biob111 sn09 lecture propertiesfunctgroups overview part 1: exploring carbonyl containing functional...

Functional GroupsAldehydes, Ketones, Carboxylic acids,

Esters and PhenolsBIOB111

CHEMISTRY & BIOCHEMISTRY

Session 9

Key concepts: session 9From this session you are expected to develop an understanding of the following concepts:

Concept 1: Carboxylic acids behave like an acid

Concept 2: Ketones resist oxidation

Concept 3: Alcohol breakdown

Concept 4: Alcohol breakdown reactions

Concept 5: Alcohol breakdown in individuals of Asian decent

Concept 6: Esters within triacylglycerol (TAG)

Concept 7: Esters hydrolysis

Concept 8: Phenol groups are present in antioxidants

Concept 9: Consequence of too few antioxidants

These concepts are covered in the Conceptual multiple choice questions of tutorial 9

Session OverviewPart 1: Exploring carbonyl containing functional groups

• Hydrocarbon derivatives

• The carbonyl group

• Chemical properties of ketones

• Chemical properties of aldehydes

• Chemical properties of carboxylic acids

Part 2: Redox reactions involving functional groups

• Redox reactions

• Breakdown of alcohol in the liver

Part 3: Exploring the ester and phenol functional groups

• Chemical properties of esters

• TAG contains ester connections

• Chemical properties of phenols

• Free radicals

Part 1: Exploring carbonyl containing functional groups

• Hydrocarbon derivatives

• The carbonyl group

• Chemical properties of ketones

• Chemical properties of aldehydes

• Chemical properties of carboxylic acids

Hydrocarbon derivatives

Life on earth would not exist without organic compounds that contain carbon atoms

• Our genetic material (DNA) contains many carbon atoms

• Our bodies rely on the organic compounds below to function:

– Proteins are made up of amino acids

– Lipids are often made up of fatty acids (long hydrocarbons) and glycerol

– Carbohydrates are made up of one or more monosaccharide (sugar) units


Hydrocarbon derivatives are:

• Hydrocarbon compounds that contain atoms such as oxygen, nitrogen, fluorine or chlorine as well as carbon and hydrogen atoms

– The location within the hydrocarbon derivative that has atoms other than just carbon and hydrogen is where the functional group is located

Ethanol: present in alcoholic beverages

Alcohol

What are functional groups?– A functional group is a group of atoms within a compound that provides chemical reactivity

• The functional group is usually the part of the compound that is involved in chemical reactions

• All compounds with a particular functional group will behave similarly in chemical reactions

– To find a functional group within a compound,

look for atoms other than just carbon and hydrogen atoms

Alcohol


Ethanol: present in alcoholic beverages

The carbonyl group• Carbonyl group:

– A carbonyl group is made up of a carbon atom that forms a double bond to an oxygen atom

• The carbon atom within the carbonyl group must form chemical bonds to two other atoms or groups of atoms to be stable

– Carbon atoms form 4 covalent bonds

to gain 8 valence electrons

– A carbonyl group is not a functional group

• The carbonyl group is present in many functional groups

Carbonyl Group

The carbonyl group• The carbonyl group is present in many functional groups:

– Aldehyde

– Ketone

– Carboxylic Acid

– Ester

– Amide

Aldehyde Ketone Carboxylic acid Ester Amide

Carbonyl Group

Chemical properties of ketones

Functional Group: Ketone

Functional group formula:

Naming convention: Ketone compounds have –one at the end of their

name e.g. propanone

Example compound:

Propanone

R COThe ketone

functional group is a carbonyl attached

to two R-groups

R

The ketone functional group is located in the

middle of compounds, as it contains two R-groups


PROPANONE: Commonly known as acetone

– Acetone is found in paint and nail polish removers

– Acetone is a ketone body which is created

when acetoacetate (produced via ketogenesis)

breaks down

• The “sweet” odor of acetone can be detected on

the person’s breath who is in a state of ketosis

Propanone


Steroid Hormones

– Steroid hormones such as testosterone, progesterone and cortisone (can

be converted to cortisol) contain the ketone functional group

Stoker 2014, p476

Chemical properties of aldehyde

Functional Group: Aldehyde


Naming convention: Aldehyde compounds have –al at the end of their

name e.g. propanal

Example compound:

Propanal

The aldehyde function group is a carbonyl

attached to a hydrogenR CHO

The aldehyde functional group is located at the

end of a compound (or a branch point), as it

contains one R-group

Chemical properties of aldehyde

Methanal

– Methanal is commonly known as formaldehyde• Dissolved in solution to preserve biological

specimens e.g. cadavas

– Formaldhyde is a carcinogen and teratogen (causes birth defects)

• Present in tobacco smoke

• Exposure triggers burning, nausea, difficulty breathing and asthma attacks

– Many other aldehyde compounds exist that contain more carbon atoms

• Ethanal (2 carbon atoms)• Propanal (3 carbon atoms)

Methanal aka formaldehyde

https://www.freeimages.com/photo/cigarettes-1316382

Chemical properties of carboxylic acid

Functional Group: Carboxylic acid


Naming convention: Carboxylic acid compounds have –oic acid at the

end of their name e.g. propanoic acid

Example compound:

Propanoic acid

The carboxylic acid function group is a carbonyl attached

to an OH group

R COOH

The carboxylic acid functional group is located at the end of a compound (or a branch point), as it

contains one R-group


Common carboxylic acid containing compounds

Chemical name:Methanoic acid

Common name:Formic acid

Found in:Bee stings

Chemical name:Ethanoic acid

Common name:Acetic acid (acetate)

Found in:Vinegar Part of acetyl CoA

Chemical name:Butanoic acid

Common name:Butyric acid

Found in:Off butter

https://www.freeimages.com/photo/bee-1173616

Copyright © 2007 by Pearson Education, Inc.Publishing as Benjamin Cummings

https://www.freeimages.com/photo/butter-1-1328166

Conjugate base of ethanoic acid

Ethanoic acid Hydronium ion

• Carboxylic acid compounds are weak acids– Donate their H+ to a base compound ~5% of the time

• Below is an example of how a carboxylic acid compound behaves in an acid-base reaction

H2O+ H3O++



+

Once ethanoic acid donates its H+ to H2O, the oxygen that was previously attached to the H+ becomes negatively charged within the conjugate base compound. H2O is converted into the hydronium ion (H3O+) which is the conjugate acid.

Animation of a carboxylic acid donating H+ in an acid-base reaction

CHH

C OH

OH

H2OH+

O- H3O+

Ethanoic acid

Conjugate base of ethanoic acid

Hydronium ion


• Hydrocarbon derivatives– Hydrocarbon derivatives are compounds that contain atoms such as oxygen,

nitrogen, fluorine or chlorine as well as carbon and hydrogen atoms

• The carbonyl group– A carbonyl group is made up of a carbon atom that forms a double bond to an

oxygen atom

– While the carbonyl group itself is not a functional group, it is part of many functional groups including the aldehyde and ketone groups

• Chemical properties of ketones– The ketone functional group is a carbonyl attached to two R-groups

– The ketone functional group is located in the middle of compounds, as it contains two R-groups

– Ketone containing compounds have –one at the end of their names e.g. propanone


• Chemical properties of aldehydes– The aldehyde functional group is a carbonyl attached to a hydrogen

– The aldehyde functional group is located at the end of a compound (or a branch point), as it contains one R-group

– Aldehyde containing compounds have –al at the end of their names e.g. propanal

• Chemical properties of carboxylic acids– The carboxylic acid functional group is a carbonyl attached to an OH group

– The carboxylic aicd functional group is located at the end of a compound (or a branch point), as it contains one R-group

– Carboxylic acid containing compounds have –oic acid at the end of their names e.g. propanoic acid

– Carboxylic acid groups behave like weak acids, donating their H+ ~5% of the time to a base


• Redox reactions


Redox reactions

Combustion reactions are the most common type of chemical reaction

– Combustion reactions always involve a substance reacting with oxygen

– When organic hydrocarbons like methane (CH4) combust:

