bioch6chemoflife - mrs. (white) groebner's science classes

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1. Your Roadmap for Success in Chapter 6

Preview the chapter:

1. Read Summary (p. 171).

2. Skim the Assessment questions (p. 171‐173).

3. Rewrite Learning Objectives for the chapter and each section in the form of possible test questions. (So, four sets of questions.)

4. Look at pictures.


• You are expected to read all parts of each section (1, 2, 3) on your own. You are responsible for knowing this material.

• We will be covering most of the book content during class with slides, discussions, demos, and other activities. However, we can’t possibly cover all chapter content during class.


Assignments will include (at minimum):

1. Reading the chapter

2. Questions from each Section Assessment

3. Questions from the Chapter Assessment

4. Chapter notes (more later)

5. Class activities or labs

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Assessments will include (at minimum):

1. The assignments mentioned

2. Quiz for each section

3. Test at the end of the chapter

4. Behavior/positive participation

There will be at least one extra credit opportunity offered per chapter.

Biology

Chapter 6: The Chemistry of Life1. Atoms and Their Interactions2. Water and Diffusion3. Life Substances

http://www.connecticutvalleybiological.com/cell‐processes‐vhs‐p‐14026.html

Biology

Chapter 6: The Chemistry of Life

What You’ll Learn (p. 144)(Turn these statements into test questions; write them down.)1.2. 3.

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Chapter 6.1 Atoms & Their Interactions

Learning Objectives (p. 145):

(Turn these objectives into test questions.)

1.

2.

3.

4.

Vocabulary:

Matter…

• is anything that has mass and takes up space.

• Examples?

Energy …

• is anything that brings about change.

• can hold matter together or break it apart.

Atoms

• All matter (whether solid, liquid, or gas) is made of atoms.

• Center of atom is called the nucleus.

The nucleus consists of:

• protons (have a + charge)

• neutrons (have no charge)

http://bioap.wikispaces.com/file/view/atom.jpg/107303887/atom.jpg

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Matter vs. Energy

Definition Examples

Matter atoms, electrons, protons, and neutrons; __________, __________, __________, __________, __________

Energy sunlight, electricity, heat, chemical energy

Atoms ‐ Electrons

• Around the nucleus is a cloud

of electrons (have a – charge).

• Constantly moving

• VERY small mass compared to protons and neutrons!

The mass of 1,837 electrons = the mass of 1 proton

• Involved in CHEMICAL REACTIONS

http://www.freaklasers.com/laser‐pointer/how‐laser‐works‐freaklasers‐1.jpg

Parts of an Atom

Electrical Charge? Location in Atom? Relative Mass?

Protons

Neutrons

Electrons

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Elements…

• are made up of only one kind of atom.

• can’t be broken down into simpler form by chemical reactions.

• are known by their own one‐ or two‐letter symbol.

• make up everything in the

Universe.

http://www.walyou.com/blog/wp‐content/uploads/2009/07/periodic‐table‐elements‐au‐ring.jpg

http://static.howstuffworks.com/gif/periodic‐table‐2.jpg

http://facstaff.gpc.edu/~pgore/PhysicalScience/periodic‐table.gif

How many of these elements can you identify?

O _____________

C _____________

H _____________

N _____________

Ca ____________

P _____________

K ______________

S ______________

Na _____________

Cl ______________

Mg _____________

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Elements that make up the human body

65.0%

18.5%

9.5%

3.2%

1.5% 1.0%

0.4% 0.3%0.2%

0.2% 0.1%

0.1%

Percent in Human Body

Oxygen

Carbon

Hydrogen

Nitrogen

Calcium

Phosphorus

Potassium

Sulfur

Sodium

Chlorine

99% of living matter……is made up of six (6) elements. That makes these elements pretty important!

S

P

O

N

C

H

Compounds and Molecules• A Compound is a substance that is composed of atoms of two or more different elements that are chemically combined.

• Example: Water

http://kentsimmons.uwinnipeg.ca/cm1504/introchemistry.htmhttp://www.quarked.org/askmarks/images/water.jpg

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Compounds and Molecules

• A Compound is a substance that is composed of atoms of two or more different elements that are chemically combined .

• These elements are in exact proportions.

• Example: Water is always made up of ___ hydrogen atom(s) and ___ oxygen atom(s), bonded together in exactly the same way, to form a water molecule.

Compounds and Bonding

• Most matter is in the form of compounds.

• Why and how do atoms combine?

– Atoms combine with other atoms:

• Only when conditions are right

• To become more stable

• When is an atom usually most stable?

• How does an atom become more stable?

