Chapter 2Chapter 2

THE CHEMISTRY OF THE CHEMISTRY OF LIFELIFE

California State Standards

1h: most macromolecules in cells and organisms are synthesized from a small collection of simple precursor

4e: proteins can differ from one another in the number and sequence of amino acids

1b: enzymes are proteins that catalyze biochemical reactions without altering the reactions equilibrium and the activities of enzymes depend on the temperature, ionic conditions, and the pH of the surroundings

CHAPTER 2: THE CHEMISTRY OF LIFE The first job of a biologist is to understand the chemistry of life.  2-1 The Nature of Matter A. Atoms

 ___________= the basic unit of matter (has volume and mass; solid, liquid, gas, and plasma)

  Atoms are made

Atoms

subatomic particles called protons,

neutrons, and electrons

= protons - -

= neutrons - -

= electrons -

-

-

_______________=center of an atom.Home to protons and neutrons.

Carbon AtomCarbon Atom

Positively charged1 amu

No charge

1 amu

Electronegative charge1/1840 amu

electrons travel in regions outside the nucleus called orbitals

Nucleus

B B. Elements  Elements=

 More than _____known kinds;

   Found on the

100       2 dozen are common in living organisms

pure substances that consists entirely of one type of atom

Periodic table

Reading the Periodic Table Example: The element Carbon (only made of carbon atoms)

6

CCarbon12.011

Section 2-1

An Element in the Periodic Table

____________usually 1-2

letters

_______________= # Protons + # neutrons in an atom; the average of one elements isotopes

____________ of the element

Atomic number =

SYMBOL

MASS NUMBER

NAME

Number of protons in an atom; different for each element

Isotopes are the various forms of an atom that differ based on the number of neutrons in the nucleus such as C 14. The isotopes that differ from the most common form are often radioactive or unstable.

C. Chemical Compounds 1. Chemical compound=

  

Example: Sodium Chloride = Table salt Forms when

sodium and chlorine combine in a 1:1 ratio 

2. Chemical formula=  

Example: Sodium Chloride= NaCl  3. ____________________________ of a molecule Example: = white crystalline solid

= a soft silvery metal that reacts explosively with water

= poisonous greenish gas

a substance formed by the combination of 2 or more elements in definite

proportions.

a short hand that shows chemical composition

Chemical properties

NaCl Na

Cl

D. Chemical Bonds

• Atoms in compounds are

• Involves the

• 2 main types of bonds are: ___________ and _________

held together by links called chemical bonds.

interaction of electrons

covalent ionic

1. Ionic Bondsa.

 

b. ion=  

are formed by the transfer of one or more electrons from one atom to another.

an atom that has a positive or negative charge as a result of gaining or losing electrons.

FORMING AN IONIC BOND

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

Transferof electron

Protons +11Electrons -11Charge

Protons +17Electrons -17Charge

Protons +11Electrons -10Charge

Protons +17Electrons -18Charge

Section 2 -1

Figure 2 - 3 Ionic Bonding

0 0 +1 -1

c. Opposite charges attract creating a bond between the ions

 2. Covalent Bonds

a. formed by the

 

b. Sharing means   

c. atoms sharing 2 electrons= __ electrons=double bond 6 electrons=  

d. _________________= The smallest unit of most chemical compounds (those joined with covalent bonds)

sharing of electrons between 2 atoms.

that the moving electrons are actually traveling in the orbitals of both atoms.

single bond 4

triple bond

Molecule

What property of water explains why this insect can stand on water?

2-2

Why does ice float?

Solid (Ice) Liquid (water) Gas (water vapor)

Ice is less dense than water.

Water is Polar—uneven distribution of electrons

Hydrogen bonds

Water Cohesion & Adhesion

Water propertieshttp://www.uni.edu/~iowawet/H2OProperties.htmlhttp://www.ccs.k12.in.us/chsBS/kons/kons/physical_properties_of_water.htm

Solution

Water has a pH of 7 which means that [H+] = [OH-]

Acids contain higher concentrations of [H+] ions than water.Bases contain lower concentrations of [H+] ions than water.

