BIOL381 Animal Physiology Exam 1
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- What advantage does homeostasis confer on animals that practice it?
- Homeostasis allows animals to survive in stressful and varying environments.
- FEEDBACK
- Return of sensory information to a controller that controls a bodily variable
- DISTURBANCE
- An externally induced change to a variable in a controlled system
- SENSOR
- Receives output from a controlled system and funnels it to an amplifier
- AMPLIFIER
- Receives output data from a sensor and inverts the signal, then sends it to the controller (ex. amplifier receives a + (positive) signal, reverses it to a - (negative) signal, then sends it to the controller
- ERROR SIGNAL
- The output signal sent by a sensor to an amplifier that indicates the severity of a change to a controlled system (compared to a desired set point) via increases/decreases in the signal strength
- NEGATIVE FEEDBACK
- Feedback involving the inversion of a sensor output signal by an amplifier; critical to maintaining homeostasis
- POSITIVE FEEDBACK
- Feedback in which the sensor output signal is not inverted by an amplifier, resulting in the controlled system change being reinforced and strengthened over time
- What is a non-pathological example of positive feedback?
- The rising phases of cycling events: vomiting, expulsion of a fetus from the uterus, swallowing
- ANIMAL WELFARE
- The humane treatment of animals that looks after their comfort and well-being
- ANIMAL RIGHTS
- Concept that animals have intrinsic rights to "life, liberty and the pursuit of happiness"
- OSMOREGULATOR
- Maintains internal ion concentrations at a set point despite external concentrations
- OXYREGULATOR
- Maintains internal oxygen concentration as oxygen availability falls
- What is an example of an oxyregulator?
- Crayfish, mollusks
- CONFORMER
- Organism that does not maintain homeostasis with respect to one or more internal variables that are influenced by the environment
- What is an example of an osmoconformer?
- Starfish
- What is an example of an oxyconformer?
- Annelid worms
- ACCLIMITIZATION
- Animal responses to environmental condition change with season and stage of life
- ACCLIMATION
- Animal response to environmental condition change induced by a researcher
- What are some examples of bodily variables that can be regulated?
- Temperature, H2O percent, dissolved solute concentrations, O2 concentrations
- ZONE OF STABILITY
- Range of environmental values for a given variable that are most complimentary to homeostatic efforts to maintain that variable at its set point
- WILLIAM HARVEY
-
England, 1500s:
- Blood flows unidirectionally out of the heart under pressure exerted by the heart.
- Blood then circulates through blood vessels and returns to the heart, completing a round trip.
- Prior belief: blood sloshes back and forth between vessels. - CLAUDE BERNARD
-
1800s, France:
- Measured body fluids in mammals to determine: temperature, volume, composition, concentrations of constituents - CONSTITUENT CONCENTRATION (equation)
- C = constituent amount/volume of fluid when dissolved
- ENERGY
- Capacity to do work
- What 4 things do cells require from their environment?
-
1. C, N and H from nutrient molecules
2. O2 from air/water
3. Energy from nutrient molecules (energy in a form cells can use to perform work)
4. Heat - What is a triglyceride without its 18-Carbon chains?
- Fatty acid
- What is the central molecule of triglyceride?
- Glycerol (C3O3)
- What makes up a triglyceride?
- Glycerol and one or more 18-Carbon chains
- CONVECTIVE HEATING
- Deriving heat from surrounding fluid
- RADIATIVE HEATING
- Deriving heat directly from the source
- What is the classic experiment demonstrating how the molecular building blocks of life arose spontaneously on the primordial Earth?
- Miller, Stanley (1953) - Peptides, amino acids and nucleic acids (molecules essential to primitive life) appear when lightning-like electric discharges are performed on an experimental atmosphere of methane, ammonia and water.
- How is the reactivity of a given atom determined?
- By the number of electrons in the outermost shell
- Why are Carbon, Hydrogen and Oxygen the most common elements in organic molecules?
- They are the only one- and two-shell elements that form strong covalent bonds (sharing 3, 1 and 2 electrons respectively).
- The "dipole" nature of H2O causes it to have what physical/chemical properties?
