Structure of Water and Hydrogen Bonding

Water is a __ molecule

Polar

Why is water a polar molecule?

__the ends have opposite partial charges (unequal distribution of charge).__

Hydrogen is a partial ___

positive charge

 oxygen is a partial ____

negative charge

Hydrophilic Substance attracts ____

water

Does water has an affinity for hydrophilic substance?

Yes

Define Hydrophobic Substance

One that avoids water and does not have an affinity for water

What type of bond is Hydrogen

Chemical Intermolecular

When does hydrogen bonding occurs?

When a hydrogen atom bonds to a highly electronegative atom, including oxygen, nitrogen, and fluorine.

Which bonds is weaker? Hydrogen or Covalent

Hydrogen

T or F: Hydrogen bonding is responsible for many molecular properties

True

Give examples of hydrogen bonding responsibility or many molecular properties

The shapes and functions of proteins, the stability of many chemical compounds, and the formation of intermolecular interactions in crystalline solids.

What does hydrogen bonding help water with?

The properties of cohesion, adhesion, surface tension, specific heat, and evaporative cooling.

Define Cohesion

The attraction of water molecules.

__Strong cohesive forces are present because__

 __they form hydrogen bonds with each other.__

Cohesion contributions

The transport of water and nutrients against gravity in plants.

Define Transpiration

__The loss of water from a plant in the form of water vapor.__

Define Adhesion

When one substance is attracted to another. Water adheres to other molecules and surfaces.

Define Surface Tension

Difficulty to break the surface of the water because of cohesive forces.

Example of Surface Tension

water strider insects rely on surface tension to stay afloat and walk on the surface of bodies of freshwater.

Define Specific Heat

The amount of heat energy it takes to raise or lower the temperature of one gram of a substance by one degree Celsius.

Why does water has a high specific heat?

So it can absorb or release a large amount of heat with only a slight change in its own temperature so large bodies of water take a while to evaporate.

Define Evaporative cooling

 Water has a high heat of vaporization, so the water can absorb a lot of heat and leave the surface cooler.

Example of evaporative cooling

Excess body heat is used to convert beads of sweat/perspiration into vapor, which cools down the body.

Define Dissociation of Water

hydrogen shifts from one water molecule to another.

When a molecule is increasing hydronium concentration by releasing hydrogen ions into solutions, it is ______

Acid

When a molecule is increasing hydroxide concentration by absorbing or accepting hydrogen ions, it is a _______

Base

Ph scale range goes from __ to __

0-14

What is (

Acidic

What is (7)?

Neutral

What is (>7)?

Basic

What are organisms are made up of

matter

What does matter do?

takes up space and has mass.

What is matter made up of?

Atoms

Atoms are made up of

__protons, neutrons, and electrons.__

Elements

substances that cannot be broken down further by chemical reactions.

(O)

Oxygen

(C)

Carbon

(H)

Hydrogen

(N)

Nitrogen

(Ca)

Calcium

(P)

__phosphorus__

__(K),__

__potassium__

__(S)__

__sulfur__

__(Na)__

__sodium__

__(Cl)__

__chlorine__

__(Mg)__

__magnesium__

Compounds

substances that can be broken down further by chemical reactions because they are made of two or more elements that are in a fixed ratio to each other.

__H2O__

__made of two hydrogens and one oxygen. Because there is a fixed ratio of hydrogens and oxygen, water is a compound.__

Protons are ____ Charge

Positive

Neutrons are ____ charge

(neutral/no electrical)

Electrons are ____ charge

Negative

atomic number of an element is determined by

the number of protons in the nucleus.

 atomic mass number is the sum of

the protons and neutrons in the nucleus.

element diagram

Isotopes

two atoms of an element that have a different number of neutrons.

Radioactive isotopes are used for

 processes that include fossil dating and medical imaging.

An electron's potential energy (location/structure) is called an

energy level or electron shell

When electrons absorb energy,

When electrons absorb energy,

When electrons release energy

 they move closer to the nucleus.

Carbon

the unique ability to form four covalent bonds which is known as tetra-valence.

The goal for all atoms is to be

Stable

Carbon must find four more electrons to fill its

outer shell

Rule of octet rule

states that atoms will lose, gain or share electrons to achieve an electron configuration of eight valence electrons.

Nitrogen

 a building block in proteins, nucleic acids, amino acids, and enzymes.

Nitrogen is even a component of many hormones, such as

adrenaline and insulin.

Nitrogen plays a role in

balance of nutrients in ecosystems.

Functional groups

Accessory elements that give molecules a different structure, therefore, a different function.

Functional groups can be classified as

hydrophobic or hydrophilic based on their charge and polarity characteristics.

Hydroxyl Group

Hydrogen bonded to Oxygen (OH) attached to the carbon skeleton.

Carbonyl Group

Double bond (sharing of two pairs of valence electrons) between carbon and oxygen.

Amino Group

Nitrogen bonded to two hydrogens and one carbon atom.

What does R represent to

 an unknown part of the molecule that the functional group is attached to.

__Nitrogen is used to__

__build proteins and nucleic acids.__

Phosphate Group

phosphate ion covalently attached to the carbon skeleton.

Sulfhydryl Group

Sulfur bonded to a hydrogen atom.

Carboxyl Group

a combination of carbonyl and hydroxyl where carbon is double-bonded to an oxygen and a hydroxyl.

Covalent

 Sharing of electrons

__single bond__

__sharing one pair of electrons__

__double bond__

 __the sharing of two pairs of electrons.__

Structural formula is represented by

 two lines connecting two atoms.

Electronegativity

the atom's attraction for electrons in a covalent bond.

Ionic

Transfer of electrons/electrostatic attraction between a positive and negative ion.

Metallic bonds

formed by the attraction between metal ions and delocalized, or "free", electrons.

Polymer

a long molecule composed of many molecules bonded together covalently.

Poly means

many

Monomer

are small building block molecules that, when combined, make a polymer.

mono means

one

Nonpolar Covalent bond

The equal sharing of electrons and distribution of charge.

Polar covalent bond

Unequal sharing of electrons and distribution of charge causes partial positive or partial negative for each atom or molecule

InTRAmolecular bond

 __within the molecule__

__InTERmolecular bond__

__between water molecules__

T or F: Hydrogen bonds are NOT covalent bonds

True

Dehydration Synthesis

occurs when monomers combine to form a polymer through a reaction after water is removed.

dehydrate means

water lost

__anabolic__

__small molecules bind together to form larger molecules__

Hydrolysis

occurs when polymers are broken down into monomers through a reaction due to the addition of water.

Macromolecules are large molecules composed of

two or more polymers combined together

Carbohydrates are

Sugars and polymers of sugars