EXAM 3 Flashcards
How do we use cellular respiration in everyday life?
eating, digesting, absorbing nutrient molecules into our bloodstream, and delivering nutrient molecules to the cells
Through cellular respiration, our cells begin to extract some energy. What is important about this?
Our cells need ATP to maintain life, our metabolism is all chemical, a big focus is on breaking down glucose which is the main energy source during activity, and fatty acids and lipids are used during rest
What is gas exchange in cellular respiration?
Diffusion of CO2 and O2 across a cellular membrane barrier; diffusion of CO2 and O2 from air or water to body
What is circulation within cell respiration?
The bulk movement of a fluid throughout an animal body; it transports gas to/from body cells
What is cellular respiration?
Using O2 and producing CO2 to make ATP
What is ventilation in cellular respiration?
The bulk movement of an environmental fluid to the gas exchange surfaces of an animal; moving air or water to gas exchange organ
What is whole body respiration?
The rate of oxygen use and production of CO2 made by a whole animal
What are the stages of cellular respiration in order?
Glycolysis, pyruvate processing, citric acid cycle, electron transport and chemiosmosis
In ATP production, what is substrate level phosphorylation?
The transferring of a phosphate from a fuel source to ATP and it takes place in a glucose oxidation pathway
In ATP production, what is oxidative phosphorylation?
Energy is harnessed through the inner mitochondrial membrane to create ATP from protein complexes called ATP synthase and the electron transport chain
NADH transfers electrons in REDOX reactions
This is the reverse of photosynthesis; glucose is oxidized into CO2 and O2 is reduced into H20; cell respiration liberates the energy that glucose stores in its covalent bonds which will equal the amount of energy photosynthesis needs to make glucose and the cell will use this energy to make ATP; complete respiration of 1 molecule of glucose can provide enough energy to make 38 ATP
Redox: Oxidation
loss of electrons
Redox: Reduction
gaining of electrons
Within cell respiration…
Glucose is being oxidized
Glycolysis
The initial breakdown of glucose, the first set of reactions to occur within cell respiration, this is a series of 10 reactions, creates byproducts pyruvate (a 3 carbon sugar), ATP, NADH (energy carrying molecule that is similar to NADPH, Nicotinamide Adenine Diphosphate), occurs within the cytosol of the cell, does not require oxygen (anaerobic)
Steps of Glycolysis
- Glucose is phosphorylated by ATP to make Glucose 6-PO4 and ADP
- Glucose 6-PO4 is rearranged into an isomer Fructose 6-PO4
- Fructose 6-PO4 is then phosphorylated by ATP to make Fructose 1, 6 Biphosphate
4.Fructose 1,6 Diphosphate then breaks down into two molecules of G3P - Each G3P is then oxidized by NAD+ to make PGA-P and NADH
- Each PGA-P is converted into PGA by losing a PO4 to ADP and making an ATP
- Each PGA is converted into PEP (phosphoenolpyruvate)
- Each PEP donates a phosphate to ADP to make pyruvate and ATP
Summary of Glycolysis
Glucose is broken down into two pyruvates and a total of 4 ATP are made but two are used up meaning there is a net of 2 ATP, NADH (2) is produced and can be used up later in processes, its only about 2% efficient because it only produces 2 ATP from the partial breakdown of glucose
The fate of the pyruvate if oxygen is present
Pyruvate enters the mitochondrion to be broken down by aerobic respiration
The fate of pyruvate if oxygen is not present
Pyruvate remains in the cytosol and is fermented in anaerobic respiration
Aerobic respiration
requires oxygen and can produce very large amounts of ATP
Anaerobic respiration
without oxygen meaning its oxygen dependent, this produces only very small amounts of ATP, some bacteria may survive exclusively on anaerobic respiration
Pyruvate processing
Each pyruvate is processed to release one molecule of CO2 and the remaining two carbons are used to combine and form Acetyl-CoA, occurs in the mitchondrial matrix in eukaryotes, requires oxygen to occur
Steps of Pyruvate Processing
In the presence of O2 in the cytosol, pyruvate will be pumped into the mitochondria (each pyruvate has a potential to produce about 15 ATP), pyruvate is then oxidized by NAD+ and is decarboxylates (loses CO2) to become Acetyl, it then combines with an enzyme called Coenzyme A to become Acetyl-CoA
Products of Pyruvate Processing
Acetyl-CoA, CO2 (waste product), NADH per pyruvate
Fermentation
Occurs only if O2 is not present (anaerobic), pyruvate remains in the cytosol
