Quiz 3: Chapter 4

Last 2 questions of chapter 3 and the entire chapter 4 Water and Life and Carbon and the Molecular Diversity of Life

Define acid, base, and pH. Know the pH values of acids, bases, pure water, and human blood.

==Strong acids and bases dissociate completely in water• Weak acids and bases reversibly release and accept back hydrogen ions, but can still shift the balance of H+ and OH- away from neutrality==

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Most biological fluids have pH values in the range of **6 to 8**

Acid

a substance that ==**increases the H+ concentration**== of a solution

Base

a substance that ==**reduces the H+ concentration**== of a solution by %%**accepting (binding) H+ ions or forming OH- ions**%%

pH

The pH of a solution is defined by the negative logarithm of H+ concentration

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A measure of __**how acidic or basic a substance or solution is**__

pH values of acids

Acidic solutions have pH values __**less than 7**__

pH values of bases

Basic solutions have pH values __**greater than 7**__

pH values of pure water

Pure water has a pH of __**7**__

pH values of human blood

Human blood has a pH of __**7.35-7.45**__

Define buffer. Define ocean acidification and explain how it can affect the ocean's ecosystem.

As seawater acidifies, ==__**H+ ions combine with carbonate ions to produce bicarbonate ions**__==• Carbonate is required for calcification (production of calcium carbonate) by many marine organisms, including reef-building corals• Researchers believe that ocean acidification is likely to cause "==__**profound, ecosystem-wide changes in coral reefs**__=="

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Sunlight melts ice caps and causes phytoplankton to grow more. Whales eat phytoplankton (microorganisms that thrive in the sunlight).

Buffer

substances that minimize changes in concentrations of H+ and OH- in a solution (hydrogen ion and hydroxide)

Ocean Acidification

__**CO2**__ dissolved __**in seawater forms carbonic acid**__

Define organic chemistry.

the study of carbon compounds, regardless of origin, typically containing ==__**carbon-hydrogen bonds**__==

Be familiar with the Miller experiment that demonstrated abiotic synthesis of organic compounds.

This experiment is basically saying that something (==**life and organic compounds) was made from nothing**== (elements). He was trying to see how that happened. Miller put all of those elements ==(carbon, hydrogen, nitrogen, phosphorous, oxygen, sulfur==) all in one to see if organic molecules would happen. And they did

Know that the electron configuration is the key to an atom's chemical characteristics.

Carbon atoms ==__**can form diverse molecules by bonding to four other atoms**__==. Electron configuration determines the kinds and number of bonds an atom will form with other atoms (ex. 1s^2; 2s^2; 3s^2)

Know how many bonds carbon can form and know how this works with double bonds. Know single and double bonded molecules' configuration in space.

Carbon can form %%4 covalent bonds%%.

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%%__**Carbon can bond a single or double bond with itself and other molecules (ex. hydrogen or oxygen).**__%%

Define valence. Know the valence of carbon, nitrogen, oxygen, hydrogen, and phosphorus.

Valence: the %%__**number of covalent bonds an atom can form**__%%

Valence

the number of ==**covalent bonds an atom can form**==

Carbon

valence of __4__

Hydrogen

valence of __1__

Oxygen

valence of __6__

Phosphorus

valence of __3 or 5__

Know the structure of carbon dioxide. Be familiar with urea. Know their classification of being organic or inorganic.

Organic means they have ==carbon-hydrogen bonds==. They also have carbon, hydrogen, and oxygen.

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Inorganic **does not** have carbon-hydrogen bonds.

Structure of carbon dioxide

**CO2** or O=C=O

Urea

CO(NH2)2

Know that carbon chains form the skeletons of most organic molecules. Explain how they vary in length and shape.

Carbon chains form the skeletons of most organic molecules. Carbon chains vary in length and shape. __**They may have double bonds and can vary in location. They can be branched or unbranched.**__

Carbon chains vary in length and shape. They may have double bonds and can vary in location. They can be branched or unbranched.

