structure and function of large biological molecules | Ch 5

Polymers

One long molecule constructed by linking many smaller monomers

• 4 main class of macromolecules

• Carbs, proteins, nucleic, lipids

Dehydration reaction

Cells synthesize (build) polymers from monomers

• monomers release water as byproducts (H and OH combined when bonded)

• Known as condensation

Hydrolysis

Cells breakdown polymers into monomers

• H2O added to help break that bond

Carbohydrates

Macromolecule 1:

Classified as Saccharides and has 3 types of how many sugars/glucose there are

• monosaccharides

• Disaccharides

• Polysaccharides

Monosaccharides

Base (single unit) of carbs, monomer of carbs

• one sugar

• 5-6 carbons

• One carbonyl group

• 2/more hydroxyl groups

• Ring structures

Disaccharides

• 2 sugars

• Dimer

• Joined by covalent bond

• Sucrose, lactose, maltose

Polysaccharides

More than 2 sugars

• polymer!

• Complex carbs, linear or branched

Glycosidic linkage

The bond that two or more monosaccharides have between eachother

• dehydration: produces water! (Condensation)

Sucrose

• glucose and fructose

Lactose

Glucose and galactose

Maltose

Glucose and glucose

3 main types of carbs

Starch, cellulose, and glycogen

Starch

Made by plants, a ten by humans

Cellulose

Made by plants consumed by plants (cellular building material)

glycogen

Made by animals, a ten by animals (energy storage)

Starch(explained)

Polymer of alpha glucose monomers(all same pattern)

• same direction monomer(all top/or bottom)

• Coiled molecule, almost all branching (easily hydrolyzed)

Cellulose

Component of plant cell walls

• polymer of beta glucose monomers(upside down pattern)

• Upside down pattern= structure better hold in plants

• Parallel rows via hydrogen bonds

Glycogen

Polymer of alpha glucose monomers

• extensively branched

Chitin

Made by animals and fungi

• provides structural support (exoskeleton and fungal cells)

• Polymer with amine groups!!!!!

Proteins

Macromolecule 2:

Monomer: amino acids

All constructed from a set of 20 amino acids

Proteins structure

4 components attached to alpha carbon

• amino acid

• A carboxyl group

• A hydrogen atom

• An R group

R groups

Some non polar/polar

• each acid has a different R group! (20 different ones)

• Non polar groups: hydrophobic

• Polar: hydrophilic

• Electrically charged: hydrophilic

Primary structure

Amino acids(monomers) linked to eachother by a peptide bond

• Not yet a protein

Secondary structure

hydrogen bonding between segments of the peptide create 2 unique 3D shapes!

• officially a protein

• Alpha helix

• Beta pleats

Tertiary structure

Bonds between R groups

• creates globular protein shapes- complete 3D shape

Quaternary structure

Bonding of 2 or more proteins to form a large complex protein

• hemoglobin has 4 subunits

Functionality of a protein

Unique shape determines functionality

• denature: loss of 3D shape (unreaveling) due to extreme environmental conditions

• Example: pH, salt concentration, temperature

• Ex: cooked eggs

Nucleic acids

Monomer: nucleotide

Function: gene expression

• 2 types of nucleic acids: DNA and RNA

Deoxyribonucleic Acid (DNA)

• codes for traits

• Without oxygen

• DNA makes RNA

• 2 strands (runs opposite direction)

• 5’-3’

Ribonucleic Acid (RNA)

• template for making proteins

• Single strand

• Base paring still occurs within single strand (3D structure)

• No Thymine!

Nucleotide

The monomer of Nucleic Acids

• composed of three parts: pentose sugar, phosphate group, nitrogenous base

Pyramidines

Single ring nitrogenous base- bonded hy hydrogen bonds

Purines

Double ring nitrogenous base- bonded ny hydrogen bonds