homework 3
in fat digestion, fats form micelles. Which of the following must happen prior to micelle formation
bile salts must interact with fat, lipases must cleave triacylglycerols
in general, when energy is low _____ are activated
catabolic pathways
the Krebs cycle is used for cellular
catabolism and anabolism
the citric acid cycle is important for cellular
catabolism and anabolism
CoA is an acetyl carrier in
citric acid cycle, pyruvate oxidation
glycerol can enter glycolysis or gluconeogenesis by conversion to
dihydroxyacetone phosphate
which is a direct product of the cleavage of fructose 1,6-biphosphate in glycolysis
dihydroxyacetone phosphate
whenever ATP is used in a step of glycolysis, it is generated by the reverse reaction of gluconeogenesis. T/F
false
What treatment would rescue Leo being given too much fructose
glucose
which enzyme catalyzes the reaction by which glucose is trapped in the cell
hexokinase
which of the following best describes digestive enzymes
hydrolases
in liver cells the conversion of glucose-6-phosphate to glucose occurs
in the ER
which of the following is/are true of oxaloacetate
it is a metabolite in the CAC, it is not a metabolite of glycolysis, it is a metabolite of gluconeogenesis
A person with HFI who ingested fructose would have
low levels of blood glucose
Phase II of the CAC involves ______ of the organic metabolites moving through the pathway and the _____ of high energy electron carriers
oxidation, production
Phase I of the CAC involves the decarboxylation which is ______ and creation of NADH, which is _______
oxidation, reduction
in glycolysis, a kinase catalyzes the transfer a phosphoryl group from ______ to ADP to yield ATP
phosphenolpyruvate
regulation of glycolysis is achieved by MOST by regulation of _______
phosphofructokinase
the muscle biopsy showed an excess of glycogen in the muscle tissues. What is the most likely enzyme deficiency?
phosphofructokinase
which of the following catalyzes a reversible reaction
phosphoglucose isomerase
which of the following is used in BOTH glycolysis and gluconeogenesis
phosphoglycerate mutase
which of the following enzymes catalyzes a reaction that produces ATP during glycolysis?
pyruvate kinase
which of the following is/are DIRECTLY activated when energy levels are low
pyruvate kinase, phosphofructokinase
which of the following is/are DIRECTLY inhibited by high levels of ATP
pyruvate kinase, phosphofructokinase
the irreversible process that links glycolysis to the citric acid cycle is
pyruvate oxidation
following glycolysis, NAD+ can be regenerated without oxygen by:
reduction of pyruvate
which reaction is catalyzed by aldolase
reversible cleavage of F-1,6-BP into DHAP and GAP
which of the following catalyzes a reaction that generates FADH2
succinate dehydrogenase
in general, oxidation releases energy and is associated with catabolism. T/F
true
most digestive enzymes are released from cells in an inactive form. T/F
true
Following digestion in the stomach, polypeptides are digested in the intestinal lumen by ______ followed by digestion by intestinal bound _______
trypsin and chymotrypsin, peptidases
which of the following are products of converting pyruvate to Acetyl-CoA
two of the given answers
the last carbons of glucose are broken off and released from the Citric Acid Cycle as
Co2
which of the following is/are true of bile salts 1. they are amphipathic 2. they help emulsify fat 3. they give enzymes that catalyze the breakdown of fats access to fats
1, 2, 3,
which is a molecule with high phosphoryl transfer potential?
1,3-biphosphoglycerate, ATP, Phosphoenolpyruvate
if 10 glucose molecules enter aerobic respiration, how many high energy electron carriers will be generated by the end of the Krebs cycle
120
which of the following is the LOW energy version of the carrier
CoA
in the first step of the TCA cycle, a 2-C chemical is added to oxaloacetate to form
Citrate
what are the fates of pyruvate?
Ethanol, Lactate, Acetyl-CoA
which of the following is involved in gluconeogenesis and not glycolysis
GTP
compare the number of net ATP generated by glycolysis of each of the following: Glucose, Glyceraldehyde-3-Phosphate, Fructose 1,6-biphosphate and Glucose-6-Phosphate
Glyceraldehyde-3-phosphate and glucose generate the same number of ATP
protein digestion in humans begins in the stomach where ____ denatures protein and _______ cleaves peptide bonds
HCl, pepsin
what was the effect of giving Leo intravenous fructose?
a decrease in blood glucose levels
pyruvate dehydrogenase is inhibited by all of the following
acetyl-CoA, NADH, ATP
which of the following enzymes breaks one 6-carbon sugar into two 3-carbon sugars?
aldolase
which of the following catalyzes carbohydrate digestion in the mouth
alpha-amalase
if a person lacks all 3 forms of PFK, this person would
be dead
