Exam I - Quiz Review Questions Flashcards
Proteins are stored for the primary purpose of serving as an energy substrate.
* True
* False
False
If you are in a fasted state, fatty acid synthesis should be ____ active compared to the fed state.
* More
* Less
* No differently
less
Which of the following pathways do NOT require oxygen either directly or indirectly?
* Oxidative
* TCA cycle
* Glycolysis
* Citric acid cycle
glycolysis
Given the following mRNA sequence, which of the following correctly represents the DNA coding strand?
5’ ACAUCGACG 3’
* 5’ ACAUCGACG 3’
* 3’ ACATCGACG 5’
* 3’ TGTAGCTGC 5’
* 5’ TGTAGCTGC 3’
5’ ACAUCGACG 3’
Gastric lipase is particularly important for the digestion of dietary fat in infants who are fed:
* Formula
* Breast milk
* Table scraps
* Domino’s (Da-me-nose) Pizza
breast milk
Substrate level phosphorylation occurs in the _____.
* Cytosol
* Mitochondria
* ER
* Nucleus
cytosol
Consider a Carboxy-endopeptidase that recognizes the amino acid phenylalanine (Phe). If the following polypeptide were exposed to this peptidase, predict the product.
Glu-Phe-Cys-Leu-His-Ile-Phe-Met-Gln
* 2 dipeptides, 1 pentapeptide
* 1 FFA, 1 pentapeptide, 1 tripeptide
* 1 dipeptide, 1 tetrapeptide, 1 tripeptide
* 1 FFA, 1 hexapeptide, 1 dipeptide
2 dipeptides, 1 pentapeptide
Allosteric inhibition of enzyme activity occurs when…
* A substance binds to a site other then the substrate binding site to inhibit activity
* A substance binds to the substrate binding site to inhibit activity
* A substance binds to all possible binding sites to inhibit activity
* The substrate binding site is phosphorylated
A substance binds to a site other then the substrate binding site to inhibit activity
The transport of fructose across the apical membrane of the enterocyte is facilitated by…
* GLUT2
* GLUT5
* Micelles
* PEPT1
GLUT5
Over 90% of all the peptides and amino acids absorbed by the intestine are transported into circulation.
* True
* False
false
Glycolysis is a(n) _____ pathway.
* Anabolic
* Catabolic
catabolic
Some dipeptidylaminopeptidases depend on Mg+2 for their activity. Mg+2 serves as a(n)…
* Enzyme
* Coenzyme
* Cofactor
* Competitive inhibitor
cofactor
All amino acid transporters are sodium dependent.
* True
* False
false
FADH2 is produced by _____.
* Glycolysis
* The electron transport system
* The lactate dehydrogenase reaction
* The TCA cycle
the TCA cycle
The de-O-GlcNAcylation is most directly mediated by…
* O-GlcNAcase
* O-GlcNAc transferase
* AMP-Kinase
* The hexosamine biosynthetic pathway
O-GlcNAcase
Glycogenesis is a(n) _____ process.
* Anabolic
* Catabolic
* Eubolic
anabolic
The transport of glucose across the apical membrane of the enterocyte is facilitated by…
* GLUT2
* GLUT5
* Micelles
* SGLT1
SGLT1
Alpha 1-6 bonds of amylopectin are hydrolyzed by isomaltase.
* True
* False
true
Which of the following amino acids will bind with greater affinity to a carrier that facilitates absorption from the intestinal lumen, isoleucine (Ile) or alanine (Ala)?
* Alanine
* Isoleucine
* They should bind with the same affinity
* Neither of these are transported
Isoleucine
If you are in a fed state, glycogen synthesis should be _____ active compared to the fasted state.
* More
* Less
* No differently
more
An amino acid that is positively charged at pH = 7 is…
neutral
Starch has more branch points than glycogen.
* True
* False
False
Other than that which results from chewing, no digestion of _____ occurs in the mouth.
