Use of biological resources Flashcards
(21 cards)
Advantages of pesticides
Kills all pests
Relatively cheap
Easy to apply
Fast
Advantages of biological control
Does not involve chemicals
Only need to apply once
Specific to killing the pest
Disadvantages of pesticides
Can get into the food chain and poison other organisms
Pests can evolve resistance
Needs to be reapplied frequently
Disadvantages of biological control
Doesn’t wipe out pests, just controls them
May also affect other organisms in the food web
Can be slow
What is the test for protein?
Biuret
What is the color when protein is present
Lilac
What is the test for starch?
Iodine
What is the color when starch is present?
blue-black
What is the test for glucose?
Benedict’s
What is the color when glucose is present?
green, orange, brick-red
What is the test for lipids?
Ethanol
What happens when lipids is present?
turns milky white emulsion
What are the steps in the breadmaking process?
1️⃣ Mix ingredients
2️⃣ Yeast respiration (fermentation)
3️⃣ Carbon dioxide causes rising
4️⃣ Resting the dough
5️⃣ Baking
What are the ingredients in bread?
Flour, water, yeast and sugar.
What happens in yeast respiration?
First yeast uses sugar to respire aerobically but soon runs out of oxygen. So it switches to anaerobic respiration. This creates CO2 and ethanol. CO2 makes the bread rise.
What happens in baking?
The yeast dies and ethanol evaporates.
What happens in fermentation?
The amylase in the yeast first breaks down starch into maltose. Then this sugar is used for anaerobic respiration releasing ethanol and CO2 which makes dough rise.
Steps in Yoghurt production
- Sterilization
- Pasteurization
- Incubation
- Fermentation
- Cooling
- Additions
What happens in pasteurization?
Milk is heated to 72 degrees for 15 seconds then cooled rapidly.
What happens in incubation?
Lactobacillus is added and incubated at 40 degrees.
What happens in fermentation?
Bacteria convert lactose into lactic acid and pH drops.
