Module 4: Chemistry of Organic Molecules

Organic vs inorganic chemistry in terms of composition and bonding?

Organic chemistry- life, always containing carbon and hydrogen with covalent bonds.

Inorganic chemistry- nonliving matter, typically forming ionic bonds.

Why is carbon highly reactive?

Atomic number 6 - 2 in first shell, 4 in second. Since it needs 4 more to complete its outer shell, it forms 4 covalent bonds, sharing electrons with different elements

Hydroxyl Functional Group

• -OH

• makes molecules polar and water soluble

Carbonyl

• C=O

• Found in carbon chain aldehydes (end of chain) and ketones (middle of chain)

Carboxyl

• –COOH

• acts as an acid by donating H⁺

• found in amino acids and fatty acids.

Amino

• NH₂

• acts as a base by accepting H⁺

• found in amino acids and nucleotides.

Sulfhydryl

• –SH

• forms disulfide bonds that stabilize protein structure.

phosphate

• –OPO₃²⁻

• key in energy transfer (ATP)

• backbone of DNA/RNA.

What are functional groups

Speific cluters of atoms attached to carbon backbones in macromolecules

Isomers are atoms that share the same molecular formulas, but differ in…

• how their atoms are arranged

Types of isomers

• Structural

• Cis-trans

• Enantiomers

Dehydation synthesis is how your body builds macromolecules by….

• joining monomers together

What are the monomer, polymer, and primary functions of carbohydrates?

• Monomer = monosaccharide (glucose, fructose)

• Polymer = polysaccharide

• Functions: energy storage (starch, glycogen) and structural support (cellulose)

• C:H:O always in a 1:2:1 ratio

Why are lipids considered the odd one out among macromolecules?

Not true polymers…no repeating monomer chains. Built from glycerol + fatty acids. Hydrophobic due to long hydrocarbon tails.

Lipid functions

• long-term energy storage

• membrane structure (phospholipids)

• hormones

What are the monomer, polymer, and primary function of nucleic acids?

• Monomer = nucleotide (sugar + phosphate + nitrogenous base)

• Polymers = DNA and RNA

• Function: store and transmit genetic information. DNA is double-stranded (A, T, C, G); RNA is single-stranded and swaps thymine for uracil.

What are the monomer, polymer, and primary functions of proteins?

• Monomer = amino acid (20 types)

• Polymer = polypeptide. Linked by peptide bonds. Most functionally diverse macromolecule — enzymes, hormones, structural support, transport, immunity

• Key rule: shape determines function.

What are monosaccharides

The simplest carbohydrates. Can be used for energy (glucose) or structure (ribose, deoxyribose)

What is the most important monosachharide?

Glucose, it exists as many isomers. Same formula, different structure, different biological behavior. Primary fuel source broken down during cellular respiration.

What form is energy in for cellular use?

ATP Andrenosine triphosphate: glucose gets broken down through cellular respiration, and that energy is captured and stored at ATP

Ribose

The sugar backbone of RNA and ATP

Deoxyribose

The sugar backbone of DNA

Disachharides

Two monosaccharides joined together. Linked by glycosidic bond, formed through dehydration synthesis

Common disaccharides

• Sucrose — glucose + fructose. Found in plants, table sugar, fruit. Most common dietary sugar.

• Lactose — glucose + galactose. Found in milk and dairy. The one most people have trouble digesting.

• Maltose — glucose + glucose. Found in germinating seeds and some fermented foods like beer

How are disachharides broken down?

Hydrolysis — your digestive system adds water back to break the glycosidic bond, splitting the disaccharide back into its two monosaccharides so they can be absorbed.

What are Polysaccharides

Long chains of multiple monosachharides linked together by multiple glycosidic bonds through dehydration synthesis.

Energy Storage Polysacchrides

• Starch (plants) Plants store excess glucose as starch in their tissues — roots, seeds, tubers (like potatoes). When the plant needs energy, it hydrolyzes starch back into glucose.

• Glycogen (animals) The animal equivalent of starch. Stored primarily in the liver and muscle tissue.

Stuctural Polysaccharides

• Cellulose (plants) Forms the cell walls of plants. Made of long parallel chains of glucose that hydrogen bond together into rigid fibers — incredibly strong.

• Chitin (arthropods & fungi) Makes up the exoskeleton of arthropods — insects, crabs, lobsters, shrimp. Also found in fungal cell walls.

Trigylcerides are built from…

glycerol and fatty acids

Glycerol

A small 3 carbon molecule with three -OH groups, one on each carbon

Fatty acid

A long hydrocarbon chain with a carboxyl group at one end. The hydrocarbon tail is nonpolar and hydrophobic

How is a triglyceride formed?

Dehydration synthesis 3 times over, each of glycerols 3 -OH groups reacts with the -COOH of one fatty acid, releasing a water molecule each time. 3 water molecules total are released, and three fatty acids end up covalently bonded to the glycerol backbone via ester bonds.

“Saturated” in saturated fatty acids means the carbon chain is fully saturated with…

hydrogen. every carbon in the chain forms bonds with other carbons, leaving max room for hydrogen atoms.

Saturated fatty acids are solid at room temp and have high melting points because….

Molecules can pack tightly together

“Unsaturated” in unsaturated fatty acids means…

There are one or more double bonds between carbons in the chain. each double bond means fewer hydrogen atoms in the chain,

Kinks in unsaturated fatty acid chain means…

Molecules cant pack tightly together, stay at liquid temp and have lower melting point

Steriods are a class of lipids built around a core structure of….

four fused carbon rings. they don’t have fatty acid chains, grouped with lipids because of their water soluble nature

Waxes are lipids formed by joining….

A long fatty acid chain to a long alchol chain through dehydration synthesis

Protiens are polymers made of ___ linked by ___ through ____

amino acids, linked by peptide bonds, through dehydration synthesis

What are the 6 major functions of protiens?

Support, enzymes, transport, defense, hormones, motion

What are the 4 components of every amino acid?

• amino

• carboxyl

• hydrogen

What does the R group of an amino acid determine?

3 things…

• Category: Nonpolar, polar, acidic, base

• Polarity: hydrophobic vs hydrophilic

• Reactivity: ability to form bonds like disulfide bonds

Why is protein shape so critical to function

R goup polarity drives how the protien folds _ nonpolar R groups fold inwards, polar ones face outwards. The resulting 3D shape determines what the protein can do.

What are the 2 types of nucleic acids?

DNA- stores the indstructions for portien synthesis in the nucleus

RNA- transmits those indstructions out to the ribosomes where protiens are built

What are the structural differences between DNA and RNA?

DNA uses deoxyribose sugar, is double stranded, and uses bases A, T, C, G.

RNA is ribose sugar, is single stranded, and swapes thymine for uracil

What are the base pairing rules for DNA and RNA?

DNA: A pairs with T, C pairs with G.

RNA: A pairs with U instead of T

What are coenzymes?

Independent neuclotides that assist enzymes in carrying out by shuttling electrons or chemical groups. EX: NAD+ and FAD, critical in cellular respiration

How does ATP store and release energy?

ATP has 3 phophsphate groups, energy is stored in the bonds between them

When the terminal phophsphate is cleaved during hydrolysis, energy is release.