Exam 2 Flashcards
(94 cards)
1
Q
What does ADH stand for?
MEOS?
A
Alcohol Dehydrogenase
Microsomal Ethanol Oxidizing System
2
Q
How many kcal/gram is Alcohol?
What are its other two names?
A
7 kcal/gram
Ethyl Alcohol or Ethanol
3
Q
Where is ethanol readily absorbed throughout?
What happens to it in the blood stream?
Where is it primarily oxidatively degraded at?
A
GI tract
Unaltered in the bloodstream
Liver
4
Q
What does the liver first convert ethanol into?
Then what?
What does both steps produce?
A
Acetaldehyde
Acetate
NADH
5
Q
What are the three enzyme systems of ethanol oxidation?
A
ADH
MEOS (aka Cyto P-450 system)
Catalase
6
Q
Where does the Alcohol Dehydrogenase pathway occur?
What does the dehydrogenase require?
What is the Km for ethanol?
When is enzyme saturated and when can ADH not oxidize ethanol?
A
Cytoplasm of Liver cells
NAD
1mM or 5 mg/dl
3 to 4 times Km
conc. beyond 4 times Km
7
Q
What is the toxic level for ethanol?
What allows ethanol to enter cells easily?
What happens when ADH is saturated?
A
50-100 mg/dl
High lipid solubility
Spill over and metabolism by MEOS
8
Q
Describe what happens to ethanol
A
Ethanol –> Acetylaldehyde –> Acetate
9
Q
Does MEOS directly produce NADH?
A
No but it creates acetaldehyde which when oxidized produces NADH
10
Q
Which oxidizing system is able to oxidize a variety of compounds such as ethanol, FA, aromatic hydrocarbons, steroids, barbiturate drugs?
It also is associated with Endoplasmic Reticulum
A
Microsomal Ethanol Oxidizing System
11
Q
Certain enzymes of MEOS are “inducible” what does this mean and significance?
A
Ethanol in high conc. can induce synthesis of these enzymes which results in hepatocytes being able to metabolize ethanol much better
12
Q
What are two problems associated with acetaldehyde toxicity?
A
Impedes the formation of microtubules in liver cells
Cause the development of perivenular fibrosis
13
Q
Does Alcohol Dehydrogenase (used to convert Ethanol to acetaldehyde) deplete or create NADH?
A
CREATES NADH
Depletes NAD+
14
Q
What does elevated NADH signal?
A
Metabolic shift toward reduction so…
Inhibits krebs
Decreased fat burning
Increased FA synthesis (fatty liver)
Lactic Acidemia (Increased lactic acid)
15
Q
What are the four basic steps of Fatty Acid Oxidation? (NADH is a product)
A
Oxidation
Hydration
Oxidation
Thiolysis
16
Q
What are the three basic steps to Fatty Acid Synthesis? (NADPH is a reactant)
A
Reduction
Dehydration
Reduction
17
Q
Where do lipids tend to accumulate?
A
In most tissue where ethanol is metabolized
Fatty liver, myocardium, Renal tubules
18
Q
What is the reactant, enzyme, and product of TAG synthesis?
A
DHAP, Glycerol 3-phosphate dehydrogenase, and Glycerol 3 Phosphate
19
Q
What is the Reactant, Enzyme, and Product for Lactate Production?
A
Pyruvate, Lactate Dehydrogenase, and Lactate
20
Q
What is an Acyl?
A
Fatty acid attached to something
21
Q
What is a fatty acid?
A
A carboxyl group and a carbon chain
22
Q
Study the Chart from Biochem one
A
DAMMIT
23
Q
Are the fatty acids on a TriAcylGlycerol usually saturated or unsaturated?
A
First is Saturated
Second is Unsaturated
Third is Either
24
Q
Are Triglycerides Oxidized or reduced?
Anhydrous or Hydrous?
How many kcal per gram?
A
Reduced
Anhydrous
9
25
A 150 pound male has how many kcal of triglycerides?
100,000 kcal triglycerides
26
Which muscle type stores more fat? How much more?
Type 1 (aerobic) store two to three times more fat than type 2
27
Does exercise reduce or increase IMTG in type one muscle fibers?
Is the IMTG replenished faster after aerobic or resistance exercise?
Reduce
Resistance
28
Compare IMTG concentrations and insulin sensitivity in Normal population
Athletes
Obese people
Lower IMTG and Moderate insulin sensitive
Higher IMTG and greater insulin sensitive
Higher IMTG and low insulin sensitivity
29
What enzymes get a TAG to DAG to MAG?
MAG to FFA?
MAG to LCFA+Glycerol?
Adipose Triglyceride Lipase (ATGL)
Hormone Sensitive Libase (HSL)
Monoacylglycerol Lipase (MGL)
MonoacylGlycerol Lipase (MGL)
30
What gets LCFA+Glycerol to MAG?