2-2 Properties of Water- Refer to reader’s guide 2-3 Carbon Compounds

A. The Chemistry of Carbon1. Carbon has ________________ which means

carbon can form _________________ 

2. Living organisms are made up of molecules that consist

   3. Carbon can bond with itself forming

Methane Acetylene Butadiene Benzene Isooctane

Section 2-3

Figure 2-11 Carbon Compounds

4 valence electrons 4 covalent bonds.

of carbon, hydrogen, oxygen, phosphorus, nitrogen and sulfur.

chains of unlimited length and form, rings, and complex structures.

B. Macromolecules1. Macromolecules=

2. Polymerization=

3. Monomers=

4. The _____ groups of organic compounds found in living things are:•• ••

are giant molecules consisting of 1000+ smaller molecules.

process of joining small molecules to form large molecules

small units that form polymers (large molecules)

4

carbohydrates lipids nucleic acids

proteins

Polymerizationhttp://www.uwsp.edu/chemistry/tzamis/additionpolymer.html

Made of

Example

Function Monomer

Carbohy-drate

C,H,O

1:2:1

GlucoseC6H12O6

1.Stores Energy -animals =

-plants =

2. Structural

Purposes-

-

Monosaccharide =

Mono + mono +mono=

Lipids Mostly

C, H

Verylittle O

1. Stores Energy

2. Form cell membranes

3. Waterproof coverings

4. Chemical messengers

1 glycerol3 fatty acidsSaturated-

Unsaturated-

GLYCOGEN

STARCH

PLANT CELL WALLS (CELLULOSE)

CHITIN (INSECT EXOSKELETON)

SINGLE SUGAR

POLYSACCHARIDE

FATSOILSWAXESSTEROIDS NO DOUBLE

BONDS IN FATTY ACID

AT LEAST ONE DOUBLE BOND

Challenge QuestionWhy are most unsaturated fats liquid at room temperature?

• Unsaturated

Nucleic acids

C HO P N

Stores and transmits hereditary information

Nucleotide=

1.

2. 3.

Proteins

CH O N

methionine

Shape determines function1.

2. pump small molecules in and out of the cell3. aids in cell movement

Amino acids

Made of

Example Function Monomer

DNA/RNA

5-C SUGAR

PHOSPHATE GROUP

NITROGENOUS BASE

20 KINDS

HELPS CONTROL RATE OF REACTIONS (ENZYMES)

Carbohydrates

Lipids

Nucleic acids

• Nucleic acids are polymers of nucleotides joined together to make large macromolecules.

• The important nucleic acids are deoxyribonucleic acid(DNA) and various types of ribonucleic acids(RNA).

Proteins

• Protein are the building blocks of our body. We find protein in our bones, and muscles. We find protein in our hair and nails. There is protein in our brain, and also protein is part of our blood.

Summaryhttp://www.chemistryland.com/ElementarySchool/BuildingBlocks/BuildingOrganic.htm

CarbonCompounds

include

that consist of

which contain

that consist of that consist of that consist of

which contain which contain which contain

Carbohydreat

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,

Concept Summary

Choose from the following: lipids, nucleotides, amino acids, fats and oils, sugars and starches, carbohydrates, nucleic acids, proteins

IQ Quiz: Chapter 21. What kind of compounds did we test in the lab?2. What chemical was used to test for simple sugars?3. What was a positive result?4. If we want to see if peanuts have fat in them what

could we do?5. How do we know if it is positive?6. What did copper sulfate and sodium hydroxide test

for?7. What was a positive result?8. If I had a bowl of cereal and Iodine fell into my cereal

and turned a blue-black color what do I know is in my cereal?

9. Name a food that had more than 1 compound in it? (tested positive for more than 1 test)

10. What are the four most common elements in living things?

2-4 Chemical Reactions and Enzymes A. Chemical Reactions =process that changes, or

transforms one set of chemicals into another. Always involves changes in chemical bonds.

1. Reactants=  

2. Products=  

EXAMPLE: HCl H + Cl

elements or compounds that enter a reaction

elements or compounds produced by a reaction

B. Energy in Reactions

• Activation Energy=

C. Enzymes

1. Catalyst=

energy that is needed to get a reaction started

a substance that speeds up the rate of a chemical reaction without changing itself.