-
- Aligns with electrostatic fields.
- High dipole movement: 4.8 debyes
- Most important chemical feature: capable of making Hydrogen bonds between H+ of one H2O and the O of neighboring H2O
- Angle between 2 covalently bonded water molecules is 105 degrees, creating a tetrahedral lattice - Why are weak acids used in buffering systems?
- Weak acids dissociate only slightly, ensuring a large reserve of A-. New H+ ions combine with A- to reform HA, while OH- can combine with H+ to form H2O.
- MOLALITY (m)
- Number of moles of solute in 1000g of solvent
- MOLARITY (M)
- Number of moles of solute dissolved in 1 L of solution
- What is the weight of 1 mole CO2 in grams?
- 44g
- Why do only some liquids conduct electricity?
- Conduction in liquids is only supported by the presence of cations (+) and anions (-).
- How many ions flow past a point (amps) in a current of 1 mA?
- 0.001 amps (ions/sec)
- How does attraction vary between a monopole binding site and a multipolar binding site with respect to a cation?
- When a binding site is multipolar, attraction falls more rapidly with distance. When a monopole cation carrying a full charge is presented with a binding site, the a exponent of d^a is equal to 1.
- AMPHOTERIC
- Can function as an acid or a base (ex. H2O)
- Describe the 4 levels of structure in a protein.
-
PRIMARY - Specific linear sequence of amino acid residues in the polypeptide.
SECONDARY - Local organization of polypeptide chain parts
TERTIARY - Foldings of the polypeptide chain to form globular or rod-like molecules
QUARTERNARY - Joinings of 2+ polypeptide chains to from dimers - Why does cysteine commonly inhibit enzyme reactions?
- Two cysteine residues can perform a sulfhydryl group through a disulfide (S-S bond). This highly reactive group often renders enzyme binding sites catalytically inoperative.
- Why do proteins denature at high temperatures?
-
QUATERNARY: Protein sub-units dissociate
TERTIARY: Covalent interactions, noncovalent dipole-dipole interactions, and van der Waals interactions are disrupted
SECONDARY: Proteins lose repeating patterns and adopt random coil patterns
PRIMARY: No change - Do living organisms violate the 2nd Law of Thermodynamics with their consistently low entropy?
- No. Living organisms do not represent closed systems-- they maintain low entropy (disorder) at the expense of their surrounding environment, which gains disorder.
- At a particular temperature, will delta-S > delta-H be endergonic or exergonic?
-
delta-S = change in entropy
delta-H = change in heat
change in entropy > change in heat
Endergonic (exergonic reactions give off heat) - When does an endergonic reaction proceed?
- When enough energy has been absorbed from the environment
- What is delta-G for a system at equilibrium?
-
delta-G = change in Gibbs Free Energy
System at equilibrium delta-G = 0 (there is no change in GFE) - How does ATP supply energy to endergonic reactions?
- ATP decomposes into ADP + P, releasing energy for use in the reaction.
- COUPLED REACTIONS
- Endergonic reactions or transport processes are linked to exergonic reactions that provide a surplus of energy
- Why does an increase in temperature increase the rate of reaction?
- Heat causes the molecules involved in the reaction to move faster (remember 0 Kelvin temperature = no molecule movement)
- How are enzymatic reactions influenced by temperature?
- Generally, enzymatic reactions have a rate increase with temperature. However, different enzymes also denature at higher temperatures, and at that point will become less effective, then inoperative.
- HIGH-ENERGY PHOSPHATE BONDS
- Product of breaking down carbohydrates such as sugar (by glycolysis) or triglycerides; located in special molecules made in cells by concentrating energy derived from breaking covalent bonds in nutrient molecules
- What 3 substances are broken down by glycolysis?
-
Phosphoenolypyruvate
1,3-Diphosphoglycerate
Glucose 1-phosphate - When carbohydrates are broken down by glycolysis, are the products the end products or intermediates?
- Intermediates - the products must directly/indirectly transfer phosphate bond energy to the covalent bonds of ATP
- ATP
- Adenosine triphosphate; provides energy for all cell processes
- How does ATP break itself down for energy?
