Exam I - Quiz Review Questions Flashcards by Hope Carr

Proteins are stored for the primary purpose of serving as an energy substrate.
* True
* False

False

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If you are in a fasted state, fatty acid synthesis should be ____ active compared to the fed state.
* More
* Less
* No differently

less

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Which of the following pathways do NOT require oxygen either directly or indirectly?
* Oxidative
* TCA cycle
* Glycolysis
* Citric acid cycle

glycolysis

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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’

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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

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Substrate level phosphorylation occurs in the _____.
* Cytosol
* Mitochondria
* ER
* Nucleus

cytosol

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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

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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

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The transport of fructose across the apical membrane of the enterocyte is facilitated by…
* GLUT2
* GLUT5
* Micelles
* PEPT1

GLUT5

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Over 90% of all the peptides and amino acids absorbed by the intestine are transported into circulation.
* True
* False

false

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Glycolysis is a(n) _____ pathway.
* Anabolic
* Catabolic

catabolic

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Some dipeptidylaminopeptidases depend on Mg+2 for their activity. Mg+2 serves as a(n)…
* Enzyme
* Coenzyme
* Cofactor
* Competitive inhibitor

cofactor

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All amino acid transporters are sodium dependent.
* True
* False

false

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FADH2 is produced by _____.
* Glycolysis
* The electron transport system
* The lactate dehydrogenase reaction
* The TCA cycle

the TCA cycle

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The de-O-GlcNAcylation is most directly mediated by…
* O-GlcNAcase
* O-GlcNAc transferase
* AMP-Kinase
* The hexosamine biosynthetic pathway

O-GlcNAcase

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Glycogenesis is a(n) _____ process.
* Anabolic
* Catabolic
* Eubolic

anabolic

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The transport of glucose across the apical membrane of the enterocyte is facilitated by…
* GLUT2
* GLUT5
* Micelles
* SGLT1

SGLT1

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Alpha 1-6 bonds of amylopectin are hydrolyzed by isomaltase.
* True
* False

true

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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

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If you are in a fed state, glycogen synthesis should be _____ active compared to the fasted state.
* More
* Less
* No differently

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An amino acid that is positively charged at pH = 7 is…

neutral

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Starch has more branch points than glycogen.
* True
* False

False

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Other than that which results from chewing, no digestion of _____ occurs in the mouth.
* Carbohydrates
* Lipids
* Proteins

proteins

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A gene encoded by genetic material in its euchromatic state has been…
* Activated
* Repressed

activated

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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