• Water, carbon dioxide and energy (light and heat) are produced

– All combustion reactions are

redox reactionshttp://www.chem.ucla.edu/harding/IGOC/C/combustion.html

https://www.freeimages.com/photo/fire-1495233

CH4 + 2O2 → CO2 + 2H2O + energy

Electrons H atoms O atoms

OXIDATION Loss of electrons Loss of H atoms Gain of O atoms

REDUCTION Gain of electrons Gain of H atoms Loss of O atoms

OXIDATION: Loss of 1 or more hydrogen atoms

REDUCTION: Gain of 1 or more hydrogen atoms

H1p+

1e-

Redox reactions

• Oxidation and reduction are complementary processes– Oxidation and reduction occur simultaneously because the compound that

loses hydrogen (oxidation) donates it to another compound which accepts the hydrogen (reduction)

• Losing or gaining hydrogen atoms is equivalent to losing or gaining electrons – Each hydrogen atom contains 1 electron (and 1 proton)

• In a redox reaction, electrons and/or hydrogen atoms are transferred from one compound to another

OIL RIG useful to remember what happens in a redox reaction:

Oxidation Is Loss of electrons and/or hydrogen atoms (OIL)

Reduction Is Gain of electrons and/or hydrogen atoms (RIG)

Redox reactions

Redox reactions

• In a redox reaction, one reactant is oxidised and one is reduced

• To determine which reactant is oxidised and which is reduced:– Assess how each reactant changes during the chemical reaction by looking at

the products

• The reactant that has lost hydrogen to become the product has been oxidised

• The reactant that has gained hydrogen to become the product has been reduced

CH4 2O2+ 2H2OCO2 +CH4 loses hydrogen = oxidised

O2 gains hydrogen = reduced

Redox reactions

• In a redox reaction, one reactant is oxidised and one is

reduced

Biological molecule loses 2 hydrogens = oxidised

Coenzyme gains 2 hydrogens = reduced

Adapted from Timberlake 2013, p223-224

• Redox reaction are vital to many

metabolic pathways required to

generate cellular energy (ATP)

including:

– Glycolysis

– Citric acid cycle

– The electron transport chain

– Also required to breakdown alcohol in

the liver

• The coenzymes that are commonly

used in redox reactions (within

metabolic pathways) can exist in either:– An electron/hydrogen rich form

– An electron/hydrogen poor form

Electron poor coenzymes

Electron rich coenzymes

NAD+ NADH

NADP NADPH

FAD FADH2

Adapted from Timberlake 2013, p223-224

Redox reactions

Malate-H + NAD+ → Oxaloacetate + NADH

• Malate-H loses hydrogen to become oxaloacetate, hence

Malate-H is oxidised

– Oxidation is loss of hydrogen/electrons

• NAD+ gains hydrogen to become NADH, hence NAD+ is reduced

– Reduction is gain of hydrogen/electrons

Malate-H loses hydrogen = oxidised

NAD+ gains hydrogen = reduced

Redox reactions

Redox reactions

Ketones cannot be oxidised in a redox reaction

– The Ketone group does not contain any hydrogen atoms that can be lost via an oxidation reaction

Oxidised

Aldehyde compound

Carboxylic acid compound

Aldehydes are readily oxidised in

a redox reaction

– The aldehyde group contains a

hydrogen atom which can be lost

via an oxidation reaction

Resists oxidation

Ketone compound

Attempt Socrative questions: 1 and 2

Google Socrative and go to the student login

Room name:

City name followed by 1 or 2 (e.g. PERTH1)

1 for 1st session of the week and 2 for 2nd session of the week

ETHANOL CONSUMED IN AN

ALCOHOLIC BEVERAGE

Once in the blood

CREATE CELLULAR ENERGY (ATP) IN THE

COMMON METABOLIC PATHWAY

ETHANOIC ACID (ACETATE) IS THE LAST PRODUCT OF ALCOHOL

BREAKDOWN

ETHANOL IS TRAFFICKED TO THE LIVER TO BE

BROKEN DOWN VIA TWO REDOX REACTIONS

Breakdown of alcohol in the liver

Used to

ACETYL COA

ResultConverted to

Breakdown of alcohol in the liver• Once in the liver ethanol is broken down

via two redox reactions

– Frist redox reaction:

