Gen Bio I Lecture 3

Hydrocarbons

• C and H

• Nonpolar, hydrophobic (note: nonpolar → hydrophobic, polar → hydrophilic. to remember this, remember that water is a polar molecule so it’s hydrophillic or “water loving”)

Functional groups

• Hydroxyl (-OH):

• Carbonyl (-CO)

• Carboxyl (-COOH):

• Methyl (-CH3):

• Amino (-NH2):

• Phosphate (-OPO 2/3):

Hydroxyl (-OH):

• Polar

• Hydrophillic

• Alcohol (more specific example ethanol)

Carbonyl (-CO)

• Polar (less than OH)

• Hydrophillic

• Sugars (ex. glucose)

Carboxyl (-COOH):

• Polar

• Hydrophillic

• Acidic

Methyl (-CH3):

• Non-polar (the only non-polar one)

• Hydrophobic

Amino (-NH2):

• Polar

• Basic

• Hydrophillic

• Amines (in amino acid)

Phosphate (-OPO 2/3):

• Polar

• Hydrophillic

• Acidic

• Used in nucleic acids, ATP

Macromolecule terms (marcomolecules, polymers, monomers)

• Macromolecules: Large molecules made up of thousands of atoms

• Polymers: Macromolecules made of chains of monomers

• Monomers: Small molecules

Two types of actions to know with molecules

• Dehydration synthesis

• Hydrolosis

Dehydration synthesis

• Making a polymer

• Dehydration removes a water molecule forming a new bond for a polymer

• Some enzymes that perform this are:

  • DNA polymerase: joins nucleotides together to build DNA

  • Glycogen synthase: joins glucose units to build glycogen

  • Peptide synthetases: help assemble certain peptides

Hydrolosis

• Opposite of dehydration synthesis

• Adding water to break a bond

• Enzymes that perform this are called hydrolases (not important to know but yeah)

4 Classes of Biological Macromolecules

• Carbohydrates

• Lipids (note: all of these are polymers except lipids)

• Proteins

• Nucleic Acids

Carbohydrates

• Chemical formula: CH2O

• Polymer

• Made of C, H, O

• Made up of monomers called monosaccharides (sugar monomers).

• Glycosidic linkages

What connects carbohydrates?

• Glycosidic linkages: These monosaccharides are connected by glycosidic linkages to form polysaccharides

Function and examples of carbohydrates

• Function: Structure

• IRL ex. of carbohydrates:

  • Glucose → starch = plant energy storage
    Glucose → glycogen = animal energy storage
    Glucose → cellulose = plant structure/cell walls

Lipids

• Hydrophobic

  • Instead dissolves in nonpolar solvents, ex. chloroform

• Functions:

  • Storage (ex. body fat/adipose tissue)

  • Structure (ex. phospholipid bilayer)

  • Signaling (ex. hormones)

• Lipid synthesis:

  • Dehydration synthesis & ester linkage

• 3 types of lipids: fats, phospholipids

Fats

• Most abundant lipid

• Energy storage containing 9 cal/gram (meanwhile carbs and proteins are 4 cal/gram

• Structure: Glycerol

  • 3 carbon

  • 3 hydroxyl groups

  • note: not that important to know specific structure but do know glycerol

• ex. meats, oils, junk food

Phospholipids

• Glycerol + 2 fatty acids + phosphate group

• This is the head tail structure used in the phospholipid bilayer

  • Phosphate head, fatty acid tail

Steroids

• Has three 6 carbon rings, one 5 carbon ring

• Ex. cholesterol, sex hormones

Proteins

• Polymer

• Amino acids:

  • All amino acids have the same structure containing: central alpha carbon, hydrogen atom, amino group (basic pH), carboxyl group (acidic pH), R group

  • There are 20 types of amino acids, with each one having a different R groups

What connects proteins?

• Peptide bonds

• Amino acids join together through peptide bonds

• Amino acids joining → peptide bonds → polypeptide chain → folded protein

Protein structure (4 levels & what they are, denaturation)

• There are 4 levels of protein organization: primary → secondary → tertiary → quaternary structure

• Secondary structure → small folds

• Tertiary structure → 3D shape

• Quaternary → Multiple polypeptide chains

• Denaturation: A protein losing its normal shape

  • Things that can cause this are high temperatures, extreme pH, and certain chemicals

  • ex. cooking an egg making egg white clear → white

Protein functions

• Structure

• Signaling/communication

• Enzymes

• Defense

• Transport

• Basically everything except heredity

Nucleic Acids

• DNA and RNA