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LSU / Anatomy and Physiology / BIOL 1201 / What is the method used by both social science and natural science?

What is the method used by both social science and natural science?

What is the method used by both social science and natural science?

Description

School: Louisiana State University
Department: Anatomy and Physiology
Course: Introduction to Biology for Science Majors
Professor: Joseph siebenaller
Term: Spring 2017
Tags: JosephSiebenaller and BIOL1201
Cost: Free
Name: BIOL 1201 Week 1 and 2 Notes
Description: Lectures for the first two weeks of class plus the quiz review. Email me at ktrah18@lsu.edu for further questions!
Uploaded: 01/23/2017
7 Pages 45 Views 145 Unlocks
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BIOL 1201 Kristy Trahan


What is the method used by both social science and natural science?



Lecture 1

∙ Science: the pursuit and application of knowledge and understanding of the natural and  social world following a systematic methodology based on evidence 

∙ Range of conditions for Life

o Cell body temperatures from -2 °C to 132 °C

o Range of pressures: 1 atm to 1100 atm  

o The deep sea is the most commonly habitable environment  

∙ Antarctic fishes  

o Live (and have body temperatures) at -2 °C (below the freezing temperature  ▪ Ectotherm- same temperature as the environment  

∙ Penguins


What does an ectotherm do if environment temperatures are low?



o Keep warm at similar temperatures

▪ Endotherm- body temperature is not set by the environment  

∙ Diving Seals

o Can hold their breath for as long as 90 minutes  

o Dive down to 1,500 m to feed on fish  

∙ Deep-sea Fishes  

o Down to 8,000 m  

▪ Experience high pressure, low temperatures, low food availability  

o Rattails  

∙ Piezophiles (aka barophiles) If you want to learn more check out Who is defined as a criminal?

o Bacteria are “pressure loving”

▪ Thrive at pressures that would kill surface bacteria  

▪ Discovering ways to use pressure as a way to pasteurize canned foods ∙ Thermophiles  


How do endotherms regulate their body temperature?



We also discuss several other topics like Is the world good or evil?

o Bacteria- exist at temperatures up to 132 °C, but grow at 122 °C

∙ Hydrothermal Vents  

o Vents from the seafloor that give off very hot water We also discuss several other topics like What is the meaning of naturalistic observation in psychology?

o Looks like smoke, but the minerals precipitate when the hot water comes into  contact with the cold water

∙ Sharks  

o Live with ½ molar urea in their tissues  

o Urea is a potent denaturant of proteins  If you want to learn more check out Is there a difference between new guinea and papua new guinea?

∙ Halophiles  

o Halophilic bacteria live in osmotic equilibrium with 3 molar salt  

▪ Like the salt  

∙ Tuna  

o Raise the temperature of their muscles above ambient (as much as 15 °C) o Warmer muscle tissue allows them to swim faster  

▪ Are endotherms in contrast to ectothermic fish  

∙ Great white shark, swordfish  

∙ Gutless Tubeworm

o Thrive at deep-sea hydrothermal vents  

o Don’t have a digestive tract- no stomach, mouth, anus, etc.  

o Mostly stay near hydrothermal vents  

∙ Midwater fish and invertebrates

BIOL 1201 Kristy Trahan

o Angler fish, eels

∙ ALL FISH ARE NOT ECTOTHERMS

BIOL 1201 Kristy Trahan

Lecture 2

Basic Chemistry  

∙ Chemical Bonds: forces holding atoms together in molecules

∙ Number of bonds=valence  

∙ Type of bonds=Electronegativity  

o Electronegativity: measure of the tendency of an atom to attract a bonding pair of  electrons  

▪ Measure of the attraction an atom (nucleus) has for electrons  Don't forget about the age old question of What are the four criteria for revenue recognition?

∙ Chemical bonds are characterized as strong or weak depending on the energy required to  make/break the bond  

o Strong- energy it takes to break the bond

▪ Covalent bonds involve the sharing of electrons  

o Weak  

▪ Non-covalent bonds  

∙ Ionic interactions- attraction of opposite charges (one atom donates  Don't forget about the age old question of Explain the difference between an enantiomer and a diastereomer.

an electron to another  

o Ionic bonds are usually strong, but in biology, things  

happen in water, which makes them weak  

∙ Hydrogen bonds between partially charged atoms  

o Typically involve hydrogen  

∙ Valence vs. Valence Electrons

o Valence: number of electrons needed to fill the outermost shell of an atom  ▪ Not the electrons there, the electrons needed (aren’t there)

o Valence electrons: the electrons contained in the outermost shell

∙ Moles and Molar Concentrations  

o 1 Mole= the mass of a substance equal to its gram molecular weight  

o 1 molar solution= a solution containing 1 mole of a substance per 1 liter of  solution

BIOL 1201 Kristy Trahan

∙ Ionic Bonds

o Weak bond  

o Formed by transfer of electron from one atom to another

∙ Covalent Bonds

o Strong bond

o Sharing of electrons to complete the valence shell

∙ Polar Bonds  

o Unequal sharing of electrons  

o Partial positive and partial negative regions  

o No net charge

∙ Hydrogen Bonds  

o Weak (non-covalent) bonds

o Between partial positive and partial negative charges  

∙ Major categories of bonds are based on the energy needed to make or break them, not the  number of electrons  

