Biochemistry Flashcards
polar molecules
molecules which exhibit charge separation
- water is one of the most polar molecules known
- when polar molecules interact, the form hydrogen bonds which are individually very weak
cohesion
when water is attracted to other water molecules
adhesion
when water is attracted to molecules which arent water
capillary action
the ability of a liquid to rise up through a tube against the force of gravity
high specific heat
the amount of heat that must be absorbed or lost by 1 ram of a substance to change its temperature by 1 degree celsius
high heat of vaporization
the amount of heat energy needed to change 1 ram of liquid watere into a gas
solvent
substance that dissolves another
solute
substance being dissolved
hydrophobic
water hating molecules
hydrophilic
water loving molecules
ph scale
a measure of the hydrogen concentration of a solution
acid
any substance that dissociated to form an excess of H+ ions when dissolved in water
base
any substance that combines with H+ ions to lower the H+ concentration in a solution
buffer
a substance that acts as a holding tank for hydrogen ions, donating them when their concentration falls and takes them from the solution when their concentration rises
polymer
long molecules built by linking together a large number of small, similar chemical subunits (monomers)
nucleotides
repeating subunits of nucleic acids.
nucleic acid
a chain of five-carbon sugars linked together by phosphodiester bonds with anitrogenous base protruding forming sugar
amino acids
contain an animo group and an acidic carboxyl group. the specific order of amino acids determines the proteins structure and function
organic molecules
molecules which contain carbon
hydrocarbons
molecules made only of carbon and hydrogen
-make good fuel because H-C bonds store energy
nonpolar
doesn’t dissolve in water, doesn’t have partial charges
functional groups
atoms which give special properties to the molecules to which they are attached
Where is hydroxyl found
carbohydrates
where is carbonyl found
lipids
where is carboxyl found
proteins
where are aminos found
proteins
where are phosphates found
DNA and ATP
dehydration synthesis
a condensation reaction where 2 molecules are joined and a water is given off. for every subunit added, a water is given off
hydrolysis
disassembling molecules into their subunits by adding water
monomer
basic building block of macromolecules
Carbohydrates
serve as energy storage and structural molecules
contain baron hydrogen and oxygen in a ratio of 1:2:1
monosaccharides
simple carbohydrates
disaccharide
“double” sugar, 2 monosaccharides joined togehter
-often play a role in the transport of sugars
polysaccharide
macromolecule made of many monosaccharides
ex. starch (storage)
transport disaccharides
many organisms convert monosaccharides to disaccharides to transport them through the body so they are less likely to tbe broken down during transport
storage polysaccharides
disaccharides that are linked into insoluble forms so they can be stored
ex. starch
structural carbohydrates
building blocks
ex. cellose- carbohydrate in plant cell walls
chitin-carbohydrate that builds exoskeletons of insects, crabs, fungi, etc.
peptide bonds
covalent bond holding two amino acids together
polypeptides
proteins made of one or more long chains
Primary Protein Structure
the specific order of amino acids in a protein chain
Secondary Protein Structure
the polar amino acids of the main chain are attracted to each other. hydrogen bonds form.
if the attraction occurs between amino acids in same chain= alpha helix shape
if the attraction occurs between amino acids across chains= beta pleated sheet shape
motifs
supersecondary structures made of combinations of secondary structures
tertiary
the final folded shape of a protein. is driven by hydrophobic interactions with water. stability of protein depends on how well its interior fits together
quaternary
formed when two or more polypeptide chains form a functional protein (at this point, the individual chains are called subunits of the protein)
Functions of Proteins
Enzyme Catalysts Defense Transport Support Motion Regulation
Enzyme Catalysts
proteins with a 3 dimensional shape that makes chemical reaction happen faster
Defense
proteins use their shapes to recognize foreign microbes and cancer cells. these proteins sit on the surface of cell membranes and act like receptors for the immune system
transport
transport proteins move small molecules and ions
ex. hemoglobin is a protein in the blood that moves oxygen
Support
fibrous proteins make up an organisms structure
ex. hair
motion
muscles move due to the sliding motion of proteins
regulation
small proteins called hormones act like messengers in cells (INTERCELLULAR MESSENGERS) they send signals and also turn genes on and off
denaturation
the unfolding or change in the shape of a protein
happens when a proteins environment changes
when proteins are denatured, they are usually made biologically inactive
lipid
a moecule containing C, H, O with a C:H ration of > than 2:1
fat
a lipid that serves as a storage molecule for glucose
saturated fat
when all the C’s in the fatty acids possess all their H’s
unsaturated fat
when fatty acids have double bonds between the C’s therefore they contain less H
fats
efficient energy storage molecules
carbohydrates path
-some stay are glucose for immediate use
some are converted to transport disaccharides
some are converted to starch, glycogen or fat for future use
phospholipids
modified fat found in cell membranes
- have a polar head that is hydrophillic
- have two nonpolar tails which are hydrophobic
steroids
lipids made of 4 carbon rings
terpenes
long chained lipids that help make up important pigments
hormones
act as chemical messengers
hydrogen bonds
the single most outstanding chemical property of what is its ability to form weak chemical associations called hydrogen bonds
