CH17: CARBOXYLIC ACIDS & THEIR DERIVATIVES

OSU BIOPHRM 3311

What is the functional group structure of a carboxylic acid?

–COOH (carbonyl + hydroxyl group).

Give a simple example of a carboxylic acid.

Acetic acid (CH₃COOH).

Recognize this line structure:

Carboxylic acid.

What is the suffix for carboxylic acids?

-ic acid.

What is the functional group structure of an anhydride?

Two carbonyls (C=O) bonded through an oxygen atom (–CO–O–CO–).

Give a simple example of an anhydride.

Acetic anhydride.

Recognize this line structure:

Anhydride.

What is the suffix for anhydrides?

None.

What is the functional group structure of an ester?

–COOR (carbonyl bonded to –OR group).

Give a simple example of an ester.

Methyl acetate (CH₃COOCH₃).

Recognize this line structure:

Ester.

What is the suffix for esters?

-ate.

What is the functional group structure of an amide?

–CONH₂ (carbonyl bonded to NH₂).

Recognize this line structure:

Amide.

What is the suffix for amides?

-amide.

4 properties of ACIDS

• SOUR

• RED

• rxn w/ some metals to produce hydrogen gas

• rxn w/ bases to form salt & water

4 properties of BASES

• BITTER

• BLUE

• slippery feeling on skin (rxn w/ fats/oils on skin)

• rxn w/ acids to form salt & water (neutralization rxn)

Acid-Base Theories — Summary Chart (KNOW)

Similar to amines, primary, secondary, and tertiary amides are _____, with either ____, ____, or _____.

• carbon atoms directly bound to a N atom

• 1, 2, or 3 Cs, respectively

Common derivates of carboxylic acids are ________.

anhydrides, esters, and amides

O=C-OH is a _______.

carboxyl functional group

O=C-OR is

an alkoxide

ID this structure

acetic acid

ID this structure

acetic anhydride

ID this structure

methyl acetate

ID this structure

acetamide

ID this group

acyl group

ID this group + specific compound’s name

• acetyl group

• acetic acid

ID this group

carbonyl compound

ID this group

carboxylic acid

When an R group bonds to the carbonyl group, it is called _______

an acyl group. R can be H, alkyl, or aryl

An important acyl group in biochemistry is the_____

acetyl group, in which R is a methyl group

Carboxylic acid structural definition

The acyl group bonds to –OH, and after dissociation of H+ becomes carboxylate ion.

Esters structural definition

The acyl group bonds to –OR (Alkoxy group)

Amides structural definition

The acyl group bonds to nitrogen. An amide containing -NH2 group is a primary amide, one with -NHR is a secondary amine, and one with –NR2 is a tertiary amide

Carboxylic acid derivatives are generated through the ___________, including alkoxyl (ester!) and amino groups (amide!)

substitution of the -OH group with different substituents

In substitution reaction, an atom or group of atoms in a molecule is _________.

replaced by another atom or group of atoms

carboxylic acids undergo substitution reactions where _________.

-OH is substituted by another group

ID this reaction

substitution rxn

Carboxylic acids form their derivatives by _________

carbonyl-group, reversible, substitution reactions

Carboxylic acids react with alcohols to form ______

esters and water

The OH in carboxylic acid is substituted by _____.

OR group (ethoxy)

ethoxy definition

instead of alkoxy, with 1 C, this has two Cs.

ID this rxn and the indicated bond

• formation of an ester from carboxylic acid and an alcohol

• ester bond

Carboxylic acids react with ammonia or amines to form ________.

amides

Carboxylic acid reacts with _________ to form secondary amide

primary amine

ID this rxn and the indicated bond

• formation of an amide from a carboxylic acid and ammonia

• amide bond

alcohol general molecular formula

H-OR’

ammonia general molecular formula

NH3

primary amine general molecular formula

R-NH2

secondary amine general molecular formula

H-NR’2

carboxylic acids reacts with secondary amines to form ______

tertiary amides

ester general molecular formula

RCOOR’

primary amide general molecular formula

RCO-NH2

secondary amide general molecular formula

RCO-NHR’

tertiary amide general molecular formula

RCO-NR’2

carbonyl group substitution rxns are also called

acyl transfer rxns b/c the rxn can be considered as the transfer of the acyl group

The reaction involving the replacement of one functional group attached to a carbonyl carbon (C=O) with another is generally called _________.

carbonyl-group substitution reactions

carbonyl-group substitution reaction is ______. Hence the carboxylic acid derivatives can all be ________ to carboxylic acids

• reversible

• hydrolyzed (rxn w/ H2O) back

one of the fuels used by our body for energy is ______.

fatty acids

Before fatty acid can be metabolized, it has to be activated by reacting with ____ to form ______.

