Why Preserve Food?
Name one reason early humans preserved food.
To survive during seasons when food was scarce, store extra food, travel longer distances, or spend less time hunting and gathering.
Which preservation method uses very low temperatures to keep food from spoiling?
Freezing.
What is the scientific term for the classification of living organisms?
Taxonomy
What type of microorganism helps turn milk into yogurt?
Bacteria
What part of a human cell contains its DNA?
The nucleus
What major change in the way humans lived did food preservation help make possible?
It helped humans transition from a nomadic lifestyle to living in settled communities.
What are the three main categories of food preservation discussed in class?
Physical, chemical, and biological
What is the smallest unit of a living organism?
A cell
Is yeast a type of bacteria or fungi?
Fungi
What is one major difference between a bacterial cell and a human cell?
Human cells have a membrane-bound nucleus, while bacterial cells do not.
Name two foods people eat today because they contain beneficial microorganisms.
Any two: yogurt, kimchi, kefir, miso, tempeh, kombucha, sauerkraut, or aged cheeses.
Name two chemical methods of preserving food.
Any two: salting and curing, sugaring, pickling, or smoking
What does homeostasis mean?
The ability of an organism to maintain a stable internal environment, such as body temperature or pH
What gas does yeast produce that causes bread dough to rise?
Carbon dioxide
Name three conditions microorganisms need to grow in food.
Any three: nutrients, available water, suitable temperature, suitable acidity, and appropriate oxygen conditions.
How did preserving food allow early humans to spend more time developing other skills?
They no longer needed to spend as much time hunting and gathering because they could store food for later.
What is the biological method of food preservation that uses microorganisms?
Fermentation
What are the three domains of life?
Bacteria, Archaea, and Eukarya
Explain how microorganisms can be both helpful and harmful to our food
Some microorganisms help produce foods such as bread and yogurt, while others cause food to spoil or make people sick.
How do bacteria and fungi obtain the nutrients they need to survive?
They absorb nutrients from their surroundings, often using enzymes to break food down into smaller substances.
Explain two ways food preservation helped early human societies develop.
It allowed people to settle in communities, survive food shortages, travel farther, and devote more time to activities beyond finding food.
Explain how drying and pickling help prevent food from spoiling.
Drying removes available water that microorganisms need to grow. Pickling increases acidity, making it difficult for some microorganisms to grow.
Why are viruses generally not considered living organisms according to the characteristics of life discussed in class?
Viruses are not made of cells and cannot reproduce independently without a host
What happens when yeast naturally found on fruit begins feeding on the sugars in the fruit?
Alcoholic fermentation occurs, and the yeast converts sugars into alcohol.
A strawberry provides food for humans, but it can also provide a home for microorganisms. Explain why microorganisms can grow on a strawberry.
Strawberries contain water, sugars, and other nutrients that microorganisms need. When conditions such as temperature and acidity are suitable, microorganisms can grow and reproduce on the fruit.