191 Cards in this Set
| Front | Back |
|---|---|
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What 2 things is the plasma membrane made up of?
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Phospholipids & proteins
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What gives the plasma membrane its function?
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Proteins
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Plasma membranes have ___ (greater/less) CHO content and cholesterol content than other membranes
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Greater
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What is the name of the glycoprotein-polysaccharide coveringthat surrounds the cell membranes of some cells?
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Glycocalyx
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What is the name of the proteins that contain oligosaccharidechains (glycans)covalently attached to polypeptide side-chains?
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Glycoproteins
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The ___ (cytoplasmic/mitochondrial) matrix is a microtrabecular lattice or cytoskeleton
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Cytoplasmic
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What providesa structure for cell organelles, microvillae (as found in intestinal mucosacells), and large molecules?
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Cytoskeleton
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T or F: Structural arrangement of the cytoplasmic matrix influencesmetabolic pathways
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True
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The ___ (outer/inner) mitochondrial membrane is porous
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Outer
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The ___ (outer/inner) mitochondrial membrane is selectively permeable; site of electron transport chain
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Inner
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What is the site of the TCA cycle (krebs cycle) & beta fatty acid oxidation?
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Mitochondrial matrix
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What cells do not contain mitochondrion?
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Erythrocytes
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The nucleoli is condensed ___ (collagen/chromatin)
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Chromatin
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Uracil is in ___ (RNA/DNA) only
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RNA
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Thymine is in ___ (RNA/DNA) only
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DNA
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mRNA is synthesized in nucleus, thenmoves to ___ (RER/SER) in cytoplasmic matrix
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RER
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___ (Rough/Smooth/Sarcoplasmic) reticulum = protein synthesis and glycosylation
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Rough
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___ (Rough/Smooth/Sarcoplasmic) reticulum = lipid synthesis
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Smooth
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___ (Rough/Smooth/Sarcoplasmic) reticulum = calcium ion pump
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Sarcoplasmic
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What are the structures made up of a network of membranous channels?
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ER
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Where does protein trafficking & sorting, and glycoprotein modification and additionalprotein glycosylation occur?
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Golgi apparatus
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Cis-Golginetwork = ___ (entrance/exit)
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Entrance
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Trans-Golginetwork = ___ (entrance/exit)
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Exit
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The golgi apparatus is connected to ER by what?
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Transport vesicles
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Lysosomes& peroxisomes are ___ (protein/enzyme)-filled organelles
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Enzyme
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___ (Lysosomes/Peroxisomes) are the cell’s “digestive system”
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Lysosomes
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Peroxisomes are the site of ___ (oxidative/reductive) ___ (anabolic/catabolic) reactions
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Oxidative, catabolic
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What are the 4 functions of lysosomes?
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Phagocytosis, autolysis, bone resorption, hormone secretion & regulation
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What are the 3 functions of peroxisomes?
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Oxidize fatty acids to acetyl CoA, amino acid catabolism, detoxifying reactions
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What are molecular stimuli that attach to receptors?
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Ligands
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What is the function of the 1st type of receptor?
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Bind to ligand & convert it tointernal signal
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What is the function of the 2nd type of receptor?
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Serve as ion channels
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What is the function of the 3rd type of receptor?
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Internalize stimulus intact
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The ___ (maximum velocity (Vmax)/Km (Michaelis constant)) is the enzyme velocity at substrate saturation
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Maximum velocity (Vmax)
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The ___ (maximum velocity (Vmax)/Km (Michaelis constant)) is the concentration of substrate when reaction is at 1/2 of maximum velocity
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Km (Michaelis constant
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Functionality of enzymes depends on what 2 things?
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Protein& prosthetic group or coenzyme
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Covalent modification is usually the addition/removal of what type of groups?
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Phosphate
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___ (Allosteric/Induction) = enzymeswith another site besides catalytic site that can bond with modulator
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Allosteric
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___ (Allosteric/Induction) = changes in concentrations of inducibleenzymes
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Induction
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With transferases, what group is transferred from 1 substrate to another?
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Functional group
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What type of catalytic proteins are responsible for the cleavage of C-C, C-S, & C-N bonds (nohydrolysis/O-R)?