Covalent Bonds vs. Ionic Bonds

• Covalent bonds form when two atoms share electrons in their outermost shell (energy level).– Atoms are held together by the attraction between the positively‐charged nuclei and the shared, negatively‐charged electrons.

– Most compounds in organisms have covalent bonds (ex. sugars, fats, proteins, water).

• Molecule: Group of atoms held together by covalent bonds and having no overall charge.

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Compounds and Molecules• Molecular Compounds form when different atoms share their outermost electrons.

Hydrogen atoms have 1 electron.How many electrons does an oxygen atom have? (see pg. 147)

– On Earth, oxygen and hydrogen normally exist as gases.

– But as a compound (water), they can be liquid, solid, or gas.

**When a compound is formed, changes occur and a new substance forms.


• Most atoms have an equal # of electrons and protons; therefore, they have an electrical charge of ________.

• Ionic bonds form when atoms gain or lose an electron from their outer energy level.

• An ion is an atom (or group of atoms) that _____ or _____ electrons and has an _______ __________.

• An ion is a charged particle.


• Ions are held together by a different kind of chemical bond than covalent bonds.

• An ionic bond is the attractive force between two ions of opposite charge.

• Example: NaCl

• Sodium atom

(11e, 11p, 12n)

• Chlorine atom

(17e, 17p, 18n)

http://www.dmacc.edu/instructors/rbwollaston/Biology_I/Chapter_2_Chemistry_of_Life.htm

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http://www.emc.maricopa.edu/faculty/farabee/biobk/biobookchem2.htmlhttp://www.thaigoodview.com/library/contest2551/science04/56/3P/Ionic.htm

Ionic Bonds, cont’d• Ionic compounds are less abundant in living things than are covalent molecules.

• However, ions are very important in biological processes.

• Examples:– Sodium and potassium ions are required for transmission of nerve impulses.

– Calcium ions are necessary for muscles to contract.

– Plant roots absorb essential minerals in the form of ions.

Chemical ReactionsWhat is going on during a chemical reaction?

• Bonds between atoms are formed or broken, causing substances to combine and recombine as different molecules.– Chemical reactions occur over and over again inside cells.

• Metabolism: All of the chemical reactions that occur within an organism. – These chemical reactions are essential for the organism’s function.

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Chemical Reactions and Chemical Equations

• Chemical reactions are represented by chemical equations.

• Symbols and formulas are used to represent each element or substance.

2H2 + O2 2H2O

(Reactants) (Products)

Chemical Reactions and Chemical Equations

Reactants: Substances that undergo chemical reactions

Products: Substances formed by chemical reactions

https://reich‐chemistry.wikispaces.com/Combustion‐+keedy+mccormack

• Atoms are neither created nor destroyed by chemical reactions! Just rearranged.

• Same number of atoms should appear on both sides of the equation (if balanced).

Showing a Chemical Reactions With a Chemical Equation

2H2 + O2 2H2OHow many molecules are involved with this chemical reaction?

• Number before each chemical formula indicates the # of molecules of each substance.

• Subscript numbers indicate the # of atoms of each element in a molecule of the substance.

• If no # before or under a symbol, then only one atom or molecule is present.

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Showing a Chemical Reactions With a Chemical Equation

2H2 + O2 2H2O

http://molarmath.info/

Mixtures

• When substances combine, but DON’T combine chemically (no chemical reaction)…

• Mixture: A combination of substances in which the individual components retain their own properties.

• Solution: Type of mixture in which one or more substances (solutes) are distributed evenly in another substance.

Solutions

• Solution:

– Type of mixture in which one or more substances (solutes) are distributed evenly in another substance (solvent).

– Basically, one substance is completely dissolved in another and won’t settle out of solution.

Solventmeans “to loosen or dissolve.”

Water is known as the “universal solvent.”

http://www.chem4kids.com/files/matter_solution.html

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Concentration of a Solution

• The more solute in a given amount of solvent, the HIGHER the concentration of the solution (i.e., “stronger”).

• To dilute a solutionmeans that you add more solvent.

– Ex. Adding more water

to a pitcher of Kool‐Aid makes it “weaker.”

What does this mean for living organisms?

• Organisms have very specific requirements for the concentrations of solutions in their bodies…usually an extremely narrow range of tolerance.

– Ex. Blood sugar level, cellular contents

6.2 Water and DiffusionLook at the Section Preview to find the Learning Objectives.

Students will be able to:

• Relate water’s unique features to polarity.

• Explain how the process of diffusion occurs and why it is important to cells.

Vocab: polar molecule, hydrogen bond, diffusion, dynamic equilibrium

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6.2 Water and DiffusionWhy is water (perhaps) the most important compound in living organisms?

