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Terms in this set (55)
Why water is very special and necessary to life?
All organisms are made of water. Its needed ofr metabolism. cells 70%, earth 75%. 60% of body weight.
What are the properties of water?
cohesive behavior, ability to moderate temperature, expansion upon freezing, and versatility as a solvent.
attraction between molecules of the same substance. example: water attracts to water by hydrogen bonds forming ___ to form the strand.
the attraction between two molecules of different substances. Ex: water with glass. it holds the water in place to go against gravitational force.
difference between cohesion and adhesion?
cohesion is the attraction between 2 molecules of the same substance. adhesion is the attraction of 2 molecules of different substances.
What is our body temp?
37 degrees celcius
water does this due to hydrogen bonds. Ex: sweating cools down our body due to specific heat. it absorbs energy through evaporation.
ability to moderate temperature
Ice freezes at 0 degrees celsius. it is less dense tan water so the molecules spread apart and ice floats. Ice is more orderly due to the solid crystal structure because of hydrogen bonds.
Expansion upon freezing
Solution, solute, solvent. the highly polar character of water makes it an excellent solvent for other polar substances. hydrophilic, hydrophobic
Versatility of a solvent
How does water transport in plants?
Evaporation from leaves pulls water up from the roots through water conduction cells. the water molecules hold together the column of water within the cells by cohesion of hydrogen bonds. adhesion of water to the cell walls by hydrogen bonds help resist the downward pull of gravity.
what force pulls down the water in a tree?
if water molecules want to transport up, then the molecules need to overcome the
what force makes it able to overcome gravity?
evaporation transportational force. this is why the leaf is flat. this force pulls the water up.
What is meniscus curve? Why does it form?
it forms due to adhesion.this is the opposite charges on the polar bonds of the water molecules that repel each other. when they repel it causes water to climb up the sides forming a meniscus curve.
The polar character of water allows water molecules to form up to __ hydrogen bonds
What is surface tension?
a measure of how difficult it is to stretch or break the surface of a liquid.
Which property of water causes surface tension? Examples?
the cohesion(property) of water molecules along the surface produces this. Ex: spider walking on water. the high surface tension of water, resulting from the collective strength of its hydrogen bonds allows this to happen. and spider is lightweight.
the amount of heat that must be absorbed or lost for 1g of that substance to change its temperature by 1C.
What are the specific heat of water?
1 calorie per gram and per degree celsius: 1cal/g*C.
Why can water moderate temps by high specific heat?
because of high specific heat, water will change its temp less than other liquids when absorbs or loses a given amount of heat. it also stabilizes ocean temps, creating a favorable environment for marine life. because of HSH water that covers most of earth keeps temp fluctuations on land and in water within limits that permit life.
the quantity of heat a liquid must absorb for 1g of it to be converted from the liquid to the gaseous state.
heat of vaporization 540 cal/gram
Why can water moderate temp. because of heat of vaporization?
it helps cool the ecosphere and biological organisms
As a liquid evaporates, the surface of the liquid that remains behind cools down(temp decrease). It occurs because the hottest molecules are likely to leave as gas.
___ of water contributes to the stability of temp in lakes and ponds and provides a mechanism that prevents terrestrial organisms from overheating.
Why does ice float in liquid water?
ice has a lower density
what causes the molecules to have special arranged pattern in ice?
Ice has more orderly molecular arrangement because solid crystal structure. It is orderly because of hydrogen bonds.
a liquide that is a completely homogeneous mixture of two or more substances. ex: solute dissolved in a__
The substance in which the solute is dissolved in. usually water
substance that is dissolved n a solvent. Ex: sodium ion and chloride ion
How do solution, solute, and solvent relate to one another?
any substance that has an affinity for water/water soluble molecules. ex: cotton. because cells can be so large that they do not dissolve.
substances that do not have an affinity for water(insoluble) and are nonionic and non polar(cannot form hydrogen bonds) seem to repeal water. ex: vegetable oil
a substance that increases the hydrogen ion concentration of a solution. Proton donor. Ex: H+ more than OH- because they donate an H+. it dissociates in solution to yield hydrogen ions(H+)
Examples of acid?
stomach acid,coke, beer, tomato, coffee
any substance that reduces the H+ concentration of a solution. proton acceptors.
Examples of base?
toothpaste, bleach, drain cleaner
How is pH important to living?
Proteins are the essential group of biological molecules in the organisms.The shape of protein is essential for its function and it depends on lot of factors, one of that factors is pH. The change in pH changes its shape ultimately its function is affected.
How does a buffer work to regulate pH changes? examples?
It minimizes pH changes. it prevents dramatic changes in ph in a living organisms by accepting hydrogen ions from the solution when they are in excess and donating hydrogen ions in the solution where they have been depleted. ex: carbonic acid-bicarbonate buffer in blood.
Neutral in pH scale?
milk, blood, baking soda, water
carbon skeletons + hydrogen atoms/functional groups. Ex: tetrahedron when 4 separate bonds are formed. Plane when dole bonds are formed
carbon dioxide and all molecules without carbon
Why is carbon so important in the molecules that make up living organisms?
it is unparalleled in its ability to form molecules that are large, complex, and varied, making possible the diversity organisms that have evolved on earth. it is the backbone of life.
the number of electrons required to complete the valence shell
describe the versatility of carbon to make diverse molecules.
diverse bonding patterns, different molecular shape, length difference
4 ways carbon skeletons can vary?
length, branching, double bonding, presence of rings
organic molecules consisting of nobly carbon and hydrogen. Ex: plastic, motor oil, gas, diesel.
the same number of atoms of the same elements with different structures therefore different properties
same molecular formula, differ in the covalent arrangement of their atoms. ex: ethanol and dimethyl ether
diastereomers associated with compounds that have carbon-carbon double bonds, but differ in spatial arrangements due to the inflexibility of double bonds
isomers that mirror images of each other due to the presence of a n asymmetric carbon
groups of atoms covalently bonded to a carbon backbone that give properties different form of C-H bond.
How are functional groups important in chemical reactions?
they determine most of the reactive properties of organic molecules. they are active. and they determine the properties of the major classes of organic compounds.
polymers built from monomers. ex: carbohydrates, proteins, and nucleic acids
string of monomers