figure 2 OK

doc/typst/chapters/a3a2_figure_protein_polymer.typ

@@ -3,6 +3,7 @@
 #figure([
 #cetz.canvas({
 import cetz.draw: *
+
 draw-skeleton(name: "mol1",mol-anchor: "east", {
   molecule("N")
   branch({
@@ -14,6 +15,7 @@ draw-skeleton(name: "mol1",mol-anchor: "east", {
   branch({
     single(angle: 5,)
     molecule(
+        name: "Hext",
       "H",
     )
   })
@@ -22,6 +24,7 @@ draw-skeleton(name: "mol1",mol-anchor: "east", {
   branch({
     single(angle: 6)
     molecule(
+        name: "R1",
       "R_1",
     )
   })
@@ -34,6 +37,7 @@ draw-skeleton(name: "mol1",mol-anchor: "east", {
   branch({
     single(angle: 6)
     molecule(
+        name: "R2",
       "R_2",
     )
   })
@@ -43,16 +47,21 @@ draw-skeleton(name: "mol1",mol-anchor: "east", {
   branch({
     single(angle: 1)
     molecule(
+        name: "O",
       "O",
     )
   })
   branch({
     single(angle: -1,)
     molecule(
+        name: "OHext",
       "OH",
     )
   })
   })
+line((to: "mol1.north-west", rel: (-2pt, 2pt)), (to: "mol1.north-west", rel: (-2pt, -1)), "mol1.R1.south-west", "mol1.R2.south-east",(to: "mol1.O.north-east", rel: (2pt, -1)), (to: "mol1.O.north-east", rel: (2pt, 2pt)), close: true, stroke: blue)
+rect((to: "mol1.Hext.north-west", rel: (-2pt, 2pt)),(to: "mol1.Hext.south-east", rel: (2pt, -2pt)), stroke: red)
+rect((to: "mol1.OHext.north-west", rel: (-2pt, 2pt)),(to: "mol1.OHext.south-east", rel: (2pt, -2pt)), stroke: red)
  })
  
 A protein is made of a chain of residues and of two caps. The left cap is