Exam 2 Flashcards
First law of thermodynamics
Energy is neither created nor destroyed but it can be transferred
Bioenergeties
How energy gets moved around
Energy
The ability to do work
Second law of thermodynamics
Entropy increases systems tend to become more disordered with each energy transfer
Change that is spontaneous in terms of probability and ordered
Highly ordered- low probability
Disordered- higher probability
Gibbs free energy
Delta G change in final & initial
Endergonic
Delta G is positive
Energy is stored
“Going uphill on a bike “
Also
Exergonic reactions
Delta G is negative
Energy is being released “going down a hill”
Delta o G of chemical reactions makes what kind of bonds
Making covalent bonds tends to be endergonic
Delta G can be affected by
Relative energy levels of reactants & products
Concentration of reactants & products
Temperature & pressure
To look at the energy levels we usually look at the standard free energy
Delta G zero
1M each, 1 atmosphere, 25°C
Biologist prefer delta G zero prime -
as delta G zero but also ph7
Energy charts!
Left to right- exergonic
Right to left-endergonic
Delta G zero prime shows
That the products of this reaction are much more stable
So the product are energetically favored
At equilibrium, there will be more product than reactants
Products move from
Less stable to more stable
Low energy = higher stability
Exergonic at equilibrium
Will leave you with more products than reactants
Spontaneous
When delta G zero prime is less than zero
There Will be more products than reactants at equilibrium
so concentrations don’t change anymore
The rate of the forward reaction is equal to
The rate of the reverse reaction
- equilibrium Constant
’ Products over reactants
Is linked to delta G zero prime
KEQ> 1
Delta G zero prime<o
Exergonic or spontaneous
KEQ< 1
Delta G zero prime>0
Endergonic more reactant than product
Can keq be negative?
No!
Delta G zero prime tells US what about the rate of reaction
Nothing
Rate of reaction & delta G prime zero are
Independent of one another
Reaction rate is controlled
by the energetic path from reactant to products
Activation energy
- Quantitative energy that we need to activate the reaction
Activation energy & delta G prime zero
Are independent of each other
Activation energy
The input energy needed to reach the transition state
Add energy to get to unstable transition state
In chemical reaction that releases energy
Exergonic
This is the mid-point of a chemical reaction which has the highest energy
Transition state
The amount of energy that a chemical must absorb before the reaction can occur
Activation energy
This term describes the state of a chemical reaction when the rate of a forward reaction is equal to the rate of the reverse reaction
‘equilibrium
How does delta G0 prime differ from Delta G value? Why is delta G0 prime more useful to biologist?
With Delta G0 we’re only going to be looking at relative energy levels of reactants and products delta G0 prime will be looked at and a pH of seven because a lot of biological molecules are closest to zero, so adding the prime to G0 will give us an extra constraint 
If the reaction of A~>B has a delta G0, prime= +3.0 kcal/mole, what is the reaction B~>A
-3.0kcal/mole
Molecule be will be more stable because this is an exergonic which is spontaneous and this in terms means that there is going to be more products and reactants and so the KEQ is going to be less than one when we’re going from A to B but when we’re going B to A a it’s going to be bigger than one.
B to A is endergonic non spontaneous
A to B will happen quicker
KEQ is the ratio of the concentration of products to the concentration of reactant under what condition
The condition that the rate of the forward reaction is the same rate as a reverse reaction, due to equilibrium
In what ways is an activation energy barrier of a chemical reaction a lot like a phospholipid bilayer for the movement of an ion
the path of how these barriers work in terms of how easily movement is accessed for some chemicals than with others
Requires energy from one state to get to the other for example, the grasshoppers one might require more energy to get from higher state to another, which requires less energy
How are delta G prime zero and activation energy related to another
They are not. They are independent of one another.
How are the activation energy of a reaction connect to the transition state of the reaction
The activation energy is an input needed in order to reach the transition state so the activation is right before the transition, state,
Are the activation energy is of a forward and reverse reaction equal to each other
No, only the concentrations and the rate of reactions are equal to each other 
How can you speed up a reaction
Applying heat
What is the only piece that controls rate?
Activation, energy
If you heat up glucose and fructose
Vibrate quickly and interact more violently, and some of them will have enough energy to make it over the barrier
Why are you applying heat doesn’t work biologically
Proteins begin to denature membrane membranes become too fluid to permeable and fall apart, can quickly kill the organism
How did we speed up the movement across the hydrophobic zone?
We gave it a different path to go by. There is a transport protein, Lazar different path, and this is for a specific molecules.
