exam 1 (practice questions) Flashcards
emergent properties of living systems are properties that __________
are due to the arrangement and interactions of parts as complexity increases
(not shown individually but collectively)
which statement best describes when properties emerge?
“the whole is greater than the sum of the parts”
- parts work together and cannot do it alone (even a calculator!)
in an ecosystem, nutrients _________ and energy __________
are recycled; flows through
the energy for most organism for metabolism and growth ultimately comes from _________
the sun
protists are eukaryotic but ________
single-celled
evolution tends to act at which level?
population
which of the following is outside the realm of scientific inquiry?
addressing ethical dilemmas
regardless of element, first electron shell of any atom of that element can hold a max of how many electrons?
two
which types of bonds attract water molecules to each other, causing surface tension and slowing rate of evaporation?
hydrogen bonds
most of the structural components of the human body are made up of which type of bond?
nonpolar covalent
which (electrons, neutrons, protons) INDIRECTLY determine the bonds that an atom can form?
protons
what must be true for a compound to be considered organic?
it must have carbon and hydrogen
the disappearance of which functional group would most adversely affect protein shape?
sulfhydryl
in what ways are hydrogen bonds and ionic bonds similar?
both are based on attraction b/w atoms that carry differences in electrical charge
as temp of something decreases, its kinetic energy ____________
decrease
more kinetic energy = more hot
give an example of monosaccharide, disaccharide, and polysaccharide
monosaccharide: glucose, fructose
disaccharide: sucrose, lactose, maltose
polysaccharide: glycogen
the pH of the human blood is
weakly basic
individual monosaccharides primarily differ in the number of carbons and __________
orientation of carbonyl groups
polymers are made of monomer subunits that are joined by what type of bonds
covalent bonds
cellulose absorbs water in your intestines because ___________
like all carbohydrates, it is hydrophilic
molecules in which group share a carbon-ring framework?
steroids
denaturation is defined as ac change in __________ of a protein
three-dimensional shape
cholesterol is a _________
steroid
variable R-groups, or side chains, are found in which group?
proteins
proteins are formed via which process?
dehydration synthesis
what type of sugar is found in RNA?
ribose
what is the name of the most important high-energy compound in the body?
adenosine triphosphate (ATP)
thymine is found in which molecule?
deoxyribonucleic acid (DNA)
DNA consists of 2 nucleotide molecule chains held together by weak ________ bonds.
hydrogen
what class of molecule DIRECTS the synthesis of enzymes?
nucleic acids
what reaction does the liver have during times of high energy demand?
it breaks down glycogen molecules
there are ______ naturally occurring elements and ______ are essential to human life
92; 25
trace element
chemical element that is present in small amounts
what are the 4 most abundant elements found in living systems?
hydrogen
oxygen
carbon
nitrogen
why are radioactive isotopes useful in scientific research?
because they can be used as tracers to follow particular atoms and molecules through metabolic pathways
for most atoms, when does the configuration of electrons make the atom unreactive?
when the atom has 8 electrons in its outermost shell
ionic bonds form as a result of __________
attraction b/w ions that have opposite charges
a hydrogen bond is a ___________
weak chemical bond
what is the role of van der Waals interactions in biological molecules?
although they are weak bonds, van der Waals interactions help to reinforce the 3-D shapes of large molecules
when is chemical equilibrium reached?
when the forward and reverse reaction rates are equal
the tendency of water molecules to stay close to each other as a result of hydrogen bonding is called __________
cohesion
helps moderate temp, provides surface tensions that allows small molecules to move across a water surface, and helps to keep water moving through the vessels in a tree trunk
adhesion is best described as
clinging of one substance to another substance
You can fill a glass of water to just slightly above the rim without the water spilling over the glass. What property of water best explains this phenomenon?
surface tension
the amount of heat required to convert 1g of any substance from the liquid to the gaseous state is defined as ______________
the heat of vaporization of that substance
Sweating has a cooling effect because of water’s high _____________
heat of vaporization
water evaporates, cooling the surface on which it rested
how does the polarity of water contribute to its ability to dissolve so many substances?
because it is polar, water’s negatively charged oxygen atoms and positively charged hydrogen atoms are attracted to positively and negatively charged ions and molecules
a molecule that has all nonpolar covalent bonds would be ____________
hydrophobic
an acid is __________
a compound that donates hydrogen ions to a solution
each pH unit change represents a ____________ difference in the hydrogen ion concentration
tenfold
(have to multiply by 10 each time you go up scale)
Stanley miller’s experiments were significant because he demonstrated that ________
a variety of simple organic compounds could be spontaneously synthesized from components in Earth’s primitive atmosphere
enantiomers are isomers that are ___________
mirror images of each other and differ in shape due to presence of asymmetric carbon
Ethanol, propanol, and methanol are three simple alcohols. They can be grouped together because they __________
share the same functional group: a hydroxyl
hydrophilic compounds increase the ________ of organic molecules in water
solubility
which functional group is associated with a release of energy when removed from the carbon skeleton with water?
phosphate group
cleaving phosphate group from ATP releases energy that is used to perform cellular functions
in what polysaccharide form do plants store glucose to be available later as an energy source?
starch
monosaccharides have molecular formulas that are multiples of _______
CH2O
chitin
structural polysaccharide found in arthropod exoskeletons
palmitic acid
saturated fatty acid
carbohydrates are used in our bodies mainly for ___________
energy storage and release
nucleotides are linked together by __________
phosphodiester linkages
fatty acids are joined to glycerol by _________
ester linkages
glycosidic linkages ____________ by the human digestive enzymes
cannot be broken down
(present in cellulose)
the sex hormones estradiol and testosterone belong to which class of molecules?
lipids
a polypeptide is a _________
chain of amino acids that have been linked together by dehydration synthesis
The α helix and β pleated sheet represent which level of protein structure?
secondary structure
What do Alzheimer’s, Parkinson’s, and mad cow disease have in common?
all associated with the buildup of misfolded proteins in cells
which of the functional groups below acts most like an acid in water?
a. Amino
b. Carbonyl
c. Carboxyl
d. Hydroxyl
actual test question
carboxyl
which could be found to differ in a pair of structural isomers?
a. Number of atoms per molecule
b. Biological activity of each molecule
c. Ratio of elements in each molecule
d. Chemical formula
actual test question
biological activity of each molecule
which functional groups would be least likely to occur on the surface of a large biological molecule, where it would interact with water molecules?
actual test question
methyl
which functional group is hydrophobic in nature?
actual test question
sulfhydryl
a cell lacking which of the following structures is most likely to be a prokaryote?
a. nuclear membrane
b. cell membrane
c. cytoplasm
d. nucleic acid
actual test question
nuclear membrane
systems biology is mainly an attempt to _________
actual test question
understand the behavior of entire biological systems by studying interactions among its component parts
which type of interaction stabilizes the a-helix and the beta-pleated sheet structures of proteins?
actual test question
hydrogen bonds
which description best fits the class of molecules known as nucleotides?
actual test question
nitrogenous base, phosphate group, and a sugar