The oxidation ethanol (alcohol) generates acetaldehyde (aldehyde)

– Second redox reaction:

The oxidation acetaldehyde (aldehyde) generates acetate (carboxylic acid)

Ethanol Acetaldehyde Acetate

Redox reaction 1

Redox reaction 2

Alcohol functional group

Aldehyde functional group

Carboxylic acid functional group

Breakdown of alcohol in the liverFirst redox reaction in the breakdown of alcohol:

Ethanol is readily oxidised to acetaldehyde in a redox reaction

facilitated by the alcohol dehydrogenase enzyme

– The alcohol functional group is oxidised to an aldehyde group• The OH group in ethanol loses its hydrogen atom, resulting in the

oxygen atom forming a double bond to the carbon atom

+ NADH +NAD+

Ethanol

Acetaldehyde (ethanal)

NAD+ gains hydrogen = reduced

Ethanol loses hydrogen = oxidisedAldehyde

groupAlcohol

dehydrogenase


Ethanol loses two hydrogen atoms (oxidised) which are accepted by NAD+ (reduced). NAD+ becomes NADH by accepting the hydrogen atoms. After being oxidised ethanol becomes acetaldehyde.

Animation of the first alcohol breakdown reaction

H C

H

C

O

H

H

H

+ NAD+

H

NADH

Ethanol

Acetaldehyde

Electron poor coenzyme

Electron rich coenzyme

Breakdown of alcohol in the liverSecond redox reaction in the breakdown of alcohol:

Acetaldehyde is readily oxidised to acetate in a redox reaction

facilitated by the acetaldehyde dehydrogenase enzyme

– The aldehyde functional group is oxidised to a carboxylic acid group• The hydrogen atom within the aldehyde group is lost before being

replaced by an OH group from H2O

+ NADH +NAD+

Acetaldehyde (ethanal) NAD+ gains hydrogen = reduced

Acetaldehyde loses hydrogen = oxidised

acetate (ethanoic acid)

+Acetaldehyde

dehydrogenase


Acetaldehyde loses one hydrogen atom (oxidised) which is accepted by NAD+ (reduced). NAD+ becomes NADH by accepting hydrogen atoms. After losing hydrogen atoms acetaldehyde accepts an OH group from H2O to become acetate.

Animation of the second alcohol breakdown reaction

O

H C

H

C H

H

+ NAD+ +O

HH

Acetate

Acetaldehyde

Electron poor coenzyme

Electron rich coenzyme

NADH

ALCOHOL IS TOXIC TO THE BODY

REDOX REACTIONS IN THE LIVER BREAKDOWN

ALCOHOL INTO ACETATE

THE AMOUNT OF ALCOHOL IN THE BLOOD

(CONCENTRATION) DICTATES HOW

INEBRIATED THE INDIVDIUAL FEELS


THE BODY TRAFFICKS ALCOHOL TO THE

LIVER TO BE BROKEN DOWN TO ALLIAVIATE

THE EFFECTS OF ALCOHOL

THE LIVER CONTAINS SPECIFIC ENZYMES NEEDED TO BREAKDOWN

ALCOHOL

MOST INDIVIDUALS BREAKDOWN ONE STANDARD DRINK

PER HOUR

ACETATE IS CONVERTED INTO ACETYL COA TO BE USE IN METABOLIC

REACTIONS


• Specific enzymes are required to breakdown alcohol in the liver

– The toxic ethanol compound is converted into an even more toxic compound

called acetaldehyde via oxidation• Requires the alcohol dehydrogenase enzyme

– The acetaldehyde compound is broken down into the non-toxic acetate compound via oxidation • Requires the acetaldehyde dehydrogenase enzyme

– Acetate is converted into acetyl CoA before it is used in metabolic reactions such as the common metabolic pathway (to make ATP)


Alcohol dehydrogenase




Acetaldehyde dehydrogenase


• Acetaldehyde is responsible for many of the

undesirable affects of drinking alcohol

• The build-up of acetaldehyde in the blood can cause:– Headache

– Nausea and vomiting

– Dehydration







Breakdown of alcohol in the liverWhy do people of Asian ethnicity often

get a red flush when drinking alcohol?