- It typically only breaks one Phosphate bond, making ADP + P
- CALORIE
- Energy required to raise 1g water by 1 degree Celsius
- MOLE
- Amount of substance containing 6.02 x 10^23 molecules
- ATP is not the greatest energy in a living system, but it is the most _______.
- accessible
- ATP synthesis during cellular respiration (equation)
- ADP + P --> respiration + O2 + fuel ---> ATP OR CO2 + H2O (byproducts)
- What are 3 types of work ATP can be used for?
-
Biosynthesis
Mechanical work
Transport work - CATABOLISM
- Breakdown of large molecules into small ones, releasing covalent bond energy
- ANABOLISM
- Synthesis of large molecules from small ones
- What are the products of the catabolism of nutrient molecules used for?
- Sources of high-energy phosphate bonds for ADP, creating ATP
- Catabolism always requires ___ and always has ___ as a byproduct.
- O2, CO2
- What happens to nonpolar molecules like O2 and CO2 when they come in contact with the cell membrane?
- Dissolve readily in cell membrane lipids
- Cellular respiration can be measured as an exchange between O2 and ____.
- CO2
-
TRUE/FALSE:
In cellular respiration, O2 intake and CO2 output are always equal. - FALSE
- Where are 2 places ATP is created in mitochondria?
- Cytosol, mitochondrial center (at the site of respiration)
- CRISTAE
- Inner mitochondrial membrane near the site of respiration
- ATP Production in cell cytosol (equation)
- Polysaccharides ---> 5- and 6-Carbon sugars ---> 3-Carbon sugars ---> ATP OR pyruvate ---> goes inside mitochondria OR lactate
- STARCH
- Chain of individual glucose molecules bound covalently -- broken down by digestion
- DIGESTION
- Breakdown of starches that releases individual glucose molecules into the blood
- What happens to the energy of starch bonds (glucose-glucose) during digestion?
- Released as heat
- ANAEROBIC
- No O2 used
- GLYCOLYSIS
- Breakdown of 5- and 6-Carbon sugars into 3-Carbon sugars
- NAD
- Electron-accepting coenzyme that captures energy from glycolytic substrates
- GLYCOLYTIC SUBSTRATES
- 5- and 6-Carbon sugars that are transformed into 3-Carbon sugars by glycolysis
- REDUCTION
- Adding an electron to a molecule (ex. NAD is reduced to NADH)
- OXIDATION
- Removing an electron from a molecule (ex. glycolytic substrates are oxidized)
- REDOX PAIR
- Paired oxidation and reduction reactions
- SUBSTRATE PHOSPHORYLATION
- Phosphorylation of ADP to produce ATP while the glycolytic substrate is being transformed
- What is the name of the process that creates ATP inside the mitochondria?
- Kreb Cycle
- KREB CYCLE: Pyruvate
- 1. Pyruvate becomes lactate OR CO2 OR has a Carbon removed and Coenzyme A added to form acetyl CoA (2C remaining)
- KREB CYCLE: Acetyl CoA
- 2. Combines with OAA to form CA (citric acid citrate) with 6C
- KREB CYCLE: CA (citric acid citrate)
- 3. 2C removed, breaking down CA into 2CO2s, and recycling CA itself to OAA (producing one more CO2, for 3 total CO2)
- KREB CYCLE: Recycling of citric acid
- 4. Citric acid is transformed to yield new electrons captured by NAD and the secondary electron acceptor FAD
- KREB CYCLE: Recycled citric acid meets H+
- 5. H+ addition leads to transport of energy to the electron transport chain
- KREB CYCLE: Electron Transport Chain (3 products)
- 6. NADH from cytosol glycolysis and NADH/FADH from Kreb Cycle are oxidized, recycling NAD and FAD, ATP is produced, and H2O is produced where O2 is added
- In the Kreb Cycle, H2O acts as what?
- Terminal electron acceptor; H2O gathers e/p removed from NADH and FADH that combine with O2, as O2 takes up energy-poor e
- When electrons are removed from NADH and FADH (yielding NAD and FAD), where does the energy go?
- Some goes to ATP, most released as heat
- How many moles of ATP are produced per 1 mole of NADH?
