Biochemistry Lecture 1: Functional Groups

Biochemistry Lecture 1: Functional Groups

• The lecture covers functional groups, their structures, reactions, and role in medicine.
• The presenter is Dr. Shona Pedersen, an Associate Professor in Biochemistry at Qatar University.

Learning Styles

• Students should understand their learning style (visual, kinesthetic, auditory) and adjust their learning techniques accordingly.
• Prepare lecture notes based on individual learning styles.
• Review notes from lectures on the same day, ideally in the evening.
• Review notes again within the next 2-3 days.
• Review notes before the next lecture.

What is Biochemistry?

• Biochemistry is the study of the fundamental processes that make up life.
• It builds upon knowledge from chemistry to understand life processes from the cellular to molecular level.
• It studies the chemical reactions and processes of living organisms.

Importance of Biochemistry in Medicine

• Biochemistry is crucial in modern medicine.
• It helps understand and address biochemical changes.
• It explains physiological alterations during infection/disease.
• Without biochemistry, there would be no advancements in the field of medicine.

Level of Understanding in Biochemistry (BIO201)

• The course has a tiered structure extending from basic chemistry to advanced levels.
• Basic level covers core chemistry of life's building blocks.
• Intermediate level dives into main biochemical reactions in human cells.
• Advanced level delves into complex topics including the impact of drugs on respiratory functions.

Composition of Cells

• Cells consist of peptides & proteins, sugars & carbohydrates, lipids & fats, nucleic acids (DNA & RNA), and metabolites.
• Carbon is the most common element in cell's major macromolecules.

Human Body Composition

• The human body is mainly composed of water (62%), protein (16%), carbon (18%), oxygen (65%), hydrogen (9.5%), nitrogen (3.2%), etc.

Hydrocarbons

• Hydrocarbons are organic molecules solely consisting of carbon and hydrogen atoms.
• Many organic compounds, such as fats, have hydrocarbons as components.
• Hydrocarbons are a significant source of energy.
• There are four major subgroups.

Hydrocarbon Classification

• Hydrocarbons are grouped into aliphatic and aromatic.
• Aliphatic hydrocarbons are further subdivided into alkanes, alkenes, and alkynes.

Aliphatic Hydrocarbon Structure

• Alkanes have only single bonds, the maximum amount of hydrogens on each carbon.
• Alkenes have at least one double bond.
• Alkynes have at least one triple bond.

IUPAC Nomenclature

• IUPAC stands for International Union of Pure and Applied Chemistry.
• It's the universally recognized authority on chemical nomenclature and terminology.
• IUPAC establishes unambiguous names for organic compounds.

Common Alkanes

• List of hydrocarbons by number of carbons (methane, ethane, propane, butane, etc.).
• List of formulas for different numbers of hydrocarbons.

Butane and Butene

• Examples of alkanes and alkenes showing the difference in formulas and general structures in terms of number of hydrogen and carbon atoms.

Importance of Hydrocarbons

• Hydrocarbons are used in drug synthesis and in general anesthesia.
• They create dyes, flavors, perfumes, and other chemicals.
• They are used as preservatives/disinfectants.

Hydrocarbon Toxicity Symptoms

• Exposure to hydrocarbons can lead to various health problems:
• Pulmonary toxicity, including tachypnea and shallow breathing.
• Cardiac toxicity, including ventricular dysrhythmias
• Central nervous toxicity, including slurred speech.
• Peripheral nervous toxicity, affecting extremities.
• Gastrointestinal/hepatic toxicity, including nausea and vomiting.
• Hematologic toxicity, including issues such as anemia.
• Dermal toxicity, including local skin conditions.

Functional Groups

• Functional groups are important in describing the behavior and properties of organic molecules.
• Functional groups are specific groups of atoms within a molecule that cause characteristic chemical properties.
• Functional groups are used in medicine.
• Examples of functional groups: hydroxyl (-OH), carbonyl (>C=O), carboxyl (-COOH)

Functional Groups & Roles in Biochemistry

• Functional groups are essential elements of molecules in biochemistry and medicine (ex: DNA, proteins, carbohydrates).

