Lecture Exam 1 Flashcards
Acidic chyme in the small intestine
Secreted from duodenum wall
Stimulates pancreas
Bicarbonate rich juices secreted into the small intestine to maintain a slightly alkaline PH
Secretin
Responds to Fat or protein in the small intestine
Secreted from intestinal wall
Stimulates gall bladder and pancreas
Bile secreted to emulsify fats
Bicarbonate and enzyme rich juices secreted into small intestine to maintain slightly alkaline PH, digest fats and proteins, and slow GI tract motility
CCK cholecystokinin
Positive charge
Neutral charge
Negative charge
Proton
Neutron
Electron
Why is a neutral atom neutral ?
It has an equal number of positively charged protons in nucleus and electrons
How does a neutral atom become an ion ?
By gaining or losing an electron
How are ionic bonds formed ?
By gaining or losing an electron
Attraction between cations & anions
One atom electron donor
Another atom electron acceptor
Attraction between opposite charges draws two ions together
Ionic bonds
Strong electron bonds involving shared electrons
Covalent bonds
What type of bond is found between adjacent water molecules
Hydrogen bonds
Breaks a molecule into smaller fragments.
In the digestive tract break these molecules down into smaller fragments that can be absorbed
Catabolism
Decomposition
Assembles smaller molecules into larger molecules
The formation of water hydrogen and oxygen molecules is a ?
Anabolism
Synthesis
Parts of the reacting molecule are shuffled around to produce new products
Decomposition first then, synthesis
Exchange reactions
What is the PH scale used to determine ?
Measure solutions acidity and alkalinity
Indicates hydrogen ion concentrations
A gain of oxygen, or a loss of hydrogen or electrons, is a form of _________ and the net result is a DECREASE in potential energy of the atom or molecule
LOSS OF ELECTRON
Oxidation
Loss of oxygen, or gain of hydrogen or electrons, is a form of ________, and the net result is an increase in potential energy in an atom or molecule.
GAIN OF ELECTRONS
Reduction
An atom, ion, or molecule that contains unpaired electrons in its valence shell is called a
Free radical
The next simplest nutrient is water, a compound made of two elements hydrogen and oxygen. Minerals and water are ________ nutrients, which means they contain no CARBON
Inorganic
The other four classes of nutrients (carbohydrates, lipids, proteins, and vitamins) are more complex. In addition to hydrogen and oxygen, they all contain carbon, an element found in all living things; they are therefore called
Organic compounds
The process of digestion begins in the ?
Mouth
Is a flexible muscular tube that extends from the mouth through the esophagus, stomach, small intestine, and rectum to anus
GI tract
During chewing, the teeth crush large pieces of food into smaller ones, and fluids from foods, beverages, and salivary glands blend with these pieces to ease swallowing.
Mouth
The _____ has two sphincter muscles, one at each end. During a swallow, the upper esophageal sphincter opens.
The lower esophageal sphincter at the entrance to the stomach closes behind the bolus so that it proceeds forward and doesn’t slip back into the esophagus
Esophagus
Retains bolus for a little while before transferring it to the lower portion
Churns the bolus and adds digestive juices to it so it could become a semiliquid mass called chyme
Releases the chyme through he pyloric sphincter
Stomach
The chyme bypasses the opening from the common bile duct, which is dripping with fluids into the _______ from two organs outside the GI tract the gall bladder and pancreas.
Small intestine
Chyme passes through its three segments the ___________ almost 10 FT of tubing
Duodenum, Jejunum, and ileum
The ________ opens in response to swallowing
Upper esophageal sphincter
At the bottom of the esophagus, the ________ prevents reflux.
Lower esophageal sphincter
At the bottom of the stomach, the ________, which stays, closed most of the time, holds the chyme in.
Pyloric sphincter
At the end of the small intestine, the _________ allows the contents of the small intestine to empty into large intestine
Ileocecal valve
Stomach PH is
1.5-1.7
What substance accounts for the acid content of the stomach
Hydrochloric acid
When food has been digested in the stomach it becomes an acid substance known as what ?
Chyme
What enables the stomach to churn food
Segmentation
What is the role of bicarbonate
Neutralize the acidic chyme arriving in the small intestine from the stomach
Most absorption takes place in the
Small intestine
How are nutrients absorbed from the small intestine
Simple diffusion
Facilitated diffusion
Active transport
Enzyme associated with carbohydrates digestion in the mouth
Salivary amylase
What happens to fats in the mouth?