MAG to DAG?
DAG to TAG?
Glycerol-3-phosphate acytltransferase (GPAT)
Acylglycerol-3-phosphate acyltransferase (AGPAT)
Diacylglycerol acyltransferase (DGAT)
31
What is the protein that breaks down lipoproteins at the surface of capillaries? (mostly skeletal muscle, heart and adipose tissue) It releases FFAs into tissue.
Where is it produced?
Lipoprotein Lipase
Produced by muscle and fat cells
32
Does excersise increase or decrease lipoprotein lipase in skeletal muscle?
Increase!
33
Give an overview of Fat Burning
1. Mobilize (get FA off of glycerol
TAG->DAG->MAG->FFA
2. Activate (attach the FA to Coenzyme A)
FFAs -> Acyl CoA
3. Beta Oxidation (prepare molecule for Krebs)
OHOT
4. Enter Aerobic system (Krebs and ETS)
34
Fat Breakdown Overview and Enzymes used
```
Mobilize fat from TG form
Lipases
Bring Fat to Mito
Activate FA
Acyl CoA Synthetase and Pyrophosphatase
Transport FA into mito matrix
CPT and Carnitine
Beta Oxidation
OHOT (Acyl CoA Dehydrogenase)
Enter Aerobic system
Multiple Dehydroenases
Make ATP
```
35
Epinephrine, Norepinephrine, Glucagon, ACTH, Cortisol are all associated with what?
Insulin?
Stimulating Lipolysis
Inhibiting it
36
Regulation of Lipases are controlled by what?
Hormones
37
Explane Hormone Sensitive Lipase (HSL) and its correlation with Adult Onset Diabetes
Adipose Tryglyceride Lipase (ATGL) and type 2 diabetics?
HSL skeletal muscle protein content reduced or elevated in type two diabetics?
HSL much higher specific activity for DAG than TAG with diabetes
HSL is strongly inhibited by insulin
Muscle ATGL elevated a lot with type two ppl
Reduced
38
What does OHOT stand for?
Oxidation
Hydration
Oxidation
Thiolysis
39
What is interesting about any FA that enters the muscle to be oxidized?
It must be chaperoned by a protein, FABPc (cytoplasmic fatty acid binding protein) escorting it to the surface of the mitochondria
40
What is the name for when Coenzyme A is attached to FA and creates Acyl CoA using Acyl CoA Synthetase enzyme?
Where does this occur?
Is ATP consumed or produced in this process?
What happens next?
Activation
Outer Mitochondrial Membrane
Consumed
Enter the Mitochondria
41
What does Carnitine Palmitoyltransferase Complex consist of?
Responsible for?
Is it considered the RATE LIMITING STEP? (CPT I)
CPT I, Acylcarnitine Translocase, CPT II
Transport of LCFA
YES
42
What refers to the four steps that occur prior to having fat enter the Aerobic system?
What enzymes go with the steps?
Beta Oxidation (OHOT)
O: Acyl CoA Dehydrogenase
H: Enoyl CoA Hydratase
O: L-3-Hydroxyacyl CoA Dehydrogenase
T: Beta-Ketothiolase
43
What are the results of Beta Oxidation?
Both FADH2 and NADH products (go to ETC)
Acetyl CoA Product (enters krebs)
The FA (Acyl CoA) is two carbons shorter each time you run Beta Oxidation (OHOT)
44
Which two additional enzymes are required for Unsaturated FA Degradation?
Which bonds do they go with?
Reductase and Isomerase
Odd numbered double bonds = Isomerase
Even numbered ones = Reductase and Isomerase
45
Instead of OHOT what is it for Unsaturated FA?
List steps and enzymes that go with them
```
Oxidation - Acyl CoA Dehydrogenase
Reductase - 2,4-Dienoyl CoA Reductase
Isomerase - Isomerase
Hydration - Enoyl CoA Hydratase
Oxidation - L-3-Hydroxyacyl CoA Dehydrogenase
Thiolysis - Beta Ketothiolase
```
46
Difference between Odd-Chain FA and Even?
Both are degraded 2 by 2 but Odd are left with Propionyl CoA
47
Fat Oxidation Overview
```
Hormones are released during exercise or fasting
Lipases release FA from tracylglycerols
Bring FA to Mito
Activation
(Acyl CoA Synthetase and Pyrophosphatase)
Transport into matrix
CPT and Carnitine
Beta Oxidation
Each round of Beta Oxidation releases Acetyl CoA
Acetyl CoA enters aerobic system
Dehydrogenases
Make ATP
```
48
Key enzymes for Fat Burning
Lipases (HSL) free FA from triglycerides
Acyl CoA Synthetase activates FA for transport
Acyl CoA Dehydrogenase
First enzyme of OHOT
Oxidizes AcylCoA
49
What three things are Inhibitors for Fat burning?
