Ch 21 - (Biotechnology and genetic modification) Flashcards
What is used by humans to produce foods and other substances?
Microorganisms
what is the most common type of microorganism used in biotechnology?
Bacteria
Why is bacteria useful is biotechnology?
- capable of producing complex molecules
- reproduce rapidly,
What’s re additions useful effects of using bacteria?
- There are few ethical considerations to growing them in large numbers in the laboratory
- They possess plasmids
Plasmids are small, circular loops of DNA which can be an ideal way of transferring DNA from one cell to another during genetic manipulation
What is yeast?
single celled fungus that uses sugar as its food source
What happens when yeast respires?
ethanol and carbon dioxide are produced (and energy is released)
what happens when ethanol is produced by yeast?
increasingly being used as a biofuel (a fuel made from living organisms rather than a fossil fuel like oil, coal or gas)
What is sued as the substrate for producing ethanol?
- Plant material is used for producing ethanol (as a source of glucose) - it is chopped up into small pieces and mixed with yeast which respires anaerobically and produces ethanol
What happens from the leftover liquid from ethanol?
- separated from the remaining solids and any water is removed, leaving a concentrated solution of ethanol
- waste parts of crop plants, such as the stalks or outer leaves, are used, but in other places, crops are grown specifically to be harvested for making ethanol
- causing concern that there is less land available for local people to grow food crops needed for survival
How does yeast respire in bread making?
respire anaerobically if it has access to plenty of sugar, even if oxygen is available
How is respiration of yeast in bread an advantage?
- bread making, where the yeast is mixed with flour and water and respires anaerobically, producing carbon dioxide:
- Carbon dioxide produced by the yeast during respiration is caught in the dough, causing the bread to rise
How is fruit juice produced?
- by squeezing the fruits to remove the juice
- chopping the fruit up before squeezing helps to release a lot more juice, but this does not break open all the cells, so a lot of juice is lost
- adding an enzyme called pectinase
- Pectinase works by breaking down a chemical called pectin that is found inside plant cell walls
- Once pectin is broken down, the cell walls break more easily, and more juice can be squeezed out of the fruit
- Adding pectinase to fruits also helps to produce a clearer juice as larger polysaccharides like pectin can make the juice seem cloudy - once they are broken down into smaller molecules, the juice becomes clearer
How is biological washing powders made?
- stains on clothes are organic molecules
- detergents that only contain soap can remove some of these stains when mixed with hot water, but it can take a lot of time and effort and very high temperatures
- Biological washing powders contain enzymes
What is the advantage of using biological washing powders?
- Quickly breaking down large, insoluble molecules such as fats and proteins into smaller, soluble ones that will dissolve in washing water
- They are effective at lower temperatures, meaning less energy (and money)
- They can be used to clean delicate fabrics that would not be suitable for washing at high temperatures
What is lactose?
the sugar found in milk
What are human babies born with?
the ability to produce lactase, the enzyme that breaks down lactose