Fat digestion is minimal
Lipid digestion in the small intestine
Fat is emulsified by bile/ lipases breakdown fats
Is not an enzyme; it is an emulsifier that disperses fats in watery solutions, thereby giving digestive enzymes access to them
Bile
An exocrine secretion made by the liver
Bile
Secretin is released from ?
CCK is released from ?
Duodenum wall
Intestinal wall
What is the function of the gall bladder
Store and concentrate bile
How does protein digestion occur in the stomach
Hydrofloric acid breaks down protein in the stomach
The protective coating of ______ around the kernel of grain is rich in nutrients
Bran
The ______ contains the starches and proteins
Endosperm
The _____ is the seed that grows into a wheat plant, so it is essentially rich in vitamins and minerals to support new life.
Germ
Is the inedible part of a grain
Husk or chaff
The process by which the coarse parts of a food are removed.
Grains have lost many nutrients during processing
Refined
Have some nutrients added back
Enriched
Have all the nutrients and fiber found in the original grain
Whole grain
Contribute folate, vitamin A, vitamin C, potassium and fiber
Fruits
Contribute folate, vitamin A, vitamin C, vitamin K, vitamin E, magnesium, potassium, and fiber
Vegetables
Contribute folate, niacin, riboflavin, thiamin, iron, magnesium, selenium, and fiber
Grains
Contribute protein, essential fat acids, niacin, thiamin, vitamin B6, vitamin B12, iron, magnesium, potassium, and zinc
Protein foods
Contribute protein, riboflavin, vitamin b12, calcium, potassium, and when fortified, vitamin A and D
Milk products
Contribute vitamin E and essential fatty acids
Oils
Congress mandated that all grain products crossing state lines must be enriched with
Iron
Thiamin
Riboflavin
Niacin
Provides valuable nutrition information such as serving sizes, nutrient quantities, and daily values
Nutrition facts label
“Good source of fiber”
“Rich in calcium”
“Cholesterol free”
Low reduced or free
Nutrient claims
“Diets low in sodium may reduce the risk of high blood pressure”
“ very limited and preliminary research suggests that eating one half to one cup of tomatoes/tomato sauce a week may reduce the risk of prostrate cancer”
Health claims
Are permitted on labels to describe relationships between food and diseases or health related conditions
Health claims
“Slow aging” “improve memory” “build strong bones”
“May reduce the risk of heart disease”
“Promote a healthy heart”
Structure function claims
Is the body’s way of breaking down foods into nutrients in preparation for absorption
Digestion
Inner space within the GI tract is called
Lumen
The process of digestion begins in the
Mouth
Prevents choking
Epiglottis
When a mouthful of food is swallowed it passes through the
Pharynx
The break down of food into nutrients requires secretions from five different organs
Salivary glands
Stomach
Pancreas
Liver
Small intestine
An _____ is a protein that facilitates a chemical reaction making a molecule, breaking a molecule apart, changing the arrangement of a molecule, or exchanging parts of a molecule
Enzyme
The enzymes involved in digestion facilitate a chemical reaction known as _____ the addition of water to break a molecule into smaller pieces
Hydrolysis
The _____ contains water, salts, mucus, and enzymes that initiate the digestion of carbohydrates
Saliva
The _______ acts primarily in protein digestion, the only major event that occurs in the stomach
Hydrochloric acid
The acid is so strong that it causes the sensation of heartburn if it happens to reflux into the esophagus
Hydrochloric acid
To protect themselves from gastric juice, the cells of the stomach wall secrete
Mucus
Fingerlike projections
Villi
In the crevices between the villi are tubular glands that secrete intestinal juices
Crypts
Any nutrient molecule small enough to be absorbed is trapped among the _____ and then drawn into the cells
Microvilli
The strong muscles of the _________ hold back waste until it’s time to defecate
Rectum and anal canal
Organ system responsible for the movement of nutrients in the body
Digestive system
Shortest segment
Middle segment
Last segment
Dueodenum
Jejunum
Ileum
First to receive nutrients
Prepares nutrients for use by body
Detoxing substances
Liver
Stimulates the stomach glands to secrete Hydrochloric acid
Gastrin
