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47 Cards in this Set
- Front
- Back
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List 8 characteristics of Life
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Complex/ordered
well adapted responsive uses energy regulated carries Instructions Grows Reproduces Life is cellular |
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List org listed as prok and euk
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Prok - bacteria, archae
Euk - Protists, animals, plants, fungi |
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Atom
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smallest unit of matter that still remains element.
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Element
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Substance that can't be broken down to other substances by chemical reactions.
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Compound
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Substance consisting of two or more diff elements in a fixed ration.
EX NaCl |
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Molecule
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A group of two or more atoms joined together. Ex. DNA
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Isotope
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atoms of the same element that have diff numbers of neutrons and thus diff. atomic mass
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Ion
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Atom that has acquired a positive or neg. charge due to the loss of an electron or gain of electrons.
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How many elements req. for life
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About 25
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Which 4 are most common in living things?
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CHON
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Other 7 most common elements
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Ca, P, K, S, Na, Cl, Mg
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Why remaining referred to as trace elements
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Because they are only req. in minute quantities.
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Neutron
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Location - Found in nucleus
Mass - 1.7 x 10^-24 g Charge - neutral |
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Proton
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Location - Found in nucleus
Mass - 1.7 x 10^-24 g Charge - positive |
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Electron
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Location - Orbit cloud around nucleus
Mass - Very small compared to proton and neutron Charge - Negative Charge |
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Mass #
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# of protons plus neutrons
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atomic #
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# of protons in an element.
( 2He ) ( 2 is subscript ) |
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Atomic Mass
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total mass of an atom
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Potential Energy
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Energy that matter possesses because of its location or structure.
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What happens when the potential energy of an electron changes?
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Its energy is correlated to avg dist from nucleus. First shell closest to nucleus has lowest potential energy. An electron can change shell it occupies, only by absorbing or losing amount of energy equal to diff in potential energy between pos. in old shell to new shell. Loses energy - falls back - releases energy as heat.
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Valence Electrons
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Electrons on outermost shell
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Valence Shell
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Outermost electron shell
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Explain how covalent bonds are either polar or nonpolar depending on the electronegativies of bonded atoms.
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In the covalent bond of an element of the same element, the two atoms are equally electronegative, and atoms are shared equally results in nonpolar covalent bond. Polar covalent bond results when one atom is bonded to a more electronegative atom.
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Summ. characteristics of strong and weak chemical interactions or bonds.
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Strong - covalent bond - Link atoms to form a cells molecules.
Weak Ionic Bonds - exists between ions dissociated in water Hydrogen Bonds - when hydrogen atom cov. bonded to an electroneg. atom is attracted to another elctroneg. atom, gen. O or N. Give protein 3D shapes. Van der Waals Interactions - transient partial charges in nonpolar molecules. Hydrophobic Interaction- clustering of nonpolar molecules away from H20. |
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Strong Interaction
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Hold atoms together in molecules
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Weak interactions
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Both intermolecular and intramolecular.
Transient/easily reversibly collectively they have strength. |
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How many covalent bonds CHON form
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C - 4
H- 1 0- 2 N - 3 |
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Which atoms in CHON form SP3 hybridization and when?
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CON. Occurs when covalent bond form, the valence shell orbitals combine and rearrange.
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What do orbital shapes have to do with the special arrangment of any covalently bonded atom?
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The position of the atoms orbitals determine the shape.
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Chemical Reaction - Reactants
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Starting Material
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Chemical Reactions - Products
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Ending material
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Chemical Reaction - Reversible Reaction
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All chemical reaction are reversible, with product of forward reaction becoming reactants of reverse reaction.
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Chemical Equilibrium
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When there is no net effect on the concentrations of reactants and products. Conc. have stabilized at a particular ratio.
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When did life appear on earth?
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3-4 byo
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Why is water an effective solvent?
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It is a polar molecule. The positive and negative charge bind and separate.
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WHat makes substance hydrophillic?
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Sub. that have affinity for water. They can be this without dissolving. Ex. Cotton
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What makes substance soluble?
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It can dissolve. Ionic substances are soluble.
Polar substance are soluble. |
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What makes substance Hydrophobic?
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Substances that dont have affinity for water. Substances that are nonionic and nonpolar or for some other reason can't form Hydrogen bonds. Ex. Oil
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Explain how water molecules dissociate.
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A hydrogen atom participating in a hydrogen bond between two water molecules shifts from one molecule to the next. Hydrogen atom leaves electron behind, and what is transferred is a hydrogen Ion, a single proton with a charge of 1+. The water molecule that lost an ion is now a hydroxide ion with charge of 1-. Proton binds to other water molecule, making it hydronium ion.
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What does the Ph of a solution tell you about the [H+] and [OH-] ?
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the product of both concentrations is constant at 10^-14 . When we know one we know the other.
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Why must cells control and maintain their pH?
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A change in ph can alter a cells proteins and other molecules. It would affect weak interactions. Would disrupt chemical processes necessary for life.
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What is the pH of most biological fuels?
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Between 6-8
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Explain imp of buffers in biological fluids
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Buffers maintain cellular ph. Cells/organims can alter pH need be. They accept Hydrogen ions from the solution when they are in excess and donating hydrogen ions to the solution when they have been depleted.
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What is pH of most living cells
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7
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How did experiments performed by Wohler and Miller challenge vitalism?
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Vitalism says that biomolecules are made by a life force.They were able to make organic molecules, such as urea. Views shifted from vitalism to mechanism.
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What shapes do carbon backbones form in biological molecules?
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They vary in length, some have double bonds, have branching and can form rings.
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How do double bonds affect a molecule's shape and flexibility?
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When 2 C joined by double bonds, all atoms attached to that double bond are in same plane, it is flat.
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