Biomolecules Summary

Monomers

Small units that are components of larger molecules

Polymers

Molecules made from many monomers joined together

Condensation reaction

Chemical reaction where monomers are joined and a water molecule is eliminated

Hydrolysis

Chemical reaction where water is added to break a chemical bond between two molecules

Carbohydrates

Molecules consisting of carbon, hydrogen, and oxygen, and long chains of sugar units

Monosaccharides

Single sugar units, such as glucose, with the general formula (CH2O)n

Disaccharides

Two monosaccharides joined together in a condensation reaction

Polysaccharides

Molecules formed from many glucose units joined together

Glycosidic bond

Bond formed in a condensation reaction between monosaccharides

Glucose

Monosaccharide containing six carbon atoms, main substrate for respiration

Maltose

Disaccharide formed by condensation of two glucose molecules

Sucrose

Disaccharide formed by condensation of glucose and fructose

Lactose

Disaccharide formed by condensation of glucose and galactose

Glycogen

Main energy storage molecule in animals, formed from many alpha glucose molecules

Starch

Energy storage molecule in plants, mixture of amylose and amylopectin

Amylose

Unbranched chain of glucose molecules joined by 1, 4 glycosidic bonds

Amylopectin

Branched chain of glucose molecules joined by 1, 4 and 1, 6 glycosidic bonds

Cellulose

Component of cell walls in plants, composed of long chains of beta glucose

Benedict's reagent

Used to test for the presence of reducing sugars

Iodine/potassium iodide

Chemical test for starch, turns blue/black in the presence of starch

Lipids

Biological molecules made of carbon, hydrogen, and oxygen, only soluble in organic solvents

Triglycerides

Lipids made of glycerol and three fatty acids joined by ester bonds

Saturated lipids

Lipids that don't contain any carbon-carbon double bonds

Unsaturated lipids

Lipids that contain carbon-carbon double bonds, liquid at room temperature

Phospholipids

Lipids with one fatty acid substituted by a phosphate-containing group

Emulsion test

Test for the presence of lipids, cloudy-white color indicates the presence of a lipid

Amino acids

Monomers from which proteins are made, contain an amino group, carboxylic acid group, and a variable R group

Peptide bonds

Bonds formed in condensation reactions between amino acids

Primary structure

Order and number of amino acids in a protein

Secondary structure

Shape of the chain of amino acids, either alpha helix or beta pleated sheet

Tertiary structure

3D shape of the protein, formed from further twisting and folding

Proteins

3D tertiary structured globular proteins, shape determined by the primary sequence of amino acids

Biuret test

Test for the presence of peptide bonds in a protein, purple color indicates the presence of a protein

Enzymes

3D tertiary structured globular proteins that catalyze reactions by lowering the activation energy

Active site

Area of the enzyme where the substrate binds

Substrate

Molecule that the enzyme acts upon

Enzyme substrate complex

Complex formed when the enzyme and substrate bind together

DNA

Double helix composed of two polynucleotides joined by hydrogen bonds

RNA

Relatively short polynucleotide chain, carries genetic information from DNA to ribosomes

Nucleotides

Monomers of DNA and RNA, consist of pentose, nitrogen-containing organic base, and phosphate group

Base pairing

Adenine pairs with thymine, guanine pairs with cytosine

DNA replication

Semi-conservative replication of DNA to ensure genetic continuity

ATP

Nucleotide derivative consisting of ribose, adenine, and three phosphate groups

Water

Polar molecule with many important properties, major component of cells

Inorganic ions

Ions in solution in the cytoplasm and body fluid of organisms

Hydrogen ions

Determine the pH of substances, higher concentration leads to lower pH

Iron ions

Component of hemoglobin, an oxygen-carrying molecule

Sodium ions

Involved in co-transport of glucose and amino acids

Phosphate ions

Component of DNA and ATP