Exam 3 Study Guide Part A: Digestive System & Metabolism

Describe the process of generating ATP from glucose. Your answer should include: ATP synthase, mitochondria, CO2,O2, electron transport chain, glucose, acetyl CoA, H2O, H+ ions, NADH and FADH2, glycolysis, and of course,


How are fatty acids broken down? Using the number of carbons in acetyl CoA, explain why fats contain a lot of energy.


In what form are simple carbohydrates stored as in tissues such as the liver and skeletal muscle?


Connect the dots between diabetes (Type I) and ketoacidosis, with high levels of ketone bodies in the blood.


Why are vegetarians advised to eat multiple types of vegetables to get the proper protein diet?


Can glucose be turned into and stored as fat?


What are the uses of fats?


Why are minerals important in our diet?


What are the main organs involved in digestion?

Alimentary canal: gastrointestinal tract (mouth to anus)
Accessory digestive organs: teeth, tongue, gall bladder, salivary glands, liver, pancreas

What are the main classifications of enzymes that digest the main components of food?

Proteins (protease-pepsin), Lipids (lipase), Carbohydrates (amylase)

Identify the mechanical or chemical digestive function of the mouth and associated structures (lips, teeth, tongue, hard/soft palate, salivary glands).

Lips: seal off oral cavity, manipulation, sensitivity (feeling)
Teeth: mechanical break down, increase surface area for chemical digestion
Tongue: manipulating food
Hard palate: mechanical break down with tongue
Soft palate: barrier, prevents flow to nasal cavity
Salivary glands: chemical beak down, provide saliva, break down complex carbs, lubrication (bolus)

How is saliva produced and what are its contents?

Saliva is produced by the sight, smell,and thought of food as well sensory input. It is mostly composed of water (electrolytes, digestive enzymes, proteins, protective substances like lysozyme and antibodies, and metabolic wastes.

Compare and contrast intrinsic vs. extrinsic factors controlling an increase in saliva production and digestive activity.

extrinisic factors would be our senses such as sigh and smell. Intrinsic factors are dectected by contraction of muscles and by nerve plexuses and hormone. -producing cells.

Does an increase in sympathetic nervous system activity increase saliva production? Overall digestive activity?

yes, and inhibits digestive activities. (flight or fight response)

Compare and contrast peristalsis vs. segmentation. What tissue drives these movements?

They are both a type of mechanical digestion that is involved in the gastrointestinal tract. Peristalsis is the slow and gradual movement of food through the digestive system. The food is crushed and propelled in one direction as smooth muscle contracts and forces the food along the gastrointestinal tract. Peristalsis is not to churn, but to slowly move food along towards the large intestine, however, segmentation is the local mixing of food with enzymes and intestinal juices (from pancreas etc). Therefore the food is mixed and and exposed to absorptive cells as it moves along.

Identify the cells within gastric pits that produce the components responsible for the acidic environment in the stomach and the main enzyme involved in protein production. What are these components?

chief cells: protease- (inactive)
pepsinogen (active) pepsin
paretal cel-hcl activates pepsinogen to pepsin
enteroendocrince cell - hormone produced by digestive system, controls chemical digestion and coordinates events in digestion.

How do bile and pancreatic secretions influence digestion and local environment in the duodenum?

bile and pancreatic juices break down food for easier absorption.

How does the duodenum communicate the stomach, gallbladder, and pancreas to control digestion?

1. chyme enter duodenum, causes entereoendocrine cells to release CCK.
2. CCK enters the blood stream

Compare and contrast the short and long reflexes controlling digestive activity.


Identify ways that the anatomy of the digestive system serves to increase surface area for absorption.


Describe, in detail, the absorption of fats (lipids), how they are transported into the cardiovascular system, and then to and from tissues (basic components involved - i.e., the lipoproteins: LDL, HDL).


What is found within the large intestine that aid in digestion and help produce important vitamins?


In what portion of the gastrointestinal (GI) tract does most absorption occur?


What are ways that the GI tract protect itself from its own digestion in the stomach and small intestine?