Fermentation: Lactic Acid Fermentation
occurs in animals, pyruvate is reduced by NADH to form lactate, lactic acid can build up and burn the tissues that creates sores in the muscles (must be removed from the tissues by the bloodstream)
Fermentation: Alcohol Fermentation
occurs in plants and fungi, pyruvate is reduced by NADH and is decarboxylated to form ethanol, this is used in many commercial products, the outcome is 2 ATP and NAD+
Where does the Krebs cycle occur
In the Matrix (the cellular fluid inside the mitochondria)
What are the steps of the Krebs cycle
- Acetyl-CoA combines with a 4-carbon oxaloacetate, to produce a 6-carbon citrate
- Citrate is oxidized by NAD+ and is decarboxylated to become a 5 carbon Ketoglutarate
- Ketoglutarate is oxidized by NAD+ and is dephosphorylated by ADP and is decarboxylated to become Succinate
- Succinate is oxidized by FAD+ to become Fumarate (4-carbon)
- Fumarate is converted to Malate
- Malate is oxidized by NAD+ to become Oxaloacetate
What is the goal of oxidative phosphorylation
Use the NADH (and FADH2) from glucose oxidation to make ATP
Oxidative Phosphorylation: Electron Transport Chain
creates a H+ gradient by pumping H+ to one side of the inner membrane
Oxidative Phosphorylation: Chemiosmosis Coupling
Harness the movement of H+ ions back across the membrane to produce ATP
Electron Transport Chain
a series of membrane proteins within the Crista that transfer electrons; each NADH and FADH is oxidized (the electrons travel through the ETC, H+ ions build up on the inner space (lumen) of the Crista, the pH becomes more acidic), chemiosmosis occurs as H+ move through an H+ channel in an ATP synthase molecule also embedded within the Crista, this generates power and is used to make ATP, each NADH supplies enough energy to make 3 ATP, and each FADH supplies enough energy to make 2 ATP
Where do the electrons in the electron transport chain come from
NADH and FADH; energy is transferred with the electrons
What are the steps of the electron transport chain
- At each step, the electrons fall to a lower energy state, releasing a little bit of energy
- At the end of the chain, the lower-energy electrons are handed off to O2 which then combines with free H+ ions to form water
- The energy is then used to power proton pumps, which pack hydrogen ions from the mitochondrial matrix into the inter membrane space
- The protons rush back into the mitochondrial matrix with great kinetic energy which can be used to build ATP
Anaerobic Bacterial Respiration
Fermentation
Aerobic Bacterial Respiration
Similar to mitochondria but uses the cell membrane, pump H+ to the outside of the cell, some bacteria (gram neg) have an inner and outer membrane, pump H+ to inner membrane space
Eukaryotes
mitochondria
Prokaryotes
Pump H+ out of the cell
Both eukaryotes and prokaryotes
Glycolysis, Electron Transport Chain, double membrane, protein gradient
Dalton’s law
the pressure exerted by a mixture of gases in a fixed volume is equal to the sum of the pressures that would be exerted by each gas alone in the same volume
1. Total pressure of gas mixture = sum of all components
2. Partial pressure = pressure contribution of one gas, percentage of total
Partial Pressure
Measure of thermodynamic activity of the gas’s molecules
1. Pressure measured in mmHg, kPa, atm
Standard Pressure = 760 mmHg, 101kPa
2. Oxygen is 21% , CO2 is 0.03%, and Nitrogen is 78% of the atmosphere
3. The standard pressure of oxygen is 20 kPa
Fick’s 2nd Law of Diffusion
Square distance from gas exchange affects the diffusion time
time it takes for diffusion = distance squared/ 2x diffusion coefficient
Diffusion
Small or inactive animals can rely on diffusion alone, it is effective for animals that are small (<1mm), higher concentration to lower concentration, random movement of particles within a fluid, effective for fast transport of molecules for distance of <1 mm
Bulk Flow and Diffusion
Relied on by larger/more active animals, bulk flow to gas exchange surfaces, diffusion at gas exchange surfaces, bulk flow to cells (not likely to lose any content), diffusion into cells (relies on the difference in pressure), higher hydrostatic pressure to lower hydrostatic pressure, directed movement of a mixture fluids carrying dissolved particles, effective for fast, long distance transport
More bulk flow leads to
small diameter vessel, longer pathway, greater pressure gradient
Less bulk flow leads to
Larger diameter vessel, shorter pathway, smaller pressure gradient
What are the variables in gas exchange
Respiratory medium (air or water), epithelium, blood
