Exam 1 Flashcards
trials with a control group for comparison
controlled trial
subjects allocated to an intervention or control group but without randomization method
non-randomized controlled trial
subjects allocated randomly to an intervention or control group
randomized controlled trial
Type of observational study which looks at the cohort at a specific point in time
cross-sectional study
observational
type of observational study which looks at a group with a case and one without the case
case-control study (observational)
study which looks into the past of a cohort
retrospective cohort study (observational)
study which follows a cohort into the future
prospective cohort study (observational)
Examine etiology and causal associations
analytic study
organelle responsible for lipid synthesis
Smooth ER
organelle responsible for protein synthesis
Rough ER
organelle which is the packaging center of the cell
golgi apparatus
organelle responsible for digestion
lysosome
power house of the cell
mitochondria
examples of materials which make up the cytoplasmic matrix
microtubules
microfilaments
intermediate filaments
Reactions that occur in the mitochondria
TCA ETC FAox amino acid metabolism carboxylation of pyruvate
Functions of proteins in cells
receptors
transporters
enzymes
molecular stimuli that attach to receptors
ligand
ex. hormones, growth factors, antibodies, nutrients
Mechanisms of signal transduction
internal chemical signal
ion channel
internalized stimuli
This occurs to start an internal chemical signal
ligand binds to external receptor
g-protein activates adenylyl cyclase
cAMP activates protein kinase A resulting in cellular response
This type of channel often uses a ligand to allow charge particles across an otherwise impassable membrane
ion channels
In this process, a ligand binds to a receptor that is then invaginated into the cell, digested by the lysosome, and then stimulates cellular response
internalized stimuli
maximum reaction rate
Vmax (top line on graph)
substrate concentration at which the rxn rate is half of Vmax
Km
enzyme responsible for reactions in which one compound is oxidized, another reduced
oxidoreductases
enzyme responsible for reactions in which a functional group transferred from one substrate to another
transferase
enzyme responsible for reactions in which carbon bonds are hydrolyzed
hydrolases
enzyme responsible for reactions in which the cleavage of C-C, C-S, and C-N bonds occur
lysases
enzyme responsible for reactions in which interconversion of optical or geometric isomers occur
isomeraces
enzyme responsible for reactions which catalyze formation of C and other bonds (O,S,N,others)
Ligases
enzyme responsible for reactions in which phosphorylation occurs
Kinases
type of enzyme regulation which causes another enzyme to change from inactive to its active form
covalent modification
Type of modification in which the enzyme has another site besides the catalytic site that affects enzyme activity
allosteric modification
Type of enzyme regulation which leads to an increase/decrease of enzyme concentration depending on the presence of substrate
induction
The energy which must be imposed on the system to raise the reactants to their transition state
activation energy
If deltaG is less than 0
exothermic
If deltaG is greater that 0
endothermic
osmotic work
active transport
chemical work
biosynthesis
anabolism
mechanical work
muscular contraction
energy is released during this process and stored as ATP
Nutrient catabolism
detecting gene variants within an individual
nutrigenetics
enviormental factors that have an effect on the expression of genes, identifying which genes respond to which environmental factors, defining the mechansim involved, and determining useful health-related application of those interventions
nutrigenomics
study of changes in gene expression that do not involve changes in the nucleotide sequence of DNA
nutritional epigenetics
These types of reactions are favorable (downhill)
exothermic
components of saliva (5/6)
water electrolytes mucus enzymes antibacterial and viral compounds
Salivary amylase
small amount of carb breakdown
lingual lipase
breaks down lipids, more prevalent in infants
key electrolytes in saliva
sodium
potassium
chloride
food mixed with saliva
bolus
bolus mixed with gastric juices
chyme
components of gastric juice
HCl
3 enzymes, pepsin, amylase, lipase
mucus
intrinsic factor
Functions of HCl in the gastric juice
kills bacteria
releases nutrients from organic compounds
denatures protein
converts pepsinogen to pepsin
functions of pepsin in the gastric juice
most active enzyme in the juice, digests proteins
function of amylase, and lipase in gastric juice