__Shape__: this can be a ==ring== or ==hexagon== shape.

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__Length__: __ethane__ (==shorter==; 2 carbons) or __propane__ (==longer==; 3 carbons)

Single bonds

2 electrons are 1 bond

Double bonds

4 electrons are 2 bonds or a double bond

Define hydrocarbons.

organic compounds containing only ^^__**hydrogen and carbon atoms**__^^

Define isomers, structural isomers, cis-trans isomers, enantiomers, and stereoisomers.

Ethyl alcohol and dimethyl ether are isomers of each other as @@__**both of the compounds have the same molecular formula – C2H6O while different structural formulae**__@@

Isomer

compounds with the ==__**same molecular formula**__== but ==__**different structures and properties**__==

Structural Isomer

have __**different covalent arrangements**__ of their atoms

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For example, the formula C 4H 10 represents both butane and 2 - methylpropane

Cis-Trans Isomers (geometric isomers)

same covalent bonds but **differ in their spatial arrangements**

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but-2-ene

Enantiomers

stereoisomers that are ^^__**mirror images of each other**__^^

Stereoisomers

have the ==__**same covalent arrangements**__== of their atoms, but are ==__**arranged differently in space**__==

Know the significance of enantiomers.

Enantiomers are %%**important in the pharmaceutical industry**%%• Two enantiomers of a drug may have different effects• Often only one enantiomer is biologically active• @@__**Differing effects of enantiomers demonstrate that organisms are sensitive to even subtle variations in molecules.**__@@

Enantiomer example

ex. ibuprofen and albuterol

Know that different chemical groups can affect properties of organic molecules.

^^__**If you change anything from one compound then you turn it into another compound**__^^__**.**__ Ex. estradiol has HO but testosterone doesn't have H but only O by itself.

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H = hydrogen O = Oxygen

Define functional group and know the **7 most important ones** in the chemistry of life.

%%Hydroxyl, Carbonyl, Carboxyl, Amino group, Sulfhydryl, Phosphate, Methyl%%

Functional groups

the components of %%**organic molecules**%% that are %%**most commonly involved in chemical reactions**%%• The number and arrangement of functional groups give each molecule its unique properties

Hydroxyl

__polar (hydroxide)__ group: (-OH or HO-); compound name - **alcohol**. ex. ethanol; ==HYDROGEN BONDS==

Carbonyl group

__polar__: (C=O); (with the carbon atom bonded to two other atoms); compound name - **Ketone/Aldehyde**; ex. acetone (nail polish remover) and propanal; ==CARBON CHAIN==

Carboxyl group

__charged, ionizes to release H+__: (-COOH or -CO2H); compound name - **Carboxylic acid ~ organic acid**; ex. Acetic Acid (vinegar); ==CARBON ACTS AS ACID==

Amino group

__charged, accepts H+ to form NH3+__: (-NH2); compound name - **Amine**; ex. glycine (enzyme) ==PROTEINS/ENZYMES==

Sulfhydryl group

strong unpleasant odor, __polar__: ^^(-SH or HS-)^^; compound name - **Thiol**; ex. Cysteine. ==SULFUR==

Phosphate group

__charged, ionizes to release H+__: ^^(-OPO3^2-)^^; compound name - **organic phosphate**; ex. glycerol phosphate (a sweet colorless syrupy alcohol usually obtained from fats and oils.) ==PHOSPHORUS==

Methyl group

__nonpolar__: ^^(-CH3)^^; compound name - **methylated compound** (methane - CH4); ex. 5-methylcytosine ==METHANE==

Know what ATP is and how it can release energy.

==**ATP breaks a phosphate bond to become ADP which also reacts with water (H2O).**==

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ATP and ADP (adenosine diphosphate - 2) continue in a cycle.

ATP

(adenosine triphosphate); releases energy by ==**breaking a bond.**==