Chapter 2 - The Chemistry of Life

Buffer

A buffer solution (more precisely, pH buffer or hydrogen ion buffer) is an aqueous solution consisting of a mixture of a weak acid and its conjugate base, or vice versa. Its pH changes very little when a small or moderate amount of strong acid or base is added to it and thus it is used to prevent changes in the pH of a solution. Buffer solutions are used as a means of keeping pH at a nearly constant value in a wide variety of chemical applications. Many life forms thrive only in a relatively small pH range so they utilize a buffer solution to maintain a constant pH. One example of a buffer solution found in nature is blood.

Carbohydrate

A carbohydrate is a biological molecule consisting of carbon (C), hydrogen (H) and oxygen (O) atoms, usually with a hydrogen:oxygen atom ratio of 2:1 (as in water); in other words, with the empirical formula Cm(H2O)n (where m could be different from n)

Element

A chemical element (often just element when the chemical context is implicit) is a species of chemical objects, characterized by a number of protons in an atom's nucleus. Substances that cannot be broken down into other substances by chemical reactions. 92 naturally occurring Elements on Earth several other have been artificially created in the laboratory.

Chemical reaction

A chemical reaction is a process that leads to the transformation of one set of chemical substances to another.[1] Classically, chemical reactions encompass changes that only involve the positions of electrons in the forming and breaking of chemical bonds between atoms, with no change to the nuclei (no change to the elements present), and can often be described by a chemical equation. Chemical reactions always involve the breaking of bonds in reactants and the formation of new bonds in products.

Covalent Bond

A covalent bond is a chemical bond that involves the sharing of electron pairs between atoms. These electron pairs are known as shared pairs or bonding pairs and the stable balance of attractive and repulsive forces between atoms when they share electrons is known as covalent bonding. Nonpolar covalent bonds Polar covalent bonds

Molecule

A molecule /ˈmɒlɪkjuːl/ is an electrically neutral group of two or more atoms held together by chemical bonds.[1][2][3][4][5][6] Molecules are distinguished from ions by their lack of electrical charge. However, in quantum physics, organic chemistry, and biochemistry, the term molecule is often used less strictly, also being applied to polyatomic ions.

Monomer

A monomer (/ˈmɒnəmər/ mon-ə-mər[1]) (mono-, "one" + -mer, "part") is a molecule that may bind chemically to other molecules to form a polymer.

Polymer

A polymer (/ˈpɒlɨmər/[2][3]) (Greek poly-, "many" + -mer, "parts") is a large molecule, or macromolecule, composed of many repeated subunits. Because of their broad range of properties,[4] both synthetic and natural polymers play an essential and ubiquitous role in everyday life.[5] Polymers range from familiar synthetic plastics such as polystyrene to natural biopolymers such as DNA and proteins that are fundamental to biological structure and function. Polymers, both natural and synthetic, are created via polymerization of many small molecules, known as monomers.

Single Bond

A single shared pair of electrons; is represented in a chemical structure by a solid line.

Solvent

A solvent (from the Latin solvō, "I loosen, untie, I solve") is a substance that dissolves a solute (a chemically different liquid, solid or gas), resulting in a solution. A solvent is usually a liquid but can also be a solid or a gas. The quantity of solute that can dissolve in a specific volume of solvent varies with temperature.

Hydrogen Bonds

A weak bond between two molecules resulting from an electrostatic attraction between a proton in one molecule and an electronegative atom in the other. Attractions between opposite charges.

Adhesion

Adhesion is the tendency of dissimilar particles or surfaces to cling to one another (cohesion refers to the tendency of similar or identical particles/surfaces to cling to one another). The forces that cause adhesion and cohesion can be divided into several types. The intermolecular forces responsible for the function of various kinds of stickers and sticky tape fall into the categories of chemical adhesion, dispersive adhesion, and diffusive adhesion.

Subatomic particles

All matter is composed of atoms. But atoms themselves are composed of even smaller subatomic particles. Two of these particles - neutron and protons- have about equal mass an are located in the nucleus at the center of the atom. The number of protons in an atom determine its chemical element. Particles of the third type - Electron- have very little mass and orbit the nucleus at high speed. Electron are not found just anywhere around the nucleus: they orbit at specific locations called electron shells.

Amino acid

Amino acids (/əˈmiːnoʊ, ˈæmənoʊ, əˈmaɪnoʊ/) are biologically important organic compounds composed of amine (-NH2) and carboxylic acid (-COOH) functional groups, along with a side-chain specific to each amino acid.[1][2][3] The key elements of an amino acid are carbon, hydrogen, oxygen, and nitrogen, though other elements are found in the side-chains of certain amino acids. About 500 amino acids are known

Acid

An acid (from the Latin acidus/acēre meaning sour[1]) is a chemical substance whose aqueous solutions are characterized by a sour taste, the ability to turn blue litmus red, and the ability to react with bases and certain metals (like calcium) to form salts. Aqueous solutions of acids have a pH of less than 7.

Atom

An atom is the smallest constituent unit of ordinary matter that has the properties of a chemical element. Every solid, liquid, gas, and plasma is made up of neutral or ionized atoms.

