2-1 The Nature of Matter

The Nature of Matter A. What three subatomic particles make up atoms? Protons + positively charged Neutrons carry no charge Electrons - a negative charge

The Nature of Matter B. Elements and Isotopes Because atoms have equal numbers of electrons and protons, atoms are neutral. Elements are represented by a one- or two-letter symbol. C stands for carbon. Na stands for sodium. K stands for potassium Cl stands for chlorine. O stands for oxygen

The Nature of Matter B. Elements and Isotopes The number of protons in an atom of an element is the element's atomic number. Carbon has 6 protons, so its atomic number is 6. More than 100 elements are known, but only about two dozen are commonly found in living organisms

 The Nature of Matter How are all of the isotopes of an element similar? Isotopes of Carbon C. Isotopes Atoms of the same element that differ in the number of neutrons they contain are known as isotopes 6 electrons 6 protons 8 neutrons

2-1 The nature of matter D. Chemical Compounds Water, H2O, contains two atoms of hydrogen for each atom of oxygen. The formula for table salt, NaCl, indicates that sodium and chlorine combine in a 1 : 1 ratio.

2-1 The nature of matter E. Ionic Bonds An ionic bond is formed when opposite charges are attracted to each other. How does James Bond like his ionic drinks? shaken not shared

2-1 The nature of matter F. Covalent Bonds Are the Sharing of electrons. In a water molecule, each hydrogen atom forms a single covalent bond with the oxygen atom.

2-2 Properties of Water A. The Water Molecule Like all molecules, a water molecule is neutral. It has a pH of 7 A water molecule is polar because there is an uneven distribution of electrons between the oxygen and hydrogen atoms. Why did the white bear dissolve in water?   Because it was polar

2-2 Properties of Water B. Hydrogen Bonds Hydrogen bonds are not as strong as covalent or ionic bonds. Hydrogen bonds form between water molecules.

2-2 Properties of Water C. Cohesion is an attraction between molecules of the same substance. Because of hydrogen bonding, water is extremely cohesive. D. Adhesion is an attraction between molecules of different substances. Why didn’t Dora like the protein. He was a mean o acid.

2-2 Properties of Water Acids, Bases, and pH F. Acids, Bases, and pH A water molecule can react to form hydrogen H + and hydroxide ions OH- .

2-2 Properties of Water Acids, Bases, and pH F. Acids, Bases, and pH Chemists devised a measurement system called the pH scale to indicate the concentration of H+ ions in solution. The pH scale ranges from 0 to 14.

Chapter 2 How to make life G. Carbohydrates fuel and building material. This makes all life. You start with an atom, then make sugars or saccharides. Polysaccharides are usually polymers of a few hundred or thousand monosaccharide. Important polysaccharides include starch, glycogen, cellulose, and chitin Polysaccharides can be used to make amino acids and carboxyl groups, eventually leading to proteins. Organism usually store polysaccharides for energy as starch-in plants, and (glycogen- in humans) Starch VS Cellulose

Chapter 2 Chemistry of Cells ·       H. A Lipid is a nonpolar carbon chains that is connected by a glycerol. Lipids include fats, phospholipids, steroids, and waxes. Fats are placed into 2 categories. Saturated fatty acids are solid at room temperature, and linked by single bonds. Unsaturated fatty acids are liquid at room temperature and contain double bonds. Proteins are made up of amino acids. Amino acids are made up of nucleotides. Nucleotides are made up of sugars, and phosphorus. Carbohydrates Lipids Proteins Nucleotide

Chapter 2 Chemistry of Cells A nucleotide which is the base of a DNA

Enzyme Caused Activation Energy

Chapter 2- Activation Energy Energy is needed for a chemical reaction. Your body performs thousands of chemical reaction. For these reactions to occur quickly enzymes are used. A catalyst or enzyme will speed up a reaction The amount of energy needed for a chemical reaction is called Activation Energy