Ib Bio Human Digestion Questions

Front 1

What are three functions of the stomach?

Back 1

-Secretes acid and enzymes that digest foods

-Contracts periodically, churning food to enhance digestion

-Has pyloric Sphinctor which is muscular valve that opens to allow food to pass from stomach to small intestine

Front 2

What are two non-enzyme roles of proteins?

Back 2

-Hemoglobin transports oxygen in blood.

-Anti-bodies are a large part of the bodie's immune system.

Front 3

What is the significance of polar and non-polar amino acids?

Back 3

Since water tends to hydrophobically exclude non-polar molecules shoves the non-polar portions of the amino acid chain into the protein's interior. Polar and charged amino acids are restricted to the surface of the protein.

Enzymes: Polar amino acids within the active site of an enzyme allow a chemical interaction between the substrate and the enzyme to form an activated complex.

Front 4

What happens to an enzyme if it is not within its optimum temperature?

Back 4

If the temperature is too low, the enzyme's hydrogen bonds and hydrophobic interactions will be too strong to permit an induced fit. If the temperature is too high, these forces will be too weak to overcome the effects of the increased movement, and the enzyme will not be able to hold its shape

Front 5

What are the effects of inhibitors and activators on enzymes?

Back 5

Inhibitors (competative and non competative) lower the enzyme activity while activators increase the activity of the enzyme.

Front 6

What happens in the secondary folding structure?

Back 6

hydrogen bonds link amino acids together. when parallel chains are linked, it creates beta sheets. When one amino acid links to another further down the chain, it coils forming an alpha helix.

Front 7

Where does amylase function? Where is it made? What is its pH? What substrate does amylase break down?

Back 7

Amylase can be found in saliva which is produced from the salivary glands. Amylase breaks down starch and has a pH of 7.0.

Front 8

What is the difference between competitive and non-competitive inhibitors?

Back 8

Both of these inhibitors bind to an enzyme and decreses its activity, however a competitive inhibitor competes with the substrate for the same active site while noncompetitive inhibitors bind to the enzyme in a location other than the active site, (usually the allosteric site) changing the shape of the enzyme and making it unable to bind to the substrate.

Front 9

What is the role of a chaperone protein?

Back 9

It helps new proteins fold correctly. It also rescues protein that are caught in a wrongly folded state.

Front 10

How does negative feedback work?

Back 10

The end products of a series of reactions actually shut off the enzyme earlier on in the reaction. This stops (or slows) the reaction until the end product gets used up. Then the low concentration frees up the inhibited enzyme and starts the reaction again.

Because the reaction is starting again, it allows the end product to build up again, slowing the reaction.

Front 11

Lipase: Where is it found, what does it do

Back 11

breaks down dietary fats in the human digestive system

Found in the pancreas

Front 12

Explain the difference between primary and secondary protein structure.

Back 12

Primary structure is the specific sequence of amino acids within a protein. Secondary structure, on the other hand, is the result of the hydrogen bonds which occur along a single chain, linking one amino acid to another amino acid further along the chain. With secondary structure, you can either get a pleated shape (beta) or a coiled shape (alpha).

Front 13

What does the shape of a protein determine?

Back 13

The shape of a protein determines the protein's function

Front 14

Define Denaturation and explain why it happens

Back 14

Denaturation- when a protein changes shape or unfolds. This happens when the pH, Temperature, or ionic concentration that the protein is in is changed.

Front 15

Explain the primary function of the Small Intestine.

Back 15

The primary function of the small intestine is to absorb the minerals and nutrients from the food being digested. Most of the enzymes are secreted by the pancreas. The duodenum is the first and smallest section of the small intestine and is largely responsible for the chemical breakdown of food. The jejunum is the second section of the small intestine and its purpose is to secrete digestive juices and pass the food on smoothly through the small intestine. The final stage is the ileum and its primary purpose is to absorb any products that were not previously taken in by the jejunum.