Biological Macromolecules, Proteins, and Nucleic Acids

Vocabulary practice flashcards generated from lecture notes covering lipids, protein structures, enzymes, and nucleic acids.

Unsaturated Fatty Acid

A hydrocarbon chain that contains at least one double bond, which creates a tilt or bend in its structure.

Ester Bond

The bond formed in fats between a glycerol molecule and hydrocarbon chains with the removal of a water molecule via a dehydration reaction.

Oleic Acid

An unsaturated fatty acid containing a single double bond in its hydrocarbon chain, resulting in a tilted shape.

Cis Unsaturated Fatty Acid

An unsaturated fatty acid where hydrogen atoms are located on the same side of the double bond, producing a kink or bend in the hydrocarbon chain.

Trans Unsaturated Fatty Acid

An unsaturated fatty acid where hydrogen atoms are located on opposite sides of the double bond, resulting in a straight hydrocarbon chain.

Low Density Lipoproteins (LDL)

Known as the bad cholesterol in the body, whose levels are increased by the consumption of trans fats deposited in arteries and veins.

Phospholipid

A lipid molecule composed of a hydrophilic glycerol phosphate head and two hydrophobic fatty acid tails, forming the cell's plasma membrane bilayer.

Catabolic Enzymes

Enzymes that break down larger molecules into smaller ones, such as pepsin breaking down food in the stomach.

Anabolic Enzymes

Enzymes that build up larger complex molecules from smaller components, such as DNA polymerase during DNA assembly.

Amino Acid

The structural building block of proteins, consisting of a central carbon bonded to a carboxyl group ($\text{COOH}$), an amino group ($\text{NH}_2$), and a variable side chain (R group).

Peptide Bond

The covalent bond that connects two adjacent amino acids together through a dehydration reaction that removes a water molecule.

N-terminus and C-terminus

The two distinct ends of a completed polypeptide chain, where the N-terminus features a free amino group ($\text{NH}_2$) and the C-terminus features a free carboxyl group ($\text{COOH}$).

Primary Structure

The initial linear sequence or chain of amino acids held together by peptide bonds before protein folding occurs.

Secondary Structure

The localized folding pattern of a polypeptide chain into alpha helices or beta sheets, stabilized by hydrogen bonds.

Tertiary Structure

The overall three-dimensional shape of a single polypeptide chain, maintained by ionic bonds, hydrophobic interactions, disulfide bonds, and hydrogen bonds.

Quaternary Structure

A complex protein structure formed by the assembly of two or more folded polypeptide units.

Hemoglobin

A quaternary protein made of four folded subunit chains that functions in the blood to transport oxygen throughout the body.

Deoxyribose

The five-carbon sugar component of DNA nucleotides that lacks an oxygen atom at the second carbon ($2'$) position.

Ribose

The five-carbon sugar component of RNA nucleotides that possesses an oxygen atom at the second carbon ($2'$) position.

Purine

A class of double-ringed nitrogenous bases that includes adenine and guanine.

Pyrimidine

A class of single-ringed nitrogenous bases that includes cytosine, thymine (in DNA), and uracil (in RNA).

Phosphodiester Bond

The linkage connecting adjacent nucleotides in nucleic acids, formed between the $5'$ phosphate group of one nucleotide and the $3'$ hydroxyl ($\text{OH}$) group of another via dehydration.