TheChemistryofLife

“What You’ll Learn”: Ø Why water is important to life. Ø Relating an atom’s interactions to its structure. Ø Compare the role of biomolecules in organisms. Section 1 Vocabulary: · Element: a substance that cannot be broken down into simpler chemical substances · Atom: the smallest particle of an element that has the characteristics of that element; the basic building block of all matter · Nucleus: the center of an atom, has a positive charge · Isotope: atoms of the same element that have different numbers of neutrons in the nucleus · Compound: substance composed of two or more elements that are chemically combined · Covalent bond: chemical bond formed when two atoms share electrons · Molecule: a group of atoms held together by covalent bonds · Ion: atom or group of atoms that gain or lose electron; has an electrical charge · Ionic bond: a chemical bond formed by the attractive forces between two ions of opposite charge · Metabolism: all of the chemical reactions that occur within an organism · Mixture: combination of substances in which individual components retain their characteristics · Solution: mixture in which one or more substances are distributed evenly in another substance · pH: the level of acidity in a substance · acid: any substance that forms hydrogen ions in water and has a pH below 7 · base: any substance that forms hydroxide ions in water and has a pH above 7 okay, now for the learning stuff: The difference between a mixture and a solution is… in a mixture, the components do not change their characteristics, and (in general) can be taken apart again. In a solution, the components change their characteristics and it is more difficult to distinguish or separate them. The Structure of an atom in relation to the elements: Elements are made of atoms. An atom’s atomic number determines its identity (which element it is) and is based on the number of protons found in the nucleus of the atom. The atomic number also dictates how many negatively charged electrons will be present to give the atom a stable charge.

The formation of covalent and ionic chemical bonds in relation to stability. There are two kinds of bond that atoms can make to create molecules: covalent and ionic. In a covalent bond, the atoms combine to become more stable by filling all spots for electrons. This results in a sharing of electrons and a tighter, more durable bond. Ionic bonds are formed between two atoms that have a positive or negative charge. One atom transfers an electron to the other, resulting in a positive charge for one and a negative charge for the other. The charges attract and form an ionic bond.

How acids and bases are pertinent to life Some chemical reactions can only occur in certain situations. Acids and bases can contribute to those situations and can affect the outcomes of others. Most of the food we consume is acidic, and the acidity of a soil can contribute to the quality of the food grown in it. Without the differences and characteristics of acids and bases, life would not be sustainable. In case you are wanting something “fun” to do while learning: You can play around with pH strips to test the acidity of substances, such as milk, water, lemon juice, soda pop, soap, or other things you find that are legal and safe substances. Section 2 Vocabulary: · polar molecule: a molecule with unequal distribution of charge · hydrogen bond: attraction of opposite charges between hydrogen and oxygen · diffusion: the spreading of particles from a high to low concentration · dynamic equilibrium: result of diffusion where there is continuous movement of particles, but no overall change in concentration Learning Stuff: The polarity of water molecules is a very important trait. It allows for water to form hydrogen bonds. The formation of hydrogen bonds between water molecules is important, as it contributes to water’s adhesive and cohesive qualities. The polarity of water also makes it an incredible solvent. The positively and negatively charged molecules attract particles of a solute and the charges pull it apart, causing it to dissolve. Because of the Hydrogen bonds formed through polarity, when water freezes, the bonds stiffen and spread out, making ice less dense than water, causing it to float.

Diffusion occurs as particles move from a high to low concentration, eventually obtaining equilibrium. Diffusion helps cells retain homeostasis, where the cell is in equilibrium with itself and its surroundings. It also is a basis for many transactions and operations within and surrounding the cell. Something ‘fun’ to do so that you can facilitate learning: Observe diffusion by chopping a potato into a cube and placing it into a purple solution (water and food dye works), so that it is completely submerged. After a length of time (suggested: between 10 and 30 minutes), remove the potato and chop it in half to observe the changes. Measure how far the solution has diffused into the potato. To find the rate of diffusion, measure how far the solution diffused in millimeters and divide that by how long the potato was in the solution. Section 3 Vocabulary: · isomer: compounds that have the same chemical formula but different three-dimensional structures · polymer: a large molecule formed by the bonding of several smaller molecules · Carbohydrate: a biomolecule composed of carbon, hydrogen, and oxygen with a ration of about two hydrogen atoms and one oxygen atom for every carbon atom · Lipid: a large biomolecule that is made mostly of carbon and hydrogen with a small amount of oxygen · Protein: a large, complex polymer, composed of carbon, hydrogen, oxygen, nitrogen, and sometimes sulfur · Amino acids: the basic building blocks of proteins · Peptide bond: the covalent bond formed between amino acids · Enzyme: a protein that changes the rate of chemical reactions · Nucleic acid: a complex biomolecule that stores information in the form of a code · Nucleotide: smaller subunits that make up nucleic acids And, to perpetuate our learning… An organic compound is any chemical compound that contains carbon, including carbohydrates, lipids, and proteins. These organic compounds make up cells and are vital to sustaining life and providing nutrition and metabolism. The simplest form of a carbohydrate is a sugar called a monosaccharide, such as glucose or fructose. Two of these monosaccharides can combine to form a disaccharide, such as sucrose. Polysaccharides are the largest and most complex carbohydrates, like starches, glycogen, and cellulose, which are made of long chains of cellulose. Lipids include fats, oils, waxes, and steroids. Lipids are insoluble in water because their molecules are nonpolar and therefore unattracted to the water molecules. Lipids are made of three fatty acids (a long chain of hydrogen ad carbon) linked together with a molecule of glycerol. Depending on if bonds are double or single, the fatty acid is classified as unsaturated or saturated, or in some cases, polyunsaturated. Lipids are used by cells for energy storage, insulation, and protective coverings. Most of the membrane in a cell consists of lipids. Proteins provide structure to tissues and organs and fulfill metabolism. Amino acids make up proteins and bond when molecules are removed from them to make water, forming a covalent bond called a peptide bond. The shape o a protein is determined by how many and in what order amino acids are organized. Some amino acids are acidic, some are basic, and some are neutral, which cause them to bond in different ways. The structure of a protein is vital to its functionality in a cell. Enzymes are proteins that change the rate of chemical reactions. They are involved in nearly all metabolic processes and speed the digestion of food and the use of energy. Polymers are formed by many smaller molecules bonded together. Condensation is where small molecules bond together to make a polymer have groups of molecules be removed to create water creates polymers. The remaining molecules are bonded by covalent bonds.

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