Biomolecules of the Central Dogma

DNA RNA Protein

Nucleotide Structure

DNA vs. RNA

• Sugar (C2’)

• Single vs. Double Stranded– Stem-loop (Hairpin)

• Thymine vs. Uracil

Nucleic Acids

• Sugar phosphate backbone– 5’ Phosphate– 3’ Hydroxide

• Base Pairing Rules– Purine: A, G– Pyrimidine: C, U, T– A=T, G≡C

DNA Coiling to form Chromosomes

Protein: Primary Structure

• The sequence of amino acids

• N-terminus, C-terminus

Protein: Secondary Structure

Protein: Secondary Structure

• β pleated sheet

• β barrel– A large beta-sheet that

twists and coils to form a closed structure

Tertiary Structure

• 3D structure of a single protein molecule

• Folding is driven by chemical interactions of R groups:

Protein: Quaternary Structure

• Assembly of several protein subunits

• Stabilized by non-covalent interactions and disulfide bonds– Dimer, trimer, tetramer,

multimer– “Homo” = same subunits– “Hetero” = different subunits

Metabolism

Metabolic Direction Water Energy Examples

Anabolic “Building up”

Condensation Used Photosynthesis

Polymerization

DNA replication

Transcription & Translation

ADP + Pi ATP

Catabolic “Breaking down”

Hydrolysis Released Digestion

Glycolysis/ Krebs Cycle

Combustion

ATP ADP +Pi

Condensation Reactions(a.k.a. Dehydration Synthesis)

• Two monomers are joined together, with the loss of water.

• Synthesis of all the important biological macromolecules:– carbohydrates, proteins, lipids, nucleic acids

Protein Synthesis

• Polymers of amino acids linked by peptide bonds

Carbohydrate Synthesis

• Linked by glycosidic bonds– Ex) Di-, Tri-, Polysaccharides– Ex) Polymers of glucose form cellulose and

starch.

Nucleic Acid Synthesis

• DNA/RNA strands string of nucleotides joined together by phosphodiester bonds

Lipid Synthesis

• “Fats” are a subgroup of lipids called triglycerides Ester linkage

Depicting Molecules in Space

Ribbon Diagrams(a.k.a. Richardson Diagrams)

• 3D schematic representations of protein structure

Alternative Views & Representations

• A: schematic/ribbon• B: molecular/ball &

stick• C: view from top• D: space filling model