Body Systems
Which system starts the process of getting energy from food?
digestive system
Chewing food into smaller pieces is an example of what type of digestion?
mechanical digestion
What is the job of an enzyme?
To speed up chemical reactions
Where does most nutrient absorption happen?
small intestine
In the iodine-starch lab, what did the iodine represent?
A nutrient or molecule moving through a membrane
Which system brings oxygen to cells so they can release energy?
respiratory system
Stomach acid breaking food into new substances is an example of what?
chemical digestion
What is the substance an enzyme acts on called?
substrate
What are the tiny finger-like structures that increase surface area?
villi
What did the starch bag represent in the diffusion demo?
A cell or part of the digestive system
Which system moves nutrients and oxygen to all parts of the body?
circulatory system
Which type of digestion changes the size of food but not the substance?
Mechanical digestion
What do we call the new substance formed after an enzyme reaction?
product
What is absorption?
The movement of small molecules from the digestive system into the bloodstream.
How did the color change show diffusion?
Iodine moved from high concentration outside to lower concentration inside.
Why do body systems need to work together to get energy from food?
Because digestion breaks food down, absorption moves nutrients into the blood, and circulation delivers them to cells.
Which type of digestion changes food into new substances?
Chemical digestion
Why are enzymes important for digestion?
They allow reactions to happen quickly at body temperature.
Define diffusion.
The movement of molecules from an area of high concentration to low concentration.
Why is a model helpful for understanding digestion and absorption?
It helps us see processes that are too small or slow to observe directly.
Describe how three body systems work together during digestion and energy use.
Digestive breaks food down, circulatory transports nutrients, respiratory supplies oxygen for cellular reactions.
Explain how mechanical and chemical digestion work together.
Mechanical digestion increases surface area, allowing enzymes and acids to chemically break food into smaller molecules.
What would happen if enzymes didn’t work properly in the digestive system?
Food wouldn’t break down into small enough molecules to be absorbed.
Why must nutrients be broken into small molecules before absorption?
Large molecules cannot pass through cell membranes.
A student says food doesn’t need to be broken down because it already has nutrients. Is the student correct? Explain.
Incorrect—nutrients must be broken into small molecules before they can be absorbed and used by cells.