The Molecules of Cells

Introduction to Organic Compounds When it comes to molecules in cells, carbon often takes center stage Carbon based molecules are called organic compounds Reminder - Carbon has 4 valence electrons in a shell that holds 8 It can have 4 bonds

Introduction to Organic Compounds Molecules that are composed of carbon and hydrogen are called hydrocarbons There are many different varieties of hydrocarbons and they all have different roles to play in a cell The most important thing to remember is that the structure of the hydrocarbon dictates its function

The Keys To Cells There are a few groups of molecules that play a pivotal role in how biological molecules operate These are the parts of biological molecules that interact the most with the cell and other molecules These functional groups are particularly important to understand how a cell works

The Keys To Cells The functional groups are often attached to a carbon chain Because of their overall structure they have the ability to be polar Polar molecules have a partial charge and can attract positive and negative molecules or ions

The Keys To Cells When molecules are polar they can be hydrophilic Hydrophilic (water loving) Hydrophobic (water fearing)

Functional Groups We are going to now list the six main functional groups for this course Follow along with your flash cards They will greatly aid your understanding of these functional groups

Functional Groups Hydroxyl Group – consists of a hydrogen atom bonded to an oxygen (which is bonded to a carbon skeleton) Names - Any molecules containing this are considered to be alcohols

*Fun fact* Sugars contain carbonyl and hydroxyl groups Functional Groups Carbonyl Group – a carbon atom is linked to an oxygen by a double bond and the carbon skeleton Names – If at the end of the skeleton it is called an aldehyde, if it is in the middle of a group it is called a ketone *Fun fact* Sugars contain carbonyl and hydroxyl groups

Functional Groups Carboxyl Group – consists of a carbon double bonded to an oxygen atom and also bonded to a hydroxyl group Names – Compounds with a carboxyl group are called carboxylic acids

Functional Groups Amino Group – Has a nitrogen bonded to two hydrogens and the carbon skeleton Names – Organic compounds with an amino group are called amines

Functional Groups Phosphate Group – consists of a phosphorous atom bonded to four oxygen atoms Name – the phosphate group is often given the abbreviation “P”

Functional Groups Methyl Group – consists of a carbon bonded to three hydrogens Name – compounds with a methyl group are considered methylated compounds