BIOMOLECULES DISCUSSION

Biology Unit 3

What is a Biomolecule?

Organic molecule made by living organisms

Consist mostly of carbon (C), hydrogen (H), and oxygen (O)

But wait…What is an Organic Molecule?

Organic Molecules:

Contain carbonConsidered the “chemicals of life”

Inorganic Molecules:

Do not contain carbon

Monomers vs. Polymers

Monomers:

Molecules that may react with similar molecules to form a chain

Polymers:

A chain of many monomers that are chemically bonded together

Formation of Polymers

Animation

How are polymers formed?

Dehydration Synthesis (Condensation): Two hydrogen atoms and one oxygen atom are removed from the monomers to form water, and the two monomers are joined together.

Breakdown of Polymers

Animation

How are polymers broken down?

Hydrolysis—the reverse of dehydration synthesis (condensation)

Water added to the polymer, un-linking the chain and breaking it back down to its original monomer units

Carbohydrates

What are they?Group of organic molecules that includes sugars,

starches and cellulose.

Carbohydrates

Structure:

Carbon, hydrogen and oxygen in a 1:2:1 ratio

(CH2O)n – n is an integer such as 5 (C5H10O5)

Subunits: Monosaccharides, such as glucose or fructose

Most often in a ring shapeSubunits are connected with covalent bonds

Monosaccharide Example

Disaccharide Example

Polysaccharide Example

Carbohydrates

Function:

EnergyStructural SupportCell WallCell Membrane Marker

Lipids

What are they?Organic molecule group including fats and

phospholipids

Lipids

Structure:

Subunits:○ Glycerol and fatty acids○ Glycerol and fatty acids plus phosphate group

Insoluble in waterDo not form large polymers (2 or 3 fatty acids

with glycerol) ○ Examples: diglyceride and triglyceride

Triglyceride Example

Phospholipid Example

Lipids

Function:

Energy storageInsulationPart of cell membrane (phospholipids)Hormones

Proteins What are proteins?

Group of organic molecules that provides structure and facilitates chemical reactions.

Proteins

Structure:

Subunits: Amino acidsAmino acids connect via peptide bondsVery large moleculesGlobular or structural

Amino Acid

Proteins

Function:

Lots of functions!Enzymes (speed rate of chemical reactions)Structural components in cellsMechanical functions in muscles and

cytoskeleton (internal cell framework)Cell signalingImmune response

Nucleic Acids

What are Nucleic Acids?

Group of organic molecules including DNA and RNA

Nucleic Acids

Structure:Subunits are nucleotides—5-Carbon sugar,

Nitrogen base and one or more Phosphate groups

Nucleic Acids

Function:

Storage and retrieval of information:○ Encode genes○ Gene expression