- 3 moles ATP per 1 mole NADH
- How many moles of ATP are produced per 1 mole of FADH?
- 2 moles ATP per 1 mole FADH (there is only 1 FADH per cycle, so only 2 moles ATP per pyruvate)
- How many moles of ATP are produced from 1 mole of pyruvate?
- 2 moles ATP per 1 mole pyruvate
- How many moles of H2O are produced per Kreb cycle?
- 3 H2O per cycle
- METABOLIC WATER
- Water produced during the Kreb cycle; relied upon by desert animals
- ANOXIA
- No O2 in cell, cell cannot produce ATP and eventually dies; drowning, CO poisoning cause this
- Why does CO poisoning cause anoxia?
- CO bonds with O2-carrying molecule in the blood
- STOICHIOMETRY: Glycolysis
-
1 mole glucose catabolized (6C)
2 moles pyruvate produces (3C each) - STOICHIOMETRY: Respiration
-
3 moles O2 required
1 mole pyruvate catabolized
3 moles CO2 produced
3 moles H2O produced - STOICHIOMETRY: Metabolism of 1 Mole Glucose
-
Requires: 6 moles O2
Requires: 2 turns of Kreb cycle
Products: 6 CO2 and 6 H2O - Metabolism of 1 mole of glucose (equation)
- C6H12O6 + 6O2 --> 6CO2 + 6H2O
- How much energy is released by the complete catabolism of 1 mol glucose?
- 686 kcal, only 288 kcal captured (38.7%) and remainder released as heat
- What is an example of anaerobic metabolism?
- Pyruvate + NADH ---> Lactate + NAD (no oxygen used)
-
TRUE/FALSE:
Some animals do not use mitochondria and do not require O2. -
TRUE
But only 2 moles of ATP are earned per 1 mole glucose (1/19 as efficient as aerobic metabolism)
Some organisms use this as an anoxia failsafe. - LDH
- Lactic Acid Dehydrogenase; catalyst to the pyruvate --> lactate reaction that applies in both directions
- What happens regardless of whether glucose is transformed for mitochondrial use OR glucose is transformed into lactate?
- NADH recycles into NAD
- What process causes oxygen debt?
- Lactate production by cells producing pyruvate from sugar
- How is oxygen debt repaid?
- Lactate is broken down in the blood by the liver, returning O2
- Why does the liver remove lactate?
-
Prevents blood/tissues from becoming too acidic
Permits lactate conversion to pyruvate (and then to sugar) - GLYCOGEN
- Sugar from pyruvate that is stored by the liver
- GLUCOGENESIS
- Conversion of lactate to pyruvate to glycogen (sugar)
- How can the liver maintain blood sugar homeostasis?
- Breaks glucose off of glycogen molecules
- Besides the liver, what other tissue removes lactate from the blood? Why?
- Muscle removes lactate and uses the resulting glycogen to fuel contraction
- BASAL METABOLIC RATE
- Rate of energy use at rest (no digestion) in nonstressful temps in kcal/hour
- When does O2 debt occur between rest and exercise?
- Exercise creates energy need; O2 debt occurs as anaerobic respiration supplies energy while aerobic respiration lags
- What are some reasons for the lag in energy produced by aerobic respiration?
-
O2 cannot be abosrbed into the blood quickly enough and lags the electron transport chain
Blood flow is not fast enough when the animal starts at rest
Heart/Respiratory activity takes time to increase -
What are 2 lactate steps of anaerobic metabolism?
What are 2 ways the body reacts to anaerobic metabolism and oxygen debt? -
1. Cells produce lactic acid from pyruvic acid (catalyzed by LDH).
2. Lactate leaves cells and dissolves in blood.
----
1. Some cells absorb blood lactate and convert it back to pyruvic acid
2. Gluconeogenesis leads to glycogen storage - Removal of lactate from the blood requires ____ _____ because ____ is required to produce glucose and glycogen.
- aerobic metabolism, ATP
- What happens related to O2 debt at the end of exercise?
