Food Flashcards
Tell me about selective breeding pretty please
Involves selecting plants or animals with good characteristics and breeding them together. Eg their characteristics - plant high yield or pest resistant, animals - large high milk yield for cows. Breed them together. Select the offspring with the best characteristics and breed them together yay incest? Continue over several generations and then you’ll get plants with high yield and pest resistance or massive cows that make tons of milk for milkshakes
Why do humans rely on plants for food
Plants are producers in all food chains, they use energy from sunlight to convert carbon dioxide and water into organic compounds eg carbohydrats. Humans and other animals eat digest and absorb thee compounds which we use for energy and growth
What are fertilisers
Chemicals that provide nutrients that plants need to grow eg nitrates phosphates and potassium
Why are fertilisers needed
Minerals in soil used up by plants and fertilisers replace these minerals so a lack of them doesn’t limit crop growth. Can be manmade or natural eg compost
What are pesticides
Chemicals that increase crop yield by killing pests that feed on the crops
What do pesticides do
Increase yield by meaning fewer plants damaged or destroyed. Problem is if pesticide isn’t specific it kills other non pest species too but farmer sjin doesn’t care because he’s got mahogany doors
What do antibiotics do
Can be given to animals to increase food production. Antibiotics kill or inhibit bacteria growth so animals can use more of their energy for their own growth increasing food production
How is cheesy cheese cheese made
From milk that has been curdled. Curds are acted upon by lactobacillus bacteria. Cheese can be given additional flavour by contamination with fungi such as penicillium to produce blue cheese
How is Bready bread bread made
Made to rise by yeast which respired anaerobically to release carbon dioxide. Bubbles of co2 collect which causes the dough to rise
What are three advantages of using microorganisms to grow foodage
Production can be many times faster than animal or plant protein. Contains no fat or Cholesterol. Good source of protein for vegetarians
What are disadvantages of using microorganisms to grow food for human consumption
Protein has to be purified to ensure uncontaminated. Isolation of protein as microorganisms are grown in huge fermenters and need to isolate the protein from the growth material
How does salting prevent food spoilage
Inhibits growth of microorganisms by interfering with their ability to absorb water, which they need to survive. Some meats preserved by salting and tinned foods often preserved in brine which is a mixture of salt and water
How does adding sugar prevent food spoilage
Inhibits growth of microorganisms by interfering with ability to absorb water. Eg lots of sugar in jams reduces growth of microorganisms so has long shelf life
How does pickling prevent food spoilage
Pickle in vinegar which has a low ph which reduces enzyme activity so microorganisms can’t function properly, inhibiting their growth. Vinegar used to pickle onions etc
How does freezing prevent food spoilage
Keeps food below -18*c. Slows down rectioms taking place in microorganisms and also freezes water so microorganism can’t use it