Enzymes
Proteins that catalyzes specific chemical reaction
Lower the activation energy and have no effect on Delta zero prime or KEQ
Enzymes in terms of binding
Act upon one substrate or reactant substrate, binds to the enzyme, specific active site face products are released
The good thing about enzymes is that they are unchanged and can act many times
Locke and key model
A substrate is added to an enzyme specific active site 
Induced fit model
Explains catalysis better than lock and key model
In this model of the enzyme and a substrate don’t fit perfectly just close close enough to get some specificity, but they don’t fit and actually have to form into each other the enzyme pushes into the substrate, and the substrate pushes into the enzyme
Doing so stabilizes the transition state 
Transition state
Chemical state between reactant and product
Highly unstable
Enzymes are what kind of catalyst
Bidirectional
Can catalase from reactant to product or product to reactant
By doing so, the enzyme did not affect the change of energy, but rather the affected how quickly we got there
Doesn’t affect the equilibrium just how quickly we get there
Enzymes lower activation energy, but don’t
Affect, Delta Chi zero, prime
No effect on KEQ
Measuring reaction rate
Concentration over time
the curve flattens out or reaches plateaus applied to due to the line, almost reaching an equilibrium
When the curve is flat
When the curve is perfectly flat. The concentration of product is no longer changing because it forward reaction is the same rate as a reverse reaction.
The curve
At zero, there is no product. The reverse reaction can’t happen. Lots of such as the product of beginning a little product to substrate.
As the time goes by the reverse reaction continues to have more and more once the reaction and the product are the same then we are at equilibrium
To find the reaction rate, we’re going to look at the slope of the curve during the early times
Concentration of product over time
We will be defining this, as our initial velocity think of this has reaction rate by looking at the early times we can avoid the complicated factor of the reverse reactor
Initial velocity is a reaction rate, and that is our enzyme activity how active our enzyme is a catalyst during this one reaction
What makes an enzyme, fast or slow? How may we compare enzymes?
The file to undergo reaction. Initial velocity depends on two aspects must be able to find the substrate and once it is bound go to catalysis which causes a reaction to happen.
Michaelis menten kinetics
We will measure the initial velocity by the concentration of substrate
How does the constitution of substrate affect initial velocity?
At zero, substrate concentration we can zero velocity
As a substrate, concentration increases velocity initially increases very quickly, but as concentration of substrate search to get super high velocity isn’t is it affected so much reaches a plateau
The maximum velocity is reached, and that’s why the plateau is reached, but maximum velocity is a theoretical value in order to get to the max. The substrate concentration has to be in a very, very very high.
Maximum velocity
It’s only reached at infinite substrate concentration
The active site is always full
As soon as catalysis happens, product is released instantly and the exercise refilled because there’s infinite amount of substrate available. The only limitation is the speed of the catalysis the faster it happens the faster the velocity is, but there’s a limit because we have gotten to the point that that is as fast as the enzyme it’s gonna go .
More than one way to get to one Vmax
KM is the concentration of substrate needed for half of V max
Km
Reflects substrate binding
Lower KM means tighter substrate binding
lower km means a more effective enzyme with a higher velocity 
KM and V max
Give info about substrate binding and catalysis
How it is achieving its particular velocity under particular conditions
More active enzymes have higher Vmax and lower cam values
But it is always advantageous
Higher KM leads to
More regulation
Most enzymes have a KM above the usual concentration of substrate, and usually acting inside of a cell, because they can show greater degree of regulation that can be adaptive and selected for, and is more useful than a higher enzyme activity
This is the Location on an enzyme that directly binds to the substrate molecules
Active site
What concept helps to explain why enzyme only catalyze on specific reactions
Lock and key model
This variable reflects how well and enzyme and substrate bind each other
Km
This idea helps to explain how an enzyme can lower an activation energy
Induced fit model
Which variable describes the fastest possible read that an enzyme can work out and it’s only achieved when there is an infinite substrate concentration
Vmax
Is it applying heat a good way to speed up a reaction why does it not work well for biological systems?
In chemistry, that might be the solution however, in biology, adding heat, can denature the protein cause the membrane to become too fluid and eventually kill the organism
Why do enzymes generally catalyze only one specific reaction?
Highly specific
How does the lock and key model different from the induced fit model?
Locke and key model expresses that the active site is made specifically for a substrate. However, the induced fit model suggest that the substrate make room for themselves against the active site.
