unit 4 Flashcards
biochemistry
oxygen and hydrogen is bonded by–
covalent bonds
what do both oxygen and hydrogen share?
both share some electrons
water is a what type of molecule?
water is a polar molecule
which one is bigger, oxygen atom or hydrogen atom?
oxygen is bigger with 8 protons
O (oxygen) is–
“stronger”, pulls most of the electrons towards it
O becomes a little–
negative
H (hydrogen) is–
“weaker”, loses electrons
H becomes a little–
positive
what does the unevenness of O and H make the water molecule?
the unevenness makes the water molecule polar
how does water stick together?
the positive end of one water molecule attracts the negative end of another water molecule, until all the water molecules are connected
what are these types of water connections called?
hydrogen bonds
what is a hydrogen bond?
a weak attraction between the slightly negative oxygen of one water molecule, and the slightly positive hydrogen of another water molecule
H-bonds are weak alone, but–
strong in high numbers
cohesion–
attraction between molecules of the same substance. water-water
why is water very cohisive?
because of the H-bonds, molecules hold on to each other very tightly and create high surface tension
adhesion–
attraction between molecules of different substances, water loves other substances.
what is an example of adhesion?
meniscus in graduated cylinder: water sticks to the glass and “crawls up”
capillary action–
when water moves up a thin tube by itself, it’s called capillary action. this is how water moves up in plants
how does water move up in plants from the roots to the leaves?
through tubes called xylem (the thinner the tube, the higher the water)
true or false: water can move up through small tubes against gravity
true
true or false: water is able to absorb large amounts of heat, lakes and oceans stabilize land.
true
true or false: water temperatures most substances (good solvent). water inside the cells and body can carry nutrients and waste around.
true
true or false: water absorbs heat when it evaporates, organisms can cool off
true
how does some insects walk and other things float on water?
because water has high surface tension
which is less dense; solid water (ice) or liquid water?
solid water (ice) is less dense
what happens to water when it freezes?
it turns into ice, making it float. this prevents rivers, lakes, and oceans from freezing solid
the top ice does what to the water?
the top ice insulates the water underneath from the extreme cold
cohesion + adhesion =
capillary action
pH–
a measure of how acidic or basic a solution is [pH scale: 0-14 with 0 being very acidic, and 14 being very basic (alkaline)]
true or false: all macromolecules are monomers, and they are also an inorganic compound
false, all macromolecules are polymers, and they are all organic compounds
macromolecules are big molecules that compare to–
H2O and O2
how are macromolecules made?
by joining/bonding together thousands of smaller monomers
small/single molecules are called what?
monomers
monomers join together to make what?
polymers
organic compounds–
compounds that contain a backbone of carbon and hydrogen at the same time (carbohydrates, lipids, protein, and nucleic acids)
inorganic compounds–
no carbon backbone or C without H [H2O, salt (NaCl), O2, vitamins, CO2, minerals]
how many types of organic macromolecules are there?
there are four types of macromolecules: carbohydrates (sugars), lipids (fats, oils, waxes, steroids), proteins, nucleic acids (DNA, RNA, ATD)
carbohydrates (fruits, vegetables, rice, potato, bread, etc.)–
made of CHO (carbon, hydrogen, and oxygen) elements in a ratio of 1:2:1
what kind of monomers are carbohydrates made out of?
monosaccharides, glucose and fructose are monosaccharides
monosaccharides are made up of–
1 monomer
dissaccharides are made up of–
2 monomers
polysaccharides are made up of–
many monomers
plants store the extra glucose in the form of–
starch (polysaccharide, which is a carbohydrate)
true or false: in plants, glucose molecules join together to make cellulose
true
true or false: in animals, glucose molecules join together to make glycogen, which is stored for energy in the muscles and liver
true
carbohydrates (sugar and starch) are the main source of–
quick energy
how do plants make glucose (sugar)?
through photosynthesis
glucose is stored as what in plants?
