Biological Molecules Overview

Flashcards covering key vocabulary terms related to biological molecules, including organic compounds, functional groups, macromolecules (carbohydrates, lipids, proteins), and their structures and functions, based on lecture notes.

Lactose intolerant

A condition where an individual cannot digest milk-based foods due to a lack of the lactase enzyme.

Lactase

An enzyme required to break down lactose (a sugar).

Organic compounds

Molecules of a cell that are composed of carbon; carbon-based molecules.

Inorganic compounds

Molecules that do not contain carbon.

Carbon skeleton

A chain of carbon atoms that can differ in length, be straight, branched, or arranged in rings.

Isomer

Compounds with the same chemical formula but different structural arrangements.

Functional groups

Specific groups of atoms attached to organic compounds that determine their chemical properties and reactivity.

Hydrophilic

Water-loving; substances that are soluble in water and polar.

Hydrophobic

Water-fearing; substances that are insoluble in water.

Hydroxyl group

A chemical functional group consisting of a hydrogen atom bonded to an oxygen atom (-OH).

Carbonyl group

A chemical functional group consisting of a carbon atom double-bonded to an oxygen atom (C=O).

Carboxyl group

A chemical functional group consisting of a carbon atom double-bonded to an oxygen atom and also bonded to a hydroxyl group (-COOH).

Amino group

A chemical functional group consisting of a nitrogen atom bonded to two hydrogen atoms (-NH2).

Phosphate group

A chemical functional group consisting of a phosphorus atom bonded to four oxygen atoms (PO4).

Methyl group

A chemical functional group consisting of a carbon atom bonded to three hydrogen atoms (-CH3); it is nonpolar and not reactive but affects molecular shape.

Macromolecules (Polymers)

Large molecules that are essential to organisms, typically made from identical or similar building blocks.

Monomers

The smaller, repeating building blocks that make up polymers.

Dehydration reaction

A chemical reaction in which two monomers join together by removing a water molecule.

Hydrolysis

A chemical reaction that breaks a bond in a polymer by adding a water molecule.

Enzymes

Specialized macromolecule proteins that serve as catalysts to speed up chemical reactions within cells.

Carbohydrates

Macromolecules ranging from small sugar molecules (monomers) to large sugar molecules (polymers), primarily for energy.

Monosaccharides

The monomers (simple sugars) of carbohydrates.

Fructose

An example of a monosaccharide (simple sugar).

Glucose

An example of a monosaccharide (simple sugar) and the main fuel for cellular work (C6H12O6).

Honey

An example of a monosaccharide (simple sugar).

Disaccharide

A carbohydrate formed by two monosaccharides joined together by a dehydration reaction.

Sucrose

An example of a disaccharide, formed from one glucose monomer and one fructose monomer.

Maltose

An example of a disaccharide, formed from two glucose monomers.

Polysaccharides

Polymers of carbohydrates composed of thousands of monosaccharides, functioning as storage molecules or structural compounds.

Starch

A polysaccharide used by plants for energy storage, composed of many glucose molecules.

Glycogen

A polysaccharide used by animals for energy storage, composed of many glucose molecules.

Cellulose

A polysaccharide that functions as a structural compound, found in plant cell walls (e.g., cotton).

Chitin

A polysaccharide that functions as a structural compound, found in the exoskeletons of insects and cell walls of fungi.

High Fructose Corn Syrup (HFCS)

An artificial sweetener where glucose atoms are rearranged to make fructose; a mix of fructose and glucose.

Lipids

Water-insoluble (hydrophobic) compounds important for long-term energy storage, containing twice as much energy as polysaccharides.

Fats (Triglycerides)

A large lipid made from one glycerol molecule linked to three fatty acid molecules.

Glycerol

The 'head' component of a fat molecule.

Fatty acids

The 'tail' components of a fat molecule.

Saturated fats

Fats with the maximum number of hydrogen atoms, consisting of single carbon-carbon bonds, making them solid at room temperature (e.g., butter, meat fats).

Unsaturated fats

Fats with fewer than the maximum number of hydrogen atoms due to double carbon-carbon bonds, creating kinks and making them fluid at room temperature (e.g., olive oil, salmon).

Hydrogenated vegetable oils

Unsaturated fats that have been artificially converted to saturated fats by adding hydrogen atoms.

Trans fats

Unsaturated fats with artificially introduced double bonds that have a higher risk of cardiovascular disease than saturated fats.

Phospholipids

Lipids that are the major component of all cell membranes, consisting of a hydrophilic phosphate group 'head' and two hydrophobic fatty acid 'tails'.

Phospholipid bilayer

The structural arrangement of phospholipids in water, where hydrophilic heads face the watery environment and hydrophobic tails cluster together internally, forming the cell membrane.

Steroids

Lipids in which the carbon skeleton contains four fused rings.

Cholesterol

An example of a steroid, a common component in animal cell membranes and a starting material for making other steroids, including sex hormones.

Anabolic steroids

Synthetic variants of the male hormone testosterone, which can be abused by athletes and lead to serious health consequences.

Proteins

The most diverse macromolecules, composed of amino acid monomers, with a wide range of structures and functions.

Amino acids

The monomers (building blocks) of proteins; there are 20 different kinds.

Peptide bond

The covalent bond that links amino acids together in a protein, formed by a dehydration reaction.

Dipeptide

Two amino acids linked together by a peptide bond.

Polypeptide

Multiple amino acids linked together by peptide bonds.

Denaturation

The process where a protein's functional shape is altered and unraveled due to changes in temperature, pH, or salt concentration, causing it to lose its function.

Primary structure (of protein)

The specific sequence of amino acids linked together by peptide bonds in a polypeptide chain.

Secondary structure (of protein)

The specific patterns of coiling (alpha helix) or folding (beta pleated sheets) of a polypeptide chain.

Tertiary structure (of protein)

The overall three-dimensional shape of a polypeptide, resulting from interactions among the R groups of the amino acids.

Quaternary structure (of protein)

The structure resulting from the association of two or more polypeptide chains, forming a functional protein.