Having too much specificity can be bad but also not good
How do enzymes affect
Delta G 0’ effect
keq no effect
Ea lowers activation energy
Enzymes, lower activation energy
To increase rate, but has no effect on delta G0, prime or KEQ
Vmax reflects
Catalysis rate
KM reflects
Substrate binding 
Other than changing the concentration of substrate how, can we change enzyme activity I terms of regulation
Any enzymes can be regulated by post translational modification  in addition, or subtraction of a phosphorylation can impact how an enzyme is regulated, and their speed phosphorylation has a negative charge, which can impact a 3-D structure of an enzyme that can change the enzyme from an inactive to an active 
Another way that we can change enzyme activity
Regulated by other small molecules
inhibitors
Bind to the active site
Inhibitors can, and are not limited to drugs
Inhibitors are produced by humans to slow down enzymes under the appropriate physiological circumstance 
Competitive inhibitor
A competitive inhibitor is a molecule that looks like the substrate, however, can’t be acted upon by the enzyme
Looks enough like a substrate that you can bind on the active site  call me no catalysis happens once it is found there
Once that inhibitor is bounded to the active site, the substrate can no longer get in there
How does the competitive inhibitor affect the max and KM
No effect on Vmax however, the km is increased
Velocity on inhibitors is
Always lower
Vmax reflects
how fast catalysis is happening after the substrate is bound
Allosteric site
Site that binds to the enzyme outside of the active site
When an allosteric inhibitor binds to an enzyme, it changes the whole structure of the enzyme pushes on the enzyme through induced fit
As a result, this distorts, the active site and this in turn lower the rate of enzyme activity,
How does allosteric inhibitor in fact, the max and KM
There are two sub classes
Pure, non-competitive inhibitors lower Vmax, but have no effect on KM
Have subtle shifts on the active site such that the substrate still binds, but there is no catalysis
Mixed noncompetitive, inhibitors lower Vmax, and raise KM 
Are enzyme binding doesn’t happen, and catalysis doesn’t happen 
Activators
Always work through the allosteric site may be pure or mixed 
If we have any equilibrium of one over two, and the Delta G0 prime is +0.43 kcal per mole how many molecules will we have at equilibrium if we start with 3000 molecules of two peachy
Because the ratio is 2 to 1 in other words for every one product we have two reactants we need to add up to 3000 so 2000+1000 
If we wanted more products,
we would have to add more products
How can we compare enzyme activities?
specific utility
Specific activity
Take the initial, velocity and normalize it right by the total amount of protein present in our lyse
E. coli had an enzyme velocity of 120 µmol per second and 10 µg of protein
S pyogenes a velocity of 40 µmol per second and 4 µg per protein
By dividing for E. coli, you have 120÷10 which equals 12 micromol per second per microgram
40÷4= 10 micro moles per second per microgram
How would pH affect an enzymes function
Not ideal pH denature some of the enzymes however, each enzyme has its own optimal pH 
Pepsin is active in our stomach
Has a pH of two or an acidic environment
Trypsin
Has an optimal pH of eight  or a basic environment 
Howard temperature have an effect on enzyme function
Each enzyme has a different optimum
Denaturation happens at too high temperatures
More heat energy helps overcome the activation energy. Barrier.
on  the other hand less heat, apply less energy to overcome the activation energy barrier
enzymes can’t change a delta G0, prime
But can help overcome it and do so by coupling two reactions together 
Hess law
When you couple to reactions together
You can simply add delta G prime together 
Gastrointestinal tract
Tube within a tube because it entrance to the mouth leads into the Soffa guess through the stomach to the intestines and at the rectum
Lots of hydrolysis reactions to depolarize macromolecules in order to extract the nutrients that are needed 
Salivary, glands and mouth
Use the mechanical and chemical breakdown of food
Because you’re chewing a big piece into smaller pieces this the  increase of surface area to volume ratio 
In terms of getting one whole piece of food and cutting it up into little pieces 
The volume doesn’t change, because we still have the same amount of food however, the surface area increases dramatically know when it comes to, in terms of the enzyme, and now has a wide range of products to buy into when we increase the surface area to volume ratio. We have an increase of potential for interaction 
Lysozyme cuts,
peptidoglycan, many bacteria, cell walls
First line of defense against any bacteria in a environment 
Saliva
Is created by many glands,
mostly water some key enzymes ( one lysozyme)
no absorption. Just cutting things as a little defense.
Salivary amylase
Cut a glucose alpha one orientation to four glucose bonds 
As a result starch is the polymerized to glucose 
Salivary lipase
Cut lipids, and
 triglycerides, is two glycerol and three fatty acids 
During swallowing
Food is pushed out of the mouth, and the epiglottis is a flat that keeps food out of the trachea
The esophagus is a muscular tube that transfers food from mouth to stomach via a Peristalis
Peristalis
Wavelike contractions of muscle rings food is pushed to the stomach
Entry to the stomach is controlled by
Gastroesophageal sphincter
Gastroesophageal sphincter
Ring a muscle that opens briefly
The food is stored in the stomach and released slowly through the pyloric sphincter. There is some digestion and little absorption focuses on storage .
Stomach surface is covered with
Deep pits
What type of cells line the stomach?
