part 1. δ + δ - water molecules are polar covalent bonds. biochemistry: the unique properties of...

Part 1

δ +

δ +

δ -

Water molecules are polar covalent bonds.

Biochemistry: The unique properties of water

They are attracted to other water molecules through relatively weak Hydrogen bonds.

Can water form ions?Yes, at a very small rate (1 out of 500,000,000!)

H2O H+ OH-+

+ -

How would you quantify (count) this ionic disassociation? The pH scale

The “powerpower of HydrogenHydrogen” scale

pH

Biochemistry: The unique properties of water

Stomach Acid, lemon juiceVinegar, cola

Tomato juice

Black coffee; RainwaterUrine

Pure water; Human blood

Seawater

Milk of magnesia

Household ammonia

Household bleach

Oven cleaner

Incr

easi

ngly

Aci

dic

Inc

reas

ingl

y B

asic

Neutral

<[H+] >[OH-]

[H+] = [OH-]

>[H+] <[OH-]

Worksheet

• Do Properties of Water (pg 42)

Part 2

Besides water, what elements and compounds are essential to life?

Organic compounds1. Mostly contain Carbon, Hydrogen, Oxygen,

Nitrogen, Phosphorus and Sulfur*Carbon

C CC CC C

H

H HH

H HH

OHO H

HHHO O

O

O

Organic Compounds: An Overview

Organic compounds (continued…)2. Four categories of organic compounds:

a. Carbohydrates

b. Lipids

c. Proteins

d. Nucleic Acids

3. All formed and separated in similar waysa. Formation (Polymerization): Dehydration

Synthesis

b. Separation: Hydrolysis

Hey Sugar, I sure am happy that you’re a Carbohydrate

like me.

Awww, how sweet!

Hurry up, Lipids! You should have more energy

stored up than this!

Does this bond structure make

me look fat?

Hi there! My name is Polly

Peptide.

Can you believe that each of your cells contains

about 2 meters of me?

Organic Compounds: Carbohydrates

Polymerization

• Polymerization (definition):– Forming of large organic macromolecules by

the joining of smaller repeating units called monomers

Bonding: Polymerization

Worksheet

• Polymerization page 44 (use the next two slides)

Dehydration Synthesis

• Dehydration Synthesis is the removal of a water molecule to form a new bond.

HOH

H2O

HO H

HHO

Short Polymer Monomer

Dehydration removes a water molecule forming a new bond

1 2 3

1 2 3 4

Bonding: Polymerization: Dehydration Synthesis

Hydrolysis

HOH

H2O

HO

H

H

HO

Short Polymer Monomer

Hydrolysis adds a water molecule to break a bond

1 2 3

1 2 3

4

• Polymers are broken by adding water.

• Literally, “Water Splitting”

Bonding: Polymerization: Hydrolysis

C CC CC C

Carbon = The element of life

• Carbon’s Valence has ____ electrons

• Can bond with ____ elements

• Can form chains, rings, branches, & isomers

44

CCHO

OHH

HCC

HO OH

H H

Bonding: Carbon

Lipids

• A lipid is any molecule that DOES NOT mix with water.

• Lipids function in:– Energy (E) storage, – forming cell membranes, – and as chemical messengers

(e.g., hormones)

• Nonpolar (hydrophobic)• Made up mostly of Carbon and Hydrogen (with

a few Oxygen)

Organic Compounds: Lipids

Lipids1. Fats (Triglycerides)

– Glycerol + 3 Fatty Acids– Saturated = No Double Bonds (solid)– Unsaturated = Double Bonds (liquid)

Organic Compounds: Lipids: Fats

OH

OH

OH

OH

OH

OH

Ester Bonds

Lipids2. Phospholipids

– Glycerol with Phosphate Head + 2 Fatty Acid Chains

– Amphiphilic (“Both” “lover”)• Hydrophilic head• Hydrophobic tail

– Forms 2 layers in water– Makes up cell membranes

Organic Compounds: Lipids: Phospholipids

Phosphate

Glycerol

Fatty Acids

Organic Compounds: Lipids: Sterols

Lipids

OH

O

Testosterone

HO

O

Estrogen

3. Sterols– Lipids whose Carbon Skeleton consists of 4

fused rings– Includes:

• Hormones• Cholesterol• Cortisol

– Makes up cell membranes

HOOH

O

O

OH

Lipids Review Worksheet

• Lipids and phospholipids—page 58-59