diff --git a/notebook.ipynb b/notebook.ipynb
index 0cb4c87d901ec0f1b37b591f5fbb38db72be2574..f77eefb76ea91307c6c0704812a8b86f5d14fd20 100644
--- a/notebook.ipynb
+++ b/notebook.ipynb
@@ -1,7 +1,7 @@
 {
  "metadata": {
   "name": "",
-  "signature": "sha256:50f0011df38c64a61f87d0fd5e0bd41496c221072c1ed80168340a42e699384e"
+  "signature": "sha256:ffac64912e6dd086a01e7335bc70811bb3d120474fe85a1a87e60f80994db347"
  },
  "nbformat": 3,
  "nbformat_minor": 0,
@@ -305,7 +305,9 @@
       "- Add elegant explanatory text\n",
       "- Direct output of computations\n",
       "- Add figures and video\n",
-      "- Integration in Git"
+      "- Integration in Git\n",
+      "- Export your notebooks to PDF or HTML (nbconvert)\n",
+      "- Share notebooks easily with nbviewer"
      ]
     },
     {
@@ -376,6 +378,7 @@
       "    \n",
       "    \n",
       "- Remotely, Shark cluster LUMC\n",
+      "  - Connect to shark\n",
       "  - Type 'notebook' and click the given URL"
      ]
     },
@@ -384,7 +387,7 @@
      "level": 1,
      "metadata": {},
      "source": [
-      "The user interface"
+      "The notebook user interface"
      ]
     },
     {
@@ -556,7 +559,7 @@
      "level": 1,
      "metadata": {},
      "source": [
-      "Two mayor cell types"
+      "Two different cell types"
      ]
     },
     {
@@ -585,7 +588,15 @@
      "cell_type": "markdown",
      "metadata": {},
      "source": [
-      "This is a markdown cell which allows to format your document nicely and add context to code cells."
+      "- Markdown cell\n",
+      "    - Format your notebook\n"
+     ]
+    },
+    {
+     "cell_type": "markdown",
+     "metadata": {},
+     "source": [
+      "This is a markdown cell which allows to format your document **nicely** and add *context* to code cells."
      ]
     },
     {
@@ -609,7 +620,14 @@
      "level": 1,
      "metadata": {},
      "source": [
-      "Running python code"
+      "Code cells"
+     ]
+    },
+    {
+     "cell_type": "markdown",
+     "metadata": {},
+     "source": [
+      "Mainly contain Python code"
      ]
     },
     {
@@ -617,7 +635,15 @@
      "level": 4,
      "metadata": {},
      "source": [
-      "All of the python goodness works!"
+      "All of the python goodness works inside code cells!"
+     ]
+    },
+    {
+     "cell_type": "heading",
+     "level": 1,
+     "metadata": {},
+     "source": [
+      "Running cells\n"
      ]
     },
     {
@@ -819,7 +845,7 @@
      "level": 1,
      "metadata": {},
      "source": [
-      "\u00a7 Excercise : My first Notebook"
+      "\u00a7 Excercise : My first Notebook (1)"
      ]
     },
     {
@@ -837,7 +863,7 @@
       "  - Remember the keyboard shortcuts or the help function ('h')\n",
       "\n",
       "\n",
-      "Notice the laste cell produced output! We will continue to develop this notebook later this session."
+      "Notice the last cell produced output! We will continue to develop this notebook later this session."
      ]
     },
     {
@@ -900,7 +926,7 @@
      "level": 4,
      "metadata": {},
      "source": [
-      "Show some output and use it into another function"
+      "Example: Show some output and use it into another function"
      ]
     },
     {
@@ -1129,7 +1155,7 @@
      "cell_type": "markdown",
      "metadata": {},
      "source": [
-      "Since markdown is a subset of HTML, this will also work"
+      "Since markdown is a superset of HTML, this will also work"
      ]
     },
     {
@@ -1232,7 +1258,7 @@
      "metadata": {},
      "source": [
       "<br></br><br></br>\n",
-      "Some final examples:"
+      "Some other examples:"
      ]
     },
     {
@@ -1320,7 +1346,7 @@
      "level": 1,
      "metadata": {},
      "source": [
-      "\u00a7 Excercise : My first Notebook"
+      "\u00a7 Excercise : My first Notebook (2)"
      ]
     },
     {
@@ -1330,9 +1356,9 @@
       "Let's add some markdown cells to the notebook you created earlier:\n",
       "  - Select the top code cell\n",
       "  - Press ESC to go into command mode\n",
-      "  - Press 'b', this will add a cell above the selected cell\n",
+      "  - Press 'a', this will add a cell above the selected cell\n",
       "  - Notice the focus is on the new cell\n",
-      "  - Now press 'm' to set the celltype to Markdown\n",
+      "  - Now press 'm' to set the celltype to 'Markdown'\n",
       "  - Press ENTER and add some code (see below for example)\n",
       "  - Run the cell and see if it worked\n"
      ]
@@ -1424,23 +1450,48 @@
      ],
      "prompt_number": 46
     },
+    {
+     "cell_type": "heading",
+     "level": 1,
+     "metadata": {},
+     "source": [
+      "\u00a7 Excercise : My first Notebook (3)\n",
+      "    "
+     ]
+    },
+    {
+     "cell_type": "markdown",
+     "metadata": {},
+     "source": [
+      "A palindromic sequence is a nucleic acid sequence (DNA or RNA) that is the same whether read 5' (five-prime) to 3' (three prime) on one strand or 5' to 3' on the complementary strand with which it forms a double helix. Palindromic sequences play an important role in molecular biology:\n",
+      "\n",
+      "http://en.wikipedia.org/wiki/Palindromic_sequence\n"
+     ]
+    },
     {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
-      "Palindromic sequences play an important role in molecular biology:\n",
       "\n",
-      "http://en.wikipedia.org/wiki/Palindromic_sequence"
+      "<a href=\"url\"><img src=\"http://upload.wikimedia.org/wikipedia/commons/thumb/7/75/DNA_palindrome.svg/1590px-DNA_palindrome.svg.png\" align=\"center\" width=\"500\" ></a>\n"
+     ]
+    },
+    {
+     "cell_type": "heading",
+     "level": 4,
+     "metadata": {},
+     "source": [
+      "Take some time to develop your notebook further and add the following features to your notebook:\n"
      ]
     },
     {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
-      "Add the following features to your notebook:\n",
-      " - Think of function which can test if a seqeunce is palindromic\n",
+      " - Think of function which can test if a sequence is palindromic\n",
+      "   - Use the functions 'translate' and 'reverse'\n",
       " - Nicely formatted mardown cell(s) explaining the notebook\n",
-      "   - Add links as references like above"
+      "   - Add links as references like the one above\n"
      ]
     },
     {