquid-liquid phase separation, mainly resulting from association of oppositely charged molecules or from hydrophobic proteins. Coacervation is a phenomenon that produces coacervate colloidal droplets. Coacervates are remarkable protobionts that self-assemble from a solution of polypeptides, nucleic acids, and polysaccharides (polymerized sugars) under certain conditions. When enzymes are added to a coacervate solution, they are taken inside the coacervate and begin to function normally. In spite of remarkable experiments showing the ability of biomolecules and simple cells to be created abiotically, many questions remain unanswered about how life might have arisen spontaneously on the early Earth.

centrioles

a minute cylindrical organelle near the nucleus in animal cells, occurring in pairs and involved in the development of spindle fibers in cell division. In cell biology a centriole is a cylindrical organelle composed mainly of a protein called tubulin.[1] Centrioles are found in most eukaryotic cells. A bound pair of centrioles, surrounded by a shapeless mass of dense material, called the pericentriolar material (PCM), makes up a structure called a centrosome.[1] Centrioles are not present in all eukaryotes; for example, they are absent from conifers (pinophyta), flowering plants (angiosperms) and most fungi, and are only present in the male gametes of charophytes, bryophytes, seedless vascular plants, cycads, and ginkgo.[2][3] The main function of centrioles is to produce cilia during interphase and the aster and the spindle during cell division. Centrioles are involved in the organization of the mitotic spindle and in the completion of cytokinesis.[11] Centrioles were previously thought to be required for the formation of a mitotic spindle in animal cells. However, more recent experiments have demonstrated that cells whose centrioles have been removed via laser ablation can still progress through the G1 stage of interphase before centrioles can be synthesized later in a de novo fashion.[12] Additionally, mutant flies lacking centrioles develop normally, although the adult flies' cells lack flagella and cilia and as a result, they die shortly after birth.[13] The centrioles can self replicate during cell division.

Liposome

a minute spherical sac of phospholipid molecules enclosing a water droplet, especially as formed artificially to carry drugs or other substances into the tissues. A liposome is a spherical vesicle having at least one lipid bilayer. The liposome can be used as a vehicle for administration of nutrients and pharmaceutical drugs.[2] Liposomes can be prepared by disrupting biological membranes (such as by sonication).

purine

a nitrogenous base that has a double-ring structure; one of the two general categories of nitrogenous bases found in DNA and RNA; either adenine or guanine Purine is a heterocyclic aromatic organic compound that consists of a pyrimidine ring fused to an imidazole ring. It is water-soluble. Purine also gives its name to the wider class of molecules, purines, which include substituted purines and their tautomers a colorless crystalline compound with basic properties, forming uric acid on oxidation. Adenine and Guanine A and G in DNA

Pyrimidine

a nitrogenous base that has a single-ring structure; one of the two general categories of nitrogenous bases found in DNA and RNA; thymine, cytosine, or uracil a substituted derivative of pyrimidine, especially the bases thymine and cytosine present in DNA. Cytosine, Uracil and Thymine in DNA and RNA (C,T, and U)

organ

a part of an organism that is typically self-contained and has a specific vital function, such as the heart or liver in humans.

polypeptide

a polymer of amino acids (named for the chemical peptide bond that joins the amino acids); large polypeptides are usually called proteins, and the two terms are sometimes used interchangeably.

enzyme

a protein that serves as a catalyst for a biochemical reaction in the cell. catalyst protein

Nuclear pore

a protein-lined channel in the nuclear envelope that regulates the transportation of molecules between the nucleus and the cytoplasm The nuclear pore is a protein-lined channel in the nuclear envelope that regulates the transportation of molecules between the nucleus and the cytoplasm. In eukaryotic cells, the nucleus is separated from the cytoplasm and surrounded by a nuclear envelope. This envelope safeguards the DNA contained in the nucleus.

