The Chemical Building Blocks of Life

Chapter 3

Why Carbon

• Carbon is the main building molecule of all things on earth because it is able to bond up to 4 different molecules or compounds

Prefixes• Chemicals named based on number of carbons and

types of bonds.

Macromolecules are complex assemblies of molecules

Polymers: long molecular built by linking together smaller units.

How do we break bonds?

Functions of ProteinsFunction Class Examples

Enzyme Catalysis Enzymes Proteases

Defense Cell surface antigens

Antibodies

Transport Circulating transporters + membrane transporters

Hemoglobin,myoglobin

NA/K Pump

Support Fibers Collagen, elastin

Motion Muscle Myosin, Actin

Regulation Hormones Insulin

Storage Ion Binding Ferritin

Amino Acids: The building blocks of proteins

Each Amino Acids Properties are Determined by it’s side group

• 1. Nonpolar amino acids have R groups that contain CH2 or CH3

• 2. Polar uncharged AA’s have R goups that contain oxygen or only H

• 3. Charged AA’s have R goups that contain acids or bases ex HCL or NAOH

• 4. Aromatic AA’s have R groups that contain an organic carbon ring

• 5. Special Function AA’s Methionin- start codonproline- causes kinks, cysteine links chains together.

How to AA’s Make Proteins?

• They bind via peptide bonds forming polypeptides

Four Levels of Protein StructureNotice the Different Motifs of Secondary structure

5 types of bonds that contribute to protein shape

• 1. Hydrogen bonds- O-H

• 2. Disulfide Bridges S-S

• 3. Ionic Bonds- Based on Chare

• 4. Vanderwalls- weak attraction

• 5. Hydrophobic interactions

Chaperone proteins also help in protein folding

How Proteins Unfold

• When bonds are broken proteins will unfold– Caused by:

» High Temperature» Change in pH» Enzymes my cause denaturatuin

• Denaturation vs Dissacociaion- not the same thing!

Nucleic acids store and transfer genetic information

• DNA- deoxyribonucleic acid stores genetic info

• RNA- ribonucleic acid important in transcription– 3 main differences

• DNA is double stranded while RNA is single stranded

• DNA has deoxyribose as the sugar whereas RNA has ribose

• RNA has the nucleotide Uracil in place of Thymine

Structure of DNA

• Double stranded• Has sugar phosphate

backbone• Nucleotides are

bonded with hydrogen bonds

• Double bond C-G, Single A-T

Purines and Pyrimidines

What came first?

• DNA is thought to have evolved from RNA in order to protect and preserve genetic information

Lipids Make Membranes and Store Energy

• Good for long term energy storage.

• Hydrophobic/hydrophilic interactions make bilipid layered membrane

Good Fats vs Bad Fats

• Saturated- has max number of possible Hydrogen atoms- no double bonds ex butter

• Unsaturated- has double bonds ex veggie oil

• Polyunsaturated- has more than one double bond

Carbohydrates: Short term energy storage and building materials

• General Formula for a carbohydrate is CH2O

• Monosacharides- simple sugars ex, glucose, fructose, galactose, ribose, deoxyribose

• Disacharides- 2 monosacharides joined by a covalent bond- dex maltose ( glucose+glucose)

• Polysacharides- more than 2 monosacharides joined together.

Sugar Isomers

• An isomer has the same empirical formula but different structural forms.

Transport

• Most of the sugar we eat are disacharides. Why?

• This allows for better transport

• Less of the important monosacharide is lost in transport when it is joined to another sugar. In our case we get the most glucose possible when it is paired with another sugar.

Storage Polysacharides

• Plants store energy in starches

• Animals store energy in glycogen

Structural Carbohydrates

• Cellulose- found in the cell walls of plants

• Chitin- found in the shells of many arthropods

• These types of carbohydrates are not easily digested.