Physical and Chemical Changes and Digestion

What should be done first to conduct an experiment safely?

• Get any chemical that are needed from the supply cabinet and open the bottles.

• Begin heating any chemicals that will need to be hot.

• Begin mixing any chemicals that are needed for the experiment.

• Read every step of the procedure to make sure they understand it.

• Begin collecting any equipment you think you will need.

Which of the following describe chemical changes that occur in the digestive system. May be more than one answer.

• Teeth tear food into small pieces

• Esophagus carries food to the stomach

• Amylase mixes with food and breaks down carbohydrates into sugars

• Gastric juices mix with food in the stomach to create a new substance, chyme.

• Excess water is absorbed in the large intestine

What distinguishes each process as a chemical change

• Mixing of substances

• New substance are created

• Substances move to different locations

• Substances are broken into smaller pieces

• Substances are dissolved

Both chemical and physical changes occur in digestion. A physical change occurs when ___

• a change in color occurs

• a new substance is created

• shape or size is altered

• Light is produced

• All of the above

Which best describes why a diabetic should not have too many carbohydrates?

• Carbohydrates break down into sugars, which could cause a diabetic to have a high blood sugar level.

• Carbohydrates are known for giving people energy and diabetics do not need that much energy.

• Diabetic should eat a healthy diet and carbohydrates are not healthy.

• Carbohydrates are too difficult for the body to break down putting too much stress on the organs of a diabetic.

Which step in the digestive process represents a chemical change in food?

• Storing of swallowed food in the stomach

• Churning of food liquids and digestive juices in the stomach.

• Movement of food down the esophagus to the stomach.

• Chewing food to break it down into smaller pieces

• Substances in the mouth and stomach breaking down fats and proteins.

Which of the following examples includes only chemical changes that occur in the digestive process?

• Absorption of nutrients by villi in the small intestine

• Chewing and swallowing food

• Recycling of water from dissolved food back into the body

• Reaction of saliva, stomach acid, bile, and pancreatic juices with food.

• Churning food in the stomach.

Which of the following would this be considered a chemical in matter?

• Food is torn into smaller pieces by grinding or smashing of food before swallowing.

• Sand and water are mixed to form sandy water.

• Waves crashing against rocks smashing them into smaller pieces

• Water evaporating from a sidewalk after a rainstorm.

• Carbohydrates must be broken down into sugar to get energy.

Which of the following processes best describes a physical change that occurs during digestion

• Stomach acid breaks down proteins

• Bile breaks down fat

• Saliva breaking down large molecules into smaller molecules

• Chewing food to break down large pieces so they can be swallowed

• Pancreatic enzymes breaking carbohydrates into sugars

Which of the following processes describe physical changes in the food particles. Could be more than one answer.

• Teeth tear and grind food down into smaller pieces.

• Enzymes in saliva in the mouth breaks down the starch in food.

• The tongue reforms the food as it is pushed by stomach muscles

• Food is broken into smaller pieces by stomach muscles.

• Food is exposed to acid in the stomach, which causes food particles to break down even further.