Fruit fly as a context to learn Biochemistry by building up from basics!

So today’s discussion started with arunan sir’s question that was what are enzymes and what’s enzymatic reaction? I could only think of one enzyme that is amylase as it’s present in our saliva which breaks starch into it’s smaller form that is glucose

Next question was 'Is this enzyme (amylase) present in fruitfly?
To know the answer, we need to look at the composition of media and nutrients that fruit fly get from media. So you can see the list on board (also given below) and as there are 2 types of sugars used sucrose and dextrose i knew that sucrose is a disaccharide and will contain 2 sugar molecules but I thought that dextrose is a polysaccharide and contains 10 monomer… but no! dextrose is D glucose and @saida786110 corrected it. Then for yeast extract, I told it contains just protein cause that’s what i heard before in previous discussion, well then we went true wikipedia site according to which it also contains fiber, vitamin (not vitamin B12) and glutamic acid or free glutamate

I didn’t knew what is glutamic acid so @saida786110 told that it’s an amino acid so i didn’t knew the structure of amino acid so we started building up on that, basic idea was that there’s amino group (NH2) and an acid group (-COOH) so i joint them directly, but it was not correct so @PChitralekha ma’am made it right by saying that there will be a carbon (H-C-R group) in between, that will connect amino group with acid group

Then with that idea we made a basic or smallest amino acid
Which is glycine made when R is replaced by H and then we have alanine which has a methyl (CH3) in place of R and valine which has a propyl (C3H7) attached to middle carbon

Again we went to first White board and talked about std cornmeal agar media and compared it with BRSV and TRSV media…

As per me a proper comparison would be…
According to their their nutritive value and amount (to make 250ml of media) used with respect to their role in media

To provide nutritents

  1. Maize powder - Carbs, fiber & Vitamins - 20.75gms
  2. Yeast extract - Rich in proteins also has some vitamins and fiber - 3.75gms
  3. Sucrose - Carbs - 6.25gms
  4. Dextrose - Carbs - 12.5gms

To solidify media
5. Agar - Vitamins, Carbohydrates, Nitrogen, and Salts. (According to wikipedia) - 4gm

To avoid contamination
6. Propionic acid - Acid - 1ml
7. Orthophosphoric acid - Phosphorus and Acid - 0.17ml


  1. CUBE Chatshaala:- The Causerie will still be on! - #18 by Lydia

  2. Bloomington Drosophila Stock Center: Indiana University Bloomington

Media we use at home lab is BRSV (Banana Rava Sugar Vinegar media) or TRSV (Tomato Rava Sugar Vinegar) media used in other home labs ingredients are same but proportion might differ…

To provide nutrition

  1. Banana for BRSV - Calories: 89
    Water: 75%
    Protein: 1.1 grams
    Carbs: 22.8 grams
    Sugar: 12.2 grams
    Fiber: 2.6 grams
    Fat: 0.3 grams [A]

Or Tomato for TRSV - folate, vitamin C, and potassium. [B]

  1. Sugar - Carbs

To solidify media
3. Rava -
Fat, Carbohydrate, Protein, Dietary Fibre, Folate, Niacin, Pantothenic acid, Riboflavin, Thiamin, Vitamin B6 [C]

To avoid contamination
4. Vinegar - Acetic acid

[A] Bananas 101: Nutrition Facts and Health Benefits

[B] Nutrient content of tomatoes and tomato products - PubMed.

[C] Times Foodie: Recipes, Food news, Vegetarian Recipes, Non Vegetarian Recipes, Nutritional Facts

and sir asked if it’s working well I told yes and I’ll start this again so sir told we should design what we will do and then do it so here’s the design :arrow_down:

Aim: To trap native fruit flies from Bandra, Mumbai

Objective: To trap fruit flies using Tomato (You can try with any fruit, curd, butter milk & vinegar too)

Research question: How to trap fruit flies at home

Hypothesis: Would get approximately 20 flies in 3 bait bottles

Materials - 3 empty bottles (for bait), 1 empty bottle (for transferring to media), tomato (or any other fruit),


  1. Put pieces of tomato in 3 empty bottles
  2. keep these 3 bottles near the dustbin
  3. Cover the mouth of the bottle when you see many fruitflies
  4. transfer the fruitflies in an empty bottle
  5. now transfer the fruitflies from empty bottle to the media bottle

Precaution: be careful while transferring the fruitflies as they might fly away

Design: Check the bottles 2 hours after keeping near the dustbin

Expectations: there would be at least 5 fruitflies in each bait bottle

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Isn’t it amazing how we are building a culture where people are not scared and nervous about sharing what they don’t know and what mistakes they made, which we very opposite of what we are taught in school and colleges where getting marks becomes a priority and easy by rattafication but understanding concept is at its least importance.

Let’s celebrate this with Smiti from Elphinstone College, Mumbai and others who helped simti to develop on her concept.