Exam 1 Flashcards
Sum of all chemical and physical changes that occur in living organisms that allow for growth and survival of the organism
Metabolism
Metabolism is the balance of what two processes
Catabolic: breakdown, exothermic
Anabolic: buildup, endothermic, need energy
What are these 4 processes used for: electrostatic repulsion, resonance stabilization, ionization, hydration
ATP having a high energy bond
ATP is thermodynamically __________ but kinetically _______
unstable
stable
What are phosphoenol pyruvate, 1,3 BPG, and Phosphocreatine used for
to make ATP
What are the two major routes of ATP production
Substrate level phosphorylation (glycolysis)
Oxidative phosphorylation (ETC)
What is niacin’s cofactor
NAD+ or NADP+
What is riboflavin’s cofactor
FAD, FMN
What vitamin is derived from pyridine nucleotides
Niacin, Vit B3
What vitamin is derived from flavin nucleotides
Riboflavin, Vit B2
What is pantothenic acid’s cofactor
Acetyl CoA
What vitamin is derived from acetyl coA
pantothenic acid, Vit B5
The major pathways of carbohydrate metabolism and end with ________
glucose
The breakdown of glycogen into glucose is called what
glycogenolysis
The breakdown of glucose into pyruvate is called
glycolysis
The breakdown of pyruvate into lactate is called
anaerobic conditions
The buildup of lactate into pyruvate is called
lactic acid cycle (Cori Cycle)
The buildup of pyruvate into glucose is called
gluconeogenesis
The buildup of glucose into glycogen is called
glycogenesis
Glycolysis can occur in the presence or absence of _______
oxygen
What is the net result of ATP from glycolyis
2 ATP
Electrons are transferred from substrate to NAD+ in the form of a _________ _______ to form NADH
hydride ion (H:-)
In order for glycolysis to continue, NADH must be converted back into ______
NAD+
Where does glycolysis occur
cytosol
Where does pyruvate dehydrogenase, tricarboxylic acid, and ETC occur
mitochondria
In absence of O2 the 2NADH made during glycolysis are used by lactate dehydrogenase to convert pyruvate into ______
lactate (lactic acid)
What organ deals with lactate produced in the muscles during anaerobic conditions
liver
The liver converts lactate back into ______ and then converts the ______ back into glucose called gluconeogenesis
pyruvate
pyruvate
(cori cycle)
In prokaryotes the 2NADH made during glycolysis are used by alcohol dehydrogenase to convert acetaldehyde into what
ethanol
Yeast has a pyruvate decarboxylase enzyme to convert pyruvate into ethanol do humans have the same enzyme
no, humans can not convert pyruvate into ethanol instead we have alcohol dehydrogenase for ethanol metabolism
The first 5 steps in glycolysis consumes how many ATP
2
What are the three steps in glycolysis that are regulated
Hexokinase (1st step)
Phosphofructokinase (PFK; committed step, 3)
Pyruvate Kinase (PK; Exit Step, 10)
How is the first step of glycolysis (hexokinase) regulated
Glucose -> G6P
if there is a lot of G6P then it will be slower to phosphorylate more glucose to make more G6P
What is the first step of glycolysis
glucose to glucose 6 phosphate
enzyme: hexokinase
What is the second step of glycolysis
glucose 6-phosphate to fructose 6-phosphate
enzyme: phosphohexose isomerase
What is the third step of glycolysis
fructose 6-phosphate to fructose 1-6-bisphosphate
enzyme: phosphofructose kinase
What is the fourth step of glycolysis
fructose 1-6-bisphosphate to dihydroxyacetone phosphate and glycerALDEHYDE 3-phosphate
enzyme: aldolase
What is the fifth step of glycolysis
dihydroxyacetone phosphate to glycerALDEHYDE 3-phosphate
enzyme: triose phosphate isomerase
What is the sixth step of glycolysis
glyceraldehyde 3-phosphate to 1,3-bisphosphoglycerate
enzyme: glyceraldehyde 3-phosphate dehydrogenase
What is the seventh step of glycolysis
1,3-bisphosphoglycerate to 3-phosphoglycerate
enzyme: phosphoglycerate kinase
What is the eighth step of glycolysis
3-phosphoglycerate to 2-phosphoglycerate
enzyme: phosphoglycerate mutase
What is the ninth step of glycolysis
2-phosphoglycerate to phosphoenolpyruvate
enzyme: enolase
What is the tenth step of glycolysis
phosphoenolpyruvate to pyruvate
enzyme: pyruvate kinase
What cycle is when lactate is supposed to go to liver to be converted back to pyruvate and then go through gluconeogensis to make glucose again
Cori cycle
Is lactic acid is not removed then it decreases your pH which leads to what
acidosis, decreased brain function, coma
PPP: If the need for NADPH and Ribose 5 P are equal what happens
Go though oxidative phase then 1st conversion reaction and stop
PPP: Need ribose 5 P but not NADPH what happens
Do not go through oxidative phase instead take G6P and go backwards through interconversion
