DNA 复制叉机制图

一幅扁平编辑风格的 DNA 复制叉示意图，略从左上方俯视。亲本双链（蓝色与青色交织带）在解旋酶（红色环形）处解开。前导链模板（蓝色）由 DNA 聚合酶 III（深蓝泪滴形）连续合成新链（浅青色，向右延伸）；后随链模板（青色）向后弯曲，以冈崎片段（虚线青色短段）不连续合成；引发酶（品红色菱形）标注 RNA 引物。SSB 蛋白（浅黄色小椭圆）稳定单链区域。象牙色背景，纯色无渐变，8 pt 无衬线标签。

A flat editorial diagram of a DNA replication fork, viewed from slightly above and to the left. The parental double helix (two intertwined blue-and-teal ribbons) unwinds at the fork point where a helicase enzyme (red ring shape) is illustrated mid-unwinding. The leading strand template (blue) is copied continuously by DNA polymerase III (dark blue teardrop), with the new strand (light cyan) growing smoothly rightward. The lagging strand template (teal) is looped back and copied in Okazaki fragments (short dashed cyan segments with gaps); primase (magenta diamond) marks the RNA primers. SSB proteins (small pale-yellow ovals) stabilize the single-stranded regions. Labels with thin hairline arrows: "Helicase", "Leading strand", "Lagging strand", "Okazaki fragment", "Primase", "SSB". Ivory background, flat colors, no gradients, 8 pt sans-serif labels.