Ch 14 - Human Digestive System Flashcards
Why do we need carbohydrates?
They provide our body with energy.
What are sources of carbohydrates?
- starch (rice, bread, cereal)
- sugars (glucose in fruit, sucrose in sweets)
Why do we need protein?
- grow and repair damaged tissues in our body
- provide energy
What are sources of protein?
- animal - fish, meat, egg white, cheese
- plant - soya beans, nuts
Why do we need fats?
- provide our body with energy
- keep our body warm
What are sources of fats?
- butter, margarine
- cooking oil
- coconut
Why does food need to be digested?
- Molecules of nutrients (starch, protein fats) are too large to pass through the cell membrane.
- Must first be broken down into small molecules.
What is digestion?
The breaking down of large, insoluble and complex food molecules into smaller, simpler and soluble molecules in the body.
The digestion of food begins in the…
MOUTH 👄
What is the starting and ending point for digestion?
start: mouth
end: small intestine
What is physical digestion?
It involves mechanical break up of food into smaller particles.
What are two types of physical digestion?
- chewing
- churning action
What is chemical digestion?
It involves break down of large molecules into small soluble molecules that can be absorbed.
What are enzymes?
Biological catalysts that speed up chemical reactions without changing itself at the end of the reactions.
Enzymes only react with…
substances that have a complementary shape to their molecules.
What are substances that react with enzymes called?
substrates
Lipase is effective in removing what type of dirt?
grease dirt
Protease is effective in renoving what type of dirt?
protein dirt
What are the organs in the alimentary canal?
- mouth
- esophagus
- stomach
- small intestine
- large intestine
- anus
What organs help in digestion (but are not in the alimentary canal)?
- liver
- gall bladder
- pancreas
Describe the physical digestion in the mouth?
The teet cut and grind food into smaller pieces –> increases surface area for digestion
Describe the chemical digestion in the mouth.
Salivary amylase digests starch into maltose.
What can be digested in the mouth?
carbohydratess (only)
Are enzymes present in the oesophagus?
NOPE 🙅 NUH UH
