Chapter 14: Digestion and some Chapter 15: Metabolism

Question 0

Digestion will have no __________.

Answer 0

ATP Production

Question 1

Mechanical and chemical breakdown; prep stage

• proteins
• -AAs
• polysaccharides
• sugars
• fat
• fatty acids

Answer 1

Digestion

Question 2

From AAs, sugars, fatty acids

-small amount of ATP production

Answer 2

Acetyl CoA Production

Question 3

Citric acid cycle and oxidative phosphorylation

Answer 3

ATP Production (90% of energy generated)

Question 4

Stomach

Answer 4

• pH 1-2, denaturation of proteins
• Pepsin (protease) breaks peptide bonds
• Protein fragments move to small intestine

Question 5

Pepsin shows optimal activity in the _____, only one of few that can be active in these conditions.

Answer 5

Stomach

Question 6

Small Intestine

Answer 6

• low pH of food stimulates the release of secretin
• secretin stimulates release of sodium bicarbonate from pancreas to neutralize pH of the food
• Oligopeptides stimulate CCK -CCK causes secretion of digestive enzymes from pancreas and bile salts from gallbladder

Question 7

Zymogens are…

Answer 7

Proenzymes secreted from pancreas as inactive precursors

Question 8

Enteropeptidase activates…

Answer 8

Trypsinogen to Trypsin

Question 9

Enteropeptidase is the only enzyme in the ________.

Answer 9

Small Intestine

Question 10

Trypsin activates…

Answer 10

Remaining pancreatic zymogens

-only activated in SI and all at the same time

Question 11

Zymogens start in the _______ form so that they cannot destroy the ______.

Answer 11

Inactive Pancreas

Question 12

Pancreatic proteases hydrolyze proteins to _______ and small _______ in the intestines.

Answer 12

Animo acids and small oligopeptides (protein fragments)

Question 13

Oligopeptides are cleaved into AAs and di- and tri- peptides by…

Answer 13

Intestinal peptidases

Question 14

AAs are released into….

Answer 14

The blood for use by other tissues

Question 15

Primary source of dietary carbohydrates are…..

Answer 15

Complex carbs (ie. starch - small amounts of glycogen)

Question 16

Starch is digested by….

Answer 16

a-amylase

Question 17

a-amylase cleaves

Answer 17

1,4-bonds NOT 1,6

Question 18

Products of starch…

Answer 18

Maltose, maltotriose and limit dextrin (has a-1,6 bonds)

Question 19

Maltose converted to glucose by… Maltotriose is digested by… Limit dextrin is digested by

Answer 19

Maltase a-glucosidase a-dextrinase to simple sugars

Question 20

Disaccharides are…

Answer 20

Sucrose and Lactose

Question 21

Sucrose

Answer 21

-present in vegetables, is cleaved to glucose and fructose by sucrase

Question 22

Lactose

Answer 22

-present in milk is degraded by lactase into glucose and galactose

Question 23

Monosaccharides are transported from intestinal cells into the bloodstream to be used as…

Answer 23

Fuel/generate energy

Question 24

The major lipids in our diet are...

Answer 24

Triacylglycerols \*form lipid droplets in the stomach\*

Question 25

Bile salts secreted by gallbladder insert into...

Answer 25

The lipid droplets, making them more digestible in SI Bile salts considered amphipathic

Question 26

Lipases secreted by the pancreas, convert triacylglycerols into...

Answer 26

- 2 fatty acids - monoacylglycerol

Question 27

Ionized fatty acids made by lipases form...

Answer 27

Micelles

Question 28

Micelles prevent

Answer 28

exposure to water and are carried to intestinal cells for absorption

Question 29

In intestinal cells, triacylglycerols are resynthesized and packed into lipoproteins called...

Answer 29

Chylomicrons

Question 30

Chylomicrons transport triacylglycerols into the....

Answer 30

Lymph system

Question 31

Cannot directly transport triacylglycerols, so they must be ______ before they can enter the mucosal cell

Answer 31

Degraded

Question 32

Ability to maintain adequate but not excessive energy stores

Answer 32

Caloric homeostasis

Question 33

Some health consequences of being obese:

Answer 33

Diabetes Coronary heart disease Cancers Stroke Hypertension (high blood pressure)

Question 34

Short-term signals are active during

Answer 34

Only a meal

Question 35

2 Types of Short-term signals

Answer 35

CCK - generate feels of satiety by acting on hypothalamus GLP-1 -acts like CCK on brain but also acts on pancreas too and potentiates insulin action

Question 36

Long-term signals...

Answer 36

report on the overall energy status of the body

Question 38

2 Types of Long-term signals

Answer 38

Leptin - secreted by adipocytes and produces feelings of satiety (long-term); reports on status of triacylglycerol or fat stores Insulin - secreted by pancreas - reports on status of blood glucose levels (carb availibility)

Question 39

When you lack leptin or the leptin receptor, you...

Answer 39

Do not realize that you are full and will continue to eat --\> obesity

Question 40

List of proteins

Answer 40

* Pepsin * Secretin * CCK * Zymogen * Enteropeptidase * Trypsin

Question 41

List of carbs

Answer 41

* a-amylase * malatase * a-glucosidase * a-dextrinase

Question 42

List of lipids

Answer 42

* Bile salts * lipases * chylomicrons

Question 43

Long-term control of caloric homeostasis is regulated by:

Answer 43

Leptin and insulin

Question 44

T or F: The gall bladder secretes bile salts to neutralize the low pH of the stomach.

Answer 44

False

Question 45

T or F: Fats are a more efficient food source than glucose, because fats are more oxidized.

Answer 45

False

Question 46

T or F: Muscle contains only enough ATP to power contraction for less than a second.

Answer 46

True

Question 47

T or F: Activated carriers are common in biochemistry and often are derived from vitamins.

Answer 47

True

Question 48

T or F: NADPH is used primarily for reductive biosynthetic pathways.

Answer 48

True

Question 49

T or F: Coenzyme A is an activated carrier of two-carbon fragments.

Answer 49

True

Question 50

Metabolic pathways that involve the oxidation of fuels to generate ATP are called ____________ pathways.

Answer 50

Catabolic

Question 51

Which compound has the highest phosphoryl-group transfer potential? ATP or Phosphenolpyruvate

Answer 51

Phosphenolpyruvate

Question 52

What is the relationship between anabolic and catabolic pathways?

Answer 52

Anabolic pathways synthesize more complex organic molecules using the energy derived from catabolic pathways.

Question 53

The role of ATP in cellular metabolism

Answer 53

The free energy released by ATP hydrolysis may be coupled to an endergonic process via the formation of a phosphorylated intermediate.

Question 54

What metabolite is NOT in a high-energy state and therefore cannot release free energy for ATP generation

Answer 54

Glycerol-3-phosphate