What does epithelium mean and how does it relate to gas exchange
it is a layer between the air and the blood, the thinner the better, on cold days breathing in the cold air for a long time can damage the epithelium
What is the gas exchange surface
A very large surface area is needed (if you spread out the tissue, it would be about the size of a tennis court), thing walls are also needed (diffusion distance plays a role which allows gas exchange)
Aquatic
Thing gill structures
Terrestrial
Respiratory structures inside the body, ventilation needed, respiratory surfaces are internal so they are less likely to become damaged
Requirements to Breathe
large surface area, thin walls between respiration medium and blood, ventilation where the movement of RM to surface for gas exchange, nearby blood that can pick up the oxygen from the lungs and drop off CO2
What can make it hard to breathe
Emphysema (the walls between alveoli break down which makes the interior surface of the lungs more smooth, less surface area), pneumonia (fluid accumulating in the lungs, increasing the distance between the RM and the lung capillaries for diffusion), chest wound (equalizes pressure gradient between lung and atmosphere where there should be a gradient), pulmonary embolism (a blood clot blocks an artery which takes blood into the lungs)
What are the differences in respiration
Respiratory medium, ventilation method, respiratory surface, countercurrent/crosscurrent flow
Respiratory medium
Water vs. Air; water contains less partial pressure of O2 than air; there is O2 in water but it varies depending on what type of water it is in
Ventilation method
When air is intentionally provided to a space and stale air is removed, how the respiratory medium gets to the respiratory surface
Respiratory surface
part of the animal where gas is exchanged with the environment; gills, lungs, etc.
Insect Respiration
since insects don’t breathe through their mouths they have holes in the surface of their body in their exoskeleton, this works well for insects because they don’t have to bring oxygen in very far, they are cold blooded and need less oxygen because it does less cell respiration,
Tracheoles
smaller sections of tubules that are specific to parts of the insects body; these are connected to the tracheae
Air sacs
these are contained within the lungs of insects that aid by lowering the specific gravity
Spiracles
the holes within the exoskeleton that allows air into the body; these can be opened or closed (if its cold outside, they will close to prevent water loss; if they are active, they can open them to help with ventilation)
Tracheae
the passageways that are connected to the spiracles that allow air to move through the body; this is not connected to the throat of the insects; they are not ventilated; site of gas exchange
Fish Gills
Pass water over gills to exchange gas
Lamelle in fish gills
a thin structure that contains blood vessels
Sharks: Ram Ventilation
Open mouth, allow water to flow over gills, must be moving forward
Bony Fish: Operculum
Bony covering over the gills, allows fish to increase pressure inside their mouth then open operculum (little holes) so water will be pushed across the gills
Countercurrent exchange
Diffusion of O2 from water into the blood, blood is going to be gaining O2 as it moves to the head of the fish and water is going to be losing O2 as it moves toward the tail of the fish
Concurrent Flow
Less efficient because hey are moving in the same direction, there will be no more exchange at 50%
Breathing water
Lower risk of dehydration across thin respiratory surface, higher buoyancy of tissue requires less support of exchange surfaces
Breathing air
Higher solubility of oxygen (by 1000x), lower density so its easier to pump across exchange surface, faster diffusion of gasses, osmotic differences can increase loss of water
Swim Bladder
Some fish may breathe air on occasion as a floatation device that helps them stay neutrally buoyant, gulp air from the surface, and occasionally use the blood vessels on the surface to take O2 from the blood
lungfish/early tetrapods use swim bladder for gas exchange
Amphibians: Positive Pressure Ventilation
Gulp air in by positive pressure that increases the pressure within their mouths and then uses muscles to push the air into their lungs
Reptiles: Adaptations for Dryness
No gas exchange through their skin because it is so thick it prevents water loss, their lungs are more intricate and they have larger surface area, their ribs expand (increase volume=decrease pressure) then air will flow to a space of high to low pressure and goes into the lungs from the air, negative pressure so air is sucked in
