bio-sequence-properties

GC at Codon Positions (GC123)

Analyze GC content at each codon position (useful for codon bias analysis):

from Bio.SeqUtils import GC123

seq = Seq('ATGCGATCGATCGATCGATCG')
gc_total, gc_pos1, gc_pos2, gc_pos3 = GC123(seq)

## GC Skew

Calculate (G-C)/(G+C) in sliding windows to identify replication origins:

## Molecular Weight

```python
from Bio.SeqUtils import molecular_weight

dna = Seq('ATGCGATCG')
mw = molecular_weight(dna)  # Single-stranded DNA weight