chapter02 revised

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What’s the Matter?

All of the materials around you are made up of matter. You are made up of matter, as are the chair you sit on and the air you breathe.

1. Give an example of solid matter.

2. Give an example of liquid matter.

3. Give an example of gaseous matter.

4. Is all matter visible?

5. Does all matter take up space?

Section 2-1

Interest Grabber

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2–1 The Nature of Matter

A. Atoms1. Protons (charge = +1, atomic mass = 1)2. Neutrons (charge = 0, atomic mass = 1)3. Electrons – orbit the nucleus

Charge = -1Atomic mass = 1 x 10-18 0In an atom, the number of electrons = # of protons

B. Elements and Isotopes1. Isotopes – atoms with different number of neutrons (# of protons are

the same)2. Radioactive Isotopes

Radioactive – nucleus is unstable, and will decay (break down) over time

Radioactive dating (Carbon-dating) – uses the calculated radioactive decay of an element to estimate the age of a sample

Half-life – the amount of time it takes for half (50%) of the radioactive isotopes to decay (change)

Carbon’s half-life is about 5700 years, so it can be used to age samples less than 60,000 years old

Section Outline

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6

CCarbon12.011

Section 2-1

An Element in the Periodic Table

Atomic number= # of protons

Atomic mass (average)= # of protons + # of neutrons

= chemical symbol

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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

Isotopes of Carbon

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Section 2-1 Outline, continued:

C. Chemical CompoundsA. Compound – combination of two or more elements

that are held together by a bondB. Molecule – smallest part of a covalently bonded

compoundD. Chemical Bonds

· Atoms react to fill their outer shell of electrons· Max. # of electrons in first shell = 2· Max. # of electrons in 2nd and 3rd shells = 8· Atoms with atomic number 5 or less try to get 2

electrons in the first energy level · Atoms with atomic number 6 or greater try to get 8

electrons in their outer energy level (8 is the magic number!)

· Atoms that have full outer energy levels are unreactive = noble gases, far right column of the periodic table

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Periodic Table of the Elements

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Ionic Bonds

Ionic bond – weaker bond involving the transfer of electrons

Ex: Salt (NaCl) is an example of an ionic bond, and it dissociates (breaks apart) in water to form sodium+ and chloride- ions

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

Transferof electron

Protons +11Electrons -11Charge 0


Protons +11Electrons -10Charge +1

Protons +17Electrons -18Charge -1

Section 2-1

Figure 2-3 Ionic Bonding

Ionic bonding:

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

Transferof electron



Protons +11Electrons -10Charge +1

Protons +17Electrons -18Charge -1

Section 2-1

Figure 2-3 Ionic Bonding

…results in formation of ions

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Covalent Bonds

Covalent bond – stronger bond resulting from a shared electron pair between two atoms

Ex: Glucose (C6H12O6) is a molecule

held together with covalent bonds; sugar molecules do not break apart in water!

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Water, Water Everywhere

If you have ever seen a photograph of Earth from space, you know that much of the planet is covered by water. Water makes life on Earth possible. If life as we know it exists on some other planet, water must be present to support that life.

Section 2-2

Interest Grabber

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1. Working with a partner, make a list of ten things that have water

in them.

2. Exchange your list for the list of another pair of students. Did your lists contain some of the same things? Did anything on the other list surprise you?

3. Did either list contain any living things?

Section 2-2

Interest Grabber continued

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2–2 Properties of WaterA. The Water Molecule

1. Polarity

2. Hydrogen Bonds

B. Solutions and Suspensions

1. Solutions

2. Suspensions

C. Acids, Bases, and pH

1. The pH Scale

2. Acids

3. Bases

4. Buffers

Section 2-2

Section Outline

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Oven cleaner

Bleach

Ammonia solution

Soap

Sea water

Human bloodPure waterMilkNormalrainfall

Acid rainTomatojuice

Lemon juice

Stomach acid

NeutralIn

crea

sing

ly B

asic

Incr

easi

ngly

Aci

dic

Section 2-2

pH Scale

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Cl-

Water

Cl-

Na+

Water

Na+

Section 2-2

Figure 2-9 NaCI Solution

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Section 2-2

Figure 2-9 NaCI Solution

Cl-

Water

Cl-

Na+

Water

Na+

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Life’s Backbone

Most of the compounds that make up living things contain carbon. In fact, carbon makes up the basic structure, or “backbone,” of these compounds. Each atom of carbon has four electrons in its outer energy level, which makes it possible for each carbon atom to form four bonds with other atoms.

