BIOLOGY NOTES BIOLOGY & BIOCHEMISTRY PART 2 PAGES 36-39

Standards ___ Interpret formula representations of molecules and compounds in terms of composition and structure Essential Question Why are carbon based molecules the foundation of life?

I. Matter Matter = anything that occupies _____ and has _____. List three different types of matter… space mass

A. The Structure of Matter 1.Atoms = the basic units of ________ Atoms can be broken down into smaller parts called ____________ particles a. proton = subatomic particle that has a ________ charge matter subatomic positive

 nucleus = the center of the ______ where protons and neutrons are located c. electron = subatomic particle that has a ________ charge  electrons are in constant ________ around the _________ in an area known as the electron cloud atom negative motion nucleus b. neutron = subatomic article that has ____ charge no

 The electron cloud has different ________ levels that can hold a specific number of electrons  1 st level (closest to the nucleus) = ______ electrons  2 nd level = ______ electrons 2 8 energy

2. Elements Element = a pure substance that consists entirely of _______ type of atom elements cannot be _______ down into simpler substances each element is represented by a _______ symbol 1 broken chemical

Oxygen = ___ Sodium = ___ Chlorine = ___ Sulfur = ___ Hydrogen = ___ Carbon = ___ Potassium = ___ Magnesium = ___ Calcium = ___ Phosphorus = ___ Nitrogen = ___ Iron = ___ O Na Cl S H C K Mg Ca P N Fe

Of the naturally occurring elements, only about 25 are essential to ______. Of these 25, four ___, ___, ___, and ___ make up 96% of the mass of a human and are essential for life. The rest of the elements are present in very _______ amounts. life CHON small

1. Atomic Number = the number of _________ in an element. This is the element’s __________ because no two elements have the same amount of protons. e.g. protons fingerprint C = 6, N= 7, O = 8, etc.

II. The Combination of Matter A. Compounds Compound = a substance formed by the ________ combination of ___ or more elements. e.g. chemical2 NaCl (salt) H 2 O (water) C 6 H 12 O 6 (glucose)

chemical formula = a shorthand method of writing compositions of ___________ e.g. salt = NaClwater = H 2 O subscript = in chemical formulas, the small _______ next to the element that tells how many ______ of that element are in the compound e.g. H 2 O = 1 atom O, 2 atoms H C 6 H 12 O 6 = 6 atoms C, 12 atoms H, 6 atoms O number atoms compounds

How many atoms of each element are there in….. C 7 O 3 H 2 = C 57 H 110 O 6 = 7 atoms carbon, 3 atoms oxygen, 2 atoms hydrogen 57 atoms carbon, 110 atoms hydrogen, 6 atoms oxygen

C 7 N 4 O 2 H 9 = CO 2 CaNa = 7 atoms carbon, 4 atoms nitrogen, 2 atoms oxygen, 9 atoms hydrogen 1 atom carbon, 2 atoms oxygen, 1 atom calcium, 1 atom sodium

B. Chemical Bonds – the formation of compounds Elements will only combine to form compounds when they become more ______ by forming a compound Atoms of different elements become more stable when they have ______ electrons in their outer ___________ stable eight energy level (valence shell = outer energy level)

1. Types of Chemical Bonds a.Ionic Bond = a chemical bond formed between two ______ when one or more _________ are transferred between the atoms resulting in atoms of _________ charge which are attracted to each other e.g. atoms electrons opposite salt

b. Covalent Bond = a chemical bond formed between two _____ when they share two or more _________ e.g. atoms electrons water, carbohydrates, & fats

molecule = the structure that results when atoms are joined by _________ bonds  molecules make up most of the compounds found in ______ things  superscript = in chemical formulas, the large number found in ________ of compounds that tells how many ___________ of that compound exist e.g. covalent living front molecules 2H 2 0 = 2 molecules of water (4 atoms of Hydrogen, 2 atoms of Oxygen)

How many molecules? vs. How many atoms? 5C 10 O 4 H 4 = 3C 12 H 13 ON = 5 molecules of polyester vs. 50 atoms carbon, 20 atoms oxygen, 20 atoms hydrogen 3 molecules of bug spray vs. 36 atoms of carbon 39 atoms of hydrogen 3 atoms of oxygen 3 atoms of nitrogen