3_Nutrition and Digestive Flashcards

Terms Definitions

 enzymes that break down disaccharides into monosaccharides.

Lactase (breaks down lactose into glucose and galactose)

Maltase (breaks down maltose into 2 glucoses)

made in: pancreas - carboxypeptidases are initially produced in an inactive form;

ex) the inactive zymogen form, (pro-carboxypeptidase A), is converted to its active form - carboxypeptidase A, by enterkinase 

why? mechanism ensures that the cells wherein pro-carboxypeptidase A is produced are not themselves digested.

used in: small intestine 

function: hydrolyze terminal peptide at carboxyl terminal
 involved in catabolism; they help to mature proteins or regulate biological processes

Exocrine and endocrine (hormone)
exocrine: produces several hydrolytic enzymes and an alkaline solution rich in bicarbonate that buffers the acidity of the chyme from the stomach.
exocrine: accessory glands include the salivary glands, the pancreas, the liver, and the gallbladder.
made in: intestinal glands 
used in: small intestine 
function: hydrolyze peptide bond at amino terminal size
 a zinc-dependent enzyme .
salivary amylase
enzyme that hydrolyzes starch
The oral cavity, pharynx, and esophagus initiate food processing.
After chewing and swallowing, it takes 5 to 10 seconds for food to pass down the esophagus to the stomach, where it spends 2 to 6 hours being partially digested.
The esophagus conducts food from the pharynx down to the stomach by peristalsis.
The muscles at the very top of the esophagus are striated and, therefore, under voluntary control.
Involuntary waves of contraction by smooth muscles in the rest of the esophagus then take over.
enterokinase (aka Enteropeptidase)


made in: intestinal glands (cells in the duodenum wall)
used in: small intestine 

function: converts trypsinogen (zymogen) to trypsin and indirectly activating a number of pancreaticdigestive enzymes and itself and cutsarginine and lysine.

secreted from duodenum's glands whenever ingested food enters the duodenum from the stomach.

part of the Chymotrypsin-clan of serine proteases, and is structurally similar to these proteins.

submucosa: aread of connective tissue, a lot of aredar tissue; blood supply; lymph and nerves. 
chylo micron 
can't move trigylceride in water (cell) so package them in protein so it's water soluble
pancreatic amylase
made in : pancreas 
used in: small intestine 
breaks: starch -> maltose
chief cells
release pepsin: inactive form called pepsinogen but HCl converts it into pepsin by exposing active site
the large intestine
-cecum important for fermenting ingested material (like plant material)-reabsorbs water as well by actively pumping out ions and water follows-rectum stores feces-colon also absorbs vitamin K produced by bacteria in colon such as e.coli
HDL and LDL 

basket of protein that carry cholestrol.
One has more protein than lilpid (HDL),
HDL is a good form of cholesterol
HDL cleans
one has more lipid than protein (LDL- low density).
LDL deposts
no such thing of good or bad choletsterol. depends on how it's carried to the liver. 

GI Tract
What is it?
tube from mouth to anus 
anything inside the tube is essentially outside the body 

goal: take complex bio-molecules and break it down to constituent parts. 

Parietal cells
Secrete hydrogen and chloride ions but aren't active until they reach lumen and form HCl
carbohydrate digestion
-begins in mouth with amylase and continues in small intestine-dietary fiber broken down in by bacteria in large intestine
small intestine
major organ for chemical digestion and absorption

pathway to get rid of waste

ex) bruise / hemoglobin: when it starts to break down, pigement gets green/yellow. this color represents bilireubin. liver gets rid of this and puts it in the bile. If this builds up, you get jaunice.

Digestive System (4 step process) ? 
Indigestion, Digestion, Absorption, Elimination (egestion) 

Ingestion: placing food into the mouth 

Digestion (Mechanical and chemical breakdown) mastication + mix bolus with water, acids, bile and enzymes in the stomach and intestine to break down complex molecules into simple structures,

Absorption: of nutrients from the digestive system to the circulatory and lymphatic capillaries through osmosis, active transport, and diffusion, and

Egestion: Removal of undigested materials from the digestive tract through defecation.

the cephalic phase - saliva is produced in the mouth and digestive enzymesare produced in the stomach.
Mechanical and chemical digestion begin in the mouth where food is chewed, and mixed with saliva to begin enzymatic processing of starches. The stomach continues to break food down mechanically and chemically through churning and mixing with both acids and enzymes. 
Absorption occurs in the stomach and gastrointestinal tract, and the process finishes withdefecation.[1]
Foregut and Hindgut Fermenters
Foregut: microbes before stomach and are digestedHindgut: microbes after stomach and NOT digested
bulk of bulk of feces ...

is bacteria, bit of cellulose,
High-Density Lipoprotein and Low-Density Lipoprotein
HDL: good cholesterol and a high enough number will take bad cholesterol outLDL: bad cholesterol
Path of Food when being digested (top to bottom)?

Think about food: Cephalic 
Food in mouth: Gastric 
In stomach: intestinal 
Oral Cavity:  chew > salivary amylase >  bolus > swallowing 
Pharynx:   larynx moves up  > epiglottis close over trachea (windpipe) > bolus goes down esophagus via perstalisis > stomach 
Stomach: bolus > cardiac orfice > gastrin stimulate secretion of pepsinogen, gastric acid, HCl(parietal cell) >  mix > break proteins + kill organism > chyme 
Small Intestine: chyme > pyloric sphincter > duodenum > 
*acidity of chyme stimulate secretin  >  pancreatic juice (bicarbonate) + bile creation from liver > pH becomes more basic > stimuate other hormone and enzyme
AND / or
*carb in chyme stimulate pancreas > produce maltase, lactase and sucrase) 
*protein in chyme stimulate CCK >  trypsin, chymotrypsin 
*fat in chyme stimuate CCK > bile released from gallbladder
and entergasterone > blocks gastrin > decrease amount of acid > slow stomach churning 
 > 1 or 2 
1. absorbed by microvilli >   lymphatic system or circulatory > circuatory:  blood carries nutrients away to liver by hepatic portal vein 
2.  peristalsis >jejunum and illeum > undigested to large intestine 
Large intestine (cecum, colon, rectum),: undigestable food >  cecum > breaks down cellulose and minor defense > colon> enteric bacteria system: rest ferments in gut bacteria  > bacteria consumes things we do not eat >  absorb some nutrients like vitamin A, B through villi > produce H2S and methane> absorb mostly fluid > rectum > store shit > anal sphincter > anus

what are the 4 stages of food processing?
1. ingestion
2. digestion
3. absorption
4. elimination
what are the two types of digestion?
mechanical - breaking into small pieces
chemical - enzymes breaking down food particles
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