Digestive System and Enzymes Unit - Honors Biology Grade 9

Where does the digestive tube and respiratory tube meet?

pharynx

What stops food from traveling down the windpipe?

epiglottis

What macromolecule does the stomach digest and with which enzyme?

proteins and pepsin

What macromolecule does the small intestine digest and with which enzyme?

lipids and lipases

What does the large intestine do?

absorbs water, salts, and vitamins

What small organ is attached to the cecum of the large intestine?

appendix

What from the stomach enters the duodenum?

chyme

What is the first part of the small intestine called?

duodenum

What is the middle part of the small intestine called?

jejunum

What is the last part of the small intestine called?

ileum

What substance is created by what organ and stored in which organ to prepare fat for digestion in the small intestine?

bile created by the liver and stored in the gall bladder

What enzyme is made by what organ and digests what macromolecule in the small intestine? What are the products of that digestion?

lipase is contained in pancreatic juices created by the pancreas and digests lipids breaking them down into fatty acids and glycerol

How much percent of absorption happens in the small intestine?

90%

What is food mixed with gastric juices called?

chyme

What are rhythmic contractions that let food flow down the esophagus called?

peristalsis

What does saliva contain?

salivary amylase

What does salivary amylase do?

begins starch digestion by breaking it down from polysaccharides into disaccharides (maltose)

What is the mixture of food and saliva called?

bolus

What other macromolecule does the small intestine digest?

carbohydrates

What is extracellular digestion?

digestion that takes place outside of cells (in organs)

What is intracellular digestion?

digestion that happens inside of cells

What are catalysts?

substances that speed up a process (lower the amount of energy required for a reaction to occur)

What is activation energy?

energy required to break down bonds and initiate chemical reactions

What is a substrate?

a molecule that interacts with enzymes

What is denaturization?

to lose form or shape

What is an active site?

the part of an enzyme where the substrate attaches

What happens to an enzyme after it completes a reaction?

it is reused

What 2 factors affect enzyme activity?

temperature and pH levels

What is an inhibitor?

a substance that binds to the enzyme and does not let it do its job

What are the 2 types of inhibitors?

competitive inhibitor and allosteric inhibitor

What does a competitive inhibitor do?

occupies an active site so that the right substrate cannot attach

What does an allosteric inhibitor do?

attaches to an allosteric site which miss shapes the active site not letting the right substrate attach

What is an allosteric activator?

an inhibitor that attaches to an allosteric site and miss shapes the active site letting a different substrate fit into the active site

What are conenzymes?

organic molecules (vitamins) that help enzymes do their job

What are cofactors?

inorganic molecules (ions) that help enzymes do their job

What do teeth tell about an organism?

its diet

What do villi do?

increase surface area of food to make nutrients easier to absorb

What enzymes does the pancreas create?

trypsin, lipase, amylase

What does trypsin digest?

polypeptides

What does lipase digest?

smaller fat molecules

What does pancreatic amylase digest?

carbohydrates