Ions

An atom or group of atoms that has acquired a charge by the gain or loss of electrons.

Ion

An ion (/ˈaɪən, -ɒn/)[1] is an atom or molecule in which the total number of electrons is not equal to the total number of protons, giving the atom or molecule a net positive or negative electrical charge.

Matter

Anything that occupies space and has mass (substance).

Double Bond

Atoms that share two pairs of electron; show as a pair of solid lines.

Catalyst

Catalysis is the increase in the rate of a chemical reaction due to the participation of an additional substance called a catalyst.[1] With a catalyst, reactions occur faster and with less energy. Because catalysts are not consumed, they are recycled. Often only tiny amounts are required.

Cohesion

Cohesion (n. lat. cohaerere "stick or stay together") or cohesive attraction or cohesive force is the action or property of like molecules sticking together, being mutually attractive. It is an intrinsic property of a substance that is caused by the shape and structure of its molecules, which makes the distribution of orbiting electrons irregular when molecules get close to one another, creating electrical attraction that can maintain a microscopic structure such as a water drop. In other words, cohesion allows for surface tension, creating a "solid-like" state upon which light (in weight) or low-density materials can be placed.

Deoxyribonucleic acid (DNA)

Deoxyribonucleic acid (Listeni/diˌɒksiˌraɪbɵ.njuːˌkleɪ.ɨk ˈæsɪd/; DNA) is a molecule that carries most of the genetic instructions used in the development, functioning and reproduction of all known living organisms and many viruses. DNA is a nucleic acid; alongside proteins and carbohydrates, nucleic acids compose the three major macromolecules essential for all known forms of life. Most DNA molecules consist of two biopolymer strands coiled around each other to form a double helix. The two DNA strands are known as polynucleotides since they are composed of simpler units called nucleotides.

Polar Bond

Electrons are more strongly attracted to one atom than the other. Unequal sharing of electrons

Nonpolar bond

Electrons are shared equally between the two atoms in the bond. Equal sharing of electrons.

Enzyme

Enzymes /ˈɛnzaɪmz/ are macromolecular biological catalysts. Enzymes accelerate, or catalyze, chemical reactions. The molecules at the beginning of the process are called substrates and the enzyme converts these into different molecules, called products. Almost all metabolic processes in the cell need enzymes in order to occur at rates fast enough to sustain life.

Elements that are essential to life

Four Elements Bulk of living things: 96% O - Oxygen 65.0% C - Carbon 15.5% H - Hydrogen 9.5% N - Nitrogen 3.3% Seven Elements small fraction of living things: 3.7% Ca- Calcium 1.5% P - Phosphorus 1.0% S - Sulfur 0.3% K - Potassium 0.4% Na- Sodium 0.2% Cl- Chlorine 0.2% Mg- Magnesium 0.1% Fourteen trace element minuscule amounts: 0.1% B - Boron Cr- Chromium Co- Cobalt Cu- Copper F - Fluorine I - Iodine Fe- Iron Mn- Manganese Mo- Molybdenum Se- Selenium Sn- Tin V - Vanadium Zn- Zinc

Matter three forms

Gas Liquid Solid

Ionic Bond

Ionic bonding is a type of chemical bond that involves the electrostatic attraction between oppositely charged ions. These ions represent atoms that have lost one or more electrons (known as cations) and atoms that have gained one or more electrons (known as anions)

Lipid

Lipids are a group of naturally occurring molecules that include fats, waxes, sterols, fat-soluble vitamins (such as vitamins A, D, E, and K), monoglycerides, diglycerides, triglycerides, phospholipids, and others. The main biological functions of lipids include storing energy, signaling, and acting as structural components of cell membranes.

Periodic table of elements

Lists all of the chemical elements, ordered by atomic number.

Monosaccharide

Monosaccharides (from Greek monos: single, sacchar: sugar; British English: monosaccharaides) are the most basic units of carbohydrates. They are the simplest form of sugar and are usually colorless, water-soluble, crystalline solids. Some monosaccharides have a sweet taste. Examples of monosaccharides include glucose (dextrose), fructose (levulose) and galactose.

Nucleic acid

Nucleic acids are biopolymers, or large biomolecules, essential for all known forms of life. Nucleic acids, which include DNA (deoxyribonucleic acid) and RNA (ribonucleic acid), are made from monomers known as nucleotides. Each nucleotide has three components: a 5-carbon sugar, a phosphate group, and a nitrogenous base. If the sugar is deoxyribose, the polymer is DNA. If the sugar is ribose, the polymer is RNA.

Nucleotide

Nucleotides are organic molecules that serve as the monomers, or subunits, of nucleic acids like DNA and RNA. The building blocks of nucleic acids, nucleotides are composed of a nitrogenous base, a five-carbon sugar (ribose or deoxyribose), and at least one phosphate group.

