THE BUILDING BLOCKS OF LIFE Mrs. Geist, Biology Swansboro High School, 2010-2011 1.

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THE BUILDING BLOCKS OF LIFEMrs. Geist, Biology

Swansboro High School, 2010-2011

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Warm-Up

What does the term “organic” mean to you?

Can you name foods rich in: carbohydrates/sugars lipids/fats, and proteins?

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Organic vs. Inorganic

Organic compounds: typically contain carbon (C) and are associated with life

Inorganic compounds: usually do not contain carbon and are associated with non-living things

Carbon is the building block of all living things!!

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Carbon

Has 4 electrons in its outermost shell 4 electrons to share Forms covalent bonds (shares electrons) Single, double, or triple bonds

Atoms of nitrogen (N), oxygen (O), and phosphorus (P) attach to carbon chains.

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Macromolecules—giant molecules

4 major classes: Carbohydrates Lipids Proteins Nucleic acids

Polymers- complex molecules Monomers- small molecules, single units

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Carbohydrates

Made of carbon (C), hydrogen (H), and oxygen (O)

Ex: sugars and starches

2 H: 1 O Major source of

energy

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Carbohydrates: Simple Sugars Simple

sugars (C6H12O6) smallest carbs. A.k.a.

monosaccharides

Ex: glucose, fructose, galactose

Cell’s main source of energy

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Carbohydrates: Disaccharides Disaccharide

(C12H22O11)- two monosaccharides together Ex: sucrose,

maltose, lactose

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Carbohydrates (cont’d.)

Polysaccharides- many monosaccharides

4 major classes of polysaccharides:1. Starch- plant storage of glucose2. Glycogen- animal storage of glucose3. Cellulose- plants use for structural support

Most abundant organic molecule on Earth Indigestible bulk (or “fiber”)

4. Chitin- animals use for support, insect skeletons

2nd most abundant organic molecule on Earth

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Warm-Up 8/31

In your own words, what is an organic macromolecule?

What do the terms saturated and unsaturated fat mean to you?

Where might we find protein in the body?

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Lipids

Made up of carbon (C), hydrogen (H), and oxygen (O)

Functions: Store energy Provide insulation Important parts of cell membranes

(phospholipids) Waterproof coverings (waxes, ex: bird

feathers) Not soluble in water

Ex: fats, oils, waxes, steroids, phospholipids

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Lipids (cont’d.)

Structure: 3 fatty acids

Long chains of C with H attached

1 glycerol Alcohol with a hydroxyl

(-OH) group on each of its 3 C atoms

Dehydration synthesis: attaches these parts

Removal of water (H2O)

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Lipids: Saturated vs. Unsaturated

Saturated Unsaturated

Solid at room temperature

Liquid at room temperature

Contains lots of H Contains less H

Single bonds between C atoms

1+ double bonds between C atoms

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Proteins

Made up of nitrogen (N), carbon (C), hydrogen (H), and oxygen (O)

Monomer: amino acids Structure:

Amino group (-NH2) on 1 end Carboxyl group (-COOH) on the other end Side chain (or R group) that differs for

each of the 20 amino acids

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Proteins: Amino Acids

Structure of an amino acid (monomer)

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Proteins: 4 levels of organization1. Primary: sequence of amino acids2. Secondary: the amino acids within a

chain can be twisted or folded Ex: alpha helices, beta pleated sheets

3. Tertiary: the chain itself is folded4. Quaternary: If the protein has >1

chain, each chain has a specific arrangement in space

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Protein Functions

Some proteins control the rate of reactions and regulate cell processes (called enzymes). Act as catalysts- speed up chemical

reactions some form bones, muscles, skin, and

ligaments. Others transport substances into/out of

cells Help to fight disease.

Enyzmes as catalysts

Enzymes are proteins that act as biological catalysts. Catalyst- speeds up

the rate of a chemical reaction.

Speed up reactions that are too slow or have activation energies that are too high to make them practical for living tissue.

Enzymes act by lowering the activation energy.

