Living Systems

Focus Question: How do cells get the food they need?

Investigation 1-2

Investigation ReviewLife happens in cells

Multicellular organisms are made of many living cells

Cell need certain resources to survive, including

Water

Food

Gas Exchange

Waste Removal

Circulatory system circulates blood, which transports the substances living cells need

The first part of this investigation focused on the circulatory system’s relationship with the respiratory system.

The result was gas exchange.

We found out how cells get the oxygen they need and get rid of the waste gas, carbon dioxide.

In this part of the investigation we will find out how cells get the food they need and how they get rid of wastes that are not gases.

Focus Question:

Talk in your groups about how you think cells get the food they need and what kind of food cells use.

Ideas?

Cookie ChallengeImagine that you are small enough to fit on the cookie before you.

As you eat the cookie, draw the route you are taking on the human body outline. Then, write what is happening at each stage of the route.

DigestionWhen you eat a cookie, soup and sandwich, or a burrito, you are providing food for your cells.

Cells can’t eat bread, lettuce, mustard, and cheese.

Cells can only use simple substances for food.

Food you eat has to be changed into food that cells can use.

Process is called digestion.

Digestion is a long process.

Like a disassembly line.

Complex food goes in at one end of the line.

It is taken apart bit by bit as it moves through the system.

Read an article about the digestion process to find out how food we eat is turned into food that our cells can use.

Pg. 91, Disassembly Line

Answer notebook questions when done

The Disassembly Line ReviewWhy do people eat food?

What happens to food in the digestive system?

Describe the path taken by food as it passes through the digestive system.

Explain what happens to food at each place in the digestive system.

How does digested food get to cells?

Why do people need kidneys?

Describe how kidneys work.

Digestion VideoWatch and listen for information that confirms or extends what you know about the digestive system

Think about how new information relates to the big idea of life support for cells

Review Video Questions

Experiment ReviewThe students in the video conducted an experiment to find out what happens to food (hard-boiled egg white) in different environments.

Talk in your groups about the experiment:

What was the question?

What was controlled?

What was changed?

What were the results?

What was the conclusion?

System InteractionHow do the digestive and excretory systems interact?

Digestive system breaks the food into molecules that the blood transports to all the cells in the body.

Cells produce waste, which enters the blood.

Waste travels to the kidneys, which filter it out.

Two systems interact where the cell exchanges food and waste with the blood

Digestive system -Disassembles food into nutrients that cells can use

Mouth and Teeth -Moisten and crush food before it moves through the esophagus to the stomach

Esophagus -Tube connecting the mouth and stomach

Pushes food through by peristalsis - squeezing

Digestive juices -Juices added to food in the stomach, small intestine, and large intestine to help release nutrients into the bloodstream.

Stomach -

The organ where food is reduced to mush by acid and muscle activity (squeezing).

Small Intestine -

Where digestion really happens. Nutrients from digested food are absorbed into the bloodstream.

Large Intestine -

Water is removed from undigested food, leaving solid waste.

Colon - End of the large intestine where food waste is compacted and dehydrated

Kidney - Filters cellular waste from the blood and turns it into urine

Urine - Liquid waste produced by kidneys

Bladder -Organ that stores urine until it is eliminated

How do cells in humans get the nutrients they need?The digestion system reduces food to nutrients. Nutrients pass out of the digestive system into the bloodstream for transport to all the cells.How does the digestive system work?Physical and chemical processes break complex food into simple substances as it progresses from the mouth through the esophagus to the stomach, small intestine, large intestine, and colon.

How are cellular wastes removed from the blood?

Blood filters through the kidneys, which remove cellular wastes, convert them into urine and store them in the bladder.

Your questions?