* Carbohydrates
* Lipids
* Proteins
proteins
A gene encoded by genetic material in its euchromatic state has been…
* Activated
* Repressed
activated
The following reaction is a(n) _____ reaction: NAD+ + H -> NADH
* Oxidation
* Reduction
reduction
Acetyl CoA levels tend to increase when energy demand is _____.
* Low
* High
low
Oxidative phosphorylation occurs in the _____.
* Cytosol
* Mitochondria
* ER
* Nucleus
mitochondria
Which of the following is an example of a zymogen?
* Enteropeptidase
* Pepsin
* Pepsinogen
* Trypsin
pepsinogen
Which of the following digests carbohydrates in the stomach?
* Salivary amylase
* Gastric amylase
* Pancreatic amylase
* None of these
none of these
It is easier for a human digestive system to break down alpha 1-4 glycosidic bonds than beta 1-4 glycosidic bonds.
* True
* False
true
In which of the following vehicles are lipids transported from the intestinal lumen into the enterocytes?
* Chylomicron
* CD36/FAT
* FABP
* Micelles
micelles
Transcription inhibitors/repressors work to _____ chromatin.
* Condense
* Decondense
condense
The movement of sodium from the intestinal lumen across the apical membrane is _____.
* Endogonic
* Exergonic
exergonic
As UDN-N-acetylglucosamine levels decrease, AMPK activity…
* Increases
* Decreases
increases
Carbohydrate digestion in the small intestine relies ONLY on enzymes of pancreatic origin.
* True
* False
false
As UDP-N-acetylglucosamine levels increase, glycogen synthase activity…
* Increases
* Decreases
* Does not change
increases
The first step of glycolysis has a positive ΔG. Given that this is an energetically unfavorable reaction, how is it still able to proceed?
* It exists in equilibrium with its reverse reaction
* It is coupled to ATP hydrolysis, which is energetically favorable
* An enzyme raises its activation energy
* When the concentration of glucose exceeds the Km of hexokinase, a concentration gradient drives the reaction regardless of its free energy
It is coupled to ATP hydrolysis, which is energetically favorable
Protein modulation by (de)phosphorylation refers to _____ modification.
* Allosteric
* Covalent
* Transcriptional
* Ubiquitous
covalent
Both kinases and phosphorylases add phosphate groups to their substrates.
* True
* False
true
O-GlucNAc transferase is a covalent activator of glycogen synthase.
* True
* False
true
AMPK is inhibited by _____.
* AMPK-kinase
* CAM kinase
* Liver Kinase B1
* Protein Phosphatase 1
AMPK-kinase
Which of the following amino acids are common objects of phosphorylation during enzyme modulation?
* Serine
* Threonine
* Tyrosine
* None of the above
* All of the above
all of the above
Generally speaking, which of the following classes of enzymes move atoms from one position to another within a molecule?
* Isomerases
* Phosphorylases
* Phosphatases
isomerases
Which of the following enzymes is the first to directly act on proteins during digestion?
* Pepsin
* Pepsinogen
* Trypsin
* Chymotrypsin
pepsin
Which of the following fatty acid transporters is responsive to insulin?
* Fatty acid transport protein
* Fatty acid translocase/CD36 (FAT)
* Fatty acid binding protein – cytosolic (FABPc)
* Fatty acid binding protein – membrane (FABPm)
Fatty acid translocase/CD36 (FAT)
Compared to fasting conditions, lipolysis will be _____ at 1-2 hours following a meal containing carbohydrates, proteins, and fats.
* More active
* Less active
* No different
less active
The majority of galactose that enters the bloodstream is metabolized by the kidneys.
* True
* False
false
Which of the following lipoproteins is recognized by a chylomicron remnant receptor in the liver, and is thus necessary for uptake by the liver?
* Apo AI
* Apo C-II
* Apo C-III
* Apo E
ApoE
Upon binding to its receptor, insulin stimulates the activation of a kinase system that phosphorylates the hydroxyl group of which of the following amino acids?