Anticodon

a sequence of three nucleotides forming a unit of genetic code in a transfer RNA molecule, corresponding to a complementary codon in messenger RNA. group of three bases on a tRNA molecule that are complementary to an mRNA codon the sequence of three nucleotides found on one end of a transfer RNA molecule that recognizes and binds to a corresponding codon on a molecule of messenger RNA during protein synthesis.

primordial soup

a solution rich in organic compounds in the primitive oceans of the earth, from which life is hypothesized to have originated.

Surfactant

any substance that interferes with the hydrogen bonding between water molecules and thereby reduces surface tension Surfactants are compounds that lower the surface tension (or interfacial tension) between two liquids, between a gas and a liquid, or between a liquid and a solid. Surfactants may act as detergents, wetting agents, emulsifiers, foaming agents, and dispersants.

the four major classes of organic compounds

carbohydrates (sugars) lipids (fats) proteins (amino acids) nucleic acids (DNA and RNA)

lysosome

cell organelle filled with enzymes needed to break down certain materials in the cell a membrane-bound organelle found in many animal cells.[1] They are spherical vesicles that contain hydrolytic enzymes that can break down many kinds of biomolecules. A lysosome has a specific composition, of both its membrane proteins, and its lumenal proteins. The lumen's pH (~4.5-5.0)[2] is optimal for the enzymes involved in hydrolysis, analogous to the activity of the stomach. Besides degradation of polymers, the lysosome is involved in various cell processes, including secretion, plasma membrane repair, cell signaling, and energy metabolism. Lysosomes act as the waste disposal system of the cell by digesting obsolete or un-used materials in the cytoplasm, from both inside and outside the cell. Material from outside the cell is taken-up through endocytosis, while material from the inside of the cell is digested through autophagy.[5] The sizes of the organelles vary greatly—the larger ones can be more than 10 times the size of the smaller ones.[6] They were discovered and named by Belgian biologist Christian de Duve, who eventually received the Nobel Prize in Physiology or Medicine in 1974. Lysosomes are known to contain more than 60 different enzymes, and have more than 50 membrane proteins.[7][8] Enzymes of the lysosomes are synthesised in the rough endoplasmic reticulum. The enzymes are imported from the Golgi apparatus in small vesicles, which fuse with larger acidic vesicles. Enzymes destined for a lysosome are specifically tagged with the molecule mannose 6-phosphate, so that they are properly sorted into acidified vesicles. Synthesis of lysosomal enzymes is controlled by nuclear genes. Mutations in the genes for these enzymes are responsible for more than 30 different human genetic disorders, which are collectively known as lysosomal storage diseases. These diseases result from an accumulation of specific substrates, due to the inability to break them down. These genetic defects are related to several neurodegenerative disorders, cancers, cardiovascular diseases, and aging-related diseases.

nuclear membrane

controls what goes in and out of the nucleus The nuclear membrane, sometimes referred to as the nuclear envelope, is the membrane that encloses the nucleus. This bilayer membrane is made of lipids, and encases the genetic material in eukaryotic cells. The nuclear membrane is made up of a double lipid bilayer.

ablate

cut away When you ablate something, you wear it away by rubbing or some other method. In medicine, doctors sometimes need to ablate a patient's skin to help it heal.

Biogenesis

development of life from preexisting life

proto-

first; primary

nuclear envelope

layer of two membranes that surrounds the nucleus of a cell The nuclear envelope, also known as the nuclear membrane, is made up of two lipid bilayer membranes which in eukaryotic cells surrounds the nucleus, which encases the genetic material. The nuclear envelope consists of two lipid bilayer membranes, an inner nuclear membrane, and an outer nuclear membrane

cyto-

of a cell or cells.