Epithelial cells
Are three types of cells within the epithelial
Mucus Parietal chief
Mucus cells
Higher in the gastric pits, mucus secreting cells which coach the surface of the stomach and protects it from contents
Parietal cells
Located second down from the three cells and they secrete HCL to acidify the stomach to pH two
And doing so it protects the body by denaturing proteins, but also killing microbes doing so helps from the contents to interact with our body cells 
helps disassociate large complexes increasing the surface area to volume ratio
Where does the H & CL come from in the parietal cells
English recall the ionic compounds HCl will quickly dissociate in aqueous solutions so really the parietal cells secrete protons  and CL minus 
Basal is connected to
The side with the blood
Apical is connected to
Stomach, lumen, or the interior
Inside the Parietal cell
Carbonic anhydrase can take CO2 and combine it with a molecule of water to access and carbonic and anhydrase active site which lower the activation energy for them to form a compound carbonic acid 
Because carbonic acid has a low PKa it quickly dissociates into bicarbonate and a proton  and because the proton can’t move across the membrane by itself and that’s when a proton potassium ATPase comes in via endergonic movement
How is endergonic contract for the proton achieved within the parietal cell
 The energy input is coming from the cutting of ATP into ADP
 And the movement of a potassium potassium channels, which allow the potassium to move through the membrane 
Parietal cell and cl
We use a bicarbonate to leave the cell , Exergonic  end, it follows its concentration gradient, and electrical gradient 
Now, because the bicarbonate is losing energy, we’re gonna use energy that is lost to have chloride move in and were using bicarbonate and chloride for an anti-porter once chloride begins to come accumulate into the cell, and it uses a cl, facilitated transport across cytoplasmic 
Chief cells secrete
An inactive enzyme called pepsinogen, and this is activated by acidic conditions as this enzyme is released into the stomach the pH falls
Because it wants to adapt to the environment, it rearranges a structure and cuts off the masking sequence, which, in turn, makes pepsinogen into pepsin and an active enzyme
Low specificity protease and cuts the amino acids down from being long amino acid polymers to short polymers makes any proteins in the stomach in active by destroying their function but it starts to digest them 
Dangers of pepsin
Because it cuts any protein around if chief cells were in the presence of pepsin, then those pepsin enzymes would attack chief cells 
Clarification
Because chief cells don’t want to be attacked they only allow pepsinogen, which is it in active
Only when the pepsinogen is out in the stomach does it turn into pepsin which is a active enzyme that attacks any proteins 
Activity in the stomach
The water is solution stays in the stomach for hours
And it’s mixed by muscle contractions, other stomach, which eventually leads to small amounts to leave through the pyloric sphincter 
Small intestines
where the stomach joins the small intestine there is a duct  which is a pipe through which material can flow this duct K’NEX to three additional accessories what is the pancreas the pancreas liver and gallbladder 
The pancreas is a complex organ
Contains two secretary tissues
The endocrine, which is duct, less, and goes directly from hormones to blood
The exocrine which has ducts and aids in digestion
Two key exocrine cell types
Duct cells, which is lining the duct and they secrete a buffer that neutralize acid
Acinar cells raspberries are secreting digestive enzymes 
Duct Cells secrete
Bicarbonate
 duct cells are going to pick up bicarbonate ions from the blood
, and this works against its electrochemical gradient into power, the uptake of bicarbonate we use a sodium gradient
Were using a sodium bicarbonate symporter and
Doing so will allow the drive of the Exergonic going into the cell to drive the uptake of the endergonic also going into the cell
To make sure that we don’t have too much sodium, we use a sodium potassium ATPase do the cutting of ATP to ADP we cut 3 sodium and lead in two potassium into the cell to maintain, strong, sodium gradient, and a negative membrane potential 
To go by carbonate into the lumen we have to use a bicarbonate chloride anti-porter
Because we need those chloride to leave again we use a protein called CFTR cystic fibrosis transmembrane regulator 
Hey, Siri are cells secrete many types of digestive enzymes
Trypsin and chymotrypsin
Both secreted in an inactive form and only becomes activated when it is in the small intestine once is activated there, low specificity proteases 
Acinar cells also secrete
Pancreatic amylase
Which cuts glucose alpha one to four glucose bonds
Pancreatic lipase
Which remove fatty acids from triglycerides 
Hepatocytes or liver cells
Produce bile
Key bile salts made of steroids
These cells are amphipatic
those files are produced, and then stored in the gallbladder which releases upon eating high fat meals and those are tied to insulin levels. 
