Section 6.1 Atoms and their interactions pg. 141
1. Elements are substances which cannot be broken down into simpler chemical reactions and compose all matter.
2. What 4 elements compose more than 96 % of the mass of a human? C, H, O, N
3. How can you tell the difference between an element and a compound by their symbols?
4. What is a trace element? ______
5. Plants get trace elements from ______and animals get trace elements from ______
6. Give an example of its use? ______
7. Atoms are the smallest particles of an element that has the characteristics of that element. They are the basic building blocks of all matter. Their properties and chemical behavior is based on how they are structured.
8. Atoms have a center area called the nucleus. It is composed of ______which are positive and neutrons which have a ______charge. There are shells around this which is made up of electrons which have a ______charge.
9. The name/type of atoms is determined by the number of protons. If the number of protons changes, the atom becomes a different element. The element can be identified by looking at the Periodic Table. The new number of protons will indicate the atomic number.
10. Most of the mass of an atom is composed of the ______(nucleus/electron cloud)
11. Electron energy levels are found around the nucleus. The first level has ____ electrons (#); the second level contains no more than ______(#) electrons. Pg. 143
12. Because atoms normally contain the same number of Protons which are positive and electrons which are negative, the atoms overall charge is ______.
13. If the same atom (same # of protons) has a form with a different number of neutrons is called an isotope. The most common carbon isotope is C-12 and has ______protons and ______neutrons. C-14 is an unstable atom that tends to break down and release radiation.
Radiation can damage or kill cells, but are beneficial when the isotopes are used to diagnose and treat diseases.
14. A compound is composed of 2 or more elements which are chemically combined.
15. Atoms combine to become more stable, by having a full (8) stable outside shell of electrons. Since Hydrogen has one electron in a shell which is full with 2 electrons, it is stable at 2 e-.
16. Molecules are held together by Covalent bonds and are produced by the sharing of electrons, providing all affected elements a full outer shell. Examples of covalent bonds are sugars, fats, proteins and water
17. Each capital letter in a molecule indicates a different element.
18. What elements and their number are in these compounds? CoCl, MgCO3
19. When an atom loses or gains an electron so that the charge is no longer neutral it is called an ion. Bonding of ions by transferring electrons to become more stable (8 outer e-) produces ionic bonds. Sodium and potassium ions are needed for nerve impulses, calcium ions are needed for muscles to contract.
20. Chemical reactions occur when bonds are formed or broken causing substances to recombine into different substances. In organisms these reactions are called metabolism.
21. Writing chemical equations
Subscript indicates number of atoms of each element in a molecule of substances
Law of conservation of matter; the same number of atoms is on both sides, just rearranged. Equations must always balance
22. Mixtures & Solutions; Mixtures vary and have no chemical formula (spaghetti sauce). Each part retains its properties (tomatoes are still tomato) and properties do not change and no chemical bonds are formed.
23. Solutions are mixtures where one substance is dissolved in another. Solutes are the substances in small amounts that are distributed evenly in the solvent. Reactions in the body require a narrow range of concentrations for homeostasis to be maintained.
24. Acids and Bases; the pH of a substance is a measure of how acid or base it is. The range is from 0 to 14. Neutral is 7; acids are below 7; bases are above 7;
25. Hydrogen ions (H) are released by acids in water; bases- a substance that releases HYDROXIDE ions (OH) in water.
MINILAB 6.2; Rate of diffusion.
Life Substances
1. Carbon has 4 electrons in outer shell, leaving 4 to combine (8).
a. Can form single, double or triple bonds.
b. Form straight, branched, or rings
c. ISOMER- Same chemical formula can have different structure glucose/fructose)
Molecular chains
1. Biomolecules; very large organic molecules
2. The chemical reaction Condensation forms Polymers; large molecule formed by combination of smaller molecules
3. In condensation, small molecules are bonded together to make a polymer have an H and an OH group that can be removed to form H-O-H (water) Bonded by covalent bonds
4. Polymers can be broken apart by hydrolysis- hydrogen and hydroxyl groups from water attach to the bonds between the subunits that make up the polymer, thus breaking the polymer.
5. Many polymers are formed by condensation and can be broken by hydrolysis, the reactions that occur when water is added to or removed from a polymer.
6. Structure of carbohydrates
7. Simplest-monosaccharide’s (1 sugar) join to form 2 sugar disaccharide;
8. Glucose & fructose link (condensation) forms sucrose
9. Polysaccharide- largest carb; many monosaccharides joined. Ex. Starch , glycogen, cellulose
10. Carbs provide energy to cells (starch/energy reservoir- plants; animals/glycogen in liver)
11. Cellulose forms plant cell walls/structural support. Composed of long chains of glucose
12. Lipids- C, H, (fats, oils, waxes, steroids) insoluble in water.
13. Saturated lipids have all single bonds; unsaturated fats have at least one bond that is not single. Polyunsaturated has more than one double bond
14. Lipids- energy storage, insulation, protective coverings, membranes…
15. Glycerol is a 3 carbon molecule that serves as a backbone for a lipid molecule. Attached to the glycerol are 3 fatty acid groups
16. Proteins-(C, H, O, N – sometimes sulfur) essential to all life; provide structure for tissues/organs and carry out cell metabolism. There are about 20 amino acids which are the building blocks of proteins. Combine to form a variety of shapes and sizes
17. Amino acids link when H from amino group and OH from carboxyl are removed to form water. Covalent bonds between amino acids are called peptide bonds.
18. Amino acids may be acid/base/neutral; can attract or repel; may be held together by hydrogen bonds.
19. Used for muscle tissue, transport oxygen, immunity, regulate other proteins, and carry out chemical reactions. Ex. Enzymes (protein that changes rate of chemical reaction)
20. Enzymes – affect most metabolic process; may speed u reactions; depend on temp, ionic conditions & ph. (lock & key structure)
21. Structure of nucleic Acids.
22. Nucleic acids – polymers of nucleotide subunits (C, H, O, N, Phosphorus) form nitrogenous base, simple sugar, & phosphate group
23. DNA- master copy of genetic information to form all enzymes & structural process
24. RNA- Forms copies of DNA to make proteins.