Stimulators?
Insulin, High energy charge (ATP), NADH or FADH2
Glucagon, Low energy charge (ADP/AMP), NAD+ or FAD
50
What is the other name for the Pentose Phosphate Pathway?
Hexose Monophosphate Pathway
51
What does the PPP make?
What are they needed for?
Main enzyme?
Ribose and NADPH
Ribose needed for DNA, RNA, other molecules
NADPH needed for reductive biosynthesis, detox, respiratory bursts, antioxidant regeneration
GLucose 6 phosphate dehydrgenase
52
When new cells are being created, the PPP is stimulated or inhibited?
How bout when process consumes NADPH what happens to PPP?
Stimulated
Stimulated
53
What is the location of the Hexose Monophosphate Pathway? (PPP)
How many NADPH per glucose 6-P?
ATP produced or consumed?
Cytosol
2
NO ATP produced or consumed
54
What is a Nucleoside?
Nucleotide?
Base + Sugar
Base + Sugar + Phosphate
55
Anything that consumes ribose does what to PPP?
STIMULATES PPP
56
What are the main products and their purposes of PPP
Ribose 5-P : Nuceic Acids, ATP, CoA, NAD FAD
NADPH +H: Reductive Bosynthesis, Free rad elim.
NADPH +H Detox, Respiratory Burst
Glyceraldehyde 3-P
Fructose 6-P Glycolysis
57
Which is oxidized in the electron transport chain to make ATP? NADPH or NADH
Which is an electron donor during reductive biosynthesis, respiratory burst, detox, and regeneration of antioxidants?
NADH
NADPH
58
What do the oxidative reactions of PPP do?
The Non-Oxidative ones?
Make NADPH
Ribose 5-P can be converted into products to be used in Glycolysis
It can also be used to make nucleotides and nucleic acids
59
What are the 4 individual steps of PPP?
Dehydration of glucose 6-P
Hydrolysis of 6-P gluconate gamma lactone
Oxidative Decarboxylation
6-P gluconate to yield Ribulose 5-P
Isomerization
Ribulose 5-P to Ribose 5-P
60
What is the main enzyme for PPP?
Two reactants?
Product?
Glucose 6-P Dehydrogenase
Glucose 6-P and NADP+ are reactants
Makes NADPH as a product
61
What are the enzymes that go along with the four steps of PPP?
Glucose 6-P Dehydrogenase (Dehydrogenation)
Lactonase (Hydrolysis)
6-phosphogluconate dehydrogenase (oxidative decarboxylation)
Nothing for Isomerization?
62
Molecules move back and forth from PPP and what other pathway?
Which enzymes act as "The Link" between these pathways?
Glycolysis
Transketolases and Transaldolases build a reversible link between PPP and glycolysis
63
What are the "Fantastic Four" ways NADPH is utilized?
Reductive Biosynthesis
Detoxification
Respiratory Bursts
Antioxidant Regeneration
64
What does Reductive Biosynthesis mean?
Building things by adding electrons (From NADPH)
Build fat, cholesterol, steroid hormones, bile salts
65
What does detoxification mean?
Maxing toxins more water soluble for execration by adding electrons (from NADPH)
Toxins then excreted in urine
66
Which process makes detoxification occur? Where does this process come from?
How are molecules made more water soluble?
Livers P450 monoxegenase system
Endoplasmic reticulum in liver contain system
Addition of hydroxyl groups (OH)
67
What does Respiratory Burst mean?
What happens?
This means creating "harsh chemistry" to kill bad guys (non-self like bacteria) by using electrons from NADPH
White blood cells take in more oxygen. O2 and electrons (from NADPH) make very reactive molecules
Reactive molecules and nonself bacteria are sequestered in a vesicle where bacteria dies
68
What are the roles of Hydrogen Peroxide and Myeloperoxidase in Harsh Chemistry?
Hydrogen Peroxide used to create reactive species to destroy. (bacteria, viruses, other non self )
Myeloperoxidase is an enzyme that makes hypochlorus acid from hydrogen peroxide
69
What does Antioxidant Regeneration mean?
Adding electrons (from NADPH) to antioxidants so they can keep protecting the body from free radicals
70
What are three common Reactive Species?
O2-
H2O2 Hydrogen Peroxide
.OH Hydroxyl
71
What three things do Free radicals and Reactive Species attack?
Polyunsaturated fat in phospholipids
Protein in cells
Nucleic acids in DNA
72
What is the name of the process by which electronically excited molecules are inactivated?
Quenching (this is usually an antioxidant giving an electron to the free radical)
73
When free radicals are quenched, antioxidants get what?