Inhaling
Diaphragm contracts and increases in volume, the rib muscles are relaxing creating more space by expanding, the pressure inside the lungs decreases
Exhaling
the diaphragm relaxes, rib muscles contact, the pressure inside the lungs increases
Alveoli
Air sacs are the location of gas exchange (O2 into the blood and CO2 into the air) and covered in surfactant which is a liquid that helps break things apart within the lungs, increased surface area of the lungs
Dead space in tidal breathing
Volume in passageways between outside air and alveoli
ex: if tidal volume = 500 mL and dead space = 150 mL how much air actually gets to the alveoli? (500-150=350)
Bird Respiration
No gas exchange occurs here, air sac bellows form pumping air across lungs, lungs, air is pushed across the lungs and picks up O2 containing lots of blood vessels in crosscurrent arrangement, one-way breathing with a countercurrent exchange system
Bird Ventilation: Inspiration & Expiration
Inspiration 1: air is pulled into rear air sacs as the chest expands
Expiration 1: Air pushed out of rear air sacs and over lungs
Inspiration 2: Air pulled from the lungs and into the front air sacs
Expiration 2: Air pushed out of front air sacs and out of the body
The main structures of the blood
Plasma (serum), red blood cells (erythrocytes), white blood cells (leukocytes and platelets)
Plasma (serum)
main structure of blood; a yellowish serum that consists of water (the main component), proteins (involved in the osmotic balance), solutes (nutrients like glucose and salts that need transported)
Red Blood Cells (RBC, erythrocytes)
main structure of blood; the most dense; consist of hemoglobin, carbonic anhydrase; they lack a nucleus so the red bone marrow in the body continues to produce these; they lack a mitochondria so they cannot produce proteins
if you are dehydrated you might have more RBCs because there is less plasma
Hemoglobin in RBC
In RBCs; iron containing respiratory pigment of vertebra RBC’s and consists of globin
Carbonic Anhydrase
In RBC’s; an enzyme that acts as a dehydrating factor in bicarbonates
Hematocrit
percentage of RBC in total blood
Anemia
low RBC which makes you feel tired and lethargic
White Blood Cells (leukocytes and platelets)
light beige coloring; very important to the immune system
When the heart pumps the blood to the lungs…
there is high O2 and low CO2
When the heart pumps the blood to the tissues…
there is low O2 and high CO2
Hemoglobins (Hb)
Proteins that surround the Heme (which is a molecule that contains iron, the iron binds to O2 and holds onto it, lots of species have Heme containing molecules)
VHb (Vitreoscilla Hb) bacteria
the hemoglobin binds O2 as the final acceptor in the ETC and then transports it to other molecules
Mollusks/ Crustaceans
Hemocyanin (copper used instead of iron), looks blue when it binds to O2 “blue blood”
CO2 in blood
CO2 enters the blood at tissues, dissolves in the plasma (10%), binds to the hemoglobin (30%) with less affinity than O2, and is converted to bicarbonate
How is CO2 converted to bicarbonate in the blood
- Carbonic anhydrase enzyme will take the CO2 and combines it with hydrogen to make bicarbonate
- Converted CO2 + H2O to form H2CO3
- H2CO3 is bicarbonate plus an extra H+
- Bicarbonate is then transported out of the red blood cell
- Most of the CO2 travels in plasma in bicarbonate (about 60%)
- Bicarbonate then acts as a pH buffering system (only problem with this if it creates too many H+ ions within the plasma that then makes the blood acidic)
Oxygen enters the bloodstream (net exchange) at
lungs/alveoli
Oxygen is mainly carried in blood as
Hemoglobin (HbO2)
Oxygen’s role of RBC in transport
contain Hb
Oxygen’s role of plasma in transport
2%
Oxygen is removed from blood (net exchange) at
the tissues
CO2 enters the bloodstream (net exchange) at
the tissues
CO2 is mainly carried in blood as
bicarbonate
CO2s role of RBC in transport
contains Hb and carbonic anhydrase
CO2s role of plasma in transport
10% CO2 and 60% bicarbonate
CO2 is removed from the blood (net exchange) at
the lungs
Myoglobin
hemoglobin molecules that are in your blood; a single subunit protein, binds oxygen in muscles, this makes red meat have red coloration, it gives you a head start and is a tank for oxygen in your muscles
Hemoglobin
4 subunits (tetramer) each that contains a heme that allows O2 to bind, in red blood cells
Hemoglobin process
one molecule of O2 leaves, changes the shape, other submits change their shape, other O2 molecules are likely to leave
