Bio Principles Lab: Macromolecules

Structural Molecules:

Cellulose, peptidoglycans, keratins etc.

Regulatory Molecules:

Enzymes, Hormones, etc.

Defense Molecules:

Antibodies, mucus etc.

Gene and Hereditary Molecules:

DNA, RNA

Nervous Control Molecules:

Neurotransmitters e.g. acetylcholine, dopamine, adrenaline

Monomer:

A molecule that is a building block for larger
molecules (polymers).

For example, an amino acid acts as the building blocks for proteins.

Polymer:

A large molecule made of repeating subunits
(monomers).

For example, a carbohydrate is a polymer that
is made of repeating monosaccharides.

Starch = (glucose + glucose)n

where n >100
Proteins = (amino acids + amino acids)n

where n>50

Classes of Macromolecules:

Carbohydrates
Proteins

Lipids
Nucleic acids

Carbohydrates

Are biological molecules made of carbon,
hydrogen, and oxygen in a ratio
C 2H O (one carbon atom to one water molecule)

Monosaccharides
-Just one sugar
Disaccharides
-Two sugar joined together
Polysaccharides;
-legions for they are many

Monosaccharides

(mono- = “one”)

(saccar- = “sugar”)

Simple sugars; typically contain 3-7 carbons

Classified based on # of carbons (triose, tetrose, hexose, etc.)

Ex. glucose, fructose, galactose, gulose

Aldose & Ketose

Aldose

Aldehyde Group; carbonyl C is the last one in the chain

Ketose

Ketone Group; carbonyl C is internal to the chain, so that other carbons are on both sides of it

Disaccharides

Are sugars formed by the combination of two monosaccharides

Ex. (glucose + fructose = sucrose), (galactose + glucose = lactose), (glucose + glucose = maltose)

Polysaccarides

Are long-chain polymers of monosaccharides connected by glycosidic bonds

Ex. starch, glycogen, cellulose

Benedict’s Test for Simple Sugars

Using Benedict’s Reagent

light blue (no reducing sugar)

turquoise blue (traceable)

green (low)

yellow (moderate)

red (high)

Test for Starch

Using iodine

blue-black (if starch is present)

Hydrolases

The group of enzymes that catalyze bond cleavages by reaction with water. The natural function of most hydrolases is digestive to break down nutrients into smaller units for digestion.

Breaking Glycosidic Bonds

Starch can be hydrolysed in the presence of an enzyme (boiled with dilute sulphuric acid)

Lipids

Composed mainly of carbon and hydrogen  -CH- moieties

A broad group of organic compounds which include fats, waxes, sterols, fat-soluble vitamins, monoglycerides, diglycerides, phospholipids, and others.

The functions of lipids include storing energy, signaling, and acting as structural components of cell membranes

They are insoluble in water

Soluble in organic solvents such as alcohol

Types of Lipids

Triglycerides: commonly known as fats.

Phospholipids: essential components of cell membranes

Sterols include compounds like cholesterol (chemical messengers)

Fats: Saturated vs Unsaturated

Saturated:

Have no double bonds

“saturated” with hydrogens

Very linear

Ex. Animal Fats

Unsaturated:

Have double bonds

“kinks” in hydrocarbon chain

Monounsaturated (one double bond) or Polyunsaturated (more than one double bond)

Generally healthier

Ex. Plant Oils

Brown Paper Test for Lipids

Sudan IV Test (solution) mixed with ethanol

Proteins

Amino acids + Peptide = Protein

Primary Structure

Secondary Structure

Tertiary Structure

Quaternary Structure

Amino acids

Amino Group + Hydrogen + Carboxyl Group

Classifications (3 examples)

Essential (Valine, Lysine, Histidine)

Conditionally Non-Essential (Glycine, Serine, Proline)

Non-Essential (Alanine, Cysteine, Glutamate)

Test for Proteins

Biuret Reagent reacts with protein source

Purple (proteins present)

Light Blue (proteins absent)

Mention a macromolecule that contains nitrogen as part of the chemical substituents of its subunit

Proteins

Mention one function of lipids

Moving and storing energy

What is a protein’s primary structure

This sequence of amino acids in a polypeptide chain is called the primary structure. This, in turn, determines the three-dimensional structure, including the shape of the active site.

What is the difference between a proteins tertiary structure and its quaternary structure

Aggregation of two or more polypeptides

The process of breaking down a poly-or-disaccharide into it’s constituent sugar is called

Hydrolysis

Mention one isomer of glucose

Fructose

True or false, glucose is a ketose sugar

Flase

True or false, fructose is a ketohexose sugar

True

Maltose is a disaccharide made up of ___________________ and _________________

Glucose-Glucose

What is the bond is joining two or more sugars together called

Glycosidic bond

What is the bond joining two or more amino acids together called

Peptide bonds