AP BIO Unit 1 Macromolecules

Elements that form Hydrogen Bonds

Hydrogen → Fluorine, Oxygen, or Nitrogen

Organic Molecule

Polymer

A long molecule consisting of many similar or identical monomers linked together by covalent bonds.

Monomer

subunit that serves as the building block of a polymer. 

What reaction connects monomers? +Explain

Condensation Reaction/Dehydration Reaction

1. Monomer becomes attracted to another monomer

2. Monomer releases water to form covalent bond with monomer

What reaction breaks down polymers into monomers?

Hydrolysis

• (water + break)

Carbohydrate Structure

• Elements: Carbon, Hydrogen, Oxygen

• Bond: Glycosidic Linkage (can be broken by animals)

• Ratio: 1:2:1

  • Disaccharide: Remove H₂O

Carbohydrate Functions

• Storage of Energy

  • Starch: Plants store extra glucose (in amylose or amylopectin)

  • Glycogen: Animals release when energy demand increases

• Structure

  • Cellulose: Cell walls

  • Chitin: Arthropod and fungi

Carbohydrate Monomer

Monosaccharides

• Glycosidic Linkages: Bond monosaccharides

Lipid Structure

• Elements: Carbon, Hydrogen, Oxygen

• Hydrocarbons → Hydrophobic

Types of Lipids

• Waxes

• Steroids

• Fats

• Phospholipids

Monomers of Lipids

• Glycerol +

• Fatty Acids: Central Carbon + Carboxyl + Chain of carbon atoms

Saturated Fats

Fatty acids without double bonds and thus are saturated in hydrogen atoms

• Solid at room temp.

• Straight chains

• ex. butter, lard (animals)

Unsaturated Fats

Fatty acids with one or more double bonds and thus unsaturated in hydrogen atoms

• Liquid at room temp.

• Bent chains—prevent molecules from packing together to form a solid

• ex. olive oil (plants)

Triglycerides/Fat Molecules

Lipids—Long-term energy storage

• Glycerol + 3 Fatty Acids

Waxes

Lipids—water proofing, adhesives, candles

• Alcohol molecule + 2 fatty acids

Phospholipid

• Bilayer: Forms boundary b/w cell and external environment → separates components in eukaryotic cells

  • Amphiphilic/Amphipathic: Hydrophilic head (phosphate + glycerol) + Hydrophobic fatty acid tails (one saturated, one unsaturated)

Steroids

Lipids—Have multiple carbon rings

• Hormones: Estrogen, testosterone, cholesterol

Protein Structure

• Alpha/Central Carbon

• Amino Group (NH₂)

• Carboxyl (O=C-OH)

• R-Group: Determine function/structure

Protein Monomers

Amino Acids

Peptide Bond

Covalent bond between the carboxyl group of one amino acid to the amino group of another

• Formed by dehydration

How to determine if protein is basic or acidic?

• Basic: Positive charge

• Acidic: Negative charge

How to determine if protein is polar or nonpolar?

Look at the end of R-Group (ignore amino and carboxyl groups)

• Nonpolar: Methyl or other hydrocarbon

• Polar: Anything with a charge

Primary Structure of Protein

The sequence of amino acids thru covalent bonds

• determined by inherited genetic information

• → determines secondary and tertiary structure.

Secondary

The coils and folds of the peptide chains that contribute to the protein’s overall shape

• regions stabilized by hydrogen bonds between atoms of the polypeptide backbone (partial negative oxygen atoms and partial positive hydrogen atoms attached to nitrogens)

Alpha Helix

Secondary structure

• Hydrogen bonding every fourth amino acid

Beta Pleated Sheet

Secondary Structure

• Two or more segments of the chain lying side by side (beta strands) connected by hydrogen bonds between parts of two parallel segments

Tertiary Structure

Three dimensional shape stabilized by interactions between side chains (R groups)

• hydrogen bonds

• covalent bonds

Hydrophobic Interaction

Tertiary structure— Usually occurs when nonpolar side chains cluster in the core of the protein away from water, creating van der waals interactions, and polar side chains create hydrogen bonds.

Disulfide Bridges

Tertiary structure— Reinforce shape by joining two sulfur atoms of cysteine monomers due to folding

Quaternary Structure

Association of two or more polypeptides (some proteins only)

• hydrogen bonds

• covalent bonds

Denaturation

Process in which a protein loses its native shape due to the disruption of weak chemical bonds and interactions, thereby becoming biologically inactive 

• Changes in–pH

• Salinity

• Temperature (excessive heat)

• Transferred from aqueous environment to nonpolar solvent

Nucleic Acid Struture

• Monomer: Nucleotides

  • Nitrogenous Base

  • Pentose

  • 1-3 Phosphate groups

Pyrimidines

Single-ring nitrogenous bases

• Uracil

• Thymine

• Cytosine

Purines

Double-ring nitrogenous bases

• Guanine

• Adenine

DNA vs. RNA

• Deoxyribose sugar vs. Ribose Sugar

• Double vs. Single-stranded

• Antiparallel vs. Varied

Which bases are found in DNA? 

Cytosine, Guanine, Adenine, Thymine

Which four are found in RNA?

Cytosine, Guanine, Adenine, Uracil

ATP vs. ADP vs. AMP

More phosphates = More energy

• ATP: 3 Phosphates

• ADP: 2 Phosphates

• AMP: 1 Phosphate

DNA Function

• Provides directions for its own replication

• directs RNA synthesis and (through RNA)

• controls protein synthesis through gene expression

RNA Function

transcribes/translates DNA in protein synthesis, gene regulation, and is the genome of some viruses. 

• messenger RNA (mRNA) molecule interacts with the cell’s protein-synthesizing machinery to direct production of a polypeptide 

• transfer RNA (tRNA) brings amino acids to the ribosome during the synthesis of a polypeptide 

What type of bond holds the nitrogenous bases together in the double helix of DNA?

Hydrogen bonds

Phosphodiester Linkages

a phosphate group that covalently links the sugars of two nucleotides

• One end has a phosphate attached to a 5′ carbon, and the other end has a hydroxyl group on a 3′ carbon;