glucose is stored as starch in plants
if a word ends with “ose”, that means it probably is a–
sugar (carbohydrates) ex: glucose, fructose, cellulose, lactose, galactose, maltose, etc.
lipids (fat, oil, butter, wax, steroids, etc.)–
are made up of CHO(P)
how are lipid monomers made?
by joining a glycerol molecule and 1 or more fatty acids
what do lipids store?
lipids store energy (fat)
lipids are a good temperature–
insulators (body fat)
what do lipids make?
they make cell membranes (phospholipids)
true or false: lipids are waterproof
true
proteins (eggs, chicken, beef, fish, nuts, tofu, lentils, soy, etc.)–
made of CHON(S)
what are proteins made up of?
made up of monomers called amino acids
how many types of different amino acids are there?
there are about 20 different amino acids
the sequence and number of amino acids makes each protein–
different
how are amino acids joined by what?
peptide bonds
polypeptide–
proteins fold in specific ways to have specific shapes = configuration
true or false: proteins are not the building blocks of of the body
false, proteins are the building blocks of the body, most of the body is made up of protein
what kind of protein does muscles have?
myoglobin
what kind of protein does nails and hair have?
keratin
nucleic acids (found in all foods)–
made up of CHONP
what kind of monomers are nucleic acids made up of?
nucleotides
nucleotides are made of how many parts?
3, 5-carbon sugar, phosphate group, nitrogenous base
what does nucleic acids store?
they store and transmit genetic information, control all cell and body activities
how many types of genetic information is there?
there are two types, DNA and RNA
what is hydrolosis?
breaking macromolecules
explain what hydrolysis does
water is added to break macromolecules (carbohydrate, lipid, protein, and nucleic acids)
what is dehydration synthesis?
building (storing) macromolecules
explain what dehydration synthesis does
water is released (produced) to build macromolecules
chemical reactions–
processes that change one set of chemicals (atoms/compounds) into another set of chemicals
where do chemical reactions occur in living organisms?
chemical reactions in living organisms occur in the cells metabolism
what are reactants?
reactants are what you start out with in a reaction
what are products?
products are what you end up with
what does the arrow show?
arrow shoes direction of the reaction and means “yields”
what do chemical reactions break?
chemical reactions break bonds in reactants and form new bonds in products
energy is released or absorbed–
whenever bonds are formed or broken
making bonds–
releases energy
breaking bonds–
absorbs/needs energy
true or false: most chemical reactions are too slow or have high activation energies, and cannot happen on their own inside the cells.
true
what do enzymes do?
enzymes speed up chemical reactions by lowering the activation energy
if a word ends in “ase”, then it’s probably an–
enzyme (ex. lipase, protease, nuclease, maltase, galactase, lactase, etc.)
how are enzymes usually named?
after the substrate (molecule that it acts on)
enzymes are special–
proteins that make reactions go faster
enzymes are what?
catalysts
what is a catalyst?
a catalyst is a chemical that changes the rate (speed) of reaction without being used up in the reaction
what type of shape does an enzyme have?
enzymes have a definite 3-dimensional shape (configuration) that allows them to bond with a specific molecule called substrate
what is the special pocket where the substrate attaches to the enzyme?
active site
true or false: when the reaction is complete, the product or products are released and the enzyme is ready to be used again - the enzyme is recycled
true
what is lock-and-key?
enzymes are substrate-specific, this is called the lock and key model or mechanism. the specificity is due to precise shape of the active site: only fits one substrate
what are enzymes sensitive to?
pH,m temperature, substrate concentration
each enzyme works at an–
optimum (ideal) pH
what happens when the wrong pH works with an enzyme?
it can denature (damage) the enzyme by changing it’s shape so it does not work properly
true or false: each enzyme works at an optimum (ideal) temperature
true
too high or too low can do what to the enzyme?
it can denature (damage) the enzyme and it does not work properly
