POB Lesson 4

5’ end

Terminal extremity of a single strand of nucleic acid where the carbon-5 position of the terminal sugar ring attaches to a phosphate group

3’ end

Terminal end that has a free hydroxyl group (-OH) attached to the 3’ carbon atom of the pentose sugar ring

Alpha helix

A common, rod-like secondary structure of proteins where a polypeptide chain twists into a tight, right-handed coil resembling a spring

Amino acid

A small organic molecule that acts as a fundamental building block for proteins

ATP

Primary energy currency of living cells

Beta sheet

A common type of protein secondary structure where parts of a protein chain lie side by side and form a flat, folded, sheet-like shape

Carbohydrate

A biological macromolecule made of carbon, hydrogen, and oxygen atoms; used for short term energy and structure

Carbon

The fundamental chemical element that acts as the structural backbone for all known living organisms

Carbonyl

A functional group composed of a carbon atom double-bonded to an oxygen atom

Carboxyl

A chemical feature written as -COOH, where a carbon atom connects to a double-bonded oxygen and a single-bonded hydroxyl group (-OH)

Complementary base

A nitrogenous base in DNA or RNA that links with a specific partner base through hydrogen bonds

C-terminus

The end of a protein or polypeptide chain that ends with a free carboxyl group (-COOH)

Dehydration

A chemical process where small molecules join together to form larger polymers while releasing a molecule of water

Denaturation

A process where proteins or nucleic acids lose their natural three-dimensional shape and biological activity due to external stress or chemicals

Deoxyribose

Five-carbon monosaccharide sugar that forms the structural backbone of DNA

Disaccharide

A type of sugar molecule made when two simple sugars (monosaccharides) join together

Disulfide

A strong covalent link formed between two sulfur atoms from the thiol groups of different cysteine amino acid residues

DNA

The molecule that carries the genetic instructions used in the growth, development, functioning, and reproduction of all living organisms

Functional group

Specific clusters of atoms attached to carbon skeletons that dictate the chemical behavior, reactivity, and physical properties of biological molecules

Hydrocarbon

An organic molecule made up entirely of two elements: carbon and hydrogen

Hydrogen

The lightest chemical element

Hydrolysis

A chemical process that uses water to break the bonds holding large biological molecules together into smaller parts

Hydroxyl

A functional group consisting of one oxygen atom covalently bonded to one hydrogen atom

Isomer

Molecules that share the exact same chemical formula (the same number and types of atoms) but have different arrangements or shapes

Macromolecule

A very large, complex molecule essential for life, made up of thousands of smaller connected atoms

Monomer

A small, simple molecule that can chemically bond with other similar or identical molecules to form a larger structure called a polymer

Monosaccharide

The simplest form of a carbohydrate, consisting of a single sugar unit that cannot be broken down into smaller sugars

Nitrogenous base

A nitrogen-containing organic molecules that acts as a base and serves a s a fundamental building block of nucleotide units in DNA and RNA

N-terminus

The start of a protein or polypeptide chain

Nucleic acid

A nitrogen-containing organic molecule that acts as the fundamental building block of genetic information

Nucleotide

Monomer of Nucleic acid; building blocks of DNA

Oxygen

Gas that makes up 21% of Earth’s atmosphere and is vital for cellular respiration and energy production

Peptide bond

A strong chemical link that joins amino acids together to make peptides and proteins

Phosphate

A chemical ion made of one phosphorus atom bonded to four oxygen atoms

Phosphodiester bond

A strong covalent chemical link that joins individual nucleotides together to form the structural backbone of DNA and RNA

Polymer

The covalent chemical linkage that connects individual small subunits (monomers) into a long, repeating macromolecule chain

Polypeptide

a long, unbranched chain of amino acids linked together by covalent chemical bonds called peptide bonds

Polysaccharide

A large complex carbohydrate made of long chains of smaller sugar units

Primary structure

Unique linear sequence of amino acids linked together by covalent peptide bonds in a polypeptide chain

Protein

Large, complex molecules made of one or more long, folded chains of amino acids linked by peptide bonds

Purine

A type of nitrogen-containing building block that cells use to form, DNA, RNA, and vital energy molecules; has two rings

Pyrimidine

A type of nitrogenous base with a single-ring chemical structure that cells use to build DNA and RNA

Quaternary structure

The final 3d shape of a protein

R group

The variable chemical group attached to the central carbon of an amino acid that makes each amino acid unique

Ribose

A simple five-carbon sugar that serves as a vital structural component of RNA and cellular energy molecules

RNA

A single stranded nucleic acid essential for building proteins and carrying out genetic instructions in all living cells

Secondary structure

The local, repeating folding patterns that form within a biopolymer

Sulfhydryl

A biological functional group consisting of a sulfur atom bonded to a hydrogen atom

Starch

Natural, complex carbohydrate that green plants use to store excess energy

Strand

Continuous chain of connected monomers/building blocks

Tertiary structure

The overall, three-dimensional shape of a single protein molecule or polypeptide chain