Ketchup is a condiment made from tomatoes, vinegar, sugar and a number of spices. To make ketchup from tomato paste, you simply add the other ingredients in the right amount. This won't be easy, because ketchup-making companies keep their recipes a secret. You can find some alternative recipes on the internet.
Tomato puree
The difference between a fruit sauce and a fruit puree is that a fruit puree is fruit that has been pureed so you are left with the juice and pulp of the fruit. A fruit sauce is fruit with other ingredients used to make the sauce.
one is smoother
I assume you mean "ketchup which is 100% tomato", since all ketchup is 100% ketchup. The equivalent of 100% tomato ketchup would be passata (sieved tomatoes), or tinned tomatoes, or even tomato puree. (Regular ketchup also contains vinegar, sugar and spices to make it taste like ketchup).
Yes, if you are making the sauce yourself you could use tomato puree instead of tomato ketchup in the recipe or if you want to be really lazy, just use curry ketchup.
usually tomato puree is added to a curry (chicken curry) to add a red/orange color along with turmeric however there are some curries which do not have tomato paste in it
puree or ketchup passata
Tomato puree
No, heating tomato puree will cause it to thicken.
how many table spoons are in 140 grams of tomato paste
It is also called tomato puree in the UK.
There is no chemical name for ketchup. Ketchup is a complex mixture of many different chemical substances.