Exam 4 study guide Flashcards

biology 112
Terms Definitions
Know and understand the role of digestive system organs and hormones as they relate to different diseases such as gall stones, diabetes, liver failure, etc.
Gall stones = crystals of uric acids
o Buildup of cholesterol from liver, which builds up in gall bladder
• Breakdown of nucleic acids
• Diabetes = inability to remove sugar from blood due to pancreas not producing insulin or insulin receptors in cell are not functioning so glucose does not get removed from blood
• Liver – functions to remove toxins; high level of toxins = failure (cells are going to die and liver is not going to function)
• Type one is the inability to produce insulin… more genetic…
• Type two (late onset) produce high level of insulin… but no receptors to respond to it
• Even tho the gall bladder releases bile… the liver produces it
• Issue with pancreas… in terms of digestive system… its provides a significant amount of digestive enzymes in the small intestine
• Small intestine is to increase surface area
• Large intestine is to absorb water producing feces… problems with diarrhea… problem with large intestine
Understand adaptations of kidney due to environmental changes (i.e. Kangaroo rat, length of loop of Henle) and the effect of hormones on water and electrolyte balance in the kidney.
• Loop of Henley = responsible for water reabsorption
o Animals in fresh water aquatic environments don’t require kidney to reabsorb large amounts of water so loop is short
o Animals in dry environments (kangaroo rat) need to conserve water so their loops are long to aid in max reabsorption of water
o ADH – secreted by posterior pituitary in response to low water/low blood volume. Stimulates creation of aquaporin, which are inserted in the walls of collecting tubule to reabsorb water into body
o Aldosterone is secreted by adrenal cortex. Increases permeability to sodium ions in ascending loop.
• Any change you do whether its affecting proximal or distal tubules,
• Proximal tubule loop of Henle distal tubule collecting duct
• If you decrease sodium reabsorption in distal tubule less sodium being lost in the urine.
• The more sodium you have the more water you are going to get rid of
• The concentration of the urine 100mm of salt, if you prevent more salt from being absorbed, you lose more water.
• Animals that live in the desert to help reduce water loss, bigger loop of Henle.
• Urine osmolarity is higher , total volume is less, ADH
Understand Fick’s law and how it applies to different adaptations or medical conditions. Be able to identify the variables in the equation and apply them to the given situation.
• Rate of diffusion
• Diffusion constant for a gas
• As liquids get warmer, the less soluble it is
o Open a warm bottle of soda vs. opening a cold bottle of soda
• Area for exchange – how much surface
• Pressure difference between where it is and where it’s going
• Thickness of barrier between diffusion between origin and destination
• When breathing, alveoli pop (emphasima) decrease surface area and have difficulty breathing
Know the differences between co-current (concurrent) and counter current flow systems, which is more efficient, and why.
• Co-current: liquids are flowing in same direction
• Counter current: as oxygen is being extracted from water, it’s being faced with levels of oxygen that has less (MORE EFFICIENT)
o Oxygen is going out of water
o Water gives up oxygen
o Encounters blood with lower oxygen content
o As oxygen is leaving water for blood, since they’re moving in opposite directions, the water will always be in contact with an area of blood that is lower in oxygen so diffusion is continual. This allows to maximum diffusion of oxygen for water.
o Going to reach point where concentrations are equal
Know the difference between a heterotroph and an autotroph
Any organism that cannot synthesize reduced organic compounds from inorganic sources and that must obtain them from other organisms. Some bacteria, some archaea, and virtually all fungi and animals are heterotrophs. Also called consumer. Any organism that can synthesize reduced organic compounds from simple inorganic sources such as CO2 or CH4. Most plants and some bacteria and archaea are autotrophs.
Know the various ways for obtaining food (suspension, deposit, fluid, mass feeders)
Suspension Feeders: filter small organisms or bits of organic debris from water by means of cilia, mucus-lined “nets”, or other structures.
Deposit Feeders: swallow organic-rich sediments and other types of deposited material. “Eat shit on the ground”
Fluid Feeders: suck or lap up fluids. Anything that sucks on blood. (Mosquito)
Mass Feeders: seize and manipulate chunks of food by using jaws, teeth, beaks, or special toxin-injecting organs.
Understand the difference between incomplete and complete digestive tracts as well as advantages of complete digestive tracts
1. Incomplete:
a. Have one opening for both ingestion of food and elimination of wastes
b. Digestion takes place in a gastrovascular cavity.
2. Complete:
a. Tube-like structure with two openings, one for mouth for ingestion and one for the anus for elimination of wastes.
The benefit for complete is that you don’t have to stop eating to take part in elimination of waste.
Understand the distinction between essential amino acids, vitamins, electrolytes, and minerals with respect to their importance to the body
Essential nutrients are nutrients that cannot be synthesized in the body and must be
obtained from other means. There are 8 essential amino acids that cannot be synthesized by humans and must be obtained from food.
Vitamins: are organic compounds that are vital for health but are required only in minute amounts. They function as coenzymes. Organic backbone contains carbon.
Minerals: inorganic substances; often components of cofactors or structural materials.