Biological Molecules  

∙ Water  

o 70-90% of weight of most life forms is water  

o Sets the lower temperature limit for life  

o Sets the upper temperature limit? (probably not)

o Important role in structures and properties of biological molecules

o Water is a biological molecule

o The unusual properties of water  

▪ Results from hydrogen bond formation  

▪ Water behaves as a much larger molecule- hydrogen bonds

∙ Bonding in water molecules

o Covalent: H-O 110 kcal per mole  

o Angle of 104.5  

o Weak (hydrogen bond): 4.5 kcal/mol

▪ H bonding effectively makes water a larger molecule

BIOL 1201 Kristy Trahan

▪ In ice, a water molecule interacts with exactly 4 other water molecules ▪ In liquid water, on average 3.6 or fewer other molecules (can be made and  broken very quickly)

∙ Unusual properties of Water  

o High heat capacity

▪ The amount of heat to raise the temperature of 1 g of water by 1 °C ▪ 1 cal per gram of water  

o High heat of vaporization  

▪ Amount of heat to vaporize 1 gram of water  

▪ 540 cal per gram at 100 °C  

▪ As water vaporizes it absorbs heat from your body- why it cools you off  o High heat of fusion  

▪ Amount of heat removed to freeze 1 gram of water (for ice to form) ▪ 79.70 cal per gram  

▪ Farmers with citrus crops will spray their crops with water to form ice  formation on the outside to keep ice crystals from forming on the inside in  freezing temperatures  

o Super-cooling (under cooling)

▪ Cooing of liquid below its freezing point without the formation of ice  crystals  

▪ A metastable state (not too stable)

∙ Below a certain temperature molecular aggregates become larger  

∙ Will undergo a spontaneous transition on addition of the stable  

phase

▪ Embryo crystal seeds the solution when a critical radius is reached  ∙ Ice forms spontaneously  

o Pure water

▪ In the absence of heterogeneous nucleaters can super-cool to -40 °C (when  homogeneous nucleation occurs)

o Ice Nucleators

▪ Proteins  

▪ Polysaccharides  

▪ Prevent super-cooling and rapid freezing

o Most dense at 4 °C

▪ Because of the hydrogen bonding  

▪ Lakes do not freeze from the bottom up  

∙ Would kill everything in the lake  

o High dielectric  

▪ Means it is a good solvent  

▪ Interacts well with polar molecules  

o Capillary action and surface tension  

▪ A water spider can walk on the surface of water because the water  

molecules on the surface are hydrogen bonded to each other  

∙ Provides enough tension  

▪ Capillary action- movement of water from the ground through the roots  through the trunk and then out through the leaves of a tree

BIOL 1201 Kristy Trahan

▪ Due to hydrogen bonding  

o Ionization  

▪ Can dissociate in to an acid (hydronium ion)

▪ And base (hydroxyl ion)  

▪ Ionized into an acid and a base  

∙ Freeze Tolerant Plant  

o Lobelia telekii

▪ Mountainous regions of Kenya and Uganda

▪ “Cousin Itt” plant  

o Alpine species experiences temperatures varying from -10-10 °C

o Ectotherm plant  

▪ As temperature drops, so does fluid and plant temperature  

▪ When reaches 0 °C, the central fluid remains slightly above 0 (freezing)  ▪ Uses sugar molecules cause ice formation to release heat  

o Ice formation  

▪ ice nucleators  

▪ release heat of fusion  

▪ maintain fluid and plant temperature at 0 °C

▪ induce freezing in the central fluid at the highest possible subzero  

temperature  

▪ prevents super-cooling and explosive freezing which would damage cells  ∙ tolerates freezing temperatures by inducing freezing  

▪ Freeze-tolerant organisms seed ice formation to control the rate of ice  formation 

*most aquatic animals are ectotherms because of the high heat capacity of water* *hydrogen bonding is responsible for the unusual properties of water*

BIOL 1201 Kristy Trahan

Quiz 1 Review

∙ The number of protons in an uncharged atom equals the number of electrons.  ∙ A particular carbon isotope has an atomic number of 6 and an atomic mass of 14. The  respective number of neutrons, protons, and electrons that this carbon isotope has is 8, 6,  and 6.

∙ Atomic Chlorine has an atomic number of 17. It has 7 electrons in its third shell.  ∙ The chemical characteristics or reactivity of an element depend mostly on the number of  electrons in its outermost shell.  

∙ An atom that has 8 electrons in its outer shell would not tend to form chemical bonds  with other atoms.  

∙ A polar covalent bond is a bond that has shared electrons pulled closer to the more  electronegative atom.  

∙ When the proton number and the electron number are unequal, the atom or molecule is an  ion.  

∙ Ionic bonds form as a result of attraction between atoms that have opposite charges. ∙ A hydrogen bond is a weak chemical bond.  

∙ Hydrogen bonds occur when partial opposite charges on molecules come close enough to  attract each other.

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