advanced phis
What enzymes are
Proteins that catalyze the thousands of chemical reactions that constitute metabolism
Steps in sliding filament theory
Ach release at neuromuscular junction (before anything happens)
Travels down t-tubule to sarcoplasmic reticular
Ca++ is released from sarcoplasmic reticulum (first considered step)
Ca binds with troponin on actin filament
Tropomyosin is moved off of active sites (for myosin head to bind)
Myosin head binds to active site
Power STROKE + muscle contract
What powers all of this? ATP
What enzyme causes ATP? Actomyosin ATPase
Protein functions
Enzymes that catalyze body chemical reactions, receptor molecules that bind specific substrates, transport molecules that move substances within the blood, contractile proteins in muscle, aid in disease protection
How an enzyme acts as a catalyst
They lower the energy barrier to a reaction so that the reaction takes place at a lower temp; convert substrates to products
Multiple things about creatine kinase
Has extremely high activity in PCr
CK exceeds all other enzymes in muscle
Ensures ATP regeneration is rapid
Found in cells where ATP is consumed and produced
How does CK mark muscle damage?
Damage to cell releases CK into blood
Heart muscle damage causes appearance of cardiac isozyme of CK in the blood
Energy changes in reversible and irreversible reactions
Irreversible reactions-all substrate is converted to product
Large energy change
Non-equilibrium reaction
Less common
reversible reactions-establishes equilibrium with the ratio of the product concentration to substrate concentration (equilibrium constant)
Small energy change
Equilibrium reaction
Product is also substrate
More common
Difference in essential and nonessential amino acids
9 essential amino acids cannot be made by the body and must be gotten through the diet, 11 nonessential amino acids can be synthesized by the body
About diet specifically
Only look at slide
What transcription is
Copying process of genes
What an isozyme is
Enzymes that catalyze a given reaction in different tissues
4 products of metabolism
CO2, H20, ATP, heat
How oxidative phosphorylation is measured
Oxygen consumption
What competitive inhibitors are
Resemble normal substrate and bind to the active site, but cannot be changed by the enzyme into a product; acts as mimics; compete with normal substrates for a place on the active site of an enzyme
Several questions about Acetyl coA
Involved in etc
Pyruvate must be converted to it to go through glycolysis
Role of vitamin B in metabolism
8 B vitamins are necessary because they form the basic components for coenzymes
**Serves as a cofactor in many metabolic reactions (he said) - nvm he said wrong… it’s coenzyme
Oxidation of carbs and lipids and ATP produced by each (comparison)
Oxidation of Cho produces more atp than oxidation of fat
Buffers
Chemicals that resist changes in the pH of a solution; aid in maintenance of body pH through absorbing protons or reducing the effects of OH- ions; usually consists of a weak acid and its salt
Bicarbonate inside the body **with TMI details
If you want to give yourself competitive advantage take antacid
Creatine and protein synthesis
***creatine supplementation does not independently increase protein synthesis following exercise (long term effects are not clear)
Feedback inhibition
Inhibition of an allosteric enzyme by a product of its reaction or a product of a pathway in which the enzyme participates
Help regulate metabolic pathways by sensing an oversupply of product
Role of ATP
Used to drive the energy involving processes in the body
Used constantly and regenerate at the same time
Anabolism and catabolism
Anabolism =building up of something
Catabolism =breakdown of something
Zwitterion form
Carboxylate group + ammonium group + variable part (side chain)
Structure of an amino acid as it would appear at a pH of 7.0, contains both a positively and negatively charged group (ammonium group instead of amino)
Appearance of an amino acid at a neutral pH (has both positive and negative charge) - said there's not much more to say about it
Has no net charge,it is isoelectric
What makes up the primary, secondary, tertiary, quaternary structure
Primary = sequence of amino acids
Secondary = spatial path taken by the 3 elements of the peptide backbone (shape)
Tertiary =Overall 3D arrangement of a polypeptide chain, including the secondary structure and any non-ordered interactions involving AA residues that are far apart
Quaternary =Refers to the arrangement of the individual subunits w/ respect to each other
Causes of acidosis and alkalosis
Acidosis - severe exercise, diabetes, starvation
Alkalosis - hyperventilation at rest, vomiting uncontrollably
Entropy, exergonic, endergonic, terms on end of last section
Entropy
Measure of energy dispersal
ΔS
Processes occur by themselves if they have a positive ΔS (entropy)
Enthalpy
Change in energy of the reactants when they are turned into products
Measured as total heat energy change
Endergonic
Free energy is consumed