– Asians often have a gene variant that produces

a less efficient acetaldehyde enzyme • Slows down the conversion of acetaldehyde into acetate

– Acetaldehyde is more likely to build-up and cause problems in those of Asian ethnicity

• Acetaldehyde dilates the blood vessels in the skin causing reddening

• Often also causes a rapid heart beat

– Women have less acetaldehyde enzyme than men • Consequently, women breakdown alcohol more slowly than men







Why is it necessary for the body to take alcohol

to the liver once it enters the blood?

What are the functional group changes

that allow alcohol breakdown to occur?

What type of chemical reaction facilitates these changes?

Why are people of Asian ethnicity often

more affected by alcohol than others? Explain.

Key concept: reactivity of functional groups

Attempt Socrative questions: 3 to 6


Room name:




• Redox reactions

– A redox reaction involves one reactant being oxidised and one

reactant being reduced

• Oxidation and reduction occur simultaneously in a redox reaction

– Oxidation is the loss of electrons and/or hydrogen atoms

– Reduction is the gain of electrons and/or hydrogen atoms

– OIL RIG: Oxidation Is Loss, Reduction Is Gain

– The reactant that has loses hydrogen to become the product

has been oxidised

– The reactant that has gains hydrogen to become the product

has been reduced



– Ethanol is trafficked to the liver to be broken down via two redox reactions

– Ethanol (alcohol functional group) is oxidised to acetaldehyde (aldehyde functional

group) in the first alcohol breakdown redox reaction

– Acetaldehyde (aldehyde functional group) is oxidised to acetate (carboxylic acid

functional group) in the second alcohol breakdown redox reaction

– The coenzyme NAD + removes hydrogen atoms from the compounds via oxidation in

the alcohol breakdown redox reactions

– Acetate is converted to acetyl CoA to be used in metabolism to generate cellular energy

(ATP)

– Specific enzymes are needed to facilitate the alcohol breakdown redox reactions

– Individuals of Asian ethnicity often have a less efficient acetaldehyde dehydrogenase

enzyme, meaning they breakdown alcohol more slowly and experience the side-effects

to a greater extent


• Chemical properties of esters

• TAG contains ester connections

• Chemical properties of phenols

• Free radicals

Chemical properties of esters

Functional Group: Ester


Naming convention: Ester compounds have –anoate at the end of their

name e.g. methyl propanoate

Example compound:

Methyl propanoate

R COOThe ester functional group is a carbonyl

attached to an oxygen and two R-groups

R

The ester functional group is located in the

middle of compounds, as it contains two R-groups

Functional groups can have one or two R-groups attached

– Single R-group functional groups are always found at the end of a compound

or at a branch point within a compound• Example: R-OH = alcohol functional group

– Two R-group functional groups are always found in the middle of a compound

and are often used to connect two compounds together• Example: R-O-R = ether functional group

Functional Groups

R OH1 R-group functional group: alcohol

R represents any atom or group of atoms capable of attaching to the functional group

OH is the group of atoms within the alcohol functional

group

R OR represents any atom or group of atoms capable of attaching to the functional group

O is the atom that makes up

the ether functional group

2 R-group functional group: ether

RR represents any atom or group of atoms capable of attaching to the functional group

R OH1 R-group functional group: alcohol

R represents any atom or group of atoms capable of attaching to the functional group

OH is the group of atoms within the alcohol functional

group

R OR represents any atom or group of atoms capable of attaching to the functional group

O is the atom that makes up

the ether alcohol functional group

2 R-group functional group: ether

RR represents any atom or group of atoms capable of attaching to the functional group

Functional group in the middle of a compound between two R-groupsR R

TAG contains ester connections

• The fats and oils in our diet are made up of the lipid triacylglycerol (TAG)

• TAG contains one glycerol and three fatty acids

– Glycerol contains the alcohol functional group

– Fatty acids contain the carboxylic acid functional group

– The fatty acids are connected to glycerol in TAG via an ester functional group

Glycerol

Fatty acid

Triacylglycerol


Carboxylic acidfunctional group Ester

functional group

TAG contains ester connections

Triacylglycerol + H2O Glycerol + 3 fatty acids

Ester hydrolysis (Removing the ester)