• Most life processes can occur only when molecules and ions are free to move and collide with one another.– This condition is met in water.

• Material transportation (blood, plant sap)

• Water makes up 70‐95% of most organisms.

Three (3) important characteristics of water…

1. Water is polar. What does this mean?

• In a covalent bond, electrons are not always shared equally. – For example: In water molecules, electrons are more strongly attracted to the O atom than to the H atoms).

Polar molecule: unequal distribution of charge resulting in a positive end (+) and a negative end (‐)

Why can water dissolve so many things? Polar water molecules attract:

• Ions (so ionic compounds like NaCl dissolve easily)

• Other polar molecules (like sugar)

• Water molecules

Hydrogen bond: A weak bond formed by the attraction of opposite charges between hydrogen and oxygen

• Hydrogen bonds hold many large molecules (e.g., organic compounds like proteins) together.

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Because of water’s polarity:

• Creeps up thin tubes (capillary action)

• Surface tension

2. Water resists temperature changes.• Good insulator

• Cells are in an aqueous environment, so they are protected from sudden changes in temperature.

3. Water expands when it freezes.

• Rare characteristic among substances.

• Ice is less dense than liquid water – floats.

– Allows life to continue underwater in winter.

– Helps make soil.

Diffusion

• Water is one way to move substances in living systems.

• Diffusion is another way.– Kinetic energy of objects in motion – applies to matter

– Ping‐Pong balls

– Random motion of molecules = Brownian motion

– Characteristic of gas, liquid, and some solid molecules

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• Diffusion is the net movement of particles from an area of higher concentration to an area of lower concentration.

• Result of random movement of atoms.

• Three KEY factors:

1. Concentration (primary controlling factor)

2. Temperature

3. Pressure

Results of diffusion

• Two substances (e.g., colored corn syrup and pure corn syrup) will eventually be evenly distributed (concentration same everywhere).

– Atoms continue to move randomly and collide, but no changes in overall concentration.

– This condition is called dynamic equilibrium.

Concentration gradient: difference in concentration of a substance across space.

• Ions and molecules diffuse from area of high concentration to low concentration “move with the gradient”

• If no interference, diffusion continues until there is NO concentration gradient (dynamic equilibrium).

• One IMORTANT way cells move stuff in and out of cell!

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Osmosis

http://www.citruscollege.edu/lc/biology/Pages/Chapter04‐Rabitoy.aspx

• Animation: Diffusion, Concentration Gradient, Dynamic Equilibrium

http://www.wisc‐online.com/Objects/ViewObject.aspx?ID=AP1903

6.3 Life SubstancesLook at the Section Preview to find the Learning Objectives.

Students will be able to:

• Classify the variety of organic compounds.

• Describe how polymers are formed and broken down in organisms.

• Compare the chemical structures of carbohydrates, lipids, proteins, and nucleic acids, and relate their importance to living things.

Vocab: isomer, polymer, carbohydrate, lipid, protein, amino acid, peptide bond, enzyme, nucleic acid, nucleotide

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Role of Carbon in Organisms

• The compounds that form the cells and tissues of the body are produced from similar compounds in the foods you eat.

• Most of these foods (and most substances found in organisms) contain carbon.

• Organic compounds

Atomic Structure of Carbon

Why does carbon play such an important role for living things?

Or maybe…how does carbon combine with other elements in so many different ways?

Carbon is versatile.• Carbon atoms can bond to form straight chains, branched chains, or rings.

• These chains and rings:

– contain almost any number of carbon atoms

– can include atoms of other elements

http://www.tutorvista.com/content/science/science‐ii/carbon‐compounds/saturated‐unsaturated.php

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Carbon is versatile.• Lots of carbon structures possible!

• Isomers: Compounds that have the same simple formula but different 3‐D structures.

The Greek root word iso‐ appeared in another vocabulary word in Ch. 6:

iso‐means _______________

‐merosmeans _______________

Isomers, cont’d• Example: glucose and fructose (p. 162)

– Both C6H12O6

– Different structures

http://encyclopedia2.thefreedictionary.com/Glucose http://www.biology.lsu.edu/introbio/summer/Summer2004/1201/RF/Chapter%205%20review.htm

Fructose

Glucose

Molecular Chains

• Carbon compounds vary greatly in size.

• One or two C atoms to thousands of C atoms

• Large molecules are called _______________.

• Polymer: large molecule formed when many smaller molecules bond together.

Poly‐means ______________.

SKIP the Condensation and Hydrolysis paragraphs on p. 162.

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Organic and Inorganic CompoundsWhat’s the difference?

Characteristic ORGANIC COMPOUNDS INORGANIC COMPOUNDS

Contain elements:

Associated with:

Relative # of atoms:

Examples

Organic Compounds Found in All Living Things

There are four groups:

1.

