DNA structure

• DNA strands pair up in an antiparallel fashion
• Read and replicated 5’→3’
• Sugar phosphate backbone (deoxyribose)
• A + T, C + G
• DNA strand associates with proteins (including histones) – wound into chromosomes

DNA replications

• DNA can be damaged during replication
• When repair mechanisms are defected, disease occurs

Cell cycle

• G1 → S → G2 → M
• DNA synthesis occurs during S phase

Mitosis

• One diploid parent cell becomes 2 identical diploid daughter cells

Meiosis

• One diploid parent cell becomes 4 haploid daughter cells
• Crossing over occurs
• Gamete formation

Transcription and translocation

1. DNA transcribed into pre-mRNA