Chemical Level of Organization

Vocabulary practice flashcards covering organic chemistry concepts, biological macromolecules, enzymes, nucleic acids, and high-energy compounds based on the Chemical Level of Organization lecture notes.

Organic compounds

Molecules consisting of carbon and hydrogen as core elements, linked by covalent bonds, that serve as a source of energy.

Functional group

A specific group of atoms within an organic molecule that undergoes characteristic chemical reactions.

Dehydration synthesis

A condensation reaction that synthesizes macromolecules from monomers by removing a water molecule.

Hydrolysis reaction

A decomposition reaction that breaks down macromolecules into smaller units by adding a water molecule.

Monosaccharides

Simple sugar monomers containing 3 to 7 carbon atoms, including glucose, fructose, galactose, deoxyribose, and ribose.

Isomers

Molecules that share the same molecular formula but have different structural arrangements.

Disaccharides

Carbohydrates composed of two monosaccharides joined via dehydration synthesis.

Glycosidic linkage

A covalent bond formed between two monosaccharides during a dehydration synthesis reaction.

Glycogen

A branched polysaccharide known as animal starch, stored primarily in liver and muscle tissues.

Starch

A plant polysaccharide composed of amylose and amylopectin that is digestible by human body enzymes.

Cellulose

An unbranched structural polysaccharide found in plant cell walls that is indigestible by human enzymes.

Fatty acids

Lipid molecules consisting of a long hydrophobic hydrocarbon tail attached to a hydrophilic carboxylic acid group ($\text{-COOH}$).

Saturated fatty acid

A fatty acid containing no double bonds between carbon atoms in its hydrocarbon tail, allowing molecules to pack closely as solids at room temperature.

Unsaturated fatty acid

A fatty acid containing one or more double bonds between carbon atoms, creating kinks that prevent tight packing.

Glycerides

Esters formed by complexing fatty acid chains with a 3-carbon glycerol backbone via dehydration synthesis.

Triglyceride

A neutral lipid composed of a glycerol molecule bound to three fatty acid chains by ester linkages.

Ester linkage

The covalent bond formed between a hydroxyl group of glycerol and the carboxyl group of a fatty acid.

Phospholipid

A lipid composed of a diglyceride linked to a non-lipid group and a phosphate group ($\text{PO}_4^{3-}$), featuring a hydrophilic head and hydrophobic tails.

Glycolipid

A lipid composed of a diglyceride linked to a carbohydrate sugar moiety.

Steroids

Lipid molecules characterized by a core structure of four interlocking carbon rings with attached functional groups.

Cholesterol

The most abundant steroid, synthesized by the liver and obtained from diet, serving as a cell membrane component and precursor for vitamin D, steroid hormones, and bile salts.

Eicosanoids

Lipids derived from the 20-carbon fatty acid arachidonic acid, functioning as cellular messengers.

Leukotrienes

Eicosanoids involved in the immune system's inflammatory response, whose actions are inhibited by NSAIDs.

Prostaglandins

Short-chain fatty acid eicosanoids that function as local hormones.

Proteins

Macromolecules made of amino acid monomers linked by peptide bonds, accounting for over 50% of the dry mass of most cells.

Amino acid

The monomer of proteins, containing a central alpha carbon bound to an amino group ($\text{-NH}_2$), a carboxyl group ($\text{-COOH}$), a hydrogen atom, and a variable side chain (R group).

Essential amino acids

The nine amino acids (His, Ile, Leu, Lys, Met, Phe, Thr, Trp, Val) that cannot be synthesized by the body and must be obtained from dietary sources.

Peptide bond

The covalent bond formed between the carboxyl group ($\text{-COOH}$) of one amino acid and the amino group ($\text{-NH}_2$) of another through dehydration synthesis.

Primary protein structure

The linear sequence of amino acids along a polypeptide chain.

Secondary protein structure

Structural coiling or folding in a polypeptide chain stabilized by hydrogen bonds, forming alpha helices or beta pleated sheets.

Tertiary protein structure

The overall three-dimensional shape of a single polypeptide chain resulting from folding and coiling.

Quaternary protein structure

The structural arrangement resulting from interactions between two or more individual polypeptide chains.

Fibrous proteins

Water-insoluble, tough, and durable proteins arranged in structural sheets or strands, such as collagen, keratin, and elastin.

Globular proteins

Water-soluble, spherical proteins that function in solution, such as enzymes, antibodies, hemoglobin, and myoglobin.

Protein denaturation

A process where globular proteins unfold and lose their three-dimensional shape and biological activity, typically due to extreme pH or heat.

Enzymes

Globular protein catalysts that accelerate biochemical reactions by lowering activation energy without being consumed.

Substrates

Reactant molecules that bind to an enzyme's active site to undergo a chemical reaction.

Active site

The specific region on an enzyme where substrate molecules bind and catalysis takes place.

Activation energy

The energy required to initiate a chemical reaction.

Cofactors

Ions or nonprotein molecules that must bind to an enzyme before specific substrates can bind.

Coenzymes

Nonprotein organic cofactors, often derived from vitamins, that assist enzyme activity.

Competitive inhibition

Enzyme regulation where an inhibitor directly competes with the substrate for binding to the active site.

Non-competitive inhibition

Enzyme regulation where an inhibitor binds to an allosteric site, distorting the active site and preventing effective substrate binding.

Nucleic acids

Polymers composed of nucleotide monomers that store, process, and transfer genetic information in cells.

Nucleotides

The building blocks of nucleic acids, consisting of a pentose sugar, a phosphate group, and a nitrogenous base.

Pyrimidines

Single-ring nitrogenous bases including cytosine, thymine (in DNA), and uracil (in RNA).

Purines

Double-ring nitrogenous bases including adenine and guanine.

Complementary base pairing

Specific hydrogen bonding between bases: adenine pairs with thymine (or uracil in RNA), and cytosine pairs with guanine.

DNA (Deoxyribonucleic Acid)

A double-stranded double-helix nucleic acid containing deoxyribose sugar and bases A, T, C, G, which stores inherited genetic information.

RNA (Ribonucleic Acid)

A single-stranded nucleic acid containing ribose sugar and bases A, U, C, G, which performs protein synthesis as directed by DNA.

Adenosine Triphosphate (ATP)

The main high-energy compound in cells, composed of adenosine and three phosphate groups, which releases energy upon phosphate hydrolysis.