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Objectives
•Answer your questions•Review
▫Chapter 2, Thibodeau & Patton: Structure and Function-Chemistry of Life
▫Chapter 1, Zumdahl: Basic Chemistry-An Introduction
3
Define chemistry
•Chemistry: the science that deals with the materials of the universe and the changes that these materials undergo
5
What are some examples of chemical changes?•Wood burns in air, forming water, carbon
dioxide and other substances
•A plant grows by assembling simple substances into more complex substances
•The steel in a car rusts
•Emissions from a power plant lead to the formation of acid rain.
8
Quantitative vs Qualitative Observations•Quantitative observations deal with
amounts•Qualitative observations deal with things
that cannot be measured
9
Scientific ThinkingEvery-day Life Scientific Problems
• Recognize the problem• Propose possible solutions• Decide which solution is
best
• Make an observation• Formulate a hypothesis• Perform an experiment
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Scientific Thought
•What is a theory?▫A set of tested hypotheses that gives an
overall explanation of some part of nature▫An interpretation or possible explanation of
why nature behaves in a particular way•What is an observation?
▫Something that is witnessed and can be recorded
•What is a law?▫A summary of observed behavior
12
Blood pH – case study•Cindy, 5 years old, has been ill for several days
with nausea and vomiting. ▫What is the pH of stomach fluid? ▫What is she losing, acid or base?
13
Slide 16LEVELS OF CHEMICAL ORGANIZATION
• Atoms (Figure 2-1) Fill in the blanks▫______________ —central core of atom
______________—positively charged particle in nucleus
______________—non-charged particle in nucleus ______________—number of protons in the nucleus;
determines the type of atom ______________—number of protons and neutrons
combined▫______________—regions surrounding atomic nucleus
______________ —negatively charged particle
Slide 17LEVELS OF CHEMICAL ORGANIZATION
• Atoms (Figure 2-1)▫Nucleus—central core of atom
Proton—positively charged particle in nucleus Neutron—non-charged particle in nucleus Atomic number—number of protons in the nucleus;
determines the type of atom Atomic mass—number of protons and neutrons
combined▫Energy levels—regions surrounding atomic nucleus
that contain electrons Electron—negatively charged particle May contain up to eight electrons in each level Energy increases with distance from nucleus
Slide 19LEVELS OF CHEMICAL ORGANIZATION
•Elements, molecules, and compounds (Figure 2-2) Fill in the blanks▫________—a pure substance; made up
of only one kind of atom▫________—a group of atoms bound
together in a group▫________—substances whose molecules
have more than one kind of atom
Slide 20LEVELS OF CHEMICAL ORGANIZATION
•Elements, molecules, and compounds (Figure 2-2)▫Element—a pure substance; made up
of only one kind of atom▫Molecule—a group of atoms bound
together in a group▫Compound—substances whose
molecules have more than one kind of atom
Slide 22CHEMICAL BONDING
•Chemical bonds form to make atoms more stable▫Outermost energy level of each atom
is full▫Atoms may share electrons or donate
or borrow them to become stable
Slide 23CHEMICAL BONDING• Ionic bonds
▫ Ions form when an atom gains or loses electrons in its outer energy level to become stable _____ ion—has lost electrons; indicated by superscript
positive sign(s), as in Na+ or Ca++
______ion—has gained electrons; indicated by superscript negative sign(s), as in Cl
▫ Ionic bonds form when positive and negative ions attract each other because of electrical attraction
▫ ________—molecule that dissociates (breaks apart) in water to form individual ions; an ionic compound
Slide 24CHEMICAL BONDING• Ionic bonds
▫ Ions form when an atom gains or loses electrons in its outer energy level to become stable Positive ion—has lost electrons; indicated by superscript
positive sign(s), as in Na+ or Ca++
Negative ion—has gained electrons; indicated by superscript negative sign(s), as in Cl
▫ Ionic bonds form when positive and negative ions attract each other because of electrical attraction
▫ Electrolyte—molecule that dissociates (breaks apart) in water to form individual ions; an ionic compound
Slide 25
CHEMICAL BONDING▫_________ bonds form when atoms
share their outer energy to fill up and thus become stable
▫_________ bonds do not ordinarily easily dissociate in water
Slide 26
CHEMICAL BONDING•Covalent bonds (Figure 2-3)
▫Covalent bonds form when atoms share their outer energy to fill up and thus become stable
▫Covalent bonds do not ordinarily easily dissociate in water
Slide 28
INORGANIC CHEMISTRY1. _________ molecules contain carbon-
carbon covalent bonds or carbon-hydrogen covalent bonds
2. _________ molecules do not contain carbon-carbon covalent bonds or carbon-hydrogen covalent bonds
• Examples of inorganic molecules: water and some acids, bases, and salts
Slide 29
INORGANIC CHEMISTRY•Organic molecules contain carbon-
carbon covalent bonds or carbon-hydrogen covalent bonds
• inorganic molecules do not•Examples of inorganic molecules:
water and some acids, bases, and salts
Slide 30
INORGANIC CHEMISTRY• Water
▫ Water is a solvent (liquid into which solutes are dissolved), forming aqueous solutions in the body
▫ Water is involved in chemical reactions (Figure 2-4)1. __________—chemical reaction in which water is
removed from small molecules so they can be strung together to form a larger molecule
2. __________—chemical reaction in which water is added to the subunits of a large molecule to break it apart into smaller molecules
Chemical reactions always involve energy transfers, as when energy is used to build ATP molecules
Chemical equations show how reactants interact to form products; arrows separate the reactants from the products
Slide 31
INORGANIC CHEMISTRY• Water
▫ Water is a solvent (liquid into which solutes are dissolved), forming aqueous solutions in the body
▫ Water is involved in chemical reactions (Figure 2-4) Dehydration synthesis—chemical reaction in which
water is removed from small molecules so they can be strung together to form a larger molecule
Hydrolysis—chemical reaction in which water is added to the subunits of a large molecule to break it apart into smaller molecules
Chemical reactions always involve energy transfers, as when energy is used to build ATP molecules
Chemical equations show how reactants interact to form products; arrows separate the reactants from the products
Slide 33
INORGANIC CHEMISTRY•Acids, bases, and salts
▫Water molecules dissociate to form equal amounts of H+ (hydrogen ion) and OH (hydroxide ion)
1._______—substance that shifts the H+/OH balance in favor of H+; opposite of base
2._______—substance that shifts the H+/OH balance against H+; also known as an alkaline; opposite of acid
Slide 34
INORGANIC CHEMISTRY•Acids, bases, and salts
▫Water molecules dissociate to form equal amounts of H+ (hydrogen ion) and OH (hydroxide ion)
▫Acid—substance that shifts the H+/OH balance in favor of H+; opposite of base
▫Base—substance that shifts the H+/OH balance against H+; also known as an alkaline; opposite of acid
Slide 35INORGANIC CHEMISTRY• Acids, bases, and salts (cont.)
