Introduction
So, why do we need to eat? Some people say "So we can go to the bathroom!" Some leftovers of your food do end up being flushed away. But is that all that happens to our food? Don't some other parts get used? Think about what they get used for.
When you were born, you probably weighed ten pounds or less. Now you weigh much more. Ask yourself why. Where did all that "new you" come from? You know that you are made from atoms and molecules that are organized into cells. In this activity, you will learn that these atoms and molecules came from your food. Your food is broken down into smaller pieces that build your cells.
Here's another thing to ask yourself. Where do you get the energy you need to run and dance? How does your heart keep beating? Everything you see needs some kind of energy to run. Cars use gasoline. Vacuum cleaners use electricity. Phones use the chemical energy stored in their batteries. In this webquest, you will learn the energy you need to live comes from your food.
You will be directed to four different web pages to gather information. You don't need to read the whole page, just look for the information you're asked for. You can turn your sentences into a small essay that will help you remember what you learnd about why we need to eat.
Task
Task 1: Use the article at the site linked here.
Learn how we get energy from food.
Paragraph 1:
1. The process through which animals and plants break down food molecules to get energy for the functions of the cells is called:
Paragraph 2:
2. In cellular respiration, __________________________ is broken down in the presence of _______________________ .
3. The waste products of cellular respiration are _________________________ and _____________________________ .
4. The chemical reaction of celelular respiration is:
__________________ + _________________ --> __________________ + __________________ + __________________
Paragraph 3:
5. All cells need _________________________ to function.
6. __________________, a simple sugar, provides the fuel the cell needs. Although energy is also stored in larger molecules, such as complex carbohydrates and fats, they must be broken down into molecules of __________________ before the cell can use their energy.
Paragraph 4:
7. Cellular respiration takes place in cell organelles called __________________ .
8. The number of _________________ per cell varies; liver and muscle cells, which require large amounts of _________________ to _________________, may have thousands.
Task 2: Learn how we use lipids (fats) in our food as building blocks of cells and to make other important compounds that our bodies need.
Paragraph 1:
Lipids are one of the four major groups of organic molecules, the others being _________________ , _________________ , and _________________ .
Paragraph 3:
The roles that lipids play in living organisms include _________________ , _________________ , and _________________ .
Paragraph 4:
Fats are used as energy _________________ .
Paragraph 5: Summarize the main ideas of this paragraph. Be sure to answer these questions:
1. Do you need fat in your diet?
2. How much fat should be in your diet?
3. What happens of you eat too much fat?
Task 3: Learn how we use carbohydrates (sugars and starches) in our food as building blocks of cells and to get energy for cell processes.
Paragraph 1:
The types of foods that contain carbohydrates are:
Paragraph 3:
The three reasons carbohydrates are important for plants and animals are:
Paragraph 6: What happens to leftover carbohydrates?
When you eat more carbohydrates than your body needs, your body converts them into ___________ . The reason your body does this is:
Task 3: Learn how we use proteins and their building blocks, amino acids, to make the molecules we need to survive.
Paragraph 1: What are amino acids?
Living organisms use amino acids to make ________________________ . We can make some amono acids in our bodies, but the rest we must get through ____________________________ .
Paragraph 2: What are proteins?
There are _____________________ of different _______________________ in our bodies. They performs al kinds of _____________________________ to help our bodies survive.
Paragraph 3: Why are they important?
About ________ of our body is made up of proteins. Every cell in our body uses ____________________ to provide functions.
Paragraph 4: How are they made?
Proteins are made inside _____________ . The instructions for making proteins are in ____________ .
Process
Sum up what you learned by answering these three questions:
1. We get proteins, fats, and carbohydrates from food. Do you need all three types of molecules? Why?
2. If you had a diet with plenty of fats and carbohydrates but no protein, could you survive? Why of why not?
3. When you eat, you break the food you ate into small pieces that can be absorbed into the bloodstream. The blood then carries these small pieces to every cell in your body. According to what you read, what do your cells do with these pieces?
Conclusion
The two reasons we need to eat are:
____________________________________________
and
____________________________________________
Word bank: mitochondria glucose (used twice) energy oxygen carbohydrates proteins lipids (fats) molecules cells
1. We get _____________________ from _____________________ to power our cells. We break down ____________________ in the presence of ______________________ The parts of our cells where this happens are the _________________________ .
2. The three major types of molecules we get from food are:
3. We break down our food when we digest it. These pieces are then transported to our ____________ . Our cells use these pieces to make the _________________________ that we need to survive.