Unit 7HS260 Anatomy, Physiology & ChemistryAmy Habeck, RD, MS, LDN

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Questions?

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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

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Define chemistry

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Define chemistry

•Chemistry: the science that deals with the materials of the universe and the changes that these materials undergo

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What is the difference between physical and chemical changes?•Physical changes:•Chemical changes:

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What are some examples of chemical changes?

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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.

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Quantitative vs Qualitative Observations•Quantitative observations deal with

amounts•Qualitative observations deal with things

that cannot be measured

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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?•What is an observation?•What is a law?

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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

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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?

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Factors Affecting Blood pH regulation•Lungs•Kidneys•GI tract

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Questions?

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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Questions?

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Farewell•Thank you for your kind attention and

participation!•Email any time -ahabeck@kaplan.edu•Call if your matter is urgent

▫630 323 3307•Follow me on Twitter

▫@ProfAmyH

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