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Lyases
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What type of catalytic proteins are responsible for the interconversion of optical or geometric isomers?
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Isomerases
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What type of catalytic proteins are responsible for catalyzing the formation of C-? Bonds (O, S, N, others)?
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Ligases
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What is free energy (G)?
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The potential energy in bonds ofnutrients that is released
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Lipase breaks down ___ (TAG/CHO)
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TAG
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Amylase breaks down ___ (TAG/CHO)
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CHO
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What are the accessory digestive organs?
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Liver, gallbladder, pancreas
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The mucosalayer of the GI tract is the most ___ (internal/external)
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Internal
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The serosa layer of the GI tract is the most ___ (internal/external)
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External
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What 3 types of cells does the epithelial layer of the GI mucosa contain?
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Absorptivecells, enteroendocrinecells, and exocrine cells
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Absorptive cells are ___ (enterocytes/enteroendocrine cells/exocrine cells)
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Enterocytes
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___ (Enteroendocrine cells/Exocrine cells) are mucusproducing globlet cells
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Exocrine cells
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What is beneath epithelial cells in the GI mucosa that anchors them?
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Lamina propria
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T or F: The lamina propria is made up of gut-associated lymphoid tissue (GALT)
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True
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The main enzyme in saliva is salivary ___ (amylase/lipase) which hydrolyzes alpha ___ (1-4/1-6) bonds in ___ (proteins/starch)
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Amylase, 1-4, starch
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___ (Chief cells/Parietal cells/Enderoendocrine G-cells) produce enzymes needed for protein digestion
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Chief cells
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___ (Chief cells/Parietal cells/Enderoendocrine G-cells) produce hydrochloric acid and intrinsic factor, which is needed for the absorption of vitamin B12
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Parietal cells
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___ (Chief cells/Parietal cells/Enderoendocrine G-cells) produce the hormone gastrin, which stimulates parietal and chief cells
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Enderoendocrine G-cells
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Crypts = small tear-drop like areas onbottom of ___ (enterocytes/villi) of the ___ (exocrine/absorptive) cells of the SI
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Villi, absorptive
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What type of cells are on the bottom of crypts?
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Stem cells
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___ (Segmentation/Peristalsis) mixes food in the GI tract with chyme
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Segmentation
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___ (Segmentation/Peristalsis) propels food forward through the GI tract
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Peristalsis
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What is thelargest endocrine organ (tissue) in the GI tract?
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Fat tissue
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Largeintestine absorbs what from fecal matter?
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Water
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Intestinal secretions and motility are orchestrated by what 3 things?
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Hormones, signaling peptides, and the nervous system
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___ (Peptide YY/Cholecystokinin) increases intestinal motility
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Cholecystokinin
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___ (Peptide YY/Cholecystokinin) inhibits gastric secretion
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Peptide YY
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What is the function of the tight junctions between intestinal epithelial cells?
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Barrier to prevent antigens andpathogens from entering
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Disregulation of the tight junctions between intestinal epithelial cells can cause what?
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A leakyintestinal barrier
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A leaky intestinal barrier is associated with what 3 disorders?
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Chronicinflammatory bowel diseases, type 1 diabetes, and multiplesclerosis
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What type of bacteria provide metabolic signals to helpmaintain a healthy intestinal barrier?
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Commensal (a nonharmful coexistance)
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GERD = Reflux disease, gastric juice moves up intothe ___ (pharynx/esophagus) and inflames it
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Esophagus
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Stereoisomers have ___ (1/2) or more chiral carbon atoms with ___ (same/different) 4 groupsattached but ___ (are/are not) mirrorimages of each other
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2, same, are not
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T or F: Stereoisomerismexists in all macronutrients
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True
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T or F: Many enzymes are stereospecific
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True
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What are 2 examples of enzymes that are stereospecific?
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Hexokinase, amylase
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In solution, what type of molecules form a cyclic ring structure?
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Monosaccharides
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In solution, the monosaccharidemolecules form a cyclic ring structure, which is a reaction between what 2 groups? What does this form?
|
Carbonyl and hydroxyl. Forms an additional chiral carbon
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Pentoses contribute ___ (a lot/little) to dietary energy
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Little
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___ (Deoxyribose/Ribose) is a constituent of ATP, ADP, and AMP, cAMP, NAD, NADP, RNA
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Ribose
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What is the constituent of riboflavin, FAD, and FMN–(a reduction product of ribose)?
