chemical groups

Hydroxyl group

−OH

Hydroxyl group example

Ethanol, an alcohol found in alcoholic drinks

Hydroxyl group properties

Polar due to electronegative oxygen; forms hydrogen bonds with water which helps dissolve compounds like sugar

Hydroxyl group compound name

Alcohol; specific names usually end in −ol

Carbonyl group

C=O

Carbonyl group example

Acetone is a ketone; propanal is an aldehyde

Carbonyl group properties

sugars with ketone groups (inside carbonyl)= ketoses
sugars with aldehydes groups (end carbonyl) = aldoses

Carbonyl group compound name

Ketone or aldehyde

Carboxyl group

−COOH

Carboxyl group example

Acetic acid, which gives vinegar its sour taste
ionized form of carboxylate has a separate H+ and negatively charged O-
ionized form is found in cells

Carboxyl group properties

Acts as an acid because the O−H bond is highly polar so hydrogen is easily removed by H2O leading to H+ donation

Carboxyl group compound name

Carboxylic acid, or organic acid

Amino group

−NH₂

Amino group example

Glycine, an amino acid with an amino and carboxyl group
When ionized, an extra H+ is attatched, giving the central N+ a positive charge
The ionized form is found in cells

Amino group properties

Acts as a base and can accept H+ from surrounding solutions, like water in living things
all amino acids have an amino group

Amino group compound name

Amine

Sulfhydryl group

−SH

Sulfhydryl group example

Cysteine, a sulfur-containing amino acid

Sulfhydryl group properties

Two −SH groups can react to form a stable cross-link used in protein structure
cross-links also cause straight or curly hair
hair treatments work by breaking these cross-links and reforming them during the right texture/shape

Sulfhydryl group compound name

Thiol

Phosphate group

−OPO₃²⁻

Phosphate group example

Glycerol phosphate, involved in important cell reactions

Phosphate group properties

Contributes negative charge; can be 1− if in the phosphate chain and 2- if at the end fo the chain
when attatched to a molecule it gives the molecule water reactivity which releases energy

Phosphate group compound name

Organic phosphate

Methyl group

−CH₃

Methyl group example

5-Methylcytosine, a modified component of DNA that has a methyl group added

Methyl group properties

Affects gene expression when bonded to DNA or proteins bonded to DNA
affects shape and function of male/female sex hormones

Methyl group compound name

Methylated compound