Reversible Binding
Hemoglobin binds to O2 in the lungs, releases O2 within the tissues (reversible binding of O2), Increases the affinity for other parts of the hemoglobin to bind to O2 (when one subunit binds, the other 3 want bind to O2 as well, all sections of hemoglobin will continue to bind to O2 until there is a full compliment of hemoglobin), reduces the binding affinity for other parts of hemoglobin to bind to O2 (when one O2 leaves hemoglobin it makes more likely for others to leave as well)
Cooperative Binding
requires that the macromolecule have more than one binding site, since cooperatively results from the interactions between binding sites. If the binding ligand at one site increases the affinity for ligand at another site, the macromolecule exhibits positive cooperatively
this is what happens with hemoglobin: gives up more O2 than you would expect it to
Non-Cooperative Binding
if several ligand binding sites exist, but ligand binding to any one site does not affect the others, the receptor is said to be non-cooperative; this is what happens with any other molecules that binds to O2
Types of circulation systems
open and closed system (single and double loop)
Advantages of open circulatory systems
Minimal energy demands since pressures are usually low.
don’t have to regulate pressure, the heart; they are very simple and there are less things that can go wrong
Disadvantages of open circulatory systems
not very good for active animals
Tubular heart
open circulatory system with no separate chambers
Vessels
Open circulatory systems with few out coming and few returning (variable) with no capillaries
Hemolymph
open circulatory system
Open circulatory systems are found mostly in
Invertebrates with low pressures
in closed circulatory systems, blood returns to the heart through
blood vessels with higher pressure
Lymphatic system
complimentary to the circulatory system so that it will properly pump blood; returns interstitial fluid to blood
Advantages of closed circulatory systems
It can control the distribution of blood as the needs of an animal changes.
It moves quickly which is great for active animals because O2 is moved quickly
Disadvantages of closed circulatory systems
A lot of things have to be constantly regulated, more systems involved, and uses up a lot of nutrients in the body so that it can function
What is flow
how much fluid is going to the blood vessels (measured in mL/second)
What is pressure
what drives the fluid through the blood vessels (measured in mmHg - the pushing on it)
What is speed
how quickly it is moving
What is the difference between pressure and change in pressure
how much the heart is putting out vs. the pressure measure from one end of a section of a blood vessel to the other (subtraction)
Blood Flow and Pressure
Highest pressure is coming right out of the heart, the pressure drops the most at the arterioles and the capillaries, the smallest change in pressure is in the veins
Resistance
how flow energy is reduced as it goes through the circulatory system; flow resistance is the process by which flow energy is reduced
In the circulatory system, resistance is from
length of the blood vessel (longer = more resistance and shorter = less resistance), diameter of the blood vessel, viscosity of the blood (how thick it is)
What is the easiest way for the body to change its resistance
By changing the diameter; this can be done through smooth muscles
Ischemia
when plague forms the resistance to blood flow increases, the diameter of the area for the blood flows has caused the resistance to change, if the the blood vessel was completely blocked by plaque the blood flow through the tissue would have to increase in pressure
Arteriole control
in a healthy body the blood vessels still change their diameter, hormones will also change the diameter which will be a flight or fight response (it can increase and decrease the resistance in different areas of the body), nerve fibers can also control the diameter of the blood vessels
Arteries branch
these maintain pressure by muscle
Arterioles
more branches, smaller diameter, resistance increases, control over the diameter
Capillaries
large area, very small diameter, very thin walls
Veins
very low pressure, one-way valves
Arteries
away from the heart; they maintain and even out pressure, thick walls with multiple layers, absorb pressure, elastic flexible but rigid like a hose, smooth muscle, large lumen (the inner area that contains blood)
Function of the arteries
they maintain and even out pressure; They always carry higher pressure blood away from the heart.
