Unit 1.2 Biomolecules, Water Properties, Cell Transport, and Enzymes Flashcards

Vocabulary flashcards covering water properties, biomolecules, cell membrane structure, and enzyme function based on Unit 1.2 lecture notes.

Organic molecules

Any molecules that contain a carbon-hydrogen bond.

Inorganic molecules

Any molecules without a carbon-hydrogen bond.

Cohesion

The attraction between molecules of the same substance.

Adhesion

The attraction between molecules of different substances.

Surface tension

A measure of how difficult it is to stretch or break the surface of a liquid, related to cohesion.

Biomolecules

The large organic molecules found in living things, also referred to as macromolecules.

Polymerization

The process in which larger compounds (polymers) are built by joining smaller ones (monomers) together.

Dehydration synthesis reaction

A chemical reaction in which monomers join together to form a polymer by removing or losing a water molecule.

Monomers

The smaller individual units that join together to build polymers.

Polymer

A large molecule composed of many smaller repeating units called monomers.

Hydrolysis reaction

A chemical reaction that involves the addition of a water molecule to break the chemical bonds in polymers to create monomers.

Monosaccharides

The monomers of carbohydrates, also known as simple sugars (such as glucose, fructose, and galactose).

Polysaccharides

The polymers of carbohydrates, also known as complex carbohydrates, formed from chains of monosaccharides (such as glycogen, cellulose, and starch).

Lipids

Large organic molecules usually not soluble in water, mostly made from carbon and hydrogen, used for long-term energy storage, cell membrane structure, and chemical communication.

Saturated fatty acid

A fatty acid chain containing the maximum number of hydrogen atoms with only single carbon-carbon bonds.

Unsaturated fatty acid

A fatty acid chain that contains at least one carbon-carbon double bond.

Triglyceride

A lipid polymer built from three fatty acid chains attached to a glycerol molecule.

Amino acids

Compounds containing an amino group on one end, a carboxyl group on the other end, and a unique R group; they serve as the monomers of proteins.

Polypeptide

A chain of many amino acids linked together by peptide bonds.

Nucleotides

The monomers of nucleic acids, consisting of a 5-carbon sugar, a phosphate group, and a nitrogenous base.

Nucleic acids

Polymers assembled from nucleotides, such as DNA and RNA, that store and transmit genetic information.

Lipid bilayer

A double-layered sheet of lipids that forms a flexible structure and strong barrier surrounding all cells.

Hydrophobic

"Water-hating"; describes nonpolar fatty acid tails that cluster together away from water.

Hydrophilic

"Water-loving"; describes polar head groups of membrane lipids that interact with water.

Selectively permeable

A property of biological membranes that allows some substances to pass across while preventing others.

Activation energy

The energy required to start a chemical reaction.

Catalyst

A substance that speeds up the rate of a chemical reaction by lowering the activation energy without being consumed.

Enzymes

Proteins that function as biological catalysts to speed up specific chemical reactions in cells.

Active site

The specific region on an enzyme where substrate molecules bind and undergo a chemical reaction.

Substrate

The specific reactant molecule that binds to the active site of an enzyme.

Denaturation

The process in which an enzyme loses its functional three-dimensional shape and becomes inactive due to extreme changes in temperature or pH.