Polysaccharide

Polysaccharides are polymeric carbohydrate molecules composed of long chains of monosaccharide units bound together by glycosidic linkages and on hydrolysis give the constituent monosaccharides or oligosaccharides. They range in structure from linear to highly branched. Examples include storage polysaccharides such as starch and glycogen, and structural polysaccharides such as cellulose and chitin.

Protein

Proteins (/ˈproʊˌtiːnz/ or /ˈproʊti.ɨnz/) are large biological molecules, 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, replicating DNA, 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 folding of the protein into a specific three-dimensional structure that determines its activity.

Ribonucleic acid (RNA)

Ribonucleic acid (RNA) is a polymeric molecule implicated in various biological roles in coding, decoding, regulation, and expression of genes. RNA and DNA are nucleic acids, and, along with proteins and carbohydrates, constitute the three major macromolecules essential for all known forms of life.

Solute

The dissolved substance in a solution

Electron

The electron is a subatomic particle, symbol e− or β−, with a negative elementary electric charge.

Product

The elements or compounds produced by a chemical reaction are known as products. (ending matter, on right). A lot of energy.

Reactant

The elements or compounds that enter into a chemical reaction are known as reactants. (starting matter, on left). Some energy

Nucleus

The nucleus is the small, dense region consisting of protons and neutrons at the center of an atom.

Chemistry

The scientific study of matter, is necessary to understand many important biological process.

Compound

The term chemical compound refers to any substance consisting of two or more different types of atoms (chemical elements) in a fixed proportion of its atoms (i.e., generally exhibits integer-value stoichiometry), and is most readily understood when considering pure chemical substances.

Substrate

The term substrate is highly context-dependent.[1] In chemistry, a substrate is typically the chemical species being observed in a chemical reaction, which reacts with reagent to generate a product.

Chemical Bonds

Within ever living cell, countless chemical reactions between molecules drive the processes of life. During a chemical reaction, atoms gain, release, or share electrons with other atoms. The atoms involved many become attracted to each other and be held together by Chemical bonds. Ionic Bonds Covalent Bonds

Mixture

a mixture is a material system made up of two or more different substances which are mixed but are not combined chemically. A mixture refers to the physical combination of two or more substances on which the identities are retained and are mixed in the form of solutions, suspensions, and colloids.

Solution

a solution is a homogeneous mixture composed of only one phase. In such a mixture, a solute is a substance dissolved in another substance, known as a solvent. The solution more or less takes on the characteristics of the solvent including its phase, and the solvent is commonly the major fraction of the mixture. The concentration of a solute in a solution is a measure of how much of that solute is dissolved in the solvent, with regard to how much solvent is present.

Suspension

a suspension is a heterogeneous mixture containing solid particles that are sufficiently large for sedimentation. Usually they must be larger than one micrometer.[1] The internal phase (solid) is dispersed throughout the external phase (fluid) through mechanical agitation, with the use of certain excipients or suspending agents. Unlike colloids, suspensions will eventually settle. An example of a suspension would be sand in water. The suspended particles are visible under a microscope and will settle over time if left undisturbed. This distinguishes a suspension from a colloid, in which the suspended particles are smaller and do not settle.[2] Colloids and suspensions are different from solutions, in which the dissolved substance (solute) does not exist as a solid, and solvent and solute are homogeneously mixed.

Activation energy

activation energy is a term introduced in 1889 by the Swedish scientist Svante Arrhenius to describe the minimum energy which must be available to a chemical system with potential reactants to result in a chemical reaction. Activation energy may also be defined as the minimum energy required to start a chemical reaction.

Base

bases are substances that, in aqueous solution, are slippery to the touch, taste bitter, change the color of indicators (e.g., turn red litmus paper blue), react with acids to form salts, and promote certain chemical reactions (base catalysis).

pH scale

pH (/piːˈeɪtʃ/) is a numeric scale used to specify the acidity or alkalinity of an aqueous solution. It is the negative of the logarithm to base 10 of the activity of the hydrogen ion. Solutions with a pH less than 7 are acidic and solutions with a pH greater than 7 are alkaline or basic. Pure water has a pH of 7 and is neutral being neither acid or alkaline. Contrary to popular belief, the pH value can be less than 0 or greater than 14 for very strong acids and alkalines respectively. However, these extremes are difficult to measure precisely.

van der Waals forces

the sum of the attractive or repulsive forces between molecules (or between parts of the same molecule) other than those due to covalent bonds, or the electrostatic interaction of ions with one another, with neutral molecules, or with charged molecules.[1] The resulting van der Waals forces can be attractive or repulsive.

Isotope

variants of a particular chemical element which differ in neutron number, although all isotopes of a given element have the same number of protons in each atom. The term isotope is formed from the Greek roots isos (ἴσος "equal") and topos (τόπος "place"), meaning "the same place". Thus, different isotopes of a single element occupy the same position on the periodic table. The number of protons within the atom's nucleus is called atomic number and is equal to the number of electrons in the neutral (non-ionized) atom. Each atomic number identifies a specific element, but not the isotope; an atom of a given element may have a wide range in its number of neutrons. The number of nucleons (both protons and neutrons) in the nucleus is the atom's mass number, and each isotope of a given element has a different mass number.