Chapter 4, Lesson 1: The Nucleic Acids

Flashcards from Chapter 4, Lesson 1 of McGraw Hill Anatomy and Physiology, Ninth Edition, by Kenneth S. Saladin.

Johann Miescher

A Swiss biochemist who lived from 1844 to 1895; he studied the nuclei of white blood cells and coined the term nuclein - what we now call genes

Deoxyribonucleic acid (DNA)

A long, thread-like molecule with uniform diameter and varied length; it’s a polymer of nucleotides

Nucleotide

A molecule made of a sugar, phosphate group, and nitrogenous base

Ribose

The sugar in nucleotides

Purines

The adenine and guanine nitrogenous bases

Pyrimidines

The cytosine, thymine, and uracil nitrogenous bases

Double helix

The structure of a DNA molecule; resembles a spiral staircase with the ‘steps’ being the nitrogenous base pairs

Base pairing

How DNA is bonded using hydrogen bonds; A always pairs to T with 2 bonds and C always pairs to G with 3 bonds

Gene

Segment of DNA coding for the synthesis of a specific protein

Genome

All the genes of one person; humans have 20,000 but only 2% is human-specific while the other 98% is for chromosome structure and gene activity regulation

Chromatin

Fine filamentous DNA material complexed with proteins; may change movement in non-dividing cells according to genetic activity

Ribonucleic acids (RNAs)

Contain the sugar ribose; uracil takes the place of thymine in DNA and is smaller

Messenger RNA (mRNA)

Sends the genetic code to ribosomes

Ribosomal RNA (rRNA)

Carries out protein synthesis in enzymes

Transfer RNA (tRNA)

Obtains amino acids for ribosomes according to mRNA