Bile salts
Break up fat globules because they’re amphipatic because they can take the large, fat globules and hydrophobic region can warm their way into the globule regions  while the hydrophilic region stay exposed because it breaks up from one big globules too many small globules it increases the surface area to volume ratio through a process of emulsification
Some of the digestive process so far
Bicarbonate from pancreas
Protease from pancreas
Lipase from pancreas
Amylase from pancreas
Bile from liver/gallbladder
Coordination happens through
Hormone signals
Lower pH and small intestine causes
Some specialize cells to release secretin which go to the exocrine cells in the pancreas and tell them to release a special bicarbonate ion
This intern, increases a pancreas secretion, including bicarbonate
What’s the pH is raised, secretin production stops
Negative feedback regulation
Stimulus predecessor response to shut off the stimulus
Cholecystokinin
Through the presence of the pets cause other cells to release CCK which in turn, causes a gallbladder to contract to squirt out Bile to emulsify  the fats, 
Small intestine
Major site for absorption and give time for enzymes to finish digestion
small in diameter belong by length 
Has three regions to duodenum jejunum ileum
Longer so you get the most out of the food that you have digested
Small intestinal, cross-section
Makossa cells, secrete enzymes and absorb nutrients
The sub, Makossa contain blood vessels and nerves
Muscular layer, both circular and longitudinal
Serosa is a protective layer 
Muscles and small intestine
Important because material is moved and mixed by segmentation
The rings of muscle, every other one contracts
The food is moved back-and-forth, which causes it to mixed
Faster, segmentation, and duodenum leads to net forward movement
Anterior surface of the small intestine is lined with villi and microvilli in order to
Increase surface area 
Villi have
A lining of epithelial cells 
And an individual epithelial cell has lining of micro villi 
Play the time we get done with the small intestine
All of our, nutrients have been absorbed, so what is left is indigestible material(cellulose”dietary fibers”
Large intestine colon
Because a lot of the material is going into the large intestine, still have water (saliva or water)the large intestine recovers at water and stores waste in rectum 
Epithelial cells absorb, sodium by simple, active transport, and water follows by osmosis
There’s a direct correlation with picking up the salts and picking up the water 
Diarrhea can be fatal, especially in children
Death, due to dehydration
And oral hydration resolution water with NACL and glucose 
Within the colon
Cells are dying all the time pieces of the feces contain you
In between individual villi, there is a section called, crypt and these cells, proliferate and replicate continuously, which replace the cells that are lost at the top of these proliferative cells overproduce that is how colon cancer is caused
Gut Micro biome
Huge micro communities, such as bacteria, fungi, and viruses
More bacterial cells and human cells.
Mutualistic and commensal 
Bacteria in the gut,
Synthesize the vitamins that you need that are hard to get into your diet route out, the pathogenic bacteria
What are the two circuits of the circulatory system?
Pulmonary circuit and systematic circuit
Systematic circuit
Begins at the at the left ventricle , and is filled with oxygen, rich carbon dioxide, poor blood
Pulmonary circuit
Begins at the right ventricle and goes into the lungs with a capillary bed of lines, exchange gas
Oxygen poor carbon dioxide, rich blood 
Plasma
Mostly water
Dissolve salutes like glucose, amino acids, hormones, nucleotides
Ions sodium plus potassium plus chlorine plus calcium 2+ bicarbonate
buffer to pH of 7.4. Meaning it’s going to resist changes in pH. 
Various proteins albumin, antibodies, clotting proteins
By volume more than half of blood is
Cells
Erythrocytes (red blood cells)
Used for gas transport
Leukocytes and lymphocytes (white blood cells)
Used for immunology
Platelets which aren’t really cells (thrombocytes)
Platelets for thrombocytes
Made of fragmentation of megakaryocyte forms in the bone marrow 
Aren’t really cells because you say that because they don’t have a nucleus  do very little metabolism don’t have a lot of the hallmarks that most cells have don’t live very long 
Abundant ~ 250,000 per microliter
Keep player in preventing blood loss
Intact blood vessel
Platelets and erythrocytes move along the flow of the bloodstream and platelets, don’t bind to the inside of an intact blood vessel

Damage to blood vessel
If there is damage to the blood vessel, the platelets were quickly bind to the site  of damage
Sticks to the basal lamina damage as area of damage becomes recognized, platelets become activated, which causes a domino effect to more platelets being activated 
Platelet plugs form very quickly, but aren’t as tough as they want to be 
Platelet plug is reinforced by
A blood clot
What is a blood clot?
Using proteins in plasma
Activated platelets, activate plasma, protease, most require calcium to as a cofactor 
Key player proteases
Prothrombin which then gets activated into thrombin with a cofactor of calcium
Thrombin, then cuts fibrinogen into fibrin
Fibrin can polymerize forming an elastic stringy tough net
Is fibrinogen soluble or insoluble
Soluble
Is fibrin soluble or insoluble
Insoluble 
Area of direction within the two circuit
You start at the heart, go to the arteries, followed by arterioles, then capillaries, which going to venules which lead to veins which go back to the heart
HA AC VV
Arteries and veins are
Wide
Capillaries are
Tiny
What makes up blood vessels?
