Biology SL Unit 1

DNA Base Pairings

DNA Base Pairings

Adenine - Thymine

Guanine - Cytosine

Nitrogenous base for RNA only

Uracil

Pyrimidine vs. Purine

Purines have 2 rings
Pyrimidines have 1 ring

Purine Nitrogenous Bases

Adenine, Guanine

Pyrimidine Nitrogenous Bases

Cytosine, Thymine, Uracil

What bond are complementary base pairs held together with?

Hydrogen Bond

Hydrogen Bond

A weak attraction between a slightly positive hydrogen and a slightly negative atom

What type of bond holds together monomers in a polymer?

Phosphodiester bonds

Type of monomer in nucleic acids

Nucleotide

Type of polymer in nucleic acids

Polynucleotide

Catabolic pathway

Break down of complex molecules into simpler ones

Anabolic pathway

The synthesis of complex molecules from simpler molecules

Condensation Reaction (Dehydration Synthesis)

Anabolic pathway reaction. Two monomers join as they lose a water molecule.

Hydrolysis

Catabolic pathway reaction. Water molecules split polymers back into individual monomers.

Four biological macromolecules

Carbohydrates, lipids, proteins, nucleic acids

Metabolism

All the chemical processes in a cell

Four functional groups

Hydroxyl, Amino, Phosphate, Carboxyl

Rosalind Franklin

Discovered the double helix shape of DNA with x-ray crystallography. Had her work stolen by Watson and Crick.

Watson and Crick

Used stolen work from Rosalind Franklin to prove that DNA had a double helix shape.

Erwin Chargraff

Disproved the tetranucleotide hypothesis. Found that the nitrogenous bases appeared in different amounts and the percentage of each could be used to determine the species a sample of DNA belonged to.

Hershey and Chase

Discovered that DNA is the genetic material of the cell, not proteins.