• coenzyme A (H-SCoA)

• fatty acyl-CoA

activation of coenzyme A (H-SCoA) is a _____ because the –OH group in carboxylic acid is substituted by coenzyme A

carbonyl-group substitution reaction / acyl transfer reaction (acyl group is transferred to coenzyme A)

_______, such as fatty acyl-CoA and acetyl-CoA, play a crucial role in biochemistry, particularly in metabolic pathways

Thioesters (sulfur bond in thiols or thioesters)

Acid anhydride (or simply anhydride) can be synthesized by _______.

a condensation rxn, w/ high temperature, b/t 2 carboxylic acids.

______ consist of phosphorus atoms in place of the carbon atoms in acid anhydrides

Phosphate anhydrides

phosphate anhydrides contain ______ bonds, which are high-energy bonds (energy released when broken) present in molecules like ATP.

phosphoanhydride

Similar to acid anhydrides, phosphate anhydrides are formed from the _______.

condensation reaction of two phosphate groups

_________ are also vital for various biochemical processes, including energy metabolism and genetic information storage

Phosphate esters and diesters

Carboxylic acids are a family of organic compounds that contain one or more ________

carboxyl functional group (-COOH)

The carboxyl functional group is so-named because it contains the _____

carbonyl group (-C=O) and a hydroxyl group (-OH)

In the carboxyl group, the carbonyl carbon is bonded to:

1. An _____ atom by a double bond,

2. A ______ by a single bond;

3. A ______ by a single bond.

1. oxygen

2. hydroxyl group (-OH)

3. hydrogen atom or a hydrocarbon chain (R, straight chain saturated or unsaturated, a ring or aromatic)

With two electronegative oxygen atoms, the carboxyl groups are highly _______

polar, with three polar covalent bonds

Alcohol behaves differently depending upon if it is bound to ____

carboxyl group vs. alkyl group

Carboxylic acids have a general formula _________

R-COOH, where R can be a hydrogen, derived from alkane, alkene, aliphatic or cyclic, or aromatic

A _____ may contain more than one carboxyl groups

carboxylic acid compound

Succinic acid has _____ carboxyl groups and citric acid contains _____ carboxyl groups

• two

• three

ID this by its common and IUPAC names and know its major source: HCOOH

• Common: formic acid

• IUPAC: methanoic acid

• Major source: ants (L. formica)

ID this by its common and IUPAC names and know its major source: CH3COOH

• common: acetic acid

• IUPAC: ethanoic acid

• major source: vinegar (L. acetum)

ID this by its common and IUPAC names and know its major source: CH3CH2COOH

• common: propionic acid

• IUPAC: propanoic acid

• major source: milk (Gk. protus prion)

ID this by its common and IUPAC names and know its major source: CH3CH2CH2COOH

• common: butyric acid

• IUPAC: butanoic acid

• major source: butter (L. butyrum)

fatty acids commonly have ______ carbons

12—24

dicarboxylic acids general molecular formula

HO2C-(R)-CO2H

Dicarboxylic acids contain ____ carboxylic groups

two

________ is the stinging toxin in ant bites

Formic acid

ID this: H2C=CHCOOH

acrylic acid

ID this: CH3CH=CHCOOH

crotonic acid

ID this

benzoic acid — simplest aromatic carboyxlic acid

ID this

salicylic acid - or 2-hydroxybenzoic acid (IUPAC name), a reactant that forms aspirin

biological functions of this compound: fatty acids

energy source

biological functions of this compound: amino acids

make proteins

biological functions of this compound: citric acid

Intermediate in the citric acid cycle (KREBS), reducing NAD and FAD to generate energy

NADH/H+ is the _____ agent, and NAD is the _____ agent

• reducing

• oxidizing

fatty acids yield more energy per gram basis than ________

carbohydrates

Polyunsaturated fatty acids = _____

contains more than 1 C=C

Monounsaturated fatty acids = ______

contains 1 C=C

in a polyunsaturated fatty acid chain the C=C are always ____.

3 Cs apart

_______ are building blocks of proteins

Standard amino acids

four groups contain in an amino acid

1. amino group, NH2

2. carboxyl group, COOH

3. a hydrogen, H

4. an R group, or side-chain that makes each amino acid unique

_____ is the smallest amino acid, w/ 2 Hs, 1 NH2, and 1 COOH

Glycine

________ is the second smallest amino acid, w/ 1 methyl group, 1 H, 1 NH2, and 1 COOH

Alanine