All contain endothelial cells
Little else in capillaries 
The bigger artery or veins have more exterior within the endothelial cells 
Endothelial
Subtype of epithelial
Junction connecting adjacent cells 
Arteries and veins have
Muscle layers and extra cellular matrix
And arteries more elastic for stretching and veins, more collagen for strength 
Veins versus arteries
Veins have a thicker layer of extra cellular matrix while arteries have a thinner layer of extra cellular matrix
Flow rate of blood is determined by
Pressure and vessel diameter
Pressure is highest when it is close to the heart, and lowest when it is closer to the veins 
Why does pressure from the blood fall in the veins?
 Because we’re increasing the volume that it has to go through 
When blood is being released from the initial artery all that blood is in that one artery, but as it’s spreading out and being released smaller and smaller areas it has the surface every muscle in the body giving it a much larger volume 
Arteries and elastin
Muscles and elastin and arteries act as a pressure, Reservoir it’s going to hold onto a certain amount of pressure and then release it
When the heart contracts blood through arteries and arterioles the elastin in the arteries expands to allow that large pressure of blood to pass through, and when it’s relaxing and filling that Reservoir the arteries go back to the normal size 
Blood pressure controls flow rate but flow rate is also controlled by 
Diameter
Blood vessel diameter can change due to
Smooth muscle around the vessel happens with arterioles
Vasoconstruction
vasodilation
Low pressure and low flow rate in
Veins 
Larger veins contain
Valves that allow for one-way movement within the lower limbs 
Where else can does one-way movement valves within the veins be found?
In the skeleton muscles
When contracted, the muscles squeeze the vein that’s in between those muscles, and this is happening as a valve is opened. This allows the blood to go into the heart. 
Capillary
Where the action happens
thin, but there are a lot
The total area is huge, and the flow rate is very slow at the capillaries
Because we have a huge area it’s going to slow down due to blood pressure being controlled by pressure and area
Capillaries properties
Optimized for exchange
Slow flow rate
Then endothelial cells and little extra cellular material
Very poor tight, junctions lots of leakage between cells
Pores between cells water and small molecules can pass proteins are too big to move
Connects plasma to extra cellular fluid
Capillaries as a filtration system
Acts as a filtration to the poison in between cells due to pressure involved
Blood pressure is higher at atrial side
Water and solutes leave (glucose amino acids)
Proteins don’t keep protein is albumin 
Arteriole end versus venule and
Arteriole and has higher blood pressure because you’re pushing stuff out from the capillaries 
Venule has lower blood pressure
High blood pressure can be balanced out with
, osmotic pressure 
So if the proteins are saying within the vessels, and the water is leaving that will change the osmotic pressure albumin is retained, and has remove the capillary albumin is becoming more and more concentrated
So, by the time we get to the venule end the plasma is hypertonic, and the ECF is hypotonic
At the Arteriole end there’s a high water movement because pressure is driving it out and that’s the osmotic pressure is fairly low
When the blood pressure is low, the osmotic pressure is higher to bring back the water to prevent swelling within the blood   
Osmotic pressure brings what percentage of water back to the plasma at the venule site
90%
Where does osmotic pressure bring the other 10% of the water
 Goes into the lymphatic vessels system 
The lymph system, passively gathers water slow
Carbohydrates consumers will be mostly digested to
Mono and disaccharides 
Why are we using active transport for glucose?
Do you want every single molecule of glucose through the NA plus glucose symporter
As a result, a NA plus K ATPASE yes will be used in order to keep a high concentration of sodium in the lumen and also a high membrane potential 
Carbohydrate uptake
Sodium glucose active transporter  is used to have high concentrations (all of the glucose) of glucose within the cell to get it into the duodenum
Sodium potassium ATPase is it gonna be used to have high concentration of sodium out of the cell in the duodenum , but maintaining a membrane potential within the cell 
GluT is going to be used as a facilitated transporter to have glucose out into the ECF
Amino acid I’ll take is very similar to carbohydrates uptake
Sodium amino acids import an apical membrane
proton, transport her with to dry and tripeptide an apical membrane
There is a facilitated amino acid, transport and basal membrane 
The capillaries receive nutrients from
I nutrients across the epithelial cells to the extra cellular fluid
Celusta fused into capillary pores and leaving venules
Veins from the small intestine, don’t go to the heart they go to
(Hepatic portal vein deliver blood to)
Liver
Liver properties
Has a second new capillary bed before returning to the heart
Is the first line to get nutrients from the diet
Bile salts are absorbed
Xenobiotics (foreign molecules) are detoxify
Some nutrients are stored while some are processed 
Most amino acids are monosaccharides remain in
Blood plasma
What happens to the amino acids are monosaccharides that remain in the blood plasma
They can be absorbed by any cell that needs it typically through facilitated transport 
Duodenum,cell and muscle cell in terms of facilitated transport
Glucose has a high concentration of glucose and uses a facilitated transport GLUT to get that glucose into the bloodstream moving forward through the muscle tissue. It uses that same, facilitated transport to get in to the cell and has a low concentration of glucose.