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Ribitol
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Disaccharides consistof two monosaccharide units joined by what type of bonds?
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Covalent
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___ (Maltose/Lactose/Sucrose)- partialhydrolysis of starch
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Maltose
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___ (Maltose/Lactose/Sucrose)- Milk sugar
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Lactose
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___ (Maltose/Lactose/Sucrose)- Cane sugar and beet sugar
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Sucrose
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Maltose is two glucose units linked through an ___ (alpha/beta) (1-4) glycosidic bond
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Alpha
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Lactose is a galactose unit linked through an ___ (alpha/beta) (1-4) glycosidic bond to glucose
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Beta
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What is the disaccharide that is a glucose linked to a fructose?
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Sucrose
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Raffinose, stachyoses, & verbascose are ___ (oligosaccharides/polysaccharides)
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Oligosaccharides
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Starch, glycogen, & c ellulose are ___ (oligosaccharides/polysaccharides)
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Polysaccharides
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What is composed of polyglucose joinedby beta(1-4) glycosidic bonds?
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Cellulose
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Sucralose is ___ (stable/unstable) at high temperatures and is ___(200-300/500-600) times sweeter than sucrose
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Stable, 500-600
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Salivary a-amylase in the mouth and pancreatic a-amylase in the small intestine break down ___ (polysaccharides/disaccharides)
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Polysaccharides
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Where does the digestion of disaccharides occur?
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Microvilli of enterocytes
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Dextrins are broken down into ___ (lactose/maltose) and limit dextrins in the SI
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Maltose
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In the brush border, maltase and the alpha- ___ (1,4/1,6) glycosidic bonds in limit dextrins are hydrolyzed, forming ___ (sucrose/glucose)
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1,6, glucose
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Which GLUT isthe only insulin regulatable transporter of glucose?
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GLUT 4
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Glucose and galactose require ___ (active/facilitated) transport and ___ (active/facilitated)diffusion
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Active, facilitated
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Fructose is likely facilitated transport via what GLUT?
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GLUT 5
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What is the anabolic hormone involved in carbohydrate, lipid, and proteinmetabolism?
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Insulin
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___ (Insulin/Glucagon) is secreted by the beta-cells of the pancreas
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Insulin
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___ (Insulin/Glucagon) is secreted by the alpha-cells of the pancreas
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Glucagon
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What GLUT transporter is in muscle and adipose tissue?
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GLUT 4
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___ (Insulin/Glucagon) causes the translocationof GLUT4 from ___ (GLUT4 storage vesicles/cell surface) to the ___ (GLUT4 storage vesicles/cell surface)
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Insulin, GLUT4 storage vesicles, cell surface
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Insulin ___ (enhances/inhibits) glycolysis
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enhances
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Insulin ___ (enhances/inhibits) gluconeogenesis
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inhibits
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Insulin ___ (enhances/inhibits) glycogenolysis
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inhibits
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Insulin ___ (enhances/inhibits) glycogenesis
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enhances
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What is the catabolic hormone antagonistic to insulin?
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Glucagon
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Glucagon affects mostly the what organ?
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Liver
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Maintaining blood glucose levels is amajor function of what 3 parts of the body?
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Liver, skeletal muscle, adipose tissue
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Glycemic ___ (index/load) measures how a carbohydrate-containingfood raisesblood glucose?
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Glycemic index
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How is glycemicload calculated?
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Multiplyingthe glycemic index by the amount of carbohydrate (in grams) provided by a food and dividing the totalby 100
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T or F: Anindividual can still reach high blood glucose level by consuming a lot of lowGI foods
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True
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Research support the relationship between ___ (high/low) GI orGL diet with the risk of type2 diabetes
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High
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Long-term consumption of high ___ (GI/GL) diet is also associated with increased risk of obesity and coronary heart disease
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GL
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___ (Long-term/Short-term) = Greater type 2diabetes risk
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Long-term
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___ (Long-term/Short-term) = Insulin resistance
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Short-term
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Patients with type2 diabetes willimprove glycemic control byadapting to low ___ (GI/GL) diet
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GI
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A high GL diet could cause ___ (increased/decreased) insulin demand which would cause beta-cell ___ (exhaustion/production) which would cause glucose ___ (tolerance/intolerance) and then diabetes
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Increased, exhaustion, intolerance
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What 3 rates determines blood glucose concentration at a given moment
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1. The rate of glucose absorption, 2. The rate of glucose taken up by tissues, 3. The rate of glucose produced by the liver
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What is the 1st mechanisms of regulation metabolism?
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1. Negative or positive modulation of allosteric enzymes(through binding of effectors), 3. Directional shifts in reversible reactions
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What is the 2nd mechanisms of regulation metabolism?
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2. Hormonal activation by covalent modification/induction (cAMP and phosphorylation)
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What is the 3rd mechanisms of regulation metabolism?
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3. Directional shifts in reversible reactions
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What is the 4th mechanisms of regulation metabolism?
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4. Translocation of enzymes within cells (glucokinase)
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What are 3 allostericmodulators?
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AMP,ADP, & ATP
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___ (AMPs/ADPs/ATPs) positive modulation causes shiftfrom inactive to active form of glycogen phosphorylase b
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AMPs
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AMPs positive modulation causes shift from inactive to active form of glycogen phosphorylase b stimulates what 2 enzymes?
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Phosphofructokinase, pyruvatekinase
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What are the minor uses of glucose?
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Synthesis of ribose, NADPH, glucose forglycoprotein and glycolipid synthesis
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What are the lowest priority uses of glucose?
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Substrate for fatty acid and TAGsynthesis
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The firststep in intracellular metabolism ofglucose converts glucose to what?
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Glucose 6-phosphate
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What 2 organs havean enzyme to convert G-6-P back to glucose?
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Liverand kidneys
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What enzyme is involved in glucose phosphorylation?
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Hexokinase
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Where is glucokinase located?
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Liver,pancreas
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Where is hexokinase located?
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Muscle,adipose, brain
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Glucokinase functions at max velocity when bloodglucose levels are ___ (normal/elevated)
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Elevated
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Hexokinase functions at max velocity when blood glucose levels are ___ (normal/elevated)
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Normal
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What happens to glucokinase in liver cells?
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GK is “parked” in the nucleusby bindingto GKRP when glucose levels in the hepatocyte approach fasting levels.
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Glucokinase is indirectly ___ (inhibited/stimulated) by fructose6-P
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Inhibited
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Glucokinase is indirectly ___ (inhibited/stimulated) by glucose andtrace fructose
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Stimulated
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What enzyme cleavesthe a-1,4bonds to release G-1-P from nonreducingends of the glycogen polymer during glycogenolysis?
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Glycogenphosphorylase
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What enzyme cleavesthe a-1,6bonds at branch pointsduring glycogenolysis?
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Debranchingenzyme
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What 2 hormones is glycogenphosphorylase covalently regulated by?
|
Glucagon,epinephrine
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What molecule is glycogen phosphorylase allosterically regulated by?
|
AMP
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In muscle, Ca2+ binds to the calmodulin subunit of phosphorylase kinase, activating it ___ (with/without) phosphorylation, which then ___ (activates/inhibits) glycogen phosphorylase, causing glycogen degradation
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Without, activates
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In muscle under extreme conditions of anoxia and depletion of ATP ___ (Ca2+/AMP) activates glycogen phosphorylase b ___ (with/without) it being phosphorylated
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AMP, without
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Where does the TCAcycle occur?
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Mitochondrialmatrix
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Where does glycolysis occur?
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Cytoplasm
|
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Where does the ETC occur?
|
Inner mitochondrial membrane
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The brain exclusively usesglucose for energy under normal circumstances, therefore ____ takes place inthe brain
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Glycolysis
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Glycogenolysis is active in the___ (fed/fasting) state
|
Fasting
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If you eat a pizza and then willnot eat anything in the next 24 hours, what are glucose sources that supplyyour body’s need during the whole process?
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Exogenousglucose, glycogenolysis, gluconeogenesis
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Liver cells may use glucose forall of the following EXCEPT ___: Energyneeds- Synthesizing ATP, makingglycogen, synthesizingand secreting insulin, synthesizingribose, synthesizingfatty acids
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Synthesizing and secreting insulin
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Glycolysis produces ___ (lactate/pyruvate) underaerobic conditions, and ___ (lactate/pyruvate) under anaerobic conditions.
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Pyruvate, lactate
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Whensomebody is skipping meals for 14 hours, what hormones related to carbmetabolism is high in blood? Whatis low? How is each carb metabolicpathways doing in each organ?
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Glucagon, insulin, liver undergoing gluconeogenesis
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Why may six meals a day lead toweight loss in some people?
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High fiber diets inhibit fat absorption
|
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What 2 products does the PPP form?
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Pentose phosphates, NADPH
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The pentose phosphates formed in the PPP are necessary for the synthesis of what?
|
Nucleic acid synthesis for DNA and RNA
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The NADPH formed in the PPP are necessary for the synthesis of what?
|
Fatty acids
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What are 3 precursors gluconeogenesis can synthesize glucose from?
|
Glycerol, lactate, and certain aminoacids
|
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What is the key site for gluconeogenesis?
|
Liver
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Gluconeogenesis is active when: Insulinlevel is high, glucagonlevel is low, someoneis on a very low carb or carb free diet, allof the above
|
Someone is on a very low carb or carb free diet
|
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___ (Dietary/Functional) fiber = nondigestibleCHO & lignin that are intact & intrinsic in plants
|
Dietary
|
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___ (Dietary/Functional) fiber = nondigestibleCHO that are isolated, extracted, or manufactured& known to have physiological benefits
|
Functional
|
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Fiber ___ (lowers/increases) cholesterol
|
Lowers
|
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T or F: Fiber helps control diabetes
|
True
|
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Most people in the US are ___ (high/low) in fiber
|
Low
|
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What are the 4 classifications of fiber?
|
Source, solubility, fermentability, viscosity
|
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What are the 4 properties of fiber that are important for theirfunctions?
|
Solubility in water, water holding capacity & viscosity, ability to bind to organic and inorganicmolecules, fermentability
|
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Some hemicelluloses, pectin, gums, b-glucans are water ___ (soluble/insoluble) fibers
|
Soluble
|
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Cellulose, lignin, some hemicelluloses,chitosan, chitin are water ___ (soluble/insoluble) fibers
|
Insoluble
|
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Soluble fibers ___ (speed up/delay) gastricemptying
|
Delay
|
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Soluble fibers ___ (increase/decrease) transittime
|
Increase
|
|
Soluble fibers ___ (increase/decrease) nutrientabsorption
|
Decrease
|
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Inoluble fibers ___ (increase/decrease) transittime
|
Decrease
|
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Inoluble fibers ___ (increase/decrease) fecalbulk
|
Increase
|
|
T or F: Bileacids undergo enterohepatic cycling
|
True
|
|
What is diverticulosis?
|
The formation of numerous tiny pockets,or diverticula, in the lining of the bowel.
|
|
Bystimulating bowel movement, ___ (fermentable/nonfermentable) fibers can prevent/relieve diverticulosis/diverticulitis
|
Nonfermentable
|
|
Fermentation is done by what?
|
Intestinal bacteria
|
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Fiber causes ___ (increased/decreased) nutrientdiffusion rate--attenuation of the blood glucose response
|
Decreased
|
|
Fiber causes ___ (increased/decreased) enzymefunction
|
Decreased
|
|
Fiber causes ___ (increased/decreased) mixingof gastrointestinal contents with digestive enzymes
|
Decreased
|
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Fiber causes ___ (increased/decreased) absorption of lipids
|
Decreased
|
|
Fiber causes ___ (increased/decreased) fecal bile acid excretion
|
Increased
|
|
Where does glycolysis occur?
|
Cytoplasm
|
|
Where does glycolysis occur?
|
Cytoplasm
|
|
Where does gluconeogenesis occur?
|
Liver
|
|
What 3 products does glycolysis produce?
|
Pyruvate, NADH, ATP
|
|
What 4 products does the TCA cycle produce?
|
CO2, NADH, FADH2, ATP
|
|
Where does the PPP occur?
|
Cytoplasm
|
HNF 461: EXAM 1