Chapter 7: Microbial Biochemistry

Covalent bond

two atoms share pairs of electrons

Polar covalent bond

unequal sharing of electrons

Nonpolar covalent bond

equal sharing of electrons

Hydrogen bonds

interaction between polar molecules

Ionic bonds

attractions between a cation and an anion

Acid

is a molecule that dissociates into H+ and anions, pH < 7

Base

is a molecule that dissociates into OH- and cations, pH > 7

Monosaccharide

simple sugars, glucose – monomers of carbohydrates

Disaccharide

two monosaccharides combined, sucrose

Polysaccharide

multiple monosaccharides combined, starch, glycogen, cellulose

Triglycerides

lipid storage

Phospholipids

form the phospholipid bilayer of the cell membrane

Sterols

stabilize the cell membrane

Peptide bond

the bond formed between two amino acids to form a protein

Primary structure

the linear AA sequence of a protein

Secondary structure

the AA chain folds/coils

Tertiary structure

folding of the polypeptide

Quaternary structure

2 or more polypeptides interact for function

Denaturation

when a protein loses their shape and function

DNA

uses deoxyribose for the sugar, bases: ATCG, structure: double helix

RNA

uses ribose for sugar, Bases: AUCG, structure: single stranded

cation

positively charged (lost an electron)

anion

negatively charge (gained an electron)

organic molecules

contain carbon and hydrogen

inorganic molecules

lack carbon bound to hydrogen 

synthesis

forming new bonds between molecules

decomposition 

bonds are broken and energy is released 

condensation

bonds are formed between two subunits creating a larger molecule+water

hydrolysis

water is used to break bonds in larger molecules

amino acids

monomers of proteins

fatty acids

monomers of lipids 

monosaccharides

monomers of carbohydrates 

nucleotides

monomers of nucleic acids

saturated fatty acid

• straight chains

• pack tightly

• solid at room temperature

unsaturated fatty acid

• bents chains

• cannot pack tightly

• liquid at room temperature