Aldehydes: Class of Carbonyl Compounds

• Aldehydes are organic compounds with the carbonyl functional group (C=O).
• The general formula for aldehydes is RCHO.
• The central carbon in the molecule is the carbonyl centre.
• Aldehydes are relatively reactive.
• Applications of aldehydes: synthetic resins, dyes, fragrances, preservatives, disinfectants.

Names and Formulas of Aldehydes

• List common and IUPAC names and formulas for methanal, ethanal, propanal, etc.

Naming Aldehydes

• Follow IUPAC rules to name aldehydes.
• Identify the longest carbon chain.
• Replace the -e ending of the alkane with -al.
• Number the carbon chain to prioritize the aldehyde group (as carbon number 1).

Naming Aldehydes with Double Bonds

• Determine the parent chain and number of carbons and the position of any double bonds.
• Change to -al ending
• Number substituents from the carbonyl carbon.

Additional Rules for Naming Aldehydes

• Number the carbon chain from the side closest to the carbonyl group.
• Name substituent groups and assign positions with prefixes.
• Prioritize the carbonyl, hydroxyl, halogens, etc groups.

Ketones: Class of Carbonyl Compounds

• Ketones are organic compounds with the carbonyl functional group (C=O).
• The general formula for ketones is RCOR'.
• The central carbon in the molecule is the carbonyl centre.
• Applications in medicine of acetone, as a treatment for acne.

Nomenclature of Ketones

• The base name of the ketone derives from the parent chain.
• The -e ending of the parent alkane is replaced by -one.
• The position of the carbonyl group is indicated with a number.

Medical uses of Ketones

• High levels of ketones can signify a risk of diabetic ketoacidosis, a potentially life-threatening condition.
• Ketones can indicate a need for increased insulin levels.
• Propanone (Acetone) is used in skin treatments for acne.
• Ketones are found in several other crucial molecules and hormones.

Reactions of Aldehydes and Ketones (Redox)

• Aldehydes and ketones can undergo reduction and oxidation reactions.
• Reduction converts aldehydes/ketones to alcohols.
• Oxidation converts aldehydes to carboxylic acids, but ketones cannot be further oxidized.

Alcohols

• Alcohols are organic compounds containing a hydroxyl group (-OH).
• Alcohols have the general formula R-OH.
• The hydroxyl group makes alcohols polar.

Classification of Alcohols and Properties

• Alcohols can be classified as primary, secondary, or tertiary depending on the number of carbon atoms bonded to the carbon bearing the hydroxyl group.
• Alcohols display varying physical properties like water solubility and boiling points.

Medically Important Alcohols

• Methanol (toxic): used in manufacturing.
• Ethanol (used for sterilization and disinfecting).
• Ethylene glycol (toxic): antifreeze.

Phenols

• Phenols are a class of aromatic compounds containing a hydroxyl group bonded directly to a benzene ring.
• Phenols are considered polar compounds and show significant water solubility.
• Phenols play a role in flavoring, fragrances, and medicines.
• Phenol use is limited due to toxicity.

Reactions of Alcohols

• Alcohols can participate in various reactions, including dehydration, oxidation, and esterification.
• Dehydration leads to alkenes.
• Oxidation results in aldehydes, ketones, or carboxylic acids.
• Esterification generates esters.

Esters

• Esters are formed through the reaction of a carboxylic acid and an alcohol.
• They have the general formula RCOOR'.
• Esters hold significance in medical treatments, including drugs for heart conditions, influenza, and hypertension.

Ethers

• Ethers are organic substances containing an oxygen atom bonded to two alkyl or aryl groups (R-O-R').
• Ethers are crucial in medicine as anesthetics (though no longer used widely).

Amides

• Amides result from the reaction between a carboxylic acid and an amine.
• Amide bonds are essential in peptide bond formation.
• Hydrolysis of amide bonds can yield carboxylic acids and amines.

Thiols

• Thiols (R-SH) are sulfur analogs of alcohols.
• They are involved in biological functions (like protein stabilization).

Additional Notes

• The presentation covers various types of organic compounds and their reactions.
• The lecture highlights the importance of organic chemistry in medicine and biochemistry.
• The information is presented using structural diagrams and chemical formulas to aid understanding.