Chapter 3 - Micro-Organisms Flashcards
What makes a Bacterial Cell different from an Animal or Plant Cell?
It has no organelles or nucleus.
What is the function of Cytoplasm in a Bacterial Cell?
Contains enzymes and food molecules but no organelles.
What does Glycogen do in a Bacterial Cell?
Stores food
What is the function of Plasmids in a Bacterial Cell?
Carries a few genes
What is the function of a Flagella in a Bacterial Cell?
Helps make the bacterial cell move.
What is an Enzyme?
Any of various proteins, originating from living cells and capable of producing chemical changes in organic substances.
How are Bacterias classified?
According to their shape and colour of colony.
What is inside a Bacterial Cell?
It contains A CELL WALL, CELL MEMBRANE, SLIME COAT, PLASMIDS, CYTOPLASM, DNA, GLYCOGEN AND A FLAGELLA
What is the process that Bacteria use to reproduce?
Binary Fission
What is Binary Fission?
It is when the DNA in a bacterial cell multiplies, then the cell is divided in two (binary fission), the process is then repeated.
When is a spore formed?
Spores are formed under unfavourable conditions. When a bacteria cell is in a bad condition, a spore is formed as a protective layer. The bacterial cell inside it is dormant. When it is good for the bacterial cell to come out the spore bursts open.
Explain the resistance of bacteria to antibiotics.
Over time bacteria can become resistant to certain antibiotics. In large population of bacteria, there may be some that are not affected by the antibiotic. These survive and reproduce, creating more bacteria that are not affected by the antibiotic.
Why are bacteria so successful?
They can survive in bad conditions such as drought, poisons and heat. They have a very fast reproduction rate.
How do bacteria survive in bad conditions?
By producing a protective coat around themselves. (Spores)
What is Saprotrophic Nutrition?
Organisms that live on decaying material (dead bodies).
What are the different human uses of micro-organisms?
Getting rid of sewage Making butter, yoghurt and cheese Making linen Brewing and baking Making vinegar Making silage Making antibiotic Genetic engineering Producing edible proteins Producing enzymes
Using bread making, explain anaerobic respiration in yeast.
Anaerobic respiration in yeast is used during brewing and bread-making.
Glucose -> ethanol + carbon dioxide
Bubbles of carbon dioxide gas expand the dough and help the bread rise.
Name at least 5 methods of food preservation techniques.
Smoking Pasteurising Canning Cooling and Freezing Irradiation Pickling Drying, salting or coating in Sugar Cooking Plastic/paper wrapping Vacuum wrapping
How does smoking technique help preserve the food?
Food develops hardened dry outer surface; smoke contains antibacterial chemicals.
How does pasteurising technique help preserve the food?
Kills harmful microbes
How does canning technique help preserve the food?
Food is heated and then sealed in airtight containers.
How does cooling and freezing technique help preserve the food?
Don’t kill microbes but retard enzyme activity so that growth and reproduction is very slow
How does irradiation technique help preserve the food?
Kills microbes by disrupting DNA synthesis/structure.
How does pickling technique help preserve the food?
Kills microbes