AE without enzyme

AE with enzyme

reactants

products

Reaction with no enzyme

Reaction with an enzyme

2. Catalysts ___________________________in a chemical reaction.lower the activation energy

3. ______________ are ___________________ that speed up favorable (spontaneous) reactions.

4. Enzymes _____________ chemical reactions that take place in cells.

5. Enzymes are

Enzymes biological catalysts

speed up

very specific

D. Enzyme Action1. The Enzyme-Substrate Complex a. Enzymes provide a site where reactants can be

brought together to react (increasing the rate of reaction by reducing the activation energy)

Glucose

Substrates

ATP

Substratesbind toenzyme

Substratesare convertedinto products

Enzyme(hexokinase)

ADPProducts

Glucose -6-phosphate

Productsare released

Section 2 -4

Figure 2 - 21 Enzyme Action

Active site=

Enzyme ActivitySite on the enzyme where the substrate attaches

The reactants of a catalyzed reaction

Enzyme-substrate complex

b. Enzymes are not  

2. Regulation of Enzyme Activity - Enzyme activity depends on environmental

factors such as:          (enzymes in the stomach function best around pH=2)         (human enzymes function best around 37°C)

 

consumed in the reaction; after products are formed, the enzyme is recycled.

pH

temperature

-Ionic conditions (coenzymes)-Substrate concentration (greater the concentration the greater the rate of the reaction)

http://www.lewport.wnyric.org/JWANAMAKER/animations/Enzyme%20activity.html

http://www.kscience.co.uk/animations/model.swf

Warm-up questions

1. Describe the difference between ionic and covalent bonds. Provide an example for each.

Warm-up

1. What are the 4 organic macromolecules which make up living organisms.

2. What are the monomers (building blocks) to these macromolecules.

Warm-up

1. What is a catalyst?

2. What are enzymes?

3. How do catalyst work?

4. What affects the activity of an enzyme?

Review

1. The positively charged particle in an atom is the

a. Neutronb. Ionc. Protond. electron

Review

2. Two or more different atoms are combined in definite proportions in any

a. Symbolb. Isotope c. Element d. Compound

Review

3. A covalent bond is formed by the

a. Transfer of electronsb. Sharing of electrons c. Gaining of electronsd. Losing of electrons

Review

4. When you shake sugar and sand together in a test tube, you cause them to form a

a. Compoundb. Mixturec. Solutiond. suspension

Review

5. A compound that produces hydrogen ions in solution is

a. Saltb. Acidc. Based. polymer

Review

6. In polymerization, complex molecules are formed by the joining together of

a. Macromoleculesb. Carbohydratesc. Polymersd. monomers

Review

8. Proteins are polymers formed from

a. Lipidsb. Carbohydratesc. Amino acidsd. Nucleic acids

Review

9. An enzyme speeds up a reaction by

a. Lowering activation energyb. Raising activation energyc. Releasing energyd. Absorbing energy

Review

10. In a chemical reaction, a reactant binds to an enzyme at a region known as the

a. Catalystb. Productc. Substrated. Active site

Standardized Test Prep

1. An attraction between different substances

2. Lower a chemical reaction’s activation energy

3. The elements or compounds that enter into a chemical reaction

Choose: Cohesion Adhesion Catalysts Reactants Products

STP

4. Which one of the following is NOT an organic molecule found in living organisms

a. Protein b. Nucleic acidc. Carbohydrated. Sodium chloridee. lipid

STP

5. Which combination of particle and charge is correct?

a. Proton: +b. Electron: +c. Neutron: -d. Proton: -e. Electron: 0

STP

6. In which of the following ways do isotopes of the same element differ?

a. # neutrons onlyb. #protons onlyc. #neutrons and protonsd. #protons and masse. #neutrons and mass

STP

7. Which of the following molecules is made up of glycerol and fatty acids?

a. Sugarsb. Starchesc. Lipidsd. Nucleic acidse. Proteins

STP

8. Nucleotides consist of a phosphate group, a nitrogenous base, and a

a. Fatty acidb. Starchc. Lipidd. 5 carbon sugare. 6 carbon sugar