Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Week 1
Atoms, cell membranes + cell structure
| Question | Answer |
|---|---|
| What is matter + what 4 major elements make up most living matter? | Anything that takes up space (volume) + has mass (weight) oxygen, carbon, hydrogen + nitrogen |
| What is a compound? | a substance made from 2 or more elements, joined by chemical bonds in a fixed ratio |
| Describe the general structure of an atom | Nucleus composed of protons (+) and neutrons (neutral), oribited by electrons (-) |
| Define valence electrons + valence shell | valence electrons: electrons in the outermost shell of an atom valence shell: outermost electron shell of an atom |
| Describe the relative reactivity of atoms with complete and incomplete valence shells | incomplete are highly reactive complete are chemically inert/non reactive |
| How do atoms form molecules? | by forming chemical bonds through sharing electrons (covalent bonds) or transferring electrons (ionic bonds) connecting atoms together |
| Nonpolar vs. polar | polar: atoms do not share electrons equally (causes partial positive or negative charge for each molecule/atom) ex. H2O nonpolar: atoms share electrons equally ex. O2 |
| Define ion, anion + cation | ion: charged ion/molecule anion: positivly charged ion cation: negativly charged ion |
| Covalent vs. hydrogen bonds | covalent: within molecules/the different atoms in the molecules hydrogen: between different molecules. weak + constantly formed and destroyed |
| How do ionic bonds form? | transfer of electrons between a metal and a nonmetal atom, which creates opositely charged ions (cation + anion) which are attracted to eachother, forming a compound. both atoms will recieve full valence shells |
| How do hydrogen bonds form? | a partically positively charged H atom in one polar molecule is attracted to a partially negatively charged atom in another polar molecule |
| What is a polar molecule? | molecule where one end is slightly positive and the other end is slightly negative becuase of unequal electron sharing |
| How do the cohesive + adhesive properties of water contribute to the upward movement of water in a tree? | the water molecules are very cohesive, sticking to eachother and forming a continuous colum in the xylem. Adhesion then helps the water adhere to the xylem walls, keeping the water colum from breaking as its drawn up through the plant |
| How do hydrogen bonds between water molecules help make to make ice less dense then water? | when water freezes into ice, the hydrogen bonds/water molecules are pushed farther apart, making ice less dense then water, where the water molcules are packed closer together |
| what would happen to arctic enviroments if water didnt form hydrogen bonds? | water would keep freezing and sinking becuase ice would be denser then water, liquid water would be rare and live would have a hard time existing |
| define solvent, solute + solution | solvent: liquid that is a homogenous mixture of substances (solvent + solute) solute: dissolving agent of a solution solution: substance that is dissolved |
| How is water such a versatile solvent? | it is polar, so its slightly positive ends (H) and slightly negative ends (O) act like magnets, pulling apart other polar molecules |
| Define hydrophobic + hydrophilic | hydrophobic: "water loving" (charged/polar molecules) hydrophilic: "water fearing" (nonpolar molecules) |
| Why is it important that carbon is capable of forming bonds with other carbon molecules? | Carbon can make 4 covalent bonds, allowing it to form large diverse molecules, making complex life possible |
| What are functional groups? | a specific configuration of atoms commonly attached to the carbon skeletons of organic molecules + invlved in chemical reactions (# + arrangment of func. groups gives each molecules its unique properties) |
| Inorganic compound traits | small + simple, does NOT contain C-H bonds (except CO2), often contains ionic bonds. ex. salts, acids, bases |
| 4 characteristics of water that make it useful for living organisms | chohesive behavior, high heat capacity, versatility as a solvent, + lower density when frozen |
| Define monomer, polymer + macromolecules | monomer: units that serve as building blocks of polymers polymer: large molcules made of a chain of sim/identical moleculer units macromolecules: large molecules, often made of thousands of covalently connected atoms |
| Name the 4 classes of large organic molecules found in all living things | carbohydrates, proteins, nucleic acids (DNA + RNA), lipids |
| Monomer vs. polymer | polymer is like a chain,while the links within the chain are the monomers |
| Dehydration synthesis definiton | cells link monomers together to form polymers by dehydration synthesis; one monomer gives up a H atom, and another gives up a hydroxl group; water is released + a covalent bond is formed between the 2 monomers |
| Hydrolysis definition | polymers are dissassembled to monomers by hydrolysis, basically the reverse of dehydration synthesis (bond between monomers is broken by the addition of a water molecule) |
| How does the structure of the cell membrane affect membrane permeability? | the structure of the cell membrane gives the membrane selectively, blocking larger/polar molecules from passing through the membrane freely |
| Describe the structure of a phospholipid | 2 fatty acids + a phosphate group are attached to glycerol. one tail is usually saturated and the other is unsaturated |
| Saturated vs. unsaturated fatty acids | unsaturated fats will have less hydrogens because they have double bonds (giving them their "bent" shape), where as saturated fats only have single bonds |
| How does fatty acid types + presence of cholesterol effect cell membrane fluidity? | they work together. more unsaturated fats means the phospholipids are less tightly packed = more fluid + vise versa. at warm temps cholesterol decreases membrane fluidity + at cold temps it increases fluidity |
| Based on polarity what kind of molecules can cross the cell membrane most readily? | small, nonpolar/uncharged molecules |
| Why are transport proteins required for movement of most polar (hydrophillic) substances? | Because they are polar they cant get through the cell membrane's hydrophobic layer, so they have to use transport proteins instead |
| Channel proteins vs. carrier proteins | ion channels: let ions move down the conc. gradient through the cell membrane carrier proteins: binds to specific ions to move them across the membrane. may or may not require energy |
| Define diffusion | Molecules move from an area of high concentration to an area of low concentration (down the concentration gradient) |
| Define osmosis | Diffusion of water - water goes down its concentration gradient (high conc. of water/low conc. of solute to low conc. of water/high conc. of solute) (water crosses cell membrane via osmosis) |
| Why are diffusion, osmosis + facilitaed diffusion passive processes? | they dont require any energy/ATP |
| Organic compound traits | large + complex, ALWAYS contain C-H bonds, contains covalent bonds, carbon is the main element ex. carbs, lipids, nucleic acids |
Created by:
every_august
Popular Biology sets