Bio 1009 sec 1
what is the ma. number of electrons in the 1s orbital of an atom?
2
when glucose monomers are joined together by glycosidic linkages to form a cellulose polymer, the changes in free energy, enthalpy and entropy are as follows
+delta H, -delta S, +delta G
which of the following sequences correctly represents the flow of electrons during photosythesis?
H2O → NADPH → Calvin cycle
What is not a molecule?
NaCl
which of the following concepts help explain why water can be transported up tall trees?
cohesion and adhesion
increasing the substrate concentration in an enzymatic reaction could overcome which of the following?
competitive inhibition
what factor would tend to increase membrane fluidity
a greater proportion of unsaturated phospholipids
which of the following is a characteristic of the lytic cycle?
a large number of phages are released and the host cell is destryed
which would you expect to dissolve poorly in water
a substance with a lot of nonpolar covalent bonds
compounds with carbonyl groups are known as
aldehydes or ketones
what kind of metabolic posion would most directly interfere with glycolysis
an agent that closely mimics the structure f glucose but is not metabolized
What group is NH2
an amino group
electrons exist only at fixed levels of potential energy. however, if an atom absorbs sufficient energy, a possible result is that
an electron may move to an electron shell farther away from the nucleus
allosteric enzyme regulation is usually associated with
an enzyme with more than one subunit
when an electron is moved further from the nucleus
it gains potential energy
which of the following are not polymers
lipids
which of the following is the least polar
lipids
animal cells contain
lysosomes
which contains hydrolytic enzymes
lysosomes
What gives rise to the cohesiveness of water molecules?
hydrogen bonds
what maintains the secondary structure of a protein
hydrogen bonds
what maintains the secondary structure of a protein?
hydrogen bonds
the reactions of the calvin cycle are
endergonic, and thus require a source of free energy to occur
which of the following modifies polypeptides that will be secreted
golgi apparatus
in the double helix structure of nucleic acids, cytosine hydrogen bonds to
guanine
After examining thousands of different species, early scientists concluded that all organisms are made up of cells. What type of reasoning does this exhibit?
inductive
which statement about membrane structure is true?
integral membrane proteins are found in both prokaryotic and eukaryotic cell structures
a covalent chemical bond is one which
outer-shell electrons of two atoms are shared so as to fill the valence shells of both atoms
one funtion of both alcohol fermentation and lactic acid fermentation is to
oxidize NADH to NAD+
the structural level of a protein that is LEAST affected by a disruption of hydrogen bonding is the
primary level
which of the following are directly associated with photosystem I
recieving electrons from the thylakoid membrane electron transport chain
when a molecule of NAD+ gains two electrons, and a hydrogen atom (a proton) the molecule becomes
reduced
If you explore a biological concept by breaking down the complex system to its similar components, you are using an approach called
reductionism
which of the following does not occur during the calvin cycle in photosythesis?
release of oxygen
which type of organelle is primarily involved in the synthesis of steroids
smooth endoplasmic reticulum
mutated yest are growing under anerobic conditions. a mutation in the yeast makes them unable to convert pyruvate to ethanol. how will this mutation affect these yeast cells?
the mutant yeast will be unable to grow anaerobically
in a plant cell, where are the ATP sythase complexes located?
thylakoid membrane and inner mitochondrial membrane
which of the following is NOT found in the RNA molecules
thymine
the primary function of polysaccharides attached to the glycoproteins and glycolipids of animal cell membranes is
to mediate cell-to-cell recognition
The mathematical expression for the change in the free energy of a system is ∆G = ∆H - T∆S. Which of the following is (are) TRUE?
∆G is the change in free energy
starting with one molecule of glucose, the energy containing products of glycolysis are
2 NADH, 2 pyruvate, and 2 ATP
starting with one molecule of glucose, the energy containt products of glycolysis are
2 NADH, 2 pyruvate, and 2 ATP
the number of electrons needed to fill the first and second electron shells is
2 in the first and 8 in the second shell
which of the following would likely move through the lipid bilayer of a plasma membrane most rapidly?
CO2
which of the following most accuratly describes the structure of a membrane formed by phospholipids?
