Chapter 2 The Chemistry of Life 2-1 The Nature of Matter

Chapter 2

The Chemistry of Life

2-1 The Nature of Matter

Everything is made of matter.And matter comes from the elements. ______ are naturally occurring. Only 4 elements- _________(C),_______________(H), _________________ (O), and __________(N) make up 96% of a human.

Elements that make up living thingsElement Symbol % in human bodyOxygen 65.0Carbon 19.5Hydrogen 9.5Nitrogen 3.3Calcium 1.5Phosphorus 1.0Potassium 0.4

Elements cont’d

Sulfur 0.3Sodium 0.2Chlorine 0.2Magnesium 0.1Iron TraceIodine TraceCopper TraceManganese TraceMolybdenum Trace

Trace ElementsEven though some elements are found in very small amounts, these trace elements play a vital role in _________________________________ in all organisms.

Atoms- The Building Blocks of AtomsAn _______________________ is the smallest part of an element.

Atoms are made up of a _________________ surrounded by an ______________________.

The nucleus and electron cloudNucleus is composed of subatomic particles called ________________________(+ charges) and ______________________ (no charges).

The electron cloud contains _________________ (- charges) in different energy levels.

ProtonsThe ____________________________ determines which element we’re talking about.The number of protons is balanced out by the number of electrons so there is _________________________ in a neutral atom.If an atom has a net charge, it has either more protons or more electrons.

If more protons (overall + charge) it’s called a ________________________.

Electrons

If there are more electrons than protons (overall – charge) it’s called an ________________________.

Electrons are found in energy levels.

Energy Levels1st energy level- holds _____ electrons 2nd energy level- holds _____ electrons3rd energy level- holds _____ electronsChanging levels utilizes energy. From lower to higher, __________ energy. From higher to lower, __________ energy.

NeutronsAn element can have a _____________

______________ and still be the same element- just a different version of it.A different number of neutrons gives each substance different ___________________.Substances with differing numbers of neutrons are called ______________________.

IsotopesBecause they have the same number of protons and electrons, the different isotopes of a single element have the ____________________________________

Some isotopes are associated with a release of radiation (their nuclei are unstable and break down).Radiation can ________________________ (cancer treatments).

QuickTime™ and aGraphics decompressor

are needed to see this picture.







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Nonradioactive carbon-12 Nonradioactive carbon-13 Radioactive carbon-14

6 electrons6 protons6 neutrons



Section 2-1

Figure 2-2 Isotopes of Carbon





Is water an element?Chemical formula is H2O- hydrogen and water.

Type of substance called a _______________.A compound is a substance composed of _______________________________________.

CompoundsA compound is a substance formed by the combination of two or more elements in ________________________________Composition is determined by chemical formula

H2ONaCl

The smallest unit of a compound is a _______________________.

BondsCombined substance are held together by bonds.

___________________: two substances that share electrons. Found in most organisms (proteins, fats, carbohydrates, water).____________________: the attractive force existing between two ions of opposite charge. (Na+ and Cl- are attracted to form a neutral compound: NaCl. The ions have combined chemically.)

Van der Waals ForcesBecause electrons are moving quickly, there may be tiny _____________________ _______ charged areas on a large molecule.If shapes and charges of two molecules match, a slight attraction may develop- easily formed

easily separated









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Sodium atom (Na) Chlorine atom (Cl) Sodium ion (Na+) Chloride ion (Cl-)

Transferof electron

Protons +11Electrons -11Charge 0

Protons +17Electrons -17Charge 0

Protons +11Electrons -10Charge +1

Protons +17Electrons -18Charge -1

Section 2-1

Figure 2-3 Ionic Bonding





2-2 Properties of Water

The Importance of WaterMost life processes can occur only when molecules and ions are free to move and collide with one another- when they are ___________

_____________________Water is an example of a __________________.

+-

-

+

--

Polar MoleculesA polar molecule is a molecule with an _______

____________________ of charge, so that the oxygen end is slightly positive and the hydrogen end is slightly negative. This makes it act like a ______________________. By being polar, water can attract and dissolve many _________ compounds.

+

--

Water molecules also attract each other- the plus side to the minus side. The they can form a weak covalent bond called a _______________.

__________________________: attraction between molecules of the same substance. Water is very cohesive.__________________________: Attraction between different substances (think meniscus)

Other molecules with hydrogen bonds are found in _________________ (an important fact!).

-

--

-+

+

SolutionA solution is a mixture in which one or more substances is _________________________ in another substance. The _______________ is dissolved into the __________________. Example: Kool-aid is a solute in water, or blood sugar.

SuspensionsSome materials don’t break into individual molecules in water but into ________________ they don’t settle out. The __________________ keeps them suspended.Example:

Milk Blood

MixturesA mixture occurs when two substances are mixed but ____________________________. Example- sand and sugar.