Esterification (Creation of an ester)

TAG contains ester connections• Esterification is required to

connect fatty acids to glycerol when generating new TAGs

– New TAGs are created

inside cells for fat storage

• Ester hydrolysis is required to breakdown TAG into individual compounds– Three fatty acids

– One glycerol

• TAGs must be broken down before they can be metabolised to create cellular energy (ATP)

Esterification reaction


Methanol Ethanoic acid Methyl ethanoate

Creation of an ester functional group:

• An alcohol and carboxylic functional group react to create an ester functional group, while releasing a H2O molecule

– Alcohol + carboxylic acid → ester

– The oxygen within the alcohol compound forms a new bond to the carbonyl within the carboxylic acid compound to create a larger ester compound

+ +Alcohol

functional groupCarboxylic acid

functional group

Esterfunctional group


Methanol loses a hydrogen atom and ethanoic acid loses an OH group. The atoms lost from the compounds come together to form water. A new covalent bond is formed between oxygen and carbon to create an ester group which forms the methyl ethanoate compound.

Animation of an ester formation via anesterification reaction

Methyl ethanoate

Methanol Ethanoic acid

CHH

OH

H HO CC

O

HH

H+

Ester

Ester hydrolysis reaction


Methyl ethanoate

Breakdown of an ester functional group:

• An ester is broken into one alcohol and one carboxylic acid compound,

with the extra atoms needed to regenerate the functional groups come from a H2O molecule

– Ester → alcohol + carboxylic acid

– The oxygen within the ester compound forms a new bond to a hydrogen atom to create an alcohol compound

– The carbonyl within the ester compound forms a new bond to an OH group to create a carboxylic acid compound

+Ester

functional group


+Alcohol

functional groupCarboxylic acid

functional group


The covalent bond connecting oxygen to the carbonyl within the ester group is broken. The oxygen forms a new bond with a hydrogen atom from H2O to create methanol. The carbonyl forms a new bond with the OH group from H2O to create ethanoic acid.

Animation of an ester breakdown via anEster hydrolysis reaction

Methyl ethanoate


CHH

OH

CC

O

HH

H

OHH + H

OH

Alcohol

Carboxylic acid

What functional groups do glycerol and fatty acids contain?

How do these functional groups assist

in creating the ester functional group?

Does esterification assist in building

or breaking down triacylglycerol? Explain.

Why is a H2O molecule required

during an ester hydrolysis reaction?

Key concept: esters



Room name:



Chemical properties of phenols

Functional Group: Phenol


Naming convention: Phenol compounds have –phenol at the end of their

name e.g. Methylphenol

Example compound:

Methylphenol

The phenol functional group is benzene ring attached to a OH group, with five positions where other atoms

or groups of atoms can attach


• The phenol functional group has 6 carbon atoms,

5 of which bond to a single hydrogen atom

• The hydrogen atoms within the benzene ring can be replaced by another atom or group of atoms via a chemical reaction

– Allows other atoms to connect to the phenol functional group

Phenol group Phenol group containing compound

Phenol group containing compound


• Phenol is a toxic compound

– Phenol is toxic to the liver

• Ingestion can be fatal

– Concentrated essential oils

(such as clove oil) contain

phenols

• Cause skin and mucous

membrane irritation

– Can result in dermatitis and

severe burns

Phenol

Chemical properties of phenols• Compounds that contain the phenol functional

group often have beneficial properties

– Some are used as antiseptics such as those used in mouthwashes

– Can be used as flavour enhances

– Some phenol containing compounds are antioxidants, which protect the body against free radicals

• Polyphenols and vitamin E

https://www.freeimages.com/photo/wine-glass-red-1324945

Polyphenols are present in commonly consumed foods and beverages

– Blue berries, cloves, dark chocolate, red wine

– Polyphenols can reduce blood pressure by promoting vasodilation

• Lower the risk of cardiovascular disease

Stoker 2014, p445-7

REACTIVE OXYGEN SPECIES

(AKA FREE RADICALS)

Common reactive oxygen species

REACT READILY TO PAIR THEIR

UNPAIRED ELECTRONS

FORMED AS A BY-PRODUCT OF THE COMMON

METABOLIC PATHWAY (CMP)

