Regents Biology 2006-2007

The Chemistry of Life

What are living creatures made of?

Why do we have to eat?

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1. Atoms

Chemistry is the study of matter.

6.1 Atoms, Elements, and Compounds

A. Atoms are the building blocks of matter.

Chapter 6Chemistry in Biology

Neutrons and protons are located at the center of the atom.

1. Protons are positively charged particles.

2. Neutrons are particles that have no charge.

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3. Electrons are negatively charged particles that are located outside the

nucleus.

Chemistry in Biology

6.1 Atoms, Elements, and Compounds

Chapter 6

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2. Elements

Chemistry in Biology

An element is a pure substance that cannot be broken down into other substances by physical or chemical means.

There are over 100 known elements, 92 of which occur naturally.

Each element has a unique name and symbol.

6.1 Atoms, Elements, and Compounds

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The Periodic Table of Elements

Chemistry in Biology

Horizontal rows are called periods. Vertical columns are called groups.

6.1 Atoms, Elements, and Compounds

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96% of living organisms is made of: carbon (C) oxygen (O) hydrogen (H) nitrogen (N)

3. Elements of Life

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What is a MoleculeCovalent bonds hold 2 or more atoms

together to form a molecule.A. Important Molecules H2O Water

O2 Oxygen

CO2 Carbon Dioxide

C6H12O6 Glucose

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Why do elements form molecules.1. To fill their outer shell with electrons.

2. This is called bonding.

3. Two types of bonding

a. covalent = Sharing

b. ionic = Transferring

4. Molecules are formed by covalent bonding.

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4. Macro-molecules of LifeA. Put C, H, O, N together in different

ways to build living organisms

B. What are bodies made of?1. carbohydrates

sugars & starches

2. proteins

3. fats (lipids)

4. nucleic acids DNA, RNA

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How do we make these molecules?

We build them!

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Why do we eat? We eat to take in more of these chemicals

Food for building materials to make more of us (cells) for growth for repair

Food to make energy calories to make ATP

ATP

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What do we need to eat? Foods to give you more building blocks

& more energy for building & running bodies

carbohydrates proteins fats nucleic acids vitamins minerals, salts water

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What do all macromolecules have in common?

C. They all contain Carbon1. Has 4 valence electrons2. Forms many types of

covalent bonds.3. Forms the backbone of

all macromolecules

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2. They are all polymers

A polymer is a long molecule consisting of many similar building blocks called monomers

What do all macromolecules have in common?

What is a polymer?

3. They are all assembled by a Dehydration reaction (Condensation).

What is a monomer?

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(a) Dehydration reaction in the synthesis of a polymer

HO H1 2 3 HO

HO H1 2 3 4

H

H2O

Short polymer Unlinked monomer

Longer polymer

Dehydration removes a watermolecule, forming a new bond

Figure5.2A

Dehydration Reaction (Condensation) Water Making

How are polymers assembled?

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Polymers are disassembled by Hydrolysis (water Breaking)

(b) Hydrolysis of a polymer

HO 1 2 3 H

HO H1 2 3 4

H2O

HHO

Hydrolysis adds a watermolecule, breaking a bond

Figure 5.2B

How are polymers taken apart?

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Building large molecules of life Chain together smaller molecules

building block molecules = monomers

Big molecules built from little molecules polymers

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Small molecules = building blocks (Monomers)

Bond them together = polymers

Building large organic molecules

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Building important polymers

sugar – sugar – sugar – sugar – sugar – sugar

nucleotide – nucleotide – nucleotide – nucleotide

Carbohydrates = built from sugars(saccharides)

Proteins = built from amino acids

Nucleic acids (DNA) = built from nucleotides

aminoacid

aminoacid–

aminoacid–

aminoacid–

aminoacid–

aminoacid–

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How to build large molecules Synthesis (Dehydration)

building bigger molecules from smaller molecules

building cells & bodies repair growth reproduction

+

ATP

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Example of synthesis

amino acids protein

amino acids = building block

protein = polymer

Proteins are synthesized by bonding amino acids

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How to take large molecules apart Digestion (Hydrolysis)

taking big molecules apart getting raw materials

for synthesis & growth making energy (ATP)

for synthesis, growth & everyday functions

+

ATP

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Example of digestion

starch glucose

ATP

ATP

ATP

ATP

ATP

ATPATP

Starch is digested to glucose

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Penguins gone bad!

AnyQuestions?

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Old Food Pyramid

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New Food Pyramid

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Water 65% of your body is H2O water is inorganic

doesn’t contain carbon

Rest of you is made of carbon molecules organic molecules

carbohydrates proteins fats nucleic acids

Don’t forget water