Fall 26’ Bio20A Macromolecules

Macromolecules

Made primarily of polymers

Polymers

Molecules made of many repeating subunits and their subunits are called monomers.

Carbohydrates

Includes sugar and polymers of sugar

Monosaccharides

The simplest carbohydrates

Carbohydrate macromolecule

Polysaccharide polymers that are composed of many sugar building blocks

Disaccharide

Formed when a dehydration reaction joins two monosaccharides

Polysaccharides

The polymers of sugar, have storage and structural roles

Lipids

Do not include true polymers, they mix poorly if at all (hydrophobic). Consist mostly of hydrocarbons.

Fats

Are constructed of two types of smaller molecules: glycerol and fatty acids. Separates from water. Major function is energy storage in humans in other mammals it’s to store their long term food reserves in adipose cells.

Fatty acid

A three carbon alcohol with a hydroxyl group attached to each carbon

Triacylglycerol

Three fatty acids are joined to glycerol by an ester linkage

Saturated fatty acids

Have the maximum number of hydrogen atoms possible and no double bonds

Unsaturated fatty acids

Have one or more double bonds

Phospholipid

Two fatty acids and a phosphate group attached to glycerol. The two fatty acid tails are hydrophobic. But the phosphate group and attachments form Hydrophilic head. When added to water they self assemble into double layered sheets called bilayers, forms a boundary between the cell and its external environment.

Steroids

Are lipids characterized by a carbon skeleton consisting of four fused rings

Cholesterol

a type of steroid, is a component in animal cell membranes and a precursor from which other steroids are synthesized

Proteins

Account for more than 50% of the dry mass of most cells. Other protein functions include defense, storage, transport, cellular communication, movement, and structural support. Biologically functional molecule that consists of one or more polypeptides.

Enzymes

Are proteins that act as catalysts to speed up chemical reactions. Can perform their functions repeatedly.

Enzymatic proteins

Function: selective acceleration of chemical reactions

Defensive proteins

Function: protection against disease

Hormonal proteins

Function: coordination of an organisms activities

Storage proteins

Storage of amino acids

Storage proteins

Storage of amino acids

Contractile and motor proteins

Function: movement

Structural proteins

Function: support

Amino acids

Are organic molecules with amino and carboxyl groups. Different in their properties due to R groups

Polypeptides

Are unbranched polymers built from amino acids. A polymer of amino acids, has a unique linear sequence with a N terminus (amino end) and a C terminus (carboxyl end)

Peptide bond

The bind between amino acids

A proteins three dimensional sequence

Is determined by the sequence of amino acids, a proteins structure determines how it works.

Primary structure

Unique sequence of amino acids, made of covalent bonds. Determined by genetic inheritance. “Is like the order of letters in a long word”

Secondary structure

Coils and folds. Results from hydrogen bonds between repeating constituents of the polypeptide backbone. A coil called an alpha helix and a folded structure called a beta sheet.

Tertiary structure

The overall structure of a polypeptide, results from interactions between R groups. Interactions include: hydrogen bonds, ionic bonds, hydrophobic reactions, and van der waals. Strong covalent bonds such as disulfide bridges may reinforce this structure.

Quaternary structure

Two or more polypeptide chains from one macromolecule.

Denaturation

Loss of a proteins native structure. Alternations in pH, salt concentration, temperature, or other environmental factors can cause a protein to unravel. Biologically inactive