unit 1 Flashcards
Describe the difference between matter and element
matter= anything that takes up space and has mass
element=building blocks of matter
Whats the difference between a molecule and compound
molecule= atoms of same element
compound= atoms of different elements
What are the most abundant elements in our bodies
Nitrogen, carbon, oxygen, calcium and hydrogen
How do isotopes differ from eachother
they have different number of neutrons
What is the relationship between electrons and chemical bonds
chemical bonds happen because of valence e- who want to achieve an octet
Which bonds are formed between molecules
H-bonds, covalent and ionic
which bonds are formed between atoms
ionic/(polar and non-polar)covalent bonds
what are the 2 types of strong bonds and how do they differ
covalent (sharing e-) and ionic (complete transfer of e-)
What is the relationship between covalent bonds, electronegativity, polar and nonpolar
compounds?
polarity depends on difference in electronegativity between atoms
Polar bonds happen when atoms do not share electrons equally
Non-polar bonds share e- equally
Of the most abundant elements in your body, what is the relative electronegative to each other?
Ca
What are examples of non-polar molecules and polar molecules?
non-polar= CH4
polar= H2O
what are the 3 types of weak bonds
1-H-bonds
2-Van der Waals interactions
3-Ionic bonds in water
whats the purpose of weak bonds
they allow molecules to interact, provide stability in large molecules,
adhering molecules briefly when they collide
why do ionic bonds weaken in water
each ion is partially shielded because it interacts with water (they dissociate easily in water)
in photosynthesis where does oxygen come from
water and CO2
Why do all organism need water
the main source of oxygen (medium of life)
why is water polar
the slight positive charges on the hydrogens and the negative charges of oxygen create partial charge/dipole moment making the molecule polar
Define cohesion
the ability of molecules of same substance to stick together
define adhesion
the ability of molecules to stick to another material
define tension
mesures how difficutl it is to break/stretch surface of a liquid
what are the four main properties of water
1-solvent
2-C.A.T
3-temperature buffer
4-Density
Why is water a universal solvent
can dissolve any polar substance
what is hydration
solvation for which the solvent is water
True of false
water can dissolve non polar substances
false
how does water dissolve ionic substances
in ionic solid, the partial + charge of hydrogens attract the anion an - charge of oxygen attract cation= they separate and solid is dissolved
How can water dissolve non polar substances like sugar
Water forms H-bonds with outer molecules and removes the monosaccharides individually until they are dispersed throughout the solution
What other kind of macromolecules can dissolve in water
proteins if they have ionic areas
where can water be found as a solvent in organisms
in the blood, inside cell (cytosol), plant sap
What cause cohesion between water molecules
H-bonding
Why is cohesion and adhesion useful for organisms
allows for capillary action
Define capillary action
tendency of water to move in narrow tubes, against gravity (ex: water moves from root to leaves)
why does water have a strong surfcae tension
strong attraction between molecules (H-bonds)
wnat is the max amount of H-bonds that a molecule can form
4
How does each state of water vary in terms of H-bonds
in solid water each molecules have 4 H-bonds, liquid have less and air have practically none.
Why is it important for water to have a high specific heat
allows water to absorb large amount of heat before its temperature increases
How does water act like a temperature buffer
high specific heat= better ability to resist temperature change
Why is moderation of temperature important to maintain life
allows oceans, lakes, etc to maintain relatively constant temperature= stable environment
What is evaporative cooling
when water is heated , the molecules that are released fatser enter gas phase and the water left behind is more cool
how do organisms utilize evaporative cooling
to help cool themselves (perspire/transpires)
What are the properties of ice
contains more stable hydrogen bonds
Ice is less dense than liquid water
Why is it important that ice is less dense than water
if ice sank it woud freeze the bottom of the oceans=life unsustainable
what is ionization
water molecules can break apart in aqueous solutions (H+ and OH-
What is the effect of a acid on pH of solution
decreases pH (donates H+)
What is the effect of a base on pH of solution
increases pH (donate OH-
Describe a pH buffer
substance that resists changes in pH by either accepting H+ ions in excess and donate H+ when they’re missing
Name a buffer
blood
Why is it important for pH in cells and in other body fluids to be tightly regulated?
any pH change could disrupt ionic/h-bonds between amino acids structure = unstable protein
can alter protein shape= cant function
How does carbonic acid (H2CO3) play a role in the fluids of the body?
