Review 7 Flashcards
Catabolism
Breaking down process that obtains energy in most cases for Anabolism
Anabolism
Building up process that uses ATP from catabolism process
What controls Catabolism and Anabolism
HORMONES - They tell the body whether they should be in a catabolic or anabolic state
Why is ATP a store of energy?
The energy are in its bonds. The electrons there are unstable, high energy (excited state). When released, it wants to go to a more stable state and in the process releases energy.
Product of ATP hydrolysis
ADP + HPO4 and H3O+ + Energy
Where is the energy in ATP hydrolysis coupled to Monomer build up
First Phosphate is transferred to monomer and then the formation with a polymer or another monomer displaces phosphate which is hydrolyzed and releases energy that pushes it forward. It is this part. The transfer is actually endothermic (lol). Think Le Chatelier. Pi that is displaced is a product and hydrolysis of it degrades the product and pushes it forward
If ATP has -G so why is not going out of control
Depends on two factors of a substrate:
1. Is it energetically favorable (G = 0)
- Kinetically stable and enzymes ensure it works so the ATP can then say it will give it fuel
Benefits of Enzymes
- Produces metabolites
- Slow and controlled oxidation of glucose to obtain final products compared to single step breakdown spontaneous process quick step. It allows harness of electrons so it can make ATP
- Makes a kinetically unfavorable reaction favorable by lowering the activation energy
Hydride
H- = H+ + 2e-
NAD+ (most oxidized form) and takes hydride and the extra His actually in solution and accompanies NADH. It can only accept one hydride
FAD accepts FADH2 because it can do that compared to NAD+
Glycolysis Important points
- Anaerobic process
- 1 molecule of glucose = 2 NADH, 2 net ATPs (4 ATPs, - 2 ATPs invested), and 2 (Glycerol-3-Phosphate or Dihydroxyacetone phosphate), and 2 Pyruvate
- 2 stages - Investment and Pay-off phase
ACTUAL DIAGRAM OF GLYCOLYSIS
REVIEW IN A TEXTBOOK, ITS ENZYMES, AND THE CHEMICAL FORMULA
ACTUAL DIAGRAM OF GLUCONEOGENESIS
REVIEW IN A TEXTBOOK, ITS ENZYMES, AND THE CHEMICAL FORMULA
ACTUAL DIAGRAM OF KREB’S CYCLE
REVIEW IN A TEXTBOOK, ITS ENZYMES, AND THE CHEMICAL FORMULA
Two stages of Body and BGL
- Fasted - Think time that you have not eaten. How does the body maintain the blood glucose level
- Fed: When you have eaten, the body is carrying out glycolysis and breakdown of food to contribute to the BGL
Fasted Stages
- Glycogen:
a. String of glucose molecules that are stored away
b. Located in the liver
c. Lasts for 10-18 hrs in the body - Gluconeogenesis - Creation of new glucose usually using lactate and amino acids (oxaloacetate)
Gluconeogenesis Unique Reactions
- Pyruvate -> Oxaloacetate -> Phosphoenolpyruvate
1st - Pyruvate carboxylase and 2nd - Phosphoenolpyruvate carboxylase - Fructose 1,6-bisphosphate -> Fructose 6-phosphate
Enzyme = Fructose 1,6-bisphosphotase - Glucose 6-phosphate -> Glucose
Enzyme = Glucose 6-phosphotase
2 Roles of Glucose 6-phosphatase
- Conversion of glucose 6-phosphatate to glucose
2. Conversion of glycogen to glucose
3 Regulatory Methods of Gluconeogenesis and Glycolysis
- Fast regulation (Think Le Chatelier’s principle)
- Midway Regulation (Think hormones)
- Slow regulation (Think DNA, TFs)
Fast regulation between Gluconeogenesis and Glycolysis
- Influx of glucose (pushes glycolysis forward)
- Influx of amino acids -> oxaloacetate (increase gluconeogenesis)
- High ATP (Increased gluconeogenesis)
- Increased AMP (Increase glycolysis)
Slow regulation between Gluconeogenesis and Glycolysis
- Transcription products
2. DNA -> RNA -> Enzymes
Midway regulation between Gluconeogenesis and Glycolysis
- Insulin - Store glucose (increase breakdown of glucose to glycogen)
- Glucagon - Breakdown glycogen to glucose (provide glucose)