Acids, Bases & pHH2O H+ + OH-

Water hydrogen + hydroxide ion ion

Acids & Bases

Chemical reactions can only occur if conditions are right, including the pH of the environment. pH is a measure of how ________________________________a solution is.Acid: any substance that forms ____________________ in water

HCl (H2O) H+ + Cl-

Base: any substance that forms ____________________ in waterNaOH (H20) OH- + Na+

Acids & Bases

Strong acids and bases can harm living tissue. ________________ keep the pH between 6.5 and 7.5 (homeostasis).

Example: buffered aspirin (ASA)

The pH ScaleIndicates concentrationof ______________.

Strong acids: ____________

Strong bases: ____________

Neutral pH = 7 ____________









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Oven cleaner

Bleach

Ammonia solution

Soap

Sea water

Human blood

Pure water

Milk

Normal

rainfall

Acid rain

Tomato

juice

Lemon juice

Stomach acid

Neutral

Incr

easi

ng

ly B

asi

cIn

creasi

ng

ly A

cid

ic

Section 2-2

pH Scale





2-3 Carbon Compounds

Carbon has 4 electrons in outer energy level available to bond, so usually forms ______________________.

C









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6

CCarbon12.011

Section 2-1

An Element in the Periodic Table





Role of Carbon cont’d.Can bond with _____________________________ or with many other elements.When carbons bond to each other, can form _____________________________________________________Rings or chains can have ______________________ in them as well. C

C C OH N C C

Molecular Chains_____________________________ can contain up to

1000s of carbon atoms.Proteins in animals and starches in plants are examples

of macromolecules in organisms.

Condensation & Hydrolysis

____________________________: molecules are bonded together by one losing an -H and the other an -OH (HOH - a water molecule!)

____________________________: the breaking apart of a molecule by adding water to it, giving an -H to one end and an -OH to the other.

Structure of CarbohydratesA _____________________________ is an organic

compound composed of carbon, hydrogen, and oxygen with a ratio of 2 hydrogens and 1 oxygen for every carbon.___________________: simple sugar like glucose or

fructose___________________: a two-sugar carbohydrate___________________: polymers composed of many

monosaccharide units, like starch, cellulose, or glycogen.

Polysaccharides__________________________: highly branched chains of glucose used as food

storage by plants__________________________: another, even more branched polymer of

glucose used for food storage in animals__________________________: a glucose polymer that forms the cell wall of

plants and gives plants structural support.









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Starch

Glucose

Section 2-3

Figure 2-13 A Starch





Proteins A protein is a large, complex polymer composed

of ____________________________________ _____________________________. The basic building blocks of proteins are called

_______________________________. _____________ common amino acids Linked by condensation and a covalent bond called a

__________________________. The __________________________________

of the amino acids determines the kind of protein.









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General structure Alanine Serine

Section 2-3

Figure 2-16 Amino Acids

Amino group Carboxyl group





Proteins are _____________________________. Build __________________________ and carry out cell

_______________________________. Muscle contraction Transporting oxygen in blood Carrying out chemical reactions Providing immunity Enzymes









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Section 2-3















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Section 2-3















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are needed to see this picture.Aminoacids

Section 2-3

Figure 2-17 A Protein





Lipids (Fats)Lipids are organic compounds that have a large proportion of C-H

bonds and _________________________ than carbohydrates. Example: C57H110O6

Commonly called ___________________________. They are insoluble in water because their molecules are ______________ and not attracted by water molecules.

Used for long-term energy storage, insulation, and protective coatings. They are major components of cell membranes.

fatty acid glycerol fatty acid fatty acid

Nucleic Acids A nucleic acid is a complex macromolecule that stores

information in cells in the form of a ______________. Made of polymers of smaller subunits called

_____________________________. They consist of carbon, hydrogen, oxygen, nitrogen, and

phosphorus atoms arranges in three groups- _________________________________________________ Examples are DNA and RNA.

2-4 Chemical Reactions“You are what you eat.”

CH4 + 2O2 CO2 + 2H2O

___________ ____________

Chemical ReactionsIn chemical reactions

Bonds between atoms are ____________________Substances ____________ into different substances

Every cell in your body has chemical reactions going on inside it.

Metabolism Metabolism is all of the ____________________ that take place in an organism.These reactions break down and build molecules that are important for the functioning of organisms.Chemical reactions are represented by chemical __________________________.

Enzymes

An enzyme is a ___________________ that speeds up a chemical reaction by lowering the _________________________________. Might not occur at all without it. Allow temperature to be ________________ or

environment to be less acidic, for example. Found in _______________________, synthesis of

molecules, and ________________________________________________________.









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Reaction pathwaywithout enzyme Activation energy

without enzyme

Activationenergywith enzymeReaction pathway

with enzyme

Reactants

Products

Section 2-4

Effect of Enzymes





Regulation of EnzymesEnzymes are effective within a narrow range of _______________________________________Cells have specialized proteins that turn enzymes _____________________________

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Chapter 2 The Chemistry of Life 2-1 The Nature of Matter