Ca, Fe, Mg
Electrolytes: inorganic ions that influence osmotic balance (required for normal membrane function)
Na+ K+ Cl-
Know and understand the function of the different segments of the digestive tract (mouth, esophagous, stomach, small intestine, large intestine, etc)
Mouth: digestion begins with the tearing and crushing activity of teeth during chewing.
• Enzymes in saliva begin breaking down carbohydrates
Stomach: protein digestion begins in the acid environment of the stomach
Small intestine: continued enzymatic digestion of carbohydrates, lipids, and proteins.
• Absorption of nutrients (sugars, amino acids, fatty acids, vitamins, ions, some water) primarily in small intestine.
Large Intestine: more water absorbed; remaining material is feces.
Esophagus: transports food
Appendix: contains immune tissue; harbors symbiotic bacteria.
Know and understand the role of the different digestive enzymes presented in lecture (salivary amylase, lingual lipase, pepsinogen, pepsin, carbonic anhydrase, enterokinase, trypsinogen, trypsin, nucleases, pancreatic amylase, pancreatic lipase)
Salivary Amylase: breakdown of carbohydrates (starches)
Lingual Lipase: begins the breakdown of lipids (produced in tongue)
Pepsinogen: chief cells release this, it is converted to pepsin (protein digestive enzyme) when it makes contact with HCL.
Pepsin: involved in protein digestion within the stomach.
Carbonic Anhydrase: this catalyzes the formation of carbonic acid (H2CO3) from carbon dioxide and water.
Enterokinase: enzyme that converts trypsin to trypsinogen.
Trypsinogen: inactive form of trypsin.
Trypsin: released in inactive form (trypsinogen). This breaks specific peptide bonds in polypeptides – releasing amino acids.
Nucleases: released to break apart nucleic acids. Released in the small intestine.
Pancreatic amylase: breaks apart carbohydrates in stomach, releasing sugars.
Pancreatic lipase: small intestine, breaks bonds in lipids, releasing monoglycerides and fatty acids.
Know and understand the different organs/cells and their secretions involved in digestion (salivary glands, tongue cells, chief cells, parietal cells, mucous cells, pancreas, liver, gall bladder)
Salivary glands: secrete enzymes that digest carbohydrates; supply lubricating mucus. Located in the mouth, produce amylase and mucins.
Tongue cells: located in the mouth and produce lingual lipase to help break down lipids.
Chief cells: release pepsinogen converted to pepsin (protein digestive enzyme) in low pH (HCL) located in the stomach. They release pepsin in inactive form so it does not destroy the cells that synthesize them.
Parietal cells: secrete HCL which eventually activates pepsinogen to break down proteins. This makes the stomach pH low.
Mucous cells: secrete additional mucus to prevent stomach lining from being destroyed by extremely low pH during digestion. It likes the epithelium for protection from HCL.
Pancreas: produces digestive enzymes. Proteases are synthesized here in the inactive form
Liver: synthesizes bile salts which go into complex solution known as “bile”
Gall bladder: bile is stored here released into small intestine raises pH and starts to emulsify fat globules increases surface area available for lipase.
Know and understand how the following hormones influence digestion: secretin, cholecystokinin, gastrin,
Gastrin: released by cells in stomach in response to food entering the stomach to stimulate parietal cells to secrete HCL.

Secretin: released by cells in small intestine in response to arrival of food from stomach.
• Signals the pancreas to release bicarbonate ions into small intestine to neutralize acid in fluid arriving from stomach.
Cholecystokinin (cck): released by cells in small intestine in response to partially digested fats and proteins.
• Signals both pancreas to secrete many digestive enzymes and gallbladder to secrete bile into the small intestine.
• Liver to produce bile
• Gallbladder releases bile into SI
Know the gut structures that increase the surface area for absorption
The Small Intestine Has an Extremely Large Surface Area.
The villi that project from folds in the small intestine are covered with microvilli . The enormous surface area of the small intestine increases the rate of nutrient absorption. And because each villus contains blood vessels and a lymphatic vessel called a lacteal, nutrients pass quickly from epithelial cells into the body’s transport systems
Understand the role of insulin, glucagon with respect to diabetes I and II
if blood glucose is too high:
1. Insulin produced in pancreas is released into bloodstream.
2. Cells increase their rate of glucose uptake and processing
3. Blood glucose levels decrease
If blood glucose is too low:
Pancreas secretes glucagon, stimulates liver and some glycogen is converted into glucose. This happens via gluconeogenesis (synthesis of glucose from non-carbohydrate compounds) blood glucose levels rise.
Type 1 Diabetes:
• Insulin-producing cells destroyed do not synthesize insulin anymore.
o Autoimmune disease
• Treatment:
o Insulin injectors
o Careful attention to diet
Type 2 Diabetes:
• Problems responding to insulin
o Receptors do not function correctly
o Reduced number of receptors
• Treatment:
o Prescribed diets
o Monitoring blood glucose levels
o Drugs that increase cellular responsiveness to insulin
• The signal to start pumping glucose out of the blood is not noted.
• Obesity is closely tied to this.
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