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Functions of Enzymes

Regulating chemical pathways.

Making material that cells need.

Releasing energy. Transferring

information.

Enyzmes as catalysts

For a chemical reaction to take place, the reactants must collide with enough energy to break existing bonds and form new bonds

If reactants do not have enough energy, no reaction will take place.

Enzymes

Enzymes are very specific, generally catalyzing only one chemical reaction.

For this reason, part of an enzyme’s name is usually derived from the reaction it catalyzes. Add –ase ending. I.e. lipase I.e. proteinase

The Enzyme-Substrate Complex Enzymes provide a site where reactants can be brought

together to react, reducing the energy needed for reaction. The reactants are known as substrates. The enzyme and substrates remain bound together until the

reaction is done and the substrates are converted to products. The products of the reaction are released and the enzyme is

free to start the process again.

Copyright Pearson Prentice Hall

The cell theory states that new cells are produced from nonliving material. existing cells. cytoplasm. animals.

Copyright Pearson Prentice Hall

The person who first used the term cell wasa. Matthias Schleiden.b. Lynn Margulis.c. Anton van Leeuwenhoek.d. Robert Hooke.

An Enzyme-Catalyzed Reaction

Substrates: glucose and ATP

Enzyme: hexokinase Substrates bind to

enzyme, forming an enzyme-substrate complex.

The fit is so precise that the active site and substrates are often compared to a lock and key.

Regulation of Enzyme Activity

Enzymes work best at certain pH and temperature ranges and can be affected by such changes.

Many enzymes are affected by changes in temperature.

Cells can regulate the activities of enzymes.

Most cells contain proteins that help to turn key enzymes “on” and “off” at critical stages in the life of the cell.

Nucleic Acids

Function: store and transmit hereditary, or genetic, information.

2 kinds of nucleic acids: 1. ribonucleic acid

(RNA)2. deoxyribonucleic

acid (DNA).

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Nucleic Acids

Monomer = nucleotides, which are composed of 3 parts: 5-carbon sugar- deoxyribose (DNA) or ribose

(RNA) Nitrogen base- adenine (A), thymine (T),

cytosine (C), guanine (G), uracil (U) Phosphate group- contains phosphorus (P) and

oxygen (O) 2 Types:

Deoxyribonucleic Acid (DNA) Ribonucleic Acid (RNA):

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Deoxyribonucleic Acid (DNA) Double helix (spiral) Stores genetic

information

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Ribonucleic Acid (RNA)

single helix Plays a role in

manufacture of proteins

Enzyme (speed up reactions)

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Nucleotides

DNA and RNA Adenine (A) Guanine (G) Cytosine (C)

DNA only Thymine (T)

RNA only Uracil (U)

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3 parts of a nucleotide

5-carbon sugar (deoxyribose in DNA or ribose in RNA)

Nucleotide base Phosphate group

The DNA and RNA Strand

Nucleotide + Nucleotide(n)

= DNA (or RNA) strand

2005 VisiScience Corporation. All Rights Reserved.

3'

5'

Base

Base

Base

1'

3'

5'

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Does temperature affect an enzyme reaction? (pp. 164-165)

Problem: Does the enzyme peroxidase work in cold temperatures? Does peroxidase work better at higher

temperatures? After being frozen or boiled?

Hypothesis: “If…, then …” statement. Materials: clock, beakers, kitchen knife,

tongs, potato, ice, hot plates, thermometers, 3% hydrogen peroxide (H2O2), hot gloves

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Peroxidase

2H2O2 2H2O + O2

Hydrogen Peroxide water + oxygen gas

Hydrogen peroxide is damaging to cells

Peroxidase speeds up the breakdown of hydrogen peroxide

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Planning Experiment

Hypothesis Boiling, ice bath,

warm water bath, room temperature

Steps to be taken Add 1 drop H2O2

to the potato slice and observe what happens

What data will you collect? How will you record them?

What factors should be controlled?

How will you achieve those temperatures?

Carry out the expt.