When antioxidants get regenerated they get what?
Oxidized
Reduced
74
What are three enzymes that may also quench free radicals?
Superoxide Dismutase (quenches superoxide)
Catalase (quenches hydrogen peroxide)
Glutathione Peroxidase (quenches hydrogen peroxide)
75
What is the location and function of Superoxide Dismutase (SOD)
Extracellular
Cytoplasm
MItochondria
Eliminate Superoxide and produce Hydrogen Peroxide
76
Catalase Location and Function
Mostly in cell peroxisomes
Smaller amounts in cytoplasm, mitochondria, microsomes
Eliminate Hydrogen Peroxide!
Nutrophils have lots of catalase
77
Remember this!
ANYTHING THAT CONSUMES NADPH STIMULATES PPP
78
What are the 6 KEY enzymes of PPP?
```
Glucose 6-Phosphate Dehydrogenase
main enzyme makes NADPH
Superoxide Dismutase
Turns superoxide to hydrogen peroxide
Catalase
turns hydrogen peroxide to water
Glutathione Peroxidase
Turns hydrogen peroxide to water
Myeloperoxidase
Turns hydrogen peroxide to hypochlorus acid
(respiratory burst)
Cytochrome P-450 mono-oxygenase system
Adds OH groups to aromatic and aliphatic
compounds (detox)
```
79
Does eating fat stimulate fat synthesis?
NO! Eating SUGAR does!
80
Give Fat synthesis overview
Eat sugar (lots of blood glucose)
Rest (energy charge is high muscle glycogen up)
Muscle hexokinase is inhibited by glucose 6 phosphate (more glucose not brought into muscle)
Liver glucokinase stimulated by lots of glucose and NOT inhibited by glucose 6 phosphate
Liver runs glycolysis (lots of ATP and Acetyl CoA)
ATP inhibits icocitrate dehydrogenase stop TCA
Citrate spills out and is acetyl CoA is given back
Acytyl CoA turned to malonyl CoA
Fatty acid synthase keeps adding malyonyl coAs to a growing FA
Palmitate (16:0) is eventually created
81
Eating carbs raises blood glucose so insulin is secreted and glucose enters the cells.... then what three questions are asked?
Do you have enough energy
Enough stored carbs?
What should I do know?
82
When will glucose move from blood to muscle?
As long as conc. of glucose is lower in muscle and transporters are available
83
You eat carbs, glucose blood up, insulin spike, fat and muscle glucose transport know what happens if the muscle is full of glycogen?
If its not?
Glucose goes to the LIVER
Glucose is stored as Glycogen
84
Does exercise increase or decrease glucose uptake in skeletal muscle?
INCREASE A TON
85
Glucose goes from blood to muscle when the blood glucose conc. is higher than the muscle glucose conc. What is done to keep the conc. in the muscle low comparatively>?
A phosphate is added to glucose in the muscle which makes it into glucose 6 phosphate and not glucose.
86
How does muscle say NO to incoming glucose?
If there is high energy charge and glycogen is full then PFK is inhibited
This causes glucose 6 phosphate to accumulate
Which inhibits hexokinase
Which inhibits glucose 6 phosphate and causes glucose accumulation
Glucose accumulation in the muscle brings the muscle and blood conc. of glucose to equal therefore preventing facilitated diffusion into muscle!
87
What Four steps does Fatty Acid Synthase make sure happens?
Condenses (adds malonyl CoA)
Reduces
Dehydrates
Reduces
88
Functions of cholesterol?
Essential component of cell membranes!
Precursors to bile salts and steroid hormones
89
Where is cholesterol made? (structures)
Where do reactions take place?
Liver is primary site but also intestine adrenal cortex and gonads
Cytosol!
90
What does HMG-CoA reductase do?>
Turns HMG-CoA to Mevalonate which is on its way to becoming cholesterol
91
What are the ingredients for cholesterol? What are they the same as?
Main enzyme?
First unique compound in cholesterol synthesis?
Acetyl CoA, NADPH, and ATP.
Same as ingredients for building FA
HMG CoA Reductase
Mevalonate
92
Describe Proglycogen
Macroglycogen
More sensative to dietary carbs
Synthesized more rapidly following post exercise glycogen depletion, plateau after 24 hours
Synthesis is slower and more constant may last for 48 hours post exercise. Responsible for cargo loading
93
Where do we store our glycogen? (structures)
Where in those structures?
LIver and skeletal muscle
Cytosol
94
Glycogen synthesis overview
Phosphoralate Glucose (hexokinase or gluckinase)
Make UDP-GLucose (pyrophosphatase)
Initiation (connect glucose to glycogenin)
Elongation of the chain (glycogen synthase adds glucose)
Branching (4:6 transfer)