break down carbs, and lipids respectively
Four major digestive system ‘juices’ in ascending order of acidity
bile
pancreatic juice
saliva
gastric juice
function of mucus in the gastric juice
protects the lining of the stomach
function of intrinsic factor in the gastric juice
helps absorb B12
What is secreted from neck cells in the stomach
located close to the surface mucosa which secrete bicarbonate and mucus
what is secrete from parietal (oxynitic) cells
hydrochloric acid and intrinsic factor
what is secreted from chief cells (peptic or zymogenic cells)
pepsinogens
What is secreted from enteroendocrine G-cells
variety of hormones
Factors that affect gastric emptying rate
fiber (slows) lipids (slows) Large volumes of chyme (increase) hypertonic/hyoptonic chyme in duodenum (slows) salts and monosaccharides (slow) Hormones (varies) hardness of food (slows)
the sublayers of the small intestine from outside to in
serosa muscularis externa submucosa Mucosa lumen
features of the submucosa
contain many immune cells
serosa
protective layer
muscularis
moves and mixes food
mucosa
start of absorption
Lipids are absorbed here
jejunum (end)
Monosaccharides are absorbed here
Jejunum (end)
aminoacids are absorbed here
jejunum (end)
bile salts/acids are absorbed here
terminal ileum
Sodium, chloride, and potassium are absorbed here
large intestine
Short chain fatty acids are abosrbed here
end of large intestine
Vit K is absorbed here
large intestine
B12 is absorbed here
ileum
majority of water is absorbed here
large intestine (Beginning)
what are the components of pancreatic juice
Sodium BiCarb Pancreatic amylase and lipase proteolytic enzymes (procarboxypeptidase, proelastase, collegenase) Tripsinogen chymotrypsinogen
enzyme that needs activated is called
zymogen
What coverts trypsinogen to trypsin
enteropeptininase
what turns chymotrypsinogen to chymotrypsin
trypsin
pepsinogen (pepsin) is produced here, and digests this molecule
stomach
protein
trypsinogen (trypsin) is produced here, and digests this molecule
pancreas
protein
chymotripsinogen (chymotrypsin) is produced here, and digests this molecule
pancreas
protein
what purpose does bicarb serve in pancreatic juice
neutralizes the acidity of the chyme
where is bile secreted
small intestine (duodenum)
how does bile aid digestion
bile causes lipids in the small intestine to form micelles so they can be acted on by lipase
What are the primary bile acids
cholic acid
chenodeoxycholic acid
where is bile stored
gallbladder
describe the enterohepatic circulation of bile
bile is synthesized from cholesterol, and as it is diegested after release a majority of it is reabsorbed in the terminal ileum and returned to the liver where it is converted back to bile salts and reenters the digestive tract
Ways to decrease blood cholesterol
phytosterols/stanols bind bile/cholesterol and cause its excretion in the feces
Bile acid sequestrants are medications which bind components of bile in the gastrointestinal tract and prevent its reabsorption
how does gastrin regulate digestion
stimulates gastric motility and/or secretions
how does motilin regulate digestion
stimulates gastric motiility and/or secretions
stimulates intestinal motility and/or secretions
how does cholecystokinin regulate digestion
inhibits gastric motility and/or secretions
stimulates pancreas and/or gallbladder secretions (increases signaling to gallbladder to release bile)
how does secretin regulate digestion
inhibits gastric motility and/or secretions
stimulates pancreas and/or gallbladder secretions (signal bile and bicarb production)
CCK and Secretin release is stimulated when this occurs
food enters duodenum
gastrin comes from here
entero-g cells
gastrin release can be stimulated by these two things
vagus nerve
gastric distension
acetylcholine, histamine, gastrin all have this affect on gastric regulation
increase acid production in the stomach
live culture that is ingested
probiotics
food that can profice nourishment for probiotics. Non-digestable CHO, like soluble plant fibers
prebiotics
Causes of GERD
weak esophageal sphincter, diet, smoking, high fat diet, alcohol, caffeine
treatment of GERD
smaller meals avoid laying down after meals control weight stop smoking avoid: caffeine, citrus, spicy foods, mints, alcohol acid neutralizers proton pump inhibitors histamine receptor blockers
causes of peptic ulcers
Heliobacter pylori
chronic use of alcohol, asprin, NSAIDS
How does a cholecystectomy affect digestion
must be careful with how much fat is consumed after the surgery
how is celiac disease treated
avoiding foods which contain gluten, a structural protein found in Rye, Barley, and Wheat