Glucose by nature follows the concentration gradient 
However, if your muscles are resting, then the muscle cell has a high concentration of glucose 
Facilitate transporters able to move in more than one direction
No
Lipid uptake
Bile salts help emulsify lipids into smaller globules that eventually had the shape of micelle
Lipases help to cut down triglycerides into three fatty acids in the intestinal lumen
Those free fatty acids can move by simple diffusion  these free fatty acids hydrophobic enough to leave the micelle and form into the phospholipid bilayer of, allowing it to cross
steroids are also able to diffuse into cells
Fatty acids to Endoplasmic reticulum
Because fatty acids were able to cross plasma membrane, they can move across any cellular membrane
however, once we reach, the smooth endoplasmic reticulum is fatty acids will be synthesized back into triglycerides 
The rough ER has proteins, called Lipo proteins that combined with our triglycerides along with steroids, another lipids
This intern forms a large Chylomicron within the ER
Chylomicron
Triglycerides are set in the middle because they’re very hydrophobic
And they’re covered by phospholipids and steroids, but are organized by Lipo proteins
Close to the duodenum cell
How does a Chylomicron leave the cell?
Exocytosis at basal membrane
The phospholipid bilayer of the Chylomicron will fused together with the membrane of the basil membrane 
How does a chylomicron into the capillary?
Enters the lymph vessel in between vili 
I lacteal is how we’re gonna move chylomicrons
Slowly because goes through lymphatic system to get to the plasma
Lipoprotein lipase is a membrane bound protein in
Some capillary endothelial cells
What are some example of tissues I like to use a lot of fat
Cardiac and muscle tissues 
the Lipo proteins lipase found on endothelial cells
Recognize the triglycerides, found within the chylomicron, the stripping it away and making those triglycerides into fatty acids
What happens to fatty acids within the plasma?
Fatty acids diffuse into tissue
May be metabolized within muscle
Or continue to be stored as triglycerides within adipose tissues 
Ways that a chylomicron is reduced in sized?
Glycerin to removeD
Lipoprotein remain
Chylomicron remnant is absorbed by liver
Examples of macro nutrients
Carbohydrates lipids proteins
Examples of micro nutrients
Essential amino acids
Essential fatty acids
Minerals
Vitamins 
Amino acids
20 amino acids in total eight amino acids cannot be synthesized by humans 
Eight. amino acids, that cannot be synthesized by humans due to the lack of enzymes
Valine Lucein isoleucine methionine trytrophan phenylalanine threonine lysine
Essential fatty acids
Linolenic c18 with three unsaturations (omega 3)
Linoleic c18 with two unsaturations (omega 6)
- Essential, dietary minerals.
Need it in various amounts 
Some examples include sodium, magnesium, potassium, calcium 
Most of our diets calcium is
Abundant
How is calcium moved through paracellular route?
Calcium is an exception to the tight junction in the duodenum cells
Through the selectively leakiness calcium is able to move from the lumen into the ecf
The term paracellular is because it went in between two cells, but not necessarily through any cell

How then is calcium collected (transcellular route)
We use a translator route when calcium is scarce in the diet
So through, facilitated transport we won’t be able to get all the calcium
But then calcium starts to bind to the protein Calbindin
Or the low concentration of calcium can travel through a simple, active transport her against its concentration gradient, and move out into the ECF
Vitamins
Small organic molecules needed in small amounts for health
Summer water soluble well summer fat soluble
They usually act as cofactors for enzymes
And sometimes act as chemical messengers 
Fat soluble, vitamins
Generally diffuse across membrane and join chylomicron
Liver removed from chylomicron, remnant, and re-packages for transport 
How to harvest energy from glucose glucose is
Burnt 
Order to metabolize glucose needs
06 moles of oxygen, which is going to convert to six moles of carbon dioxide, and six moles of water
The requirement is oxygen, but generates carbon dioxide as waste product these gases are poorly, soluble in water 
The movement of oxygen and carbon dioxide is largely done by the erythrocytes
Erythrocytes properties
usual cells
Highly abundant 25 trillion per adult 5, million per micro liters of blood
Biconcave disk which allows a higher surface area to volume ratio than sphere
Moves in a single file through capillaries
No nucleus
Terminal nondividing cells
No mitochondria
Highly specialized for oxygen transport 
How much hemoglobin is within each erythrocyte
Roughly about 250 million molecules of hemoglobin
What are hemoglobins made of
Two alpha globin into beta globin proteins
Each protein is bound to heme prosthetic group, including iron to leading to the red color
The iron 2+ and him binds oxygen when hemoglobin
And reversible binding depends on oxygen  concentration
Can you say to move to circulation about every?