Arterioles function
divide up the blood and direct it to areas of need
Arterioles structure
small diameter which maintains flow and sphincter which changes the flow
Capillaries function
smallest diameter (red blood cells have to fit single file), heavily branched to almost all cells within the body, thin walls can break it if they are under high pressure, fenestrations (holes/windows) blood leaks out of there
Capillaries structure
large surface area from exchange with cells and allows fluid in blood to mix with fluid between cells
Filtration
the blood is being filtered
Reabsorption
where the fluid comes back into the blood
Function of veins and venules
return blood to the heart and maintain movement of blood despite low pressure gradient
Structure of the veins and venules
thin walls, large lumen (it contains about 70% of the blood in your body), one way valves
Lymphatic system
plasma leaks into tissues in capillaries, mixes with interstitial fluid already present, interstitial fluid drains into lymph vessels
Vessel diameter drops to the smallest at
capillaries
Vessel diameter rises to the most in the
Veins
As vessels branch repeatedly
Velocity drops and surface area increases
Hagfish
open circulatory systems
Fish
2 chambered hearts
hearts to gills to body
Amphibian
pulmonary circuit, systemic circuit, 3 chambered heart
Most reptiles
partial septum divider
Crocodilians
4 chambers and bypass from pulmonary to systemic
Mammals and birds
4 chambers and pulmonary and systemic are separate
systole
contraction of the heart
systole = send
ventricle systole = high part of blood pressure
Diastole
filling of the heart
diastole = dilation
ventricle diastole = low part of blood pressure
Oxidation of FADH2 occurs when
it drops off electrons at the electron transport chain
In the electron transport chain, the oxygen that enters the cell becomes part of what molecule?
water
In aerobic bacteria, the electron transport chain is located in the
cell membrane
Under anaerobic conditions, lactate is formed by pyruvate accepting electrons from
NADH
In general, the longer the blood vessel is, the __________ the resistance.
higher
Animals that use diffusion rather than bulk flow in respiration
Must be only a few millimeters in tissue thickness.
How do active insects get enough oxygen into their bodies for metabolism in flight?
They move their body muscles to pump along tracheae
When the diaphragm relaxes, the pressure in the lungs ____________, causing air to __________ the lungs.
Increases; leave
One advantage of air breathing over water breathing is that
Air contains more oxygen than water
Which feature is common to gills, lungs, and tracheae?
Large surface area
Emphysema in humans is a disease caused by air pollution or smoking. In emphysema, the walls between alveoli break down, making the interior surface of the lungs more smooth. Why does this decrease the amount of O2 available to the lungs?
There is less surface area for gas exchange to take place
Red blood cells convert some of the carbon dioxide received by the tissues into ______________. This product assists with buffering the blood pH.
bicarbonate
Fluid moving through the arteries in an animal with an open circulatory system is referred to as:
Hemolymph
One advantage of the open circulatory system is that:
Minimal energy demands since pressures are usually low.
How do arteries differ from veins?
Arteries have thicker smooth muscle layers to accommodate the changes in pressure from the heart.
Where is resistance (R) very high due to red blood cells squeezing through the blood vessel one at a time?
Capillaries
What do veins use to prevent backflow?
Valves
Where is resistance the most variable in a closed circulatory system?