ΔG is positive +
Can’t occur by itself
Exergonic
Free energy is released
ΔG is negative -
Free Energy Change
Maximal energy from a process that can be harnessed to do something useful
ΔG
Endothermic
Can only occur with energy input
Exothermic
Heat energy released
ΔH is negative -
What a myofibril is
Muscle cells
Much larger than average cells
Enzyme bindings to active sites
Often represents both the binding and catalytic site
Parts of an amino acid
Amino group + carboxyl group + alpha carbon + variable part (side chain)
Equilibrium
When a reaction reaches equilibrium, the substrates and products are constantly flowing between each side of the reaction
At this point, nothing happens and no energy is released
You’d be dead
Bronsted lowry definition for an acid and base
Acid = proton donor
Base = proton acceptor
Several hormones (lactate dehydrogenase - example - know what it does)
some hormones are peptides
glucagon
insulin
growth hormone
Lactate dehydrogenase helps you convert glucose to ATP in anaerobic conditions (converts pyruvate to lactate)
Adenylate kinase = catalyzes ATP production + AMP
AMP deaminase = irreversibly deaminates (removes the amino group from) the base of AMP, producing ammonia
Fast/slow twitch fibers
Type I
Slow
MHC I
Type II A
Fast
MHC II A
Type II X
Faster
MHC II X
Type II B
Fastest
MHC II B
Polarity
Amino Acids are primarily found in a polar environment because they are in an aqueous medium
9/20 amino acids are nonpolar and hydrophobic
Oxidation/reduction
Oxidation = something loses electrons
Reduction = something gains electrons
The fuel for each metabolism reaction (what is used in glycolysis, creatine phosphate, oxidation - example)
Glycolysis (anaerobic) = carbs/glucose
Creatine phosphate = creatine phosphate
Oxidative phosphorylation = lipids
Glycolysis and use of either glucose or glycogen
If glycogen is the starting substance 3 atp are produced, if glucose is then 2 atp are produced
6/8 SA
Oxidation and reduction (difference)
LEO the lion says GER
When something is oxidized, something else is reduced
Seen in ETC; transporting molecules from one molecule to another until it ends on oxygen
Oxygen is reduced (final electron acceptor); electrons come from NADH2; thing that is passing them is oxidized; series of redox reaction; plays a significant role is oxidative phosphorylation
Oxidation: something loses electrons
Reduction: something gains electrons (charge goes down b/c electrons are neg)
Lactate formation
Lactate is produced when glucose is broken down for energy in the absence of oxygen
Pyruvate to lactate = anaerobic glycolysis
For low intensity exercise, little lactate will be formed, but for high intensity, the concentration in the muscle and blood will increase over time
Lactate is always formed even at rest
Effectors
positive and negative effectors
Effectors: control rxn rates/activity of enzyme
Positive require smaller concentrations of substrates than normal to maintain rxn velocity
Ex: turn on when exercise
Negative require larger concentrations of substrates than normal to maintain reaction velocity
Ex: turn off/slow down by adding negative eff.
Temperature and reaction rates
Increase in temperature speeds up reaction rates until a certain point
Heating too much disrupts conformation and decreases enzyme activity
** Need both of above
Blood lactate concentration and exercise intensity
for low intensity exercise, little lactate will be formed, but for higher intensities, the concentration in muscle and blood will increase over time
Active transport and facilitated diffusion
Active transport = requires ATP, against concentration gradient
Facilitated diffusion = does not require energy, down concentration gradient using a specific carrier
Facilitated diffusion is a substance crossing a membrane down its concentration gradient with the aid of a specific carrier, and does not require energy. Active transport is across a membrane against the concentration gradient so that energy is needed.
Reaction velocity
Potential question: What would influence reaction velocity? temperature, presence of enzymes, substrates, products, pH
Reaction velocity: how fast the reaction takes place
Reaction velocity and reaction rate are interchangeable
Velocity is proportional to enzyme concentration
pH: above or below optimal lowers rate
Temperature: slight increase increases rate; too much decreases enzyme activity
Aerobic and anaerobic glycolysis
Aerobic: when private enters the mitochondria and gets completely broken down to h2o and co2 (requires o2 for final breakdown of pyruvate)
Anaerobic: occurs when pyruvate is converted to lactate
From slides: Anaerobic vs. Aerobic Glycolysis
Anaerobic glycolysis occurs when pyruvate is converted to lactate (ATP is formed without the need for O2)
Aerobic glycolysis occurs when pyruvate enters the mitochondrion and gets completely broken down to H2O and CO2 (pyruvate breakdown does require O2)
Pyruvate can be generated at a faster rate than it can be oxidized in mitochondria