abiotic

physical rather than biological; not derived from living organisms. non-living

Histone

protein molecule around which DNA is tightly coiled in chromatin any of a group of basic proteins found in chromatin. In biology, histones are highly alkaline proteins found in eukaryotic cell nuclei that package and order the DNA into structural units called nucleosomes.[1][2] They are the chief protein components of chromatin, acting as spools around which DNA winds, and playing a role in gene regulation. Without histones, the unwound DNA in chromosomes would be very long (a length to width ratio of more than 10 million to 1 in human DNA). For example, each human diploid cell (containing 23 pairs of chromosomes) has about 1.8 meters of DNA; wound on the histones, the diploid cell has about 90 micrometers (0.09 mm) of chromatin. When the diploid cells are duplicated and condensed during mitosis, the result is about 120 micrometers of chromosomes.[3]

Cilium

short hairlike projection similar to a flagellum; produces movement in many cells There are two types of cilia: motile and non-motile cilia. The non-motile cilia are called primary cilia which typically serve as sensory organelles. There is a third type of cilium that is only transiently present in the early embryo. These are known as nodal cilia and are crucial in the establishment of the left to right body asymmetry.[3]

apnea

temporary cessation of breathing, especially during sleep.

chromatin

the material of which the chromosomes of organisms other than bacteria (i.e., eukaryotes) are composed. It consists of protein, RNA, and DNA. Chromatin is a complex of DNA and protein found in eukaryotic cells.[1] Its primary function is packaging very long DNA molecules into a more compact, denser shape, which prevents the strands from becoming tangled and plays important roles in reinforcing the DNA during cell division, preventing DNA damage, and regulating gene expression and DNA replication. During mitosis and meiosis, chromatin facilitates proper segregation of the chromosomes in anaphase; the characteristic shapes of chromosomes visible during this stage are the result of DNA being coiled into highly condensed networks of chromatin. The primary protein components of chromatin are histones, which bind to DNA and function as "anchors" around which the strands are wound. In general, there are three levels of chromatin organization: DNA wraps around histone proteins, forming nucleosomes and the so-called "beads on a string" structure (euchromatin). Multiple histones wrap into a 30-nanometer fibre consisting of nucleosome arrays in their most compact form (heterochromatin).[a] Higher-level DNA supercoiling of the 30-nm fiber produces the metaphase chromosome (during mitosis and meiosis). Many organisms, however, do not follow this organization scheme. For example, spermatozoa and avian red blood cells have more tightly packed chromatin than most eukaryotic cells, and trypanosomatid protozoa do not condense their chromatin into visible chromosomes at all. Prokaryotic cells have entirely different structures for organizing their DNA (the prokaryotic chromosome equivalent is called a genophore and is localized within the nucleoid region).

cytoplasm

the material or protoplasm within a living cell, excluding the nucleus. In cell biology, the cytoplasm is all of the material within a cell, enclosed by the cell membrane, except for the cell nucleus. The material inside the nucleus and contained within the nuclear membrane is termed the nucleoplasm. The main components of the cytoplasm are cytosol - a gel-like substance, the organelles - the cell's internal sub-structures, and various cytoplasmic inclusions. The cytoplasm is about 80% water and usually colorless.

polymerized

the process in which monomers combine to form a chemically large, chainlike network called a polymer. when proteins link together to form more complex peptide chains

Rough Endoplasmic Reticulum (RER)

the region of the endoplasmic reticulum that is studded with ribosomes and engages in protein modification

Interphase

the resting phase between successive mitotic divisions of a cell, or between the first and second divisions of meiosis. Interphase is the phase of the cell cycle in which a typical cell spends most of its life. Prophase, however is the longest stage of mitosis. During interphase, the cell copies its DNA in preparation for mitosis.[1] Interphase is the 'daily living' or metabolic phase of the cell, in which the cell obtains nutrients and metabolizes them, grows, reads its DNA, and conducts other "normal" cell functions.[1] This phase was formerly called the resting phase. However, interphase does not describe a cell that is merely resting; rather, the cell is living and preparing for later cell division, so the name was changed. A common misconception is that interphase is the first stage of mitosis, but since mitosis is the division of the nucleus, prophase is actually the first stage.[2]

How are all amino acids similar?

they have at least one carboxyl group

endo-

within, inner; inside