Test 2 Flashcards
Digestion
The mechanical and chemical breakdown of food into subunits so that nutrients can be absorbed
Digestive Tract
The central pathway of the digestive system; a long muscular tube that pushes food between the mouth and the anus
Esophagus
The section of digestive tract between the mouth and the stomach
Peristalsis
Coordinated muscular contractions that force food down the digestive tract
Stomach
An expandable muscular organ that stores, mechanically breaks down, and digests proteins in food
Small Intestine
The organ in which the bulk of chemical digestion and absorption of food occurs
Pancreas
An organ that helps digestion by producing enzymes (such as lipase) that act in the small intestine, and by secreting a juice that neutralizes acidic chime
Liver
An organ thataids digestion by producing bile salts that emulsify fats
Gall Bladder
An organ that stores bile salts and releases them as needed into the small intestine
Villi (Villus)
Fingerlike projections of folds in the lining of the small intestine that are responsible for most nutrient and water absorption
Large Intestine
The last organ of the digestive tract, in which remaining water is absorbed and solid stool is formed
Stool
Solid waste material eliminated from the digestive tract
Simple Diffusion
The movement of small, hydropohobic molecules across a membrane from an area of higher concentration to an area of lower concentration; simple diffusion does not require energy
Transport Proteins
Proteins involved in the movement of molecules across the cell membrane
Facilitated Diffusion
The process by which large or hydrophilic solutes move across a membrane from an area of higher concentration to an area of lower concentration with the help of transport proteins
Active Transport
the energy-requiring process by which solutes are pumped from an area of lower concentration to an area of higher concentration with the help of transport proteins
If a solute is moving through a phospholipid bilayer from an area of higher concentration to an area of lower concentration without the assistance of a protein, then the manner of transport must be…
Simple Diffusion
Sugars are large, hydrophilic molecules that are important energy sources for cells. How can they enter cells from an environment with a very high concentration of sugar?
By Facilitated Diffusion
What do simple diffusion and facilitated diffusion have in common?
Both involve the movement of a solute moving down a concentration gradient (from higher to lower concentration). In both cases additional energy is not required.
What do active transport and facilitated diffusion have in common?
Both facilitated diffusion and active transport require the function of a protein embedded in a membrane. However, the solute is moving in the opposite direction (relative to the concentration gradient) in these two cases.
Order of the structures of the digestive system:
Mouth, esophagus, stomach, small intestine, large intestine
Which part of the digestive tract has the most acidic pH?
Stomach
Gastric bypass surgery causes the ______ to become _________.
stomach, smaller
Where does the majority of chemical digestion take place?
small intestine
A person who has had his or her gallbladder surgically removed will have trouble processing…
fats
With out your gallbladder, or if you take Alli, you may experience “greasy” diarrhea if they eat a high fat meal because…
Gallbladder removal leades to the inability to store bile salts. Which means fats cant be fully processed. Alli, a lipase inhibitor, keeps fats from being digested. Undigested fats can’t be absorbed, so you shit them in.
What is the difference between being obese and morbid obese?
Obese = 20% more than ideal body weight based on BMI
Clinically serve obesity - 100 pounds or more overweight
What are the two most common types of bariatric surgery?
Gastric Bypass & Gastric banding
What does the liver do?
Produces bile salts that emulsify fats
What does the Gallbladder do?
An organ that stores bile salts and releases them as needed into the small intestine
What does the pancreas do?
Produces enzymes (such as lipase) that act in the small intestine, and by secreting a juice that neutralizes acidic chyme
What type of molecules do the enzymes in saliva break down?
carbohydrates
How is food transported from the mouth to the stomach (also see infographic 26.2)?
peristalsis
(Stomach)
At which pH is it able to function?
1 (acidic)
(Stomach)
What are the two functions of the low pH of the stomach?
break apart proteings
protect against food borne illness
(Stomach)
What prevents the stomach from digesting itself?
mucus layer
(Stomach)
How does an ulcer form?
mucus layer is damaged
(Small intestine)
Note the 3 materials added to the small intestine:
pancreas - pancreatic juice to neutralize acidic chyme
Pancreas - enzymes that breakdown cars, proteins and fats
liver - bile salts
(Small intestine) How are carbohydrates, nucleic acids, and proteins broken down in the small intestine?
What are the two sources of this material?
enzymes
pancreas/small intestine
Bile Salts
Where are they made?
Where are they stored?
What is their function?
made in liver
stored in gallbladder
emulsify fats
What is the name of the major lipid –digesting enzyme?
lipase
Why do patients need to take vitamin supplements for the rest of their life after gastric bypass surgery?
food bypasses part of the small intestine so fewer nutrients are absorbed
The cell membrane _____ what ____ and ____ the cell.
regulates
enters
exits
(Cell Membrane)
Which molecules can cross the cell membrane by simple diffusion?
small, hydrophobic molecules moving from higher concentration to lower.
no energy required
(Cell Membrane)
How is glucose transported? Does this require energy?
?
(Cell Membrane)
How can materials be transported up the concentration gradient? Does this require energy?
?
Homeostasis
the maintenance of a relatively constant internal environment
Element
a chemically pure substance that cannot be chemically broken down; each element is made up of and defined by a single type of atom
Atom
the smallest unit of an element that cannot be chemically broken down into smaller units
Molecule
atoms linked by covalent (sharing electrons) bonds
Macromolecule
large organic molecules that make up living organisms; they include carbohydrates, proteins, and nucleic acids
Monomer
one chemical subunit of a polymer
Polymer
a molecule made up of individual subunits, called monomers, linked together in a chain
Hydrophobic
do not dissolve in water
Hydrophilic
dissolve in water
pH
a measure of the concentration of H+ in a solution
Acid
A substance that increases the hydrogen ion concentration of solutions, making the more acidic
Base
a substance that reduces the hydrogen ion concentration of solutions, making them more basic
5 functional traits of life are?
growth, reproduction, homeostasis, sense and respond to stimuli, obtain and use energy (c)
what is homeostasis? why is it important to living organisms?
homeostasis is the ability of a cell or organism to maintain a stable internal environment, usually in therms of pH, temperature, and chemical makeup, even when external environment changes. Important bc molecules of life are delicate, and even small changes could destroy them
what does it mean to say a macromolecule is a polymer?
A polymer is a molecule composed of smaller, repeating, subunits called monomers.
What are the four macromolecules? Which isn’t a polymer?
Complex carbohydrates, proteins, nucleic acids, lipids. Lipids
what are the building blocks of each molecule of life?
Carbohydrates - monosaccharides (sugars)
Lipids - triglicerides / fatty acids
Proteins - amino acids
Nucleic Acid - nucleotides
Water molecules can bond to each other by _______ bonding, this is an example of _________.
hydrogen; cohesion
why is water neutral (7) on the pH scale?
it has an equal number of H+ hydrogen and Hydroxide OH-
enzyme
a protein that speeds up the rate of a chemical reaction
substrate
a compound or molecule that an enzyme binds to and on which it acts
active site
the part of the enzyme that binds to substrates
glycogen
a complex animal carbohydrate made of linked chains of glucose molecules; a source of stored energy
&
an energy storing carb found in liver and muscle
fiber
a complex plant carb that is not digestible by humans
glycagon
a hormone produced by the pancreas that causes an increase in blood sugar
insulin
hormone secreted by pancreas that regulates blood sugar
glucose
a simple sugar that is an important energy source in living organisms and is a component of many carbohydrates.