**Hormones bind to receptors and causes changes (signal transduction)
ACTUAL DIAGRAM OF PENTOSE PHOSPHATE PATHWAY
REVIEW IN A TEXTBOOK, ITS ENZYMES, AND THE CHEMICAL FORMULA
3 Products and Function of Pentose Phosphate Pathway
- No ATP is produced or used
- NADPH which donates electrons and can serve as an antioxidant
- Produces ribose-5-phosphate (Precursor for DNA and RNA)
Ratio of NAD+ and NADH
NAD+ : NADH = 1000 (More oxidized form of NAD+ than reduced form)
NADP : NADPH = 0.1 (More of NADPH and wants to donate electrons (Le Chatelier’s principle))
Important notes of Pentose 5-phosphate
- Oxidative phase produces NADPH
- Non-oxidative phase produces Ribose 5-phosphate
- Ribulose 5-phosphate is a precursor for ribose 5-phosphate
- Ribose 5-phosphate cannot be made back into glucose 6-phosphate (the starting material) and it does not use or produce ATP
Prep Phase of Kreb’s Cycle
- Pyruvate oxidation by Pyruvate dehydrogenase
- 2CO2 is released and 2NADH is released for every 2 moles of Pyruvate
- Pyruvate (3 carbon molecule) undergoes pyruvate oxidation to Acetyl-coA (2 C- S-coA)
Regulators of Pyruvate dehydrogenase
- Positive - NAD+, AMP, Ca2+, coA, and Pyruvate
2. Negative - NADH, ATP, Acetyl-coA, and fatty acids
Two functions of Acetyl-coA
- Be fed into the Kreb’s cycle for production of large amount of ATP
- In the case of excess Acetyl-coA, it can be converted to fatty acids
Why can’t Fatty acids produce glucose?
Conversion of fatty acids to acetyl-coA happens and the process of pyruvate oxidation is irreversible and so the body has not found a way around it.
General Equation of Kreb’s Cycle
Acetyl-coA + NAD+ + GDP + Pi + FAD -> CO2 + NADH + FADH2 + GTP
Regulators of Kreb’s Cycle
- Positive - NAD+ (All 3 enzymes), Ca2+ (Isocitrate dehydrogenase and alpha-ketoglutarate dehydrogenase), ADP (Citrate Synthase and Isocitrate dehydrogenase)
- Negative - NADH + H (All three levels), ATP (Citrate synthase and isocitrate dehydrogenase), Succinyl-coA (Citrate synthase and alpha ketoglutarate dehydrogenase), and Citrate (citrate synthase)
Things to consider in Prep Phase of Kreb’s Cycle for Regulation
- Substrate
- Product
- Energy State
- G < 0 is the best point of regulation
Things to consider in Kreb’s Cycle Regulation
- No hormonal control
- Allosteric regulation
- Substrate Availability
- G < 0 is the best point of regulation
Things to consider in Electron Transport Chain (Oxidative phosphorylation) Regulation
- Energy needs
- No major hormonal or allosteric regulation in oxidative phsophorylation
- Think Le Chatelier’s Principle with (NAD+/NADH, ADP/ATP, O2/H2O)
Notes on Oxidative Phosphorylation
- Redox reaction
- As the electrons pass through the enzymes, it goes from high energy state to low energy state and the energy is used to pump protons.
- The build-up of protons makes it more acidic and the matrix becomes naturally basic.
- There is a buildup of H+ that flows down the electrochemical gradient.
- Process of generating ATp in oxidative phosphorylation is oxidative phosphorylation.
- Chemiosmosis - Process of H gooing through the synthase. It is selectively that H+
- Substrate phosphorylation is when ADP + Pi merge together without influence of chemiosmosis, only enzyme. Think about Substrate Phosphorylation
Mitochondria Function
- Apoptosis
2. ATP synthesis (Powerhouse)
Apoptosis causes and Notes
- Factors:
a. Reactive oxygen species
b. Environment stress
c. DNA damage
d. Viruses
e. Development - Apoptosis - regulated by cytochrome c and C-ASP-ase (uses cysteine residues in its protease function at aspartate sites in targets)
ATP notes
- 1NADH = 2.5 ATP
- 1FADH2 = 1.5 ATP
- NADH from cytosol glycolysis is not permeable to MT and so some method transports it and it can land on any complex in the electron transport chain. It is a shuttling mechanism
How does the body produce constant energy ATP?
