Molecular Diversity (Gen Bio 2)

All living organisms are composed of___

Matter

What is matter?

Anything that takes up space and has mass

Matter is composed of ___

Chemical elements

What is an element?

A substance that cannot be broken down to other substances by ordinary chemical means

How many elements are there in nature?

92— only a few exist in a pure state

Major elements in the body

Carbon, hydrogen, oxygen, nitrogen

What property does water have that explains most of waters life supporting properties?

Polarity

Water molecules stick together as a result of …

Hydrogen bonding

Cohesion

The tendency of molecules of the same kind to stick together

This is much stronger for water than for other liquids

Hydrogen bonds give water unusually high ___ tension

Surface

Why is ice less dense than water?

When water molecules get cold enough, they move apart, forming ice

The biological significance of ice floating

When a deep body of water cools and a layer of ice forms on top, the floating ice acts as an insulating blanket over the liquid water, allowing life to persist under the frozen surface

If ice did not float, ponds, lakes, and oceans would freeze solid

Solution

A liquid consisting of a homegenous mixture of two or more substances

Solvent

Dissolving agent

Solute

The dissolved substance

Water can dissolve an enormous variety of ____ which is necessary for life

Solutes

Covalent bonds

Sharing of electrons

Acid

A chemical compound that releases H+ to a solution

Base

A compound that accepts H+ and removes them from a solution

What do scientists use to describe the acidity of a solution?

The pH scale, which measures the concentration of hydrogen ions in a solution

pH scale ranges

0 - Most acidic

14 - Most basic

Water is a…

Compound

A compound

A substance consisting of two or more different elements in a fixed ratio

More common than pure elements

The four elements that make up 96% of the weight of most living organsisms are

Carbon, hydrogen, oxygen, nitrogen

Trace elements

Essential, but only in small amounts
Required to prevent disease

Common additives to food and water

Example of trace element

Fluoride- Is added to water and dental products to help reduce tooth decay

Basic unit of an element

An atom

The number of protons equals

The number of electrons

The most outer electron shell is called

The valence shell

What determines the properties of an element/atom?

The number of electrons in the valence shell

The basic unit of an element

An atom

Nucleus and Shells fact

Protons and neutrons are found in the nucleus

Electrons zip around the nucleus in an ELECTRON CLOUD

The number of protons equals the number of electrons

What is the electron cloud formed by?

Shells

Electron shells

1st shell = 2 electrons (full)

2th-7th shell = 8 electrons (full)` v

Organic chemistry

The study of compounds that contain carbon

Alot of compounds contain hydrogen atoms also

Methane

CH4

What is methane produced by?

Methanogens (archaea)

Ethane

C2H6

Ethene

C2H4

Carbon chains form the___ of most organic molecules

Skeletons

They vary in length and shape

How does the structure of a carbon atom allow it to form diverse organic molecules?

Carbon has four valence electrons, which allows it to form four covalent bonds with multiple atoms.

The electron configuration of carbon gives it compatibility with many different elements

3 shapes of carbon skeleton chains

Straight, rings, branching

Hydrocarbon

A compound made up of carbon and hydrogen only

Can undergo reactions that release a large amount of energy

Why don’t hydrocarbons dissolve in water?

Because the great majority of their bonds are relatively nonpolar to carbon to hydrogen linkages (hydrophobic)

Combustion reaction

CH4 + O2 ——> CO2 + 2 H2O

Methane + Oxygen ——> Carbon Dioxide + Water

Ex: Burning coal

Incomplete combustion

4 CH4 + 7O2 —> 2 CO + 2 CO2 + 8 H2O

What causes carbon monoxide poisoning?

CO2 building up in the blood

ATP

Adenosine Triphosphate

Contains Adenine, ribose sugar, and 3 phosphate groups .

How does ATP store energy?

Through bonds

The six groups that are important to chemistry of life

Hydroxyl group

Carbonyl group

Carboxyl group
Amino group

Sulfhydryl group

Phosphate group

Hydroxyl Group

-OH

Compound name: Alcohol

Examples: Ethanol

Carbonyl Group

C=O

Ketone Aldehyde

Ex: Acetone Propenal

Carboxyl Group

-COOH

Carboxylic acid/ Organic acid

Ex: Acetic acid