2.

3.

4.

1. Carbohydrates

• Elements: carbon, hydrogen, oxygen

• Examples: sugars, starch, cellulose

• What function do they have?

1. Supply energy for cell processes

2. Form plant structures

3. Short‐term energy storage

http://www.fehd.gov.hk/english/safefood/nutrient/1.html

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• Monosaccharide– Simplest type of carbohydrate

– A simple sugar• Examples: glucose and fructose

• Mono‐means __________ or ____________

• Disaccharide– Two monosaccharide molecules linked together.

– A two‐sugar carbohydrate• Example: glucose and fructose joined sucrose

1. Carbohydrates (p. 163)

• Polysaccharide– Largest carbohydrate molecules– Polymers composed of many monosaccharide units– Examples of glucose polymers: 1. Starch‐ food storage in plants; highly branched

chains; e.g., seeds, bulbs2. Glycogen – food storage in mammals; more highly

branched; e.g., liver3. Cellulose – cell walls and structural support in

plants; long chains hooked together like chain‐link fence.

1. Carbohydrates

2. Lipids• Elements: carbon, hydrogen, oxygen, phosphorus

• Examples: fats, oils, waxes, phospholipids, cholesterol

• What function do they have?1. Store large amounts of energy long term

2. Form major part of cell membranes

3. Insulation and protection


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Because lipids consist of non‐polar molecules, they _______________________ in water, or are known to be _____________.

SKIP Figure 6.20 (about lipids) on p. 164.

2. Lipids

3. Proteins• Elements: carbon, hydrogen, oxygen, nitrogen, sulfur

• Examples: enzymes, skin, hair, hormones,

• What function do they have?1. Regulate cell processes2. Carry out chemical reactions3. Build cell structures4. Control immune system5. Turn genes on or off


3. Proteins: Structure

• A protein is a large, complex polymer containing C, H, O, N, and usually S.

• Basic building blocks of proteins are amino acids.• 20 amino acids in various combinations make thousands of proteins.

• Vary more in structure than other types of organic molecules.

• Protein chains – often 100s of amino acids• KIND of protein determined by the _________ and _________ of amino acids in chain.

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20 amino acids combine in specific sequences to form different proteins

Protein chains can contain 100s of amino acids in a particular sequence

Many proteins consist of two or more amino acid chains.

http://www.proteomesoftware.com/Proteome_software_ed_Proteins.html

Example: Hemoglobin is a protein that helps transport oxygen in your blood.

• The chemical reactions in your cells need enzymes.

• Enzyme: A protein that changes the rate of a chemical reaction.

Enzymes are like can openers.

• You need a can opener to open the can.• The can changes, but the can opener

doesn’t – it can be used over and over again.

Enzymes can break molecules apart (like a can opener), but enzymes also can cause molecules to join (unlike a can opener).

BUT…just any old enzyme won’t do!

There has to be a perfect fit between a particular molecule and a particular enzyme.

http://www.skinnersbiology.co.uk/enzyme.htmhttp://isbibbio.wikispaces.com/Fungal+Amylase+‐+Baking+Enzyme

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Enzymes: An important type of protein

See (and know) Action of Enzymes on p. 166.

4. Nucleic Acids

• Elements: carbon, hydrogen, oxygen, nitrogen, phosphorus

• Examples: DNA & RNA

• What function do they have?

1. Carry hereditary information

2. Used to make proteins

4. Nucleic Acids

• A nucleic acid is a complex _____________ that stores __________ in the form of a code.

• Are polymers made up of smaller subunits: nucleotides

• Nucleotides consist of C, H, O, N, P atoms arranged in 3 groups: – Base

– Simple sugar

– Phosphate group

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Nucleic Acids: DNA and RNA

• Deoxyribonucleic acid (DNA)– Master copy of organism’s info code used to form enzymes and structural proteins

– Genetic code that determines how organism looks and acts

– Passed on every time a cell divides and from one generation of the organism to the next

• Ribonucleic acid (RNA)– Nucleic acid that forms copy of DNA for use in making proteins

Inorganic Compounds

• Made from elements…

…other than carbon.

…that living things need.

• Example: Plants take up inorganic compounds from soil. These I.C. contain the elements nitrogen, phosphorus, and sulfur.

Some Inorganic Compounds Important in Humans:


Compound Use in Body

Water Blood; chemical reactions

Calcium phosphate Bone strength

Hydrochloric acid Breaks down foods in stomach

Sodium bicarbonate Digestion

Salts containing S, Cl, and K Nerve messages

bioch6chemoflife - mrs. (white) groebner's science classes

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