60 seconds and goes from the pulmonary circuit, a systematic circuit, and repeats continuously
Gas exchange begins when
Air enters the lungs do the trachea
The Aaron clothes from the trachea to Bronx tubes within begin to divide into branches to bring bronchiole
And then air sacs called the alveoli
To fill the lungs be rely on the
Muscular, diaphragm contraction, pulling down, which inflates a lungs through title inflation 
The capillary network within Alveolus
Each alveolus has a surrounding capillary system
What is inside the alveolar Lumen is the air that we breathe. Then has a result we have high concentrations of oxygen within the alveolar lumen.
Oxygen moves to erythrocytes  from a high concentration to low concentration
And it does not need specific transporters, because it is nonpolar 
Oxygen leaving erythrocytes
 If a muscle cell, for example, has been consuming oxygen, it has a low concentration of oxygen so as that muscle cell continues to work and produce oxygen, it’s going to reduce the concentration of oxygen to lower lower points which incense, optimizes oxygen delivery, all right 
Hemoglobin binding to oxygen is co-
Cooperative
Meaning that when one protein binds and encourages other proteins to bind the cap is at 100%
As a concentration of oxygen goes up, we get more oxygen binding to hemoglobin, 
Concentration of gas like oxygen is more appropriately, expressed as partial pressure
In torr or millimeters per mercury

Oxygen concentration at the alveoli versus resting muscle
At the alveoli we’re gonna have about 100 mmHg which interns allowed us to have a lot of oxygen attached to hemoglobin  95%o2 saturation
At the resting muscle we’re going to have 40 mm mercury 55% o2 saturation
Active muscle 20mm hg 20% o2saturation deliver 75%
Muscles also produce a similar protein
Myoglobin
Which is a monomer, no cooperative binding, and is short term oxygen storage
Hemoglobin is 75% saturated myoglobin it’s gonna be 95% saturated
Oxygen can move from hemoglobin to myoglobin, but as soon as muscle cells require that myoglobin, it’s going to strip oxygen from myoglobin 
Unique problem is applying oxygen to a fetus
The blood of the mother and the fetus do not mix it comes  close to each other, but do not mix entirely
So once the mother gets his oxygen and travels in through the erythrocytes, it travels through the maternal arteries and the maternal veins in order to get it to the fetus 
Fetal hemoglobin and adult hemoglobin
 I don’t hemoglobin is two copies of alpha and two copies of data
Fetal uses two copies of globin alpha, but it uses the two gamma globin‘s fetal hemoglobin, has a higher affinity for the oxygen 
Carbon dioxide transport
Produced as a waste product
Crosses membrane by simple diffusion
Needs to be removed in the blood
About 10% of carbon dioxide is dissolved in the plasma
Some diffuses into erythrocytes
Contains carbonic anhydrase 
Carbonic dioxide plus water can make carbonic acid, which then turns into bicarbonate plus proton 
In a muscle tissue
Replacing lots of carbon dioxide, which leads to a lot of bicarbonate
Bicarbonate is carried into the erythrocyte 
However, because lots of protons are being produced, blood is going to be slightly more acidic so it’s gonna go from a pH of 7.4 to us pH of 7.2.
If we remember, acidity is due to how many protons are in that area 
In the Alveoli tissue
Carbon dioxide lost by the fusion into air
Carbonic anhydrase catalyzes the reverse reaction
On the other hand and lung tissues, lots of protons are removed, which causes the blood to be slightly more basic from a pH of 7.22 a pH of 7.4. 
The pH change affects hemoglobins, oxygen affinity
Acidic  conditions in muscle cause, a right shift
Which promotes oxygen release
Some carbon dioxide directly binds to hemoglobin at in
 Hello Sarah site, which also needs to right shift
This happens in addition to pH dependent shifts
At the alveoli, the CO2 is removed so that way we know longer have anything binder to the allosteric site which means we have a a higher affinity for hemoglobin 
And Alveoli hemoglobin, binds to a lot of oxygen due to
High concentration of oxygen
Low carbon dioxide
More basic pH
And tissues, hemoglobin releases lots of oxygen to two
Low concentration of oxygen
High carbon dioxide
More acidic pH 
Erythrocytes sites have a limited lifespan of a bout
Hundred days
Approximately 2 to 3,000,000 erythrocytes die per second
Macrophages, consume old erythrocytes sites in liver and spleen by phagocytosis
Globin degrade it to amino acids for recycling
Some heme recycle some excreted 
Making erythrocytes
2 to 3,000,000 new erythrocytes per second
Erythropoiesis multipotent stem cells in bone marrow
Which is stimulated by low oxygen levels and tissue through a erythropoietin  p.m. if you are a professional when was the ass CCC