▫ pH—mathematical expression of relative H+ concentration in an aqueous solution (Figure 2-5) pH 7 is neutral (neither acid nor base) pH values above 7 are basic; pH values below 7 are
acidic
1.____________ occurs when acids and bases mix and form salts
2.____________ are chemical systems that absorb excess acids or bases and thus maintain a relatively stable pH
Slide 36INORGANIC CHEMISTRY• Acids, bases, and salts (cont.)
▫ pH—mathematical expression of relative H+ concentration in an aqueous solution (Figure 2-5) pH 7 is neutral (neither acid nor base) pH values above 7 are basic; pH values below 7 are
acidic▫ Neutralization occurs when acids and bases mix
and form salts▫ Buffers are chemical systems that absorb excess
acids or bases and thus maintain a relatively stable pH
Slide 38
ORGANIC CHEMISTRY• Carbohydrates—sugars and complex
carbohydrates (Figure 2-6)▫ Contain carbon (C), hydrogen (H), oxygen (O)▫ Made up of six-carbon subunits called
____________ or single sugars (e.g., glucose)▫ Disaccharide—double sugar made up of two
monosaccharide units (e.g., sucrose, lactose)▫ Polysaccharide—complex carbohydrate made up
of many monosaccharide units (e.g., glycogen made up of many glucose units)
▫ Function of carbohydrates is to store energy for later use
Slide 39
ORGANIC CHEMISTRY• Carbohydrates—sugars and complex
carbohydrates (Figure 2-6)▫ Contain carbon (C), hydrogen (H), oxygen (O)▫ Made up of six-carbon subunits called
monosaccharides or single sugars (e.g., glucose)▫ Disaccharide—double sugar made up of two
monosaccharide units (e.g., sucrose, lactose)▫ Polysaccharide—complex carbohydrate made up
of many monosaccharide units (e.g., glycogen made up of many glucose units)
▫ Function of carbohydrates is to store energy for later use
Slide 41
ORGANIC CHEMISTRY• Lipids—fats and oils
▫ Triglycerides (Figure 2-7) Made up of one glycerol unit and three fatty acids Store energy for later use
▫ Phospholipids (Figure 2-8) Similar to triglyceride structure, except with only two fatty
acids, and with a phosphorus-containing group attached to glycerol
The head attracts water and the double tail does not, thus forming stable double layers (bilayers) in water
Form membranes of cells▫ Cholesterol
Molecules have a steroid structure made up of multiple rings
Cholesterol stabilizes the phospholipid tails in cellular membranes and is also converted into steroid hormones by the body
Slide 45
ORGANIC CHEMISTRY•Proteins (Figure 2-9)
▫Very large molecules made up of amino acids held together in long, folded chains by peptide bonds
▫Structural proteins Form structures of the body Collagen is a fibrous protein that holds
many tissues together Keratin forms tough, waterproof fibers
in the outer layer of the skin
Slide 47
ORGANIC CHEMISTRY•Proteins (cont.)
▫Functional proteins Participate in chemical processes Examples: hormones, cell membrane channels
and receptors, enzymes Enzymes (Figure 2-10)
Catalysts—help chemical reactions occur Lock-and-key model—each enzyme fits a particular
molecule that it acts on as a key fits into a lock▫Proteins can combine with other organic
molecules to form glycoproteins or lipoproteins
Slide 49
ORGANIC CHEMISTRY•Nucleic acids
▫Made up of nucleotide units▫Sugar (ribose or deoxyribose)▫Phosphate
Nitrogen base (adenine, thymine or uracil, guanine, cytosine)
Slide 50ORGANIC CHEMISTRY• Nucleic acids (cont.)
▫ DNA (deoxyribonucleic acid) (Figure 2-11) Used as the cell’s “master code” for assembling
proteins Uses deoxyribose as the sugar and A, T (not U), C,
and G as bases Forms a double helix shape
▫ RNA (ribonucleic acid) Used as a temporary “working copy” of a gene
(portion of the DNA code) Uses ribose as the sugar and A, U (not T), C, and G
as bases▫ By directing the formation of structural and
functional proteins, nucleic acids ultimately direct overall body structure and function
Farewell•Thank you for your kind attention and
participation!•Email any time [email protected]•Call if your matter is urgent
▫630 323 3307•Follow me on Twitter
▫@ProfAmyH
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