Lecture Exam 1 Flashcards
(83 cards)
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
