Openstax-Microbiology Chapter 7 Microbial Biochemistry

Macronutrients

A chemical substance that an organism must obtain in relatively large amounts

micronutrients

vitamins and minerals

trace elements

An element indispensable for life but required in extremely minute amounts.

organic molecule

A molecule containing carbon that is a part of or produced by living systems.

biomolecules

organic molecules which combine to form living organisms; includes carbohydrates, lipids, proteins and nucleic acids

carbon skeleton

The chain of carbon atoms that forms the structural backbone of an organic molecule.

isomers

Two different molecules that have the same chemical formula

structural formula

a formula that shows the arrangement of atoms in the molecule of a compound.

structural isomers

differ in the covalent arrangements of their atoms

stereoisomers

Compounds with the same structural formula but with a different arrangement of the atoms in space.

enantiomers

isomers that are mirror images of each other

chirality

A property of a compound to exist in both left and right forms; occurs whenever a compound contains an asymmetric carbon

functional groups

the components of organic molecules that are most commonly involved in chemical reactions

macromolecules

A very large organic molecule composed of many smaller molecules

monomers

building blocks of polymers

polymers

large compound formed from combinations of many monomers

dehydration synthesis

A chemical reaction in which two molecules covalently bond to each other with the removal of a water molecule.

carbohydrate

compound made up of carbon, hydrogen, and oxygen atoms; major source of energy for the human body

saccharides

carbohydrate units

Monosaccharides

Single sugar molecules

disaccharide

A double sugar, consisting of two monosaccharides joined by dehydration synthesis.

glycosidic bond

A glycosidic bond is a covalent bond in which a carbohydrate binds to another group, which could also be a carbohydrate. A glycosidic bond is found between the two glucose molecules in maltose.

polysaccharides

Carbohydrates that are made up of more than two monosaccharides

starch

A storage polysaccharide in plants consisting entirely of glucose.

glycogen

An extensively branched glucose storage polysaccharide found in the liver and muscle of animals; the animal equivalent of starch.

cellulose

A substance (made of sugars) that is common in the cell walls of many organisms

lipid

Energy-rich organic compounds, such as fats, oils, and waxes, that are made of carbon, hydrogen, and oxygen.

saturated fatty acid

A fatty acid in which all carbons in the hydrocarbon tail are connected by single bonds, thus maximizing the number of hydrogen atoms that can attach to the carbon skeleton.

unsaturated fatty acid

A fatty acid possessing one or more double bonds between the carbons in the hydrocarbon tail. Such bonding reduces the number of hydrogen atoms attached to the carbon skeleton.

Triacylglycerols (triglycerides)

Preferred method of storing energy for long term use.

Contain:

1) One glycerol attached to three fatty acids via ester bonds. The FA usually vary within the three tails

2) Can have saturated or unsaturated FA tails.

phospholipids

A molecule that is a constituent of the inner bilayer of biological membranes, having a polar, hydrophilic head and a nonpolar, hydrophobic tail.

glycolipids

Membrane carbohydrates that are covalently bonded to lipids.

amphipathic

having both a hydrophilic region and a hydrophobic region

micelles

tiny spherical complexes of emulsified fat that arise during digestion; most contain bile salts and the products of lipid digestion, including fatty acids, monoglycerides, and cholesterol

lipid-bilayer

double-layered sheet that forms the core of nearly all cell membranes

isoprenoids

Biomolecules found in membranes that consist of terpenes (found in essential oils) and steroids

steroid

lipid molecule with four fused carbon rings

sterols

compounds containing a four-ring carbon structure with any of a variety of side chains attached.

amino acid

compound with an amino group on one end and a carboxyl group on the other end

side chain

Side chain is another name for an R group, and is a group of atoms attached to the main part of a molecule and having a ring or chain structure.

peptide bond

The chemical bond that forms between the carboxyl group of one amino acid and the amino group of another amino acid

oligopeptides

chains of fewer than 10 or 15 amino acids

polypeptide

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

proteins

Nutrients the body uses to build and maintain its cells and tissues

primary structure

The first level of protein structure; the specific sequence of amino acids making up a polypeptide chain.

secondary structure

The second level of protein structure; the regular local patterns of coils or folds of a polypeptide chain.

alpha helix

A spiral shape constituting one form of the secondary structure of proteins, arising from a specific hydrogen-bonding structure.

beta pleated sheet

One form of the secondary structure of proteins in which the polypeptide chain folds back and forth, or where two regions of the chain lie parallel to each other and are held together by hydrogen bonds.

tertiary structure

The third level of protein structure; the overall, three-dimensional shape of a polypeptide due to interactions of the R groups of the amino acids making up the chain.

disulfide bridges

A strong covalent bond formed when the sulfur of one cysteine monomer bonds to the sulfur of another cysteine monomer.

native structure

the fully folded conformation of a macromolecule

quaternary structure

The fourth level of protein structure; the shape resulting from the association of two or more polypeptide subunits.

denatured

Change the shape of an enzyme so that it can no longer speed up a reaction.

conjugated protein

A protein that derives part of its function from covalently attached molecules (prosthetic groups)

glycoprotein

A protein with one or more carbohydrates covalently attached to it.

lipoprotein

any of a group of soluble proteins that combine with and transport fat or other lipids in the blood plasma.

Fatty Acid Methyl Ester (FAME) Analysis

technique to identify a microbe by its lipid composition

phospholipid-derived fatty acids (PLFA) analysis

method of microorganism identification

proteomic analysis

Increases the complexity of a proteome, therefore proteomic analysis is necessary to understand organism functions.