1. Biochemistry Atoms, Elements, and Compounds Chemical Reactions
Water and Solutions
The Building Blocks of Life

2. Review Atoms are the building blocks of matter.
Protons- positively charged particles
Neutrons- have no charge
Protons and neutrons are located in the nucleus of the atom
Electrons- negatively charged particles
Move around the nucleus in energy levels

3. Elements
An element is a pure substance that cannot be broken down into other substances by physical or chemical means.
Isotopes- atoms of the same element that have the same number of protons and electrons but have a different number of neutrons
Compounds- a pure substance formed when two or more different elements combine

4. Chemical Bonds
The forming of chemical bonds stores energy and the breaking of chemical bonds releases energy for an organism’s life processes (growth development, reproduction)
Covalent bonds- chemical bond that forms when electrons are shared
Compounds that held together by covalent bonds are called molecules

5. Ionic bond- an electrical attraction between two oppositely charged atoms or groups of atoms
van der Waals Forces- When molecules come close together, the attractive forces between slightly positive and negative regions pull on the molecules and hold them together (water)

6. Chemical Reactions
The process by which atoms or groups of atoms in substances are reorganized into different substances
Chemical bonds are broken and formed
Production of heat or light, and formation of a gas, liquid, or solid
Reactants- starting substances
Products- substances formed during reaction

7. Energy of Reactions
Activation energy- the minimum amount of energy needed for reactants to form products in a chemical reaction
This reaction is exothermic and released heat energy.

8. Energy of Reactions
This reaction is endothermic and absorbed heat energy.

9. Enzymes
Catalyst- a substance that lowers the activation energy needed to start a chemical reaction
Enzymes- biological catalysts
Not used up in the reaction
pH and temperature affect enzyme activity

10. Enzymes Substrates- the reactants that bind to the enzyme
Active site- the specific location where a substrate binds on an enzyme

11. Water’s Polarity
Molecules that have an unequal distribution of charges are called polar molecules
Hydrogen bond- a weak interaction involving a hydrogen atom and a fluorine, oxygen, or nitrogen atom

12. Mixtures
Solution (homogenous mixture)- has the same composition throughout
Solvent- a substance in which another substance is dissolved.
Solute- the substance that is dissolved in the solvent
Heterogeneous- the parts remain distinct, can identify individual parts

13. Acids
Bases
Substances that release hydroxide ions (OH–) when dissolved in water
The more OH– released the more basic the solution
Basic solutions have pH values higher than 7
Buffer- mixtures that can react with acids or bases to keep the pH within a particular range
Substances that release hydrogen ions (H+) when dissolved in water
The more H+ released the more acidic the solution
pH- the measure of concentration of H+ in a solution
Acidic solutions have pH values lower than 7.

14. Organic Chemistry The study of organic compounds
Almost all biological molecules contain the element carbon.
Macromolecules- large molecules formed by joining smaller organic molecules together
Polymers- molecules made from repeating units of identical or nearly identical compounds linked together by a series of covalent bonds

15. Carbon Has four electrons in its outermost energy level.
One carbon atom can form four covalent bonds with other atoms.
Carbon compounds can be in the shape of straight chains, branched chains, and rings.

16. Carbohydrates
Compounds composed of carbon, hydrogen, and oxygen in a ratio of one oxygen and two hydrogen atoms for each carbon atom—(CH2O)n
Monosaccharides- short chains of carbohydrates (simple sugars)
Disaccharides- two monosaccharides linked together
Polysaccharides- longer carbohydrate chains

17. Carbohydrates Energy sources for organisms
Provide structural support in cell walls of plants and in the hard shells of shrimp, lobsters and some insects

18. Lipids Molecules made mostly of carbon and hydrogen Fats, oils, waxes
Main function: to store energy
Triglyceride- fat when solid, oil when liquid

19. Saturated fats- carbon atoms cannot bond with any more hydrogen atoms
Unsaturated- carbon atoms can bond with more hydrogen atoms
Phospholipids- fats with more than one double bond in the tail
Responsible for structure and function in cell membrane
Steroids- (cholesterol and hormones) provides starting point for other important lipids, estrogen and testosterone

20. Proteins Made of small carbon compounds called amino acids
Amino acids- small compounds that are made of carbon, nitrogen, oxygen, hydrogen, and sometimes sulfur.
20 different amino acids
Proteins are made of different combinations of amino acids joined together by peptide bonds

21. Protein: Structure Amino acid chains fold into three-dimensional shape
A protein might contain many helices, pleats, and folds, held by hydrogen bonds

22. Protein: Function Provide structural support
Transport substances inside and between cells
Communicate signals within the cell and between cells
Speed up reactions
Control cell growth

23. Nucleic Acids
Complex macromolecules that store and transmit genetic information
Nucleotides- repeating subunits that make up nucleic acids
Carbon, nitrogen, oxygen, phosphorus, and hydrogen
3 units: a phosphate, a nitrogenous base, and a sugar

25. Nucleic Acids 2 types found in living things DNA = “genetic code”
Deoxyribonucleic acid (DNA)
Ribonucleic acid (RNA)
DNA = “genetic code”
Stores all the information to grow, reproduce, and adapt
RNA uses the information stored in DNA to make protein