A&P CH2 PG11

Polar or Nonpolar?:

NH3 (Ammonia)

Polar

What makes NH3 polar?

1. Nitrogen is Highly Electronegative

2. N-H Bonds are Polar Covalent

3. The molecule is asymmetrical

4. Results in partial charges

Polar or Nonpolar?:

C4H10 (Butane)

Nonpolar

Why is C4H10 Nonpolar?

1. It contains C-C and C-H bonds

2. C-H bonds are mostly nonpolar

3. The molecule is symmetrical

Polar or Nonpolar?:

O2 (Oxygen Gas)

Nonpolar

Why is O2 Nonpolar?

1. Two identical atoms

2. Electrons shared equally

3. No partial charges

Polar or Nonpolar?:

H2O

Polar

Why is H2O polar?

1. oxygen is highly electronegative

2. O-H bonds are Polar Covalent

3. Molecule is a bent shape that creates unequal charge distribution

For this A&P class, the following will be classified as Polar:

1. Proteins

2. Sugars

These dissolve well in water

For this A&P class, the following will be classified as mixed polarity:

Amino Acids

1. Some are polar

2. Some are Nonpolar

3. Protein structure depends on this balance

For this A&P class, the following will be classified as Nonpolar:

1. Fats (Lipids)

2. Carbon dioxide (CO2)

These do not dissolve well in water.

Why is it important to classify compounds as Polar or Nonpolar?

Because polarity determines

1. Solubility

2. Transport across membranes

3. How chemicals behave in cells

4. Where substances accumulate in the body

What is a solution?

A mixture where substances are evenly distributed in a liquid.

What is an example of a solution?

Blood plasma

What is a solvent?

The substance that usually does the dissolving.

What is an example of a solvent?

Water

What is a Solute?

The substance being dissolved

What's an example of a solute in blood?

1. Salts

2. Sugars

3. Proteins

4. Ions

What is the “Like Dissolves Like” Principle?

Polar substances dissolve in polar solvents

Nonpolar substances dissolve in Nonpolar solvents

Is water a Polar or Nonpolar solvent?

1. Water has polar covalent bonds

2. Water is a polar solvents

Substances that dissolve in water usually have ____ _____ ____ or ____ ______

1. Polar covalent bonds or

2. Ionic bonds

Why does sugar dissolve in water?

• Sugar is polar

• Water is polar

Hydrogen bonds form between sugar and water

Does salt dissolve in water?

Yes

Why does salt dissolve in water ?

• Salt (NaCl) is ionic

• Water stablaizes Na+ and Cl– ions

• Water's polarity pulls ions apart

Do most proteins dissolve in water?

Yes

Why do most proteins dissolve in water?

• Proteins are classified as polar

• They contain many charged and polar regions

Which substances dissolve in fat

Nonpolar substances

Will sugar dissolve in fat?

No

Why does sugar NOT dissolve in fat?

• Sugar is polar

• Fat is nonpolar

Will salt dissolve in fat?

No

Why does salt NOT dissolve in fat?

• Salt is ionic

• Fat cannot stabilize ions

Will most proteins dissolve in fat?

No

Why do most proteins NOT dissolve in fat?

Proteins are mostly polar

What DOES dissolve in fat?

1. Lipids

2. Fat-soluble vitamins

3. Nonpolar molecules

What is a hydrogen bond?

A weak attraction between

• A partially positive hydrogen atom

• A partially negative atom (usually oxygen or Nitrogen)

How do water molecules attract each other via hydrogen bonds?

• Oxygen has a partial negative charge

• Hydrogen has a partial positive charge

Why are hydrogen bonds important?

They are important because it gives water its:

• Temperature regulation ability

• high heat capacity

• ability to dissolve polar substances

• cohesion and adhesion

• it's essential for life

Polar or nonpolar molecule:

An equal electron sharing

Nonpolar molecules

Polar or nonpolar solvent:

Water

Polar solvent

T/F: polar substances dissolve in nonpolar solvents

False