Biological Uses Flashcards
Bread
Yeast, sugar, water, flour, kneaded
Y, respire aerobically, reproduce
Y, respire anerobically, fermentation, no oxygen in dough
CO2 produced, rise
Dough cooked, kill yeast, ethanol evaporates, dough rises, CO2 expands, dries as water evaporates
Beer
Barley trains in warm water, germinate
Enzymes break down starch into sugar, grains dried, malting
Malted grain mashed, water added, made sugar solution, buts removed
Yeast added, ferments sugar into alcohol
Ethanol conc rises, kills yeast, fermentation slows down
Beer drawn off, pasterised
Wine
Grape juice, yeast, water
Yeast ferment on sugar
Ethanol, alcoholic
Yoghurt
Starter culture of bacteria added to warm pasteurised milk
Bacteria ferment, lactose, lactic acid, acidic taste
Lactic acid, milk proteins coagulate, solidifies milk
Cheese
Starter culture of bacteria added to warm milk
Ferment
Rennin added, milk curdles, curds whey
Whey removed, salt, bacteria, mound added to curds
Growing microbes
Grow on agar
Sterilised easily, prevent contanimantion
Agar with nutrients added to it
Microbes grown in fermenters
Fermenters
Anaerobic or aerobic
Microbes grown for products
Control conditions
Fish farming
Intensive rearing of fish
Prevent depleting wild fish stocks
Advantages of fish farming
Kept in large seawater enclosures Temp, oxygen, diet,water carefully monitored No predators Pesticides kill parasites Selective breeding
Disadvantages of fish farming
High potential for spread of disease
Eutrophication
Pesticides are toxic
Wild fish used to make food pellets