The Chemical Foundation of Life

What type of building blocks establish is the foundations of life?

Cells

Cells

Individual livimg units of any organism

Chemicals role in body

Break down cells even further and they are highest organized assembles of non-living molecules

Which atoms make up humans mostly?

Carbon and oxygen

What is significant about carbon?

It is a key element that organic organisms possess (carbon=organic)

What example of matter cannot be dissected into anything else (the smallest form)?

Elements

The 4 main organic elements

Carbon, hydrogen, nitrogen and oxygen

The 2 lesser organic elements

Phosphorus and sulfur

Supplementary organic elements (3)

Sodium, magnesium and calcium

Atomic number

the number of protons in the nucleus of an atom

Upper left corner

Nucleus

Center of an atom; contains protons and neutrons

How is energy illustrated in subatomic particles?

Protons and neutrons move little and this have low energy

Electrons orbit and fly around so they have very high energy

Atoms represent matter and energy

Isotopes

Versions of atoms of a particular element with alternate numbers of neutrons in their nuclei

Are isotopes stable or unstable?

Some are stable but the majority are unstable

•they decay/split apart into smaller atoms and/or subatomic particles

What is special about the decay of isotopes?

When they split apart it releases energy which can be harnessed and used

Mass number

the sum of the number of neutrons and protons in an atomic nucleus (bottom number)

Atomic mass

The average mass of all the isotopes of an element

How do geologists and archaeologists use the decay it isotopes?

They use it to date materials radiometrically

Ex: Unstable isotopes of carbon in uranium are used for dating the fossilized remains of organisms

How do physicists and engineers use unstable isotopes?

Due to the isotope generating energy it can generate large quantities of electricity in nuclear fission reactors and can be used for studying the origins of the universe

Neils Bohr's model of an atom

A model that places an atoms electrons into a series of concentric shells surrounding the nucleus

Shells closed to the nucleus...

Are lower in energy and the ones further away because they collect electrons first

How do electrons fill the shells?

In order of increasing energy by occupying the lowest energy shells first

How do photons effect the electron shells?

A photon can boost an electron in to a higher shell, this excited state electron is unstable and returns to its ground state by releasing a photon of light

How do plants use photons of light to produce energy?

Plants collect energy photons enter the cells and dislodges the electron. This energy can be transformed into bio luminescence or energy in photosynthesis.

Electron configuration of atoms

The number of electrons in each of an atoms electron shells

Valence shells

The outermost energy shell of an atom, containing the valence electrons involved in the chemical reactions of that atom (dictate the chemical properties and interaction)

•does not always have to be filled

What occurs when the valence shell is not filled?

The atoms are likely to gain or lose electrons to achieve a stable electron configuration (this is what dictates its chemical properties)

Could researchers find the exact position of an atoms? Why?

No, Due to the complexities of the speed of light

Quantum mechanics and electrons

Says the positions of electrons form some shelves that determine the overall shapes of atoms

•Gives a shape where an electron can exist at a certain time

What can one tell from the shape of an atoms subshell?

The shapes of the molecules it may form with other atoms

What is important about a molecules shape/structure?

It can be used to find it's related function

chemical bonds occur when...

Two atom, interacting through their valence electrons, from an association that is energetically more stable than it is for the atoms to be apart

What is the result when two atoms bond?

Molecule

What are the two types of molecular bonds?

Ionic bonds and covalent bonds

Why do hydrogen bonds, van der Waals forces, and electrostatic interactions not apply to the same category of bonds?

Because they are intermolecular proceses

Ionic bonds occur between...

Metal and nonmetal atoms that effectively transfer an electron from the former to the latter

The atom that donates an electron (ionic bond)

Cation (positively charged)

•one less electron than protons

The atom that receive an electron

Anion (add -ide to the end; negatively charged

•one more electron than protons

What kind of relationship to ionic bonds have?

There's is very short term, one atoms donates and electron and the other accepts it

•this creates a full valence shell for both atoms, they are more stable when by itself

Covalent bonds occur when...

Atoms fill their valence shells by sharing one or more pairs of electrons

How and why is water formed?

Oxygen has 6 electrons

Hydrogen has 1 electron

•in order to gain a full valence shell, the oxygen atoms will share an electron with two hydrogen atoms

•now each atom has a full valence shell and is more stable than before

Why doesn't hydrogen lose and electron and form ionic bonds?

It would make the atom too unstable, it's properly is to share

What occurs between the pull of an oxygen atom and the two hydrogen atoms?