- O2 use remains elevated until all blood lactate is removed
-
TRUE/FALSE:
The Rate of O2 Uptake is equivalent to the Rate of Energy Use. - TRUE
- SACCHARIDES (general formula)
-
CnH2nOn
If n = 6, C6H12O6 (glucose) - HEXOSES
- All compounds with the formula C6H12O6
- What is the primary fuel molecule?
- Glucose
- What are sugar names based on?
-
How many C they have.
3 = triose
5 = pentose
6 = hexose - What are saccharide names based on?
-
How many sugars they have linked together
0 = mono
2 = di
3+ = poly - What are 2 characteristics of lipids (triglycerides)?
-
1. Nonpolar
2. Insoluble in H2O - Fatty Acids have 3 "R"s connected to them. What does an "R" represent?
- 16-18 Carbon molecule chain
- SATURATED FATTY ACID
- When H atoms are attached to all available C
- UNSATURATED FATTY ACID
-
When H are removed and Cs double-bond
More double bonds = polysaturated fatty acid - DIGESTION (general formula)
- Glucose + 3H2O ---> glycerol + fatty acids
- ALPHA-AMINO ACIDS (general structure)
-
COOH (carboxyl group)
|
(amino group)NH2--C--H
|
R
(one of 20 residues) - In an alpha-amino acid, what is "R"?
- One of 20 different amino acid residues
- PEPTIDE BOND
- Connects amino group (NH2) of one amino acid to the carboxyl group (COOH) of another amino acid
-
TRUE/FALSE:
A tetrapeptide can have a different "R" on each of its individual amino acid groups. - TRUE
- What is the least accurate method of measuring metabolism?
-
Calorimetry
Direct: Measure heat production
Indirect: Difference between calories in food eaten + calories in waste excreted - RESPIROMETRY
- Exploits stoichiometry of metabolic summary reactions (amount of O2 used per gram metabolized) to measure metabolism
- What are the respiratory quotients (RQs) for carbohydrates, proteins and fats?
-
Carbohydrates = 6/6 = 1
Proteins = 0.80
Fats = 102/145 = 0.71 - How much energy is gained from metabolizing 1 gram of carbohydrates, proteins and fats?
-
Carbohydrates = 17 kJ/gram
Proteins = 17 kJ/gram
Fats = 39 kJ/gram
- Convert 1 kJ into joules and calories.
- 1 kJ = 1000 joules = 239 calories
- Convert 1 calorie into Joules.
-
1 calorie = 4.18 J
1 J = 0.239 calories - Convert 1000 mL H2O into kg and liters.
- 1000 mL H2O = 1 kg = 1 L
- Why is it difficult to write a summary reaction for proteins?
- Because proteins contain N, which animals also make as a metabolic byproduct and excrete as urea and other compounds
- When proteins are digested, where does the energy come from?
- Proteins are broken down into amino acids which are broken down into energy
- How much O2 is used to metabolize 1 mole of carboyhdrates, proteins and fats?
-
Carbohydrates = 6 moles O2 per 1 mole carbohydrate
Proteins = N/A
Fats = 72.5 moles O2 per 1 mole fats - Rate of O2 uptake can only be counted as energy for which type of respiration?
- Aerobic
- What is the heat production per gram of carbohydrates, proteins and fats?
-
Carb = 17.1 kJ/gram
Prot = 17.6 kJ/gram
Fat = 38.9 kJ/gram - Why is heat production a useful measurement in determining metabolism?
- Eventually all energy (even that used to create glucose) is released from the body as heat
- What are 4 occasions when heat is released?
-
1. Breakdown of molecules that used energy for their synthesis
2. Breakdown of fuel molecules (40% captured for ATP)
3. ATP use by cells
4. ATP use for work - If you have glucose fuel, and the energy used is 21 kJ/Liter O2 consumed, and 5L O2 is consumed in 1 minute, what is the energy use rate?
-
21 kJ/L O2 X 5L O2/1 min
21 kJ X 5/1 min
105 kJ/min - If RQ = 0.85 (halfway between 1.0-carbs and 0.71-fats), how can the fuel type be calculated?
- Collect urine sample to find out # of amino acids and subtract from 50/50 carb/fat ratio, but general animals do not spend protein making ATP