Lipids, Proteins, and Nucleic Acids Lecture Flashcards

Vocabulary flashcards covering lipid properties, protein structures, denaturation, nucleic acids, and molecular biology terms from the lecture.

Hydrogenation

The chemical process of adding hydrogen to unsaturated vegetable oils to break double bonds and form single bonds, resulting in solid or semi-solid fats at room temperature with trans double bonds.

Phospholipid Bilayer

A double-layered membrane structure formed by phospholipids, where hydrophilic heads containing negatively charged phosphate groups face outward toward water, and hydrophobic fatty acid tails face inward away from water.

Enzymes

Protein catalysts that speed up chemical reactions by increasing the frequency at which specific reactions occur.

Amino Acids

The $20$ different monomer building blocks of proteins, each composed of an amino group, a carboxyl group, a hydrogen atom, and a variable R group.

Peptide Bond

The specific covalent bond formed between two amino acids through a dehydration reaction during protein synthesis.

Polypeptide

An unbranched polymer made of amino acid monomers linked together by peptide bonds.

Primary Structure

The linear sequence of amino acids in a single polypeptide chain, directly determined by genetic instructions stored in DNA.

Secondary Structure

Coiled or folded patterns within a polypeptide chain, such as alpha helices or beta pleated sheets, stabilized by hydrogen bonds along the polypeptide backbone.

Alpha Helix

A secondary protein structure where a portion of the polypeptide chain coils into a spiral, held together by hydrogen bonds between backbone atoms.

Beta Pleated Sheet

A secondary protein structure formed when segments of a polypeptide chain fold back and forth parallel to each other, stabilized by hydrogen bonds.

Tertiary Structure

The overall three-dimensional globular shape of a single polypeptide chain, resulting from interactions among R groups such as hydrophobic clustering, ionic bonds, hydrogen bonds, and disulfide bridges.

Disulfide Bridges

Strong covalent bonds formed between sulfur-containing R groups that help reinforce and stabilize the tertiary structure of a protein.

Quaternary Structure

The functional protein structure resulting from the aggregation and interaction of two or more separate polypeptide chains into one macromolecule.

Denaturation

The process in which physical or chemical changes in an environment—such as extreme temperature, pH, or salinity—cause a protein to unravel, lose its shape, and lose its biological function.

Chaperone

A specialized protein structure that assists denatured proteins in properly refolding into their functional three-dimensional shape.

Collagen

A structural fibrous protein made of three helical polypeptide chains wrapped around each other, providing support in skin, hair, and connective tissues.

Marfan Syndrome

A genetic condition affecting collagen production in connective tissues, which can lead to structural weaknesses such as aortic or heart rupture.

Hemoglobin

A quaternary transport protein consisting of two alpha subunits and two beta subunits that binds and carries oxygen in red blood cells.

Sickle Cell Disease

A genetic disorder caused by a single base-pair substitution replacing glutamic acid with valine, altering hemoglobin structure and causing red blood cells to deform into a sickle shape.

Nucleotide

The monomer building block of nucleic acids, consisting of a nitrogenous base, a pentose sugar (deoxyribose or ribose), and one or more phosphate groups.

Nucleoside

The structural component of a nucleotide that includes only the nitrogenous base and the pentose sugar, lacking the phosphate group.

Pyrimidines

A class of nitrogenous bases characterized by a single six-membered ring structure, including cytosine, thymine, and uracil.

Purines

A class of nitrogenous bases characterized by a six-membered ring fused to a five-membered ring, including adenine and guanine.

Phosphodiester Bond

A covalent bond formed by a condensation reaction that links the sugar and phosphate groups of adjacent nucleotides to build a polynucleotide backbone.

Anti-parallel

The structural arrangement of double-stranded DNA in which one polynucleotide strand runs in the $5'$ to $3'$ direction while the complementary strand runs in the opposite $3'$ to $5'$ direction.

Gene Expression

The cellular process by which genetic instructions encoded in DNA direct the synthesis of RNA and functional proteins.

Bioinformatics

The application of computer technology and software tools, including artificial intelligence, to store, analyze, and search large biological datasets such as DNA and protein sequences.

Genomics

The study of whole sets of genes and their interactions across entire genomes of organisms.

Proteomics

The systematic study of full sets of proteins encoded by genomes and their functional characteristics within cells.