acts as buffer in human blood to keep it within range
what can cause blood pH to go below range
respiratory disease= the body can get rid of CO2 fast again= increase H+ concentration= acidosis
what can cause blood pH to go above range
hyperventilation= too much CO2 expelled= decrease in H+= alkalosis
Why do shells in aquatic animals thin and become fragile as oceans become more and more acidic?
they require calcium carbonate to make their shells and increase in H+ disturbed and it causes this rxn :H+ + CO32- =HCO3- which decreases calcium carbonate production
Where do autotrophs obtain organic carbon? Heterotrophs?
autotrophs obtain their carbon from light or chemical energy (atospheric CO2)
heterotrophs obtain their carbon from organic compounds
what is an biomolecule
proteins, DNA, carbohydrates and lipids
whats an organic molecule in biology
compounds formed by the living that contain a carbon hydrogen backbone
Whats a carbon skeleton
carbons of organic compounds
whats a functional group
elements that are attached to the carbon skeleton (noncarbon grps)
Which properties of carbon make it a good building block for organic biomolecules?
Has a tetravalence which makes large/complex molecules possible.
Which other elements make up the major atoms used to build biomolecules?
hydrogen, nitrogen, oxygen
When carbon is bound to four other atoms, what shape does the molecule generally take?
tetrahedral shape
what is polarity
the measure of electronegativity between two atoms (how much they can pull e- )
List the seven functional groups discussed
hydroxyl grp
carbonyl grp
carboxyl grp
amino grp
sulfhydryl grp
phosphate grp
methyl grp
what are the general properties of the hydroxyl grp
OH-
polar grp, doesnt dissociate in water
what are the general properties of the carbonyl grp
CO-
provide some degree of polarity.
what are the two types of carbonyl groups
aldehydes and ketones
whats the difference between aldehyde and a ketone
aldehydes contain the carbonyl carbon bonded to AT LEAST one H
ketones have carbonyl carbon bonded to 2 other carbons
True or false
simple sugars can only be aldehydes
false can also be ketones
What structures do monosaccharides take on when mixed with a fluid (i.e. water)
ring structure
what are the general properties of the carboxyl grp
-COOH
weakly acidic (can release proton)
provides polarity
Carboxyl group is an important part of what macromolecule (monomer)
amino acids (in protein)
what are the general properties of the amino grp
-NH2
polar, allows amino acids to act as organic buffers (can be acid or base ), weakly basic
In amino acids does the amino group accept or donate a proton
accepts a proton
why can amino acids act as natural buffers
they have a carboxyl grp (acid) and an amino grp (basic) in their structure.
what are the general properties of the sulfhydryl grp
-SH
non polar, forms disulfide bridges
what are the general properties of the phosphate grp
-OPO3 2-
polar, can donate H+ into solution= weakly acidic
Why are disulfide bridges important
strong bonds that help stabilize the internal structure of proteins (form cross links)
In what important molecules can phosphate groups be found
in phospholipids, nucleotides and ATP
Why is atp so high in energy
the 3 phosphate grp bonded to eachother are highly unstable (repulse one another)= high E bonds
what are the general properties of the methyl grp
-CH3
nonpolar, acts as an identity tag to molecules (read by enzymes)
Where can sulfhydryl groups be found
in proteins (internal structure)
Where can amino groups be found
amino acids, nitrogenous bases of DNA/RNA
how does the carbonskeleton contribute to the diversity of organic biomolecules
the arragement of the carbon skeleton gives them different properties
how do the functional groups contribute to the diversity of organic biomolecules
they can give them unique properties/behaviors
define isomers
compounds with the same molecular formula but different chemical structures=diff properties
what are the 3 kinds of isomers
structural-geometric-optical
Whats the difference between a structural and geometrical isomer
structural: different covalent arrangement of their atoms
geometric: same covalent arrangement but different spatial arrangement
what are the 2 types of geometric isomers
cis and trans isomers
How do cis isomers differ from trans isomers
cis= groups on same side
trans= grps on opposite sides of the bond
give an example of a geometric isomer
rhodopsin
what are enantiomers
isomers that are the images of each other (cant be superimposed)
True or false
Cell will only recognize one enantiomer
true
Why is it important to be aware of enantiomers
give different effect to drugs (ex: thalidomide)