The phospholipids are arranged in a bilayer, with their hydrocarbon tails pointing toward the interior of the membrane and their phosphate groups on the outside of the bilayer.
which of the following effects is produced by the high surface tension of water
a water spider can walk across the surface of a small pond
reactants capable of interacting to form products is a chemical reaction must first over come a thermodynamic barrier knows as the reactions
activation energy
the contrast to non-competitive inhibitors, competitive inhibitors of enzyme activity
always utilize an enzyme's active site
in order for the protein to be a transmembrane protein it would have to be which of the following?
amphipathic
which results from a transfer of electron(s) between atoms?
an ionic bond
with regards to orbitals what is a false statement
an orbital is a defined path that an electron follows as it orbits the nucleus
what is a true statement about plasma membranes
both prokaryotic and eukaryotic cells have plasma membranes, which act as a semi-permiable barrier
The theory of evolution can explain
both the unity and diversity of life
what statement correctly characterizes bound ribosomes
bound ribosomes generally synthesize membrane proteins ans secretory proteins
how does s noncompetetive inhibitor decrease the rate of an enzyme reaction?
by changing the shape of the enzymes active site
what is a correct relationship between cell structures and their respective functions?
cell wall; support, protection
reduction of oxygen to form water occurs during
cellular respiration only
what is the difference between covalent bonds and ionic bonds?
covalent bonds involve the sharing of electrons between atoms; ionic bonds involve the electrical attraction between atoms
the order of chemical bonds from the STRONGEST to the WEAKEST
covalent bonds, ionic bonds in the formation of salt crystals, hydrogen bonds, van der Waals interactions
where does glycolisis take place in eukaryotic cells?
cytosol
what is a true statement about enzymes?
enzymes speed up chemical reactions without being used up in the reaction
what does the chemiosmotic process in chloroplasts involve?
establishment of a protein gradient across the thylakoid membrane
the difference between prokaryotic and eukaryotic cells is
eukaryotic cells have nuclei and prokaryotic dont, eukaryotic have organelles and most prokaryotic dont, eukaryotic cells are usually larger than prokaryotic cells
Choose the pair of terms that correctly completes this sentence: Catabolism is to anabolism as ________ is to ________.
exergonic; endergonic
what is a false statement about membranes?
exocytosis results in net transfer of materials into the cell
of the following functions, which is most important for the glycoproteins and glycolipids in animal cell membranes?
helping cells distinguish one type of neighboring cell from another
Celery stalks that are immersed in fresh water for several hours become stiff and hard. Similar stalks left in a 0.15 M salt solution become limp and soft. From this we can deduce that the cells of the celery stalks are
hypertonic to fresh water by hypotonic to the salt solution
why does ice float
ice is less dense than water
which of the following best describes enthalpy
in biological systems, enthalpy is equivalent to the total energy
what is a true statement about disffusion
it is a passive process in which molecules move from a region of higher concentration to a region of lower concentration
which structure-function pair is mismatched
microtubule;protein synthesis
the cytoskeleton is comprised of
microtubules, microfilaments, intermediate filaments
organelles other than the nucleus that contain DNA include
mitochondria and chloroplasts
which of the following contains its own DNA ribosomes?
mitochondrion
which of the following makes ATP in the cell?
mitochondrion
which of the following is common to both bacteria and virsues
nucleic acids as the genetic material
the number of _____ vaires in the isotopes on an element
neutrons
the number of _____ varies in the isotope of an element
neutrons
which particles are found in the in the nuclei of atoms?
neutrons and protons
which bonds are created during the formation of the primary structure of a protein
peptide bonds
the covalent linkage between nucleotides forming a DNA molecule are known as
phosphodiester bonds
the covalent linkages between nucleotides forming a DNA molecule are known as
phosphodiester bonds
which of the following is a function of the golgi apparatus
protein modification
The atomic number of an electron refers to the number of ____ in a atom
protons
gap junctions function to
provide cytoplasmic channels between neighboring animal cells
which of the following is present in prokaryotic cells?
ribosome
Your sister calls to say that the light will not go on in her bedroom. You say that you think the bulb must be burned out, and therefore, replacing the bulb will solve the problem. In doing so, you are:
stating a specific hypothesis for why the light does not go on, and a prediction.
where does the calvin cycle take place
stroma to the chloroplast
a nucleotide is comprised of
sugar, phosphate, and a nitrogenous base
what is the primary function of the calvin cycle
synthesize simple sugars from carbon dioxide
an example of hydrogen bond is the bond between
the H of one water molecule and the O of another water molecule
osmosis refers to
the diffusion of water across a selectively permeable membrane
when a plant cell is submerged in a very hypotonic solution, what is likely to occur
the cell wall will become turgid (solid, due to being inflated)
if the cytoplasm of a cell is at a cell is at pH 7, and the mitochondria matrix is at pH 8, this means
the concentration of H+ ions is tenfold higher in the cytoplasm than in the mitochondrial matrix
which statement about glycolysis is not true
the end products of glycolisis are CO2 and H2O
the quaternary structure of a protein refers to
the overall shape of the protein formed by the association of two or more polypeptides
polar molecules are often able to dissolve in water becuase
the partially charged regions of polar molecules are able to form hydrogen bonds with water molecules
Which of the following statements describes the lysogenic cycle