PPP: Need NADPH and ATP but not ribose
Go though oxidative phase then all of interconversion and then send fructose 6 phosphate and GAP into glycolysis, TCA(citric acid cycle), ETC
PPP: NEED NADPH but not ribose and not ATP
Go though oxidative ohase then all of interconversion and then send fructose 6 phosphate and GAP into gluconeogenesis and repeat
Symptoms of G6PD deficiency
black colored urine
low RBC and low hemoglobin
elevated bilirubin
What are the 4 reasons why ATP contains stored energy
ionization
hydration
electrostatic repulsion
resonance stabilization
What 3 compounds have a higher delta G of hydrolysis and can be used to make ATP
PEP
1,3-BPG
Phosphocreatine
What are the 3 major routes of ATP production
Substrate level phosphorylation and oxidative phosphorylation
What are the 4 different fates of pyruvate
alanine
acetyl coA
lactate
oxaloacetate
Glucose is the major fuel for what
the brain
If oxygen is low how is NAD+ regenerated in eukaryotes
Glucose -> 2 pyruvate -> 2 Lactates
If oxygen is low how is NAD+ regenerated in prokaryotes
fermentation
What does kinase do
add phosphate (phosphorylates)
What does isomerase do
changes ketose to aldose ot aldose to ketose
What does aldolase do
cleaves bonds
What does dehydrogenase do
remove hydrogen by oxidation (remove water)
What does mutase do
moves a functional group
What does enolase do
dehydration to enol form
Why is GDP trapped in a cell
negative charge
What is the most important regulatory step in glycolysis
committed step
reaction 3
phosphofructokinase (PFK)
What happens if glyceraldehyde 3-phosphate dehydrogenase is inactivated
glycolysis stops
Why can 1,3 bisphosphoglycerate yield ATP
higher free energy than ATP
The loss of water in reaction 9 creates what
PEP (yields ATP because it is high energy)
The first step via hexokinase is regulated by what
Product Inhibition
What are the committed step inhibitors
high ATP
creatine
What are the committed step regulators
high AMP
Fructose-2,6-bisphosphate
Galacatose is converted to G6P by what pathway
leloir
What happens if there is extra fructose in a diet
Depletes liver of Pi (inorganic phosphate) causing decrease in ATP production
What happens if an individual is missing aldolase B enzyme
hereditary fructose intolerance (accumulates fructose)
Where does gluconeogenesis occur and not occur
occur: liver
not: brain
What are the materials we can use to generate glucose
lactate -> pyruvate
amino acid -> pyruvate -> oxaloacetate
glycerol -> dihydroxyacetone phosphate (DHAP)
Why can’t fatty acids be used to make glucose
converted to Acetyl coA
What are the 4 different reactions in gluconeogensis when compared to glycolysis
reaction 1, 2, 9, 11
Why is it bad to eat raw eggs
Avidin covalently bind to biotin (causing body to not be able to absorb it)
In the PEP carboxylase reaction what is used instead of ATP
GTP
Muscle cells do not have what enzyme so glucose stays there
glucose-6-phosphate (G6P)
we get __ ATPs from glycolysis, but use __ ATPs from gluvoneogenesis
2
6
The pyruvate carboxylase reaction is regulated by what ALLOSTERICALLY
acetyl coA
The PEP carboxylase reaction is ALLOSTERICALLY inhibited by what
ADP
Insulin ______ amount of enzyme and glucagon ______ it
decrease
increase
The fructose 1,6 BP reaction is inhibited by what 3 things
AMP
F-2,6-BP (Fructose 2,6-bisphosphate)
Insulin
What two things activate the fructose 1,6 BP reaction
Glucagon
Citrate
The G6P (in ER of liver) is activated by what
G6P
High acetyl coA levels lead to _________, which is ______ synthesis in the liver
cirrhosis
fat
EtOH metabolism can also cause _____________ after exercise or not eating
exercise
The PPP occurs un the __________
cytosol
What are the two goals of PPP
NADPH
Ribose
NADH is made in _______ reactions and used to make ATP
catabolic
NADPH is made in _____ used in anabolic biosynthesis reactions
PPP
What is the committed step in PPP
Glucose-6-phosphate dehydrogenase (Rxn 1)
What is the regulatory enzyme of the PPP
G6P Dehydrogenase
What are the 3 things that control the stopping point of the PPP
Ribose 5 phosphate
NADPH
ATP
GSH (glutathione) is an ____________
antioxidant
What is the three purposes of GSH (glutathione)
serves as a reductant
conjugates to drugs to make them water soluble
induced in A.A. transport across the cell membrane
Defective G6P dehydrogenase means that not enough ______ is made, which leads to a ________ in active GSH
NADPH
decrease
Individuals with defective G6P dehydrogenase can not produce sufficient GSH to cope with the added ROS from ingestion of oxidative agents. The hemoglobin becomes cross-linked so that ________ ________ are formed and cell lysis or ___________ occurs
heinz bodies
hemolysis
