BIOL 2401 Weeks 2&3 Unit 2: Cell Biology & Metabolism

DNA vs RNA

• DNA has a double helix, RNA is a single string

• DNA has deoxyribose sugar, RNA has ribose sugar

• DNA has thymine, while RNA has uracil

DNA function

Holds genetic code

RNA function

Involved in protein synthesis (mRNA, tRNA, rRNA)

Central dogma of life

The flow of genetic information

• DNA → (transcription) → RNA → (translation) → protein

DNA polymerase

Enzyme that makes copies of DNA

For cell division, what must be copied?

DNA must be copied

Which strand acts as a template for a “new” DNA strand?

The “old” DNA strand acts as a template for a “new” DNA strand

Events of transcription (RNA synthesis)

DNA is “coped” into an mRNA molecule by RNA polymerase → mRNA moves out of nucleus to cytoplasm to ribosomes

RNA polymerase

Enzyme that assists in transcription by “copying” DNA into a messenger RNA molecule

Events of translation (protein synthesis)

mRNA sequence translated into amino acid sequence on ribosome, makes polypeptide → mRNA sequence read, 3 nucleotides codes for amino acid → tRNA matches mRNA sequence to the amino acid