Arterioles
Vasoconstriction of an arteriole will cause ____________ in blood flow to the downstream capillary bed.
a decrease
tetralogy of fallot
congenital heart defect that includes a hold in the L and R ventricles and the blood from the L and R ventricles go to the aorta; the effects of this are that they receive less oxygen because the oxygenated and deoxygenated blood mix
Aorta
the main artery of the body that supplies oxygenated blood to the circulatory
AV node (atrioventricular node)
controls the transmission of the hearts impulses from the atria to the ventricles; introduces a delay in the beats between when the atria fill up and the ventricles beat to pump the blood; can also have its own rhythm when the SA node fails meaning it can take over and help the ventricles still pump blood; backup pacemaker
SA node (sinoatrial node)
the pacemaker cells within the heart that make all the cells coordinate when beating; sets the rhythm for the whole heart; located in the wall of the right atrium
Steps of conduction from left to right
SA node initiates a signal, atria depolarize and contract, AV node delays signal, ventricles depolarize and contract while atria repolarizes, ventricles repolarize
myogenic
the pacemaker portion of the heart that constantly beats
neurogenic
the controlling of the heart rate by neural impulses; this is the adjustments at the SA and AV nodes themselves
Parasympathetic
peace, slows down the heart rate
vagus nerve
parasympathetic; the cranial nerve that comes straight off the brain and down to the heart
sympathetic
fight or flight, accelerans nerve, stress hormone (adrenaline), opens more Na and Ca channels which means faster depolarization, increases heart rate
Cardiac output
heart rate x stroke volume = cardiac output
if you’re in good shape you will have low HR adn a high SV
osmotic pressure
the tendency for water to move to areas of higher solute concentrations; organisms that are hypotonic to their environment will lose water; organisms that are hypertonic to their environment will gain water; systems must counteract these tendencies which requires energy
electrolyte concentrations
high concentrations can denature proteins which causes lots of problems; most vertebrates like fish need lower concentrations of salt than seawater; moving ions against concentration gradient requires energy
respiration in water
thin membrane allows diffusion and osmosis; the large surface area is great for site of GE but not good for all of the water that may be lost or gained
osmoregulators
animals that use energy to maintain homeostasis of their osmotic pressures; vertebrates, specialized organs to regulate ions, freshwater fish, marine fish, terrestrial animals, blowfish
osmoconformers
allow osmotic concentrations to be equal to their environment; marine invertebrates; permeable skin; jellyfish, these do not worry about equalizing
cartilaginous fish (sharks and friends)
semi-osmoregulators: same solute concentration as in seawater and different ions than in seawater; excrete salt from rectal glands; urea (nitrogen waste), TMAO (TrimethylAmineOxide) protective against toxic effects of urea
marine fish
saltwater (water hypertonic to tissue, try to get rid of salt, try to retain water), drink saltwater, excrete salty urine, transport ions out through gills and lose water by gills
freshwater fish
water hypertonic to tissue, try to get rid of water, try to retain salts, drink very little water, excrete dilute urine, transport ions through gills and gain water by gills
terrestrial osmoregulators
gain water by drinking, eating, and metabolic water and lose water by evaporation from the skin by sweating, breathing, and urine and feces
gain electrolytes through food, lose electrolytes through sweat and urine, and ammonia (urea or uric acid) which requires less water to flush
extreme osmoregulators
reduce evaporations through sweat, respiratory system, and behavioral; reabsorb water in the kidneys through long countercurrent exchanger for water and extremely concentrated urine; efficiencies in large intestine like dry feces
A single hemoglobin molecule can bind to how many oxygen gas molecules
4
ETC and chemiostasis primarily occurs in the
inner membrane of the mitochondria
what gets reduced in the first three steps of cell resp
NAD+
what is a direct input into the krebs cycle
Acetyl-CoA
Electrons leave the mitochondrial ETC by combining with
oxygen
why do we need hemoglobin to survive
oxygen has low solubility in the watery environment of the blood
how is most of the carbon dioxide transported when it moves through the blood of a blood vessel
as bicarbonate dissolved in plasma
what will vasoconstriction of an arteriole cause in the blood flow to the downstream capillary bed
a decrease in the blood flow
during ventricular diastole
blood is pushed into the ventricles by the atria
what is the order of the typical contraction event in the heart
the right and left atrium contract then the right and left ventricles contract
what is the flow of blood through the human circulatory system
left side of the heart, systemic circuit, right side of the heart, pulmonary circuit, repeat
which chamber of the mammalian heart pumps blood to the lungs
right ventricle
what is metabolic water
water produced through cellular respiration