Superoxide: O2-

Hydroxyl radical: OH

Hydrogen peroxide: H2O2

Free radicals

Definition

CMP IS REQUIRED TO

GENERATE CELLULAR

ENERGY (ATP)

FREE RADICALS PRODUCED IN THE CMP

Significant amount of antioxidants

present

NO OXIDATIVE DAMAGE TO BIOLOGICAL

MOLECUELS

ANTIOXIDANTS REACT WITH FREE RADICALS

IN A REDOX REACTION

Free radicals

FREE RADICALS CONVERTED INTO SAFE,

STABLE COMPOUNDS

Consequence

Result

FREE RADICALS PRODUCED IN THE CMP

Few antioxidants present

WHITE BLOOD CELLS ARE RECRUITED TO THE SITE OF

OXIDATIVE DAMAGE CAUSED BY FREE RADICALSFREE RADICALS REACT

WITH BIOLOGICAL MOLECULES VIA

REDOX REACTIONS

Free radicals

BIOMOLECULES BECOME DAMAGED, WHICH CAN LEAD TO

A DISEASE STATE OVER TIME

ResultINFLAMMATION,

CARDIOVASCULAR DISEASE AND DIABETES

Can lead to

OXIDATIVE DAMAGE TO DNA, PROTEIN

AND THE LIPID MEMBRANE CAN

LEAD TO CELL DEATH

Consequence



Room name:




• Chemical properties of esters– The ester functional group is a carbonyl group attached to an oxygen and two R-groups

– Ester containing compounds have –anoate at the end of their name e.g. methyl propanoate

– The ester functional group is located in the middle of compounds, as it contains two

R-groups

– Ester formation involves an alcohol reacting with a carboxylic acid functional group to create an ester

– Ester hydrolysis involves the breakdown of an ester into two separate compounds, one alcohol compound and one carboxylic acid compound

• TAG contains ester connections– The main lipid in dietary fats and oils is triacylglycerol (TAG)

– TAG is made up of three fatty acids and one glycerol

– The alcohol groups in glycerol reacts with the carboxylic acid group in fatty acids to create an ester connection

– TAG contains three ester connections that connect the three fatty acids to one glycerol


• Chemical properties of phenols– The phenol functional group is benzene ring attached to an OH group, with five

positions where other atoms or groups of atoms can attach

– Phenol containing compounds have –phenol at the end of their name e.g. methylphenol

– Phenol is toxic to the liver

– Many antiseptics are phenol containing compounds

– Antioxidants like polyphenols and vitamin E both contain the phenol group

• Free radicals– Reactive oxygen species (aka free radicals) react readily to pair their unpaired electrons

to become more stable

– Free radicals are formed as a by-product of normal metabolic reactions

– Antioxidants react with free radicals in a redox reaction, which stabilises the free radical

– Without enough antioxidants, free radicals can cause oxidative damage via redox reactions to important biological molecules, which can lead to a disease state overtime

• Stoker, HS 2014, General, Organic and Biological Chemistry, 7th edn, Brooks/Cole, Cengage Learning, Belmont, CA.

• Stoker, HS 2004, General, Organic and Biological Chemistry, 3rd edn, Houghton Mifflin, Boston, MA.

• Timberlake, KC 2014, General, organic, and biological chemistry: structures of life, 4th edn, Pearson, Boston, MA.

• Alberts, B, Johnson, A, Lewis, J, Raff, M, Roberts, K & Walter P 2008, Molecular biology of the cell, 5th edn, Garland Science, New York.

• Berg, JM, Tymoczko, JL & Stryer, L 2012, Biochemistry, 7th edn, W.H. Freeman, New York.

• Dominiczak, MH 2007, Flesh and bones of metabolism, Elsevier Mosby, Edinburgh.

• Tortora, GJ & Derrickson, B 2014, Principles of Anatomy and Physiology, 14th edn, John Wiley & Sons, Hoboken, NJ.

• Tortora, GJ & Grabowski, SR 2003, Principles of Anatomy and Physiology, 10th edn, John Wiley & Sons, New York, NY.

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