microbes and food Flashcards
what is the role of bacteria in the production of yoghurt?
the bacteria produces lactic acid by turning lactose sugars into lactic acid, and causes the milk to ferment
what is anaerobic respiration?
the process of generating energy without oxygen
what is fermentation
a metabolic process in organisms that converts carbs into chemical energy without requiring oxygen, which results in ethanol and lactic acid
how is aerobic respiration involved in the production of bread?
cellular respiration helps bread rise by creating c02
how is anaerobic respiration linked to fermentation?
yeast respires anaerobically to produce ethanol and c02 from glucose = fermentation
why add sugar to bread?
to provide the yeast with food
why kneed the dough?
to spread c02 thoroughly threw out the dough
why put the dough in warm conditions?
yeast activity increases in warmer environments which speeds up the rise
why does the bread dough rise?
because yeast eats the sugar and releases c02 which gets trapped by the gluten & causes it to rise
what happens to the yeast cells in the cooking process?
they die because of high temp
what is the waste chemical in animals
lactic acid
what happens when oxygen is low?
aerobic respiration occurs
what does a build up of lactic acid cause?
fatigue
what is pasteurizing?
pasteurizing is heating to kill harmful microogranisms
what does the lime water experiment test for?
c02
what is the yeast cell wall made of?
chitin
what is the bacteria cell wall made of?
muerin
what do yeast cells have?
nucelus, cell wall, cytoplasm, mitchocondria
what do bacteria cells have?
cell wall, cytoplasm
what is the yeast anaerobic word equation?
carbon dioxide - ethanol
what is the yeast aerobic word equation?
glucose + 02 - co2 + water
what is the bacteria anaerobic word equation?
glucose - lactic acid