As a result, carbon atoms can form long chains. A huge number of different carbon compounds exist. Each compound has a different structure. For example, carbon chains can be straight or branching. Also, other kinds of atoms can be attached to the carbon chain.

Section 2-3

Interest Grabber

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1. On a sheet of paper, make a list of at least ten things that contain carbon.

2. Working with a partner, review your list. If you think some things on your list contain only carbon, write “only carbon” next to them.

3. If you know other elements that are in any items on your list, write those elements next to them.

Section 2-3


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2–3 Carbon CompoundsA. The Chemistry of Carbon

B. Macromolecules

C. Carbohydrates

D. Lipids

E. Nucleic Acids

F. Proteins

Section 2-3

Section Outline

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CarbonCompounds

include

that consist of

which contain

that consist of that consist of that consist of

which contain which contain which contain

Section 2-3

Concept Map

Carbohydrates Lipids Nucleic acids Proteins

Sugars and starches

Fats and oils Nucleotides Amino Acids

Carbon,hydrogen,

oxygen

Carbon,hydrogen,

oxygen

Carbon,hydrogen,oxygen, nitrogen,

phosphorus

Carbon,hydrogen,oxygen,

nitrogen,

C H O C H O NC H O N PC H O

Carbo = carbon Hydrate = H2O

=Mono-saccharides

=fatty acids

=sugar,phosphate group,nitrogenous base

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Methane Acetylene Butadiene Benzene Isooctane

Section 2-3

Figure 2-11 Carbon Compounds

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Starch

Glucose

Section 2-3

Figure 2-13 A Starch

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General structure Alanine Serine

Section 2-3

Figure 2-16 Amino Acids

Amino group Carboxyl group

Amino acid – building block of protein•20 unique amino acids•Chains of amino acids are called polypeptides and are held together by peptide bonds

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General structure Alanine Serine

Section 2-3

Figure 2-16 Amino Acids

Amino group Carboxyl group

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Aminoacids

Section 2-3

Figure 2-17 A Protein

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Nucleic acids

= DNA and RNA (deoxyribonucleic acid and ribonucleic acid)

-Nucleic acids contain the genetic code

-The “genetic code” codes for PROTEINS

-The building block of a nucleic acid is a NUCLEOTIDE

-NUCLEOTIDE = sugar, phosphate group, and nitrogenous base

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Matter and Energy

Have you ever sat around a campfire or watched flames flicker in a fireplace? The burning of wood is a chemical reaction—a process that changes one set of chemicals into another set of chemicals. A chemical reaction always involves changes in chemical bonds that join atoms in compounds. The elements or compounds that enter into a chemical reaction are called reactants. The elements or compounds produced by a chemical reaction are called products. As wood burns, molecules of cellulose are broken down and combine with oxygen to form carbon dioxide and water vapor, and energy is released.

Section 2-4

Interest Grabber

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1. What are the reactants when wood burns?

2. What are the products when wood burns?

3. What kinds of energy are given off when wood burns?

4. Wood doesn’t burn all by itself. What must you do to start a fire? What does this mean in terms of energy?

5. Once the fire gets started, it keeps burning. Why don’t you need to keep restarting the fire?

Section 2-4


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2–4 Chemical Reactions and EnzymesA. Chemical Reactions

B. Energy in Reactions

1. Energy Changes

2. Activation Energy

C. Enzymes

D. Enzyme Action

1. The Enzyme-Substrate Complex

2. Regulation of Enzyme Activity

Section 2-4

Section Outline

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Reaction pathwaywithout enzyme Activation energy

without enzyme

Activationenergywith enzymeReaction pathway

with enzyme

Reactants

Products

Section 2-4

Effect of Enzymes

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Enzymes and Substrates: A Lock and Key

Enzymes are proteins (generally) that are specialized to act as catalysts to speed up the rate of reaction by lowering the amount of activation energy required to start the reaction.