- Glycogen stored in liver and sometimes muscles.
- Proteins in muscles
- Fats in adipose tissue
How are fats the major source of storage fuel?
- Look at the triglycerides (ester linkage, glyceride, acyl groups). It is mainly the acyl groups which are naturally reduced and energy rich
- It is inert (water and oil mixture)
- No large or prominent role like proteins to make enzymes.
- Fats are hydrophobic and unlike glycogen and proteins cannot be weighed down.
DESCRIBE THE DIGESTION PROCESS OF FATS
Small intestine, Lipases, Bile (Saponification), Chylomicrons (lipoproteins ) in epithelial cell, lacteal vs regular capillaries, right and left thoracic ducts
DESCRIBE THE DIGESTION PROCESS OF FATS in CAPILLARIES
Lipoprotein lipases (liver CR, muscles, adipose tissues), insulin and enzyme lipoprotein lipase, storage method in adipose tissue sinly and in aggregates.
DESCRIBE THE DIGESTION PROCESS OF FATS in LIVER
CR, VLDL, glucose, fats, small intestine with proteins and carbs.
Functions of Liver in Fat metabolism
- Breakdown glucose, proteins, carbs to FAs and package them with CR to VLDL.
- Called VLDL (Very Low Density Lipoprotein) which is due to fair ratio and water.
DESCRIBE THE DIGESTION PROCESS OF FATS in ADIPOSE TISSUE
Hormone receptors, Hormone-sensitive lipases, albumin in muscle cells, insulin and glucagon, liver as a consumer
Sources of Fats in the body
- Diet (broken down to TAGs in lacteals)
- Adipose cells - FFAs attached to albumin and others probably.
- Liver - VLDL
DESCRIBE FATTY ACID SYNTHESIS 1
Location as liver, Excess glucose, cytoplasm, mitochondria, oxaloacetate, citrate, acetyl-coA, Oxaloacetate, NADPH and CO2 (function and source), location of fatty acid (cytoplasm or mitochondria), essence of mitochondria, essence of ATP
DESCRIBE FATTY ACID SYNTHESIS 2
Essence of ATP, Acetyl-coA carboxylase, fatty acid synthase, CO2 essence, mechanism of enzyme 1 and 2, products for each stage, main regulator and why?, allosteric regulator (inhibitor and activator), hormonal activator and inhibitor, Look at the final fatty acid synthesis one more time.
Fatty Acid Oxidation
- Activation - Acyl synthetase, carnitine acyl transferase I, ATP and AMP PPi essence, Acyl carnitine
- Transportation - Carnitine transferase II, Acyl carnitine translocase
- Oxidation - FAD, NAD+, H2O
Regulation Site for Beta Oxidation
- Carnitine Acyl Transferase I where malonyl-coA is the allosteric inhibitor and it shows that fatty acid synthesis and oxidation are mutually exclusive and cannot happen at the same time.
REVIEW HOW DOES THE BODY ADAPT TO STARVATION
CHECK THE NOTES
Why are fatty acids not considered makers of Oxaloacetate even though they go through Kreb’s cycle?
Kreb’s cycle does not ultimately form oxaloacetate or carbon atoms. They are lost as CO2.
Pitfall of using Amino acids for Gluconeogenesis
They are needed for other processes also and that will not be good. This is where Ketones come in.
Why is it that acetyl-coA will still rise even though ATP has been stopped
Fats OXIDATION cannot be stopped once it has started. There is no regulator for it.
What are the two kinds of amino acids
Non-essential and Essential
Ketogenic (acetyl-coA and Acetoacetyl-coA) and Glucogenic (Oxaloacetate and pyruvate)
Why is transamination important?
It allows the amino group to be removed in urea when it exists in equilibrium with NH3 and NH4+
Transamination
Amino acid becomes alpha-keto acid and in the process, the alpha-ketoglutarate changes to glutamate which indicates that the amino group has been transferred.