Oxygen has more protons than either of the hydrogens (6 v 1), this means that oxygen has a greater pull on the electrons than hydrogen has (opposites attract)

•therefore electro negativity exists higher on the oxygen side and oxygen has a tendency to be in a negative state

•hydrogen has tendency to be in a positive state/charge

H2O functions like a magnet

Electronegativity

The attraction of an atoms nucleus for the shared electrons in a covalent bond

(Larger atoms are more electronegative than smaller ones)

What are the two types of covalent bonds

nonpolar and polar

nonpolar covalent bond example

Two oxygen atoms forming a covalent bone, each tugs on the electrons an equal amount

•electrons are an equal distance from the nuclei of both atoms

Polar covalent bond example

A bond is formed between potassium and fluorine atoms

•fluorine atom has a stronger pull on the electrons and thus has a partial negative charge

•potassium has less of a pull on the electrons and thus has a partially positive charge

What determines a molecules overall polarity?

The shape and arrangement of polar and nonpolar covalent bonds

When two water interact, what happens?

They attract one another, the negative side bonds with a positive side of another water molecule and vice versa

•this creates stability

Which types of molecules will water interact well with?

Other polar molecules (such as salt or sugar)

Rule electrostatic relationships

Opposites will attract and therefore charges of opposites will attract and re-orient themselves to keep stable and

Behavior of molecules with respect to their polarity/nonpolarity?

Likes will interact

•non polar will interact with nonpolar

•polar will interact with polar

solid water is ______ dense than liquid water

less (ice floats)

Water is an excellent _____ for polar molecules and ions

Solvent (most molecules are polar)

What gives molecules of water it's strong surface tension?

Cohesion between the molecules (this is how things walk on water)

Cohesion

Attraction between molecules of the same substance

Adhesion

An attraction between molecules of different substances

This facilitates capillary action within thin tubes between water molecules and other materials

Adhesion (when water pulls on glass to make the U shape)

Does water have a high or low specific heat?

high specific heat, due to the great cohesion between water molecules there needs to be a lot of energy to drive them apart

What happens when table salt is placed in water?

Table salt has an ionic bond and thus interacts with water (a polar molecules)

•water surrounds the cations and anions and breaks a part their ionic bonds (water is stronger)

•the polar associations between ions are broken and the water molecules surround each ion

What is the terminology for when salt dissolves in water?

The sodium and chloride ions dissociate you produce an aqueous solution

What are the ions?

Solutes (the thing being dissolved)

What is the water?

Solvent (doing the dissolving)

Solution

A homogeneous mixture of two or more substances

Does table sugar dissolve in water Im the same manner as table salt?

Sugar is sucrose and this molecule has a covalent bond (C12H22O11)

•water is not strong enough to completely break down all the bonds, therefore sucrose molecules still remain in water

pH scale

Reflects the concentration of hydrogen ions (H+) in an aqueous solution

Acids

Contain high concentrations of H+ ions in solution

What happens when acids interact with biological molecules (proteins and lipids)?

Acids are capable of adding hydrogen ions

Where are acids on the pH scale?

0-7

Bases

Contain low concentrations of H+ ions in solution

What happens when bases are mixed with biological molecules?

They steal ions (H+)

Where are bases on the pH scale?

8-14

What happens to biological molecules that are altered by string acids and bases?

It messes up ionic compounds

Why is carbon an important element for life?

Carbon has 4 electrons in its valence shell, therefore it can share a covalent bond with up to 4 other atoms (and itself)

•it produced a very diverse set of covalent bonds with just a single atom

•it's structure is very diverse and so is its function

Any molecule with carbon structure is called...

Organic molecule

In molecular geometry, what does each line represent?

2 electrons/electron pair

Methane + molecular geometry

CH4

Tetrahedron = very distinct shape, takes up space as well

organic chemistry

The study of carbon containing molecules

Functional groups

chemical groups attached to carbon skeletons that give compounds their functionality

•these are the patterns of organic molecules

benzene ring (phenyl) (how to interpret)

Although not labeled, it is solely made up of carbon and hydrogen

•Each point represents a carbon atom

•each line represents a covalent bond

•parallel lines are double bonds

•every bonding position necessary to make carbon full is taken up by a hydrogen

Alcohol group

hydroxyl group

•carbon atom bound to oxygen and hydrogen

Ketone group

A chemical group consisting of a carbon double bonded to oxygen (must be in middle of chain)

•sugar

Amine + amide contain...

Nitrogen

What forms organic molecules?

Long chains of carbon atoms