Enzymes are shaped to fit a particular set of reactants in a chemical reaction.

Reactants fit into the active site of the enzyme.

These reactants are called substrates when they are fitting into the active site.

Once lined up in the active site, they combine to form new products and are released by the enzyme.

Because the shapes are specific, the enzyme and substrate are compared to a lock and key.

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Energy-Absorbing Reaction Energy-Releasing Reaction

Products

Products

Activation energy

Activation energy

Reactants

Reactants

Section 2-4

Figure 2-19 Chemical Reactions

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Glucose

Substrates

ATP

Substratesbind toenzyme

Substratesare convertedinto products

Enzyme-substratecomplex

Enzyme(hexokinase)

ADPProducts

Glucose-6-phosphate

Productsare released

Section 2-4

Figure 2-21 Enzyme Action

Active site

Videos

Click a hyperlink to choose a video.

Atomic Structure

Energy Levels and Ionic Bonding

Covalent Bonding

Enzymatic Reactions

Click the image to play the video segment.

Video 1

Atomic Structure


Video 2

Energy Levels and Ionic Bonding


Video 3

Covalent Bonding


Video 4

Enzymatic Reactions

Career links on forensic scientists

Interactive test

Articles on organic chemistry

For links on properties of water, go to www.SciLinks.org and enter the Web Code as follows: cbn-1022.

For links on enzymes, go to www.SciLinks.org and enter the Web Code as follows: cbn-1024.

Go Online

http://www.phschool.com/atschool/biology/PHB_CAREERS.html

http://www.phschool.com/quiz/biology_phb_quiz.html?chapter=2&questions=10

http://www.phschool.com/science/science_news/chemistry/organic_chem_bio.html

http://www.scilinks.org/

1. Give an example of solid matter.

Sample answers: books, desks, chairs

2. Give an example of liquid matter.

Sample answers: water, milk

3. Give an example of gaseous matter.

Sample answers: air, helium in a balloon

4. Is all matter visible?

No

5. Does all matter take up space?

Yes

Interest Grabber Answers


1. Working with a partner, make a list of ten things that have water in them.

Possible answers: bodies of water, rain and snow, soft drinks and other beverages, juicy foods such as fruits, and so on.

2. Exchange your list for the list of another pair of students. Did your lists contain some of the same things? Did anything on the other list surprise you?

Students’ answers will likely be similar, but not exactly alike.

3. Did either list contain any living things?

Students’ lists may include plants, animals, or other living things.


1. On a sheet of paper, make a list of at least ten things that contain carbon.

Students will likely know that charcoal and coal contain carbon. They may also list carbohydrates (starches and sugars), oil, gasoline, wood, or carbon dioxide.

2. Working with a partner, review your list. If you think some things on your list contain only carbon, write “only carbon” next to them.

Students will say that charcoal and coal contain only carbon. While these materials do contain small amounts of other elements, such as sulfur, they are composed mostly of carbon.

3. If you know other elements that are in any items on your list, write those elements next to them.

Students may know that many carbon compounds also contain oxygen and/or hydrogen.


1. What are the reactants when wood burns?Reactants are oxygen and cellulose.

2. What are the products when wood burns?Products are carbon dioxide and water.

3. What kinds of energy are given off when wood burns?Light and heat are given off. Some students may also mention sound (the crackling of a fire).

4. Wood doesn’t burn all by itself. What must you do to start a fire? What does this mean in terms of energy?To start a fire, you must light it with a match and kindling. You are giving the wood some energy in the form of heat.

5. Once the fire gets started, it keeps burning. Why don’t you need to keep restarting the fire?Once the fire gets going, it gives off enough heat to start more of the wood burning.

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chapter02 revised

Technology

wood doesnt

adp products

outer energy

substrate

absorbing

enzyme activation

sodium ion

web code