Micro and Macro nutrient digestion

Question 1

what are the three products that result from a-amylase breaking down the a 1-4 glycosidic bonds in starch?

Answer 1

1. maltose
2. maltotriose
3. alpha-dextrins

Question 2

Is starch digested in the stomach?

Answer 2

No, salivary amylase is inactivated in acidic environments. Starch digestion begins in the mouth, paused in the stomach, and then is further digested in the small intestine.

Question 3

what are the two areas of the digestive tract that produce/secrete alpha amylase?

Answer 3

salivary glands and pancreas (the latter is secreted into the small intestine)

Question 4

What are the two enzymes that can break down a 1-4 glycosidic bonds?

Answer 4

sucrase and alpha amylase

Question 5

How are glucose molecules moved from the intestinal lumen into the enterocytes of the small intestine?

Answer 5

They are absorbed via the sodium-glucose transporter on the apical surface of the enterocytes (2 Na along with every 1 Glu)

Question 6

Excess glucose can be stored within the liver as _________

Answer 6

glycogen

Question 7

Once glucose is inside an enterocyte, what kind of transporter moves the glucose through the basolateral membrane and on into the bloodstream?

Answer 7

GLUT-2 transporter

Question 8

Lipase enzymes hydrolyse triglycerides into what two component parts?

Answer 8

Fatty acids and di-glycerides

Question 9

In the process of fat digestion, where do micelles go (within the enterocyte) to assist with the synthesis of triglycerides?

Answer 9

the endoplasmic reticulum and Golgi apparatus

Question 10

Lipids enter the enterocyte as _______ and exit the basolateral aspect of the cell into the lymphatic system as __________

Answer 10

Micelles, chylomicrons

Question 11

__________ are the lymphatic vessels of the small intestine (found inside each villus) that aid with the absorption of fat

Answer 11

Lacteals

Question 12

What type of movement/contraction in the stomach helps to break up fat globules into smaller droplets?

Answer 12

Segmentation

Question 13

what converts pepsinogen into its active form of pepsin?

Answer 13

The presence of acid in the stomach (HCl released by parietal cells leads to low pH)

Question 14

Name the two primary pancreatic proteases

Answer 14

Trypsin and chymotrypsin

Question 15

The pro-enzymes trypsinogen and chymotrypsinogen are activated by which enzyme?

Answer 15

Enterokinase- secreted by the mucosal membrane (brush border) of the duodenum

Question 16

What kind of bonds do trypsin and chymotrypsin break down?

Answer 16

Peptide bonds in proteins

Question 17

Absorption of amino acids is dependent on the electrochemical gradient of ______ across the epithelium.

Answer 17

sodium

Question 18

Vitamins can often act as ___-__________ in metabolic pathways

Answer 18

co-enzymes

Question 19

Fat soluble vitamins are stored in the ______ and __________ tissues for future use

Answer 19

liver, adipose