* Tryptophan
* Tyrosine
* Phenylalanine
* Arginine
tyrosine
Which lipase hydrolyzes triacylglycerols that are associated with a chylomicron?
* Lingual lipase
* Lipoprotein lipase
* Gastric Lipase
* Pancreatic Lipase
lipoprotein lipase
Which of the following is not stimulated by insulin?
* Glycogenesis
* TAG synthesis
* Protein synthesis
* Glycogenolysis
glycogenolysis
The rates of glucose uptake and phosphorylation are proportional to the rise in blood glucose levels in pancreatic beta cells due to the relatively _____ Km of its glucose transporter and hexokinase isoform compared that of many other cell types.
* Higher
* Lower
* Indistinguishable
higher
Insulin secretion increases as the ATP:ADP ratio _____ in the pancreatic beta cell.
* Increases
* Decreases
* Stays the same
increases
Assuming that you are a metabolically healthy individual, during the postprandial state, 30 minutes following a high carbohydrate meal, it is likely you would be…
* Euglycemic
* Hypoglycemic
* Hyperglycemic
hyperglycermic
Under fasting conditions, a healthy person would likely be…
* Euglycemic
* Hyperglycemic
* Hypoglycemic
euglycemic
Under fasting conditions (12 hours after a meal), a type-2 diabetic person would likely be…
* Hypoglycemic
* Euglycemic
* Hyperglycemic
hyperglycemic
The liver is the predominant site of amino acid storage.
* True
* False
false
Prior to receiving ApoC-II and ApoE, a chylomicron is referred to as a(n) _____.
* Nascent chylomicron
* Mature chylomicron
* Chylomicron remnant
* VLDL
nascent chylomicron
Which of the following lipoproteins is the most predominant in the post-absorptive (fasted) state?
* Chylomicrons
* VLDL
* IDL
* HDL
VLDL
An increases ATP:ADP ratio results in the _____ of potassium channels in the pancreatic alpha cell.
* Opening
* Closing
opening
Compared to fed conditions, ketogenesis will be _____ at 24-48 hours following a meal.
* More active
* Less active
* No different
more active
The product of beta-oxidation is _____.
* Glucose
* Pyruvate
* Acetyl CoA
* Succinyl CoA
acetyl CoA
Which of the following enzymes help regulate insulin production by insuring that intracellular glucose levels are high prior to increasing the ATP:ADP ratio?
* Glycogen synthase
* Acyl Co-A Synthase
* CPT-1
* Glucokinase
glukokinase
Upon entry into the cell, fatty acid must be activated by the addition of a CoA prior to being either stored or oxidized.
* True
* False
true
All of the following would most likely affect blood glucose concentrations EXCEPT…
* Increases rate of liver glycogenolysis
* Increased rate of muscle glycogenolysis
* Increased rate of gluconeogenesis
* Digestion of a high carbohydrate meal
Increased rate of muscle glycogenolysis
Which of the following pathways removed ammonium produced by amino acid catabolism?
* Glycogenolysis
* Pentose Phosphate Pathway
* Urea Cycle
* Gluconeogenesis
urea cycle
Compared to fasting conditions, glucagon secretion will be _____ at 1-2 hours following a meal containing carbohydrates, proteins, and fats.
* More active
* Less active
* No different
less active
Blood levels of which of the following hormone(s) are most likely decreased in the fasted state?
* Cortisol
* Epinephrine
* Glucagon
* Insulin
insulin
Compared to the early post-absorptive period, proteolysis will be _____ at during prolonged fasting/starvation.
* More active
* Less active
* No different
more active
In the fasted state, TAG synthesis is favored over beta oxidation.
* True
* False
false
Compared to fed conditions, the urea cycle will be _____ at 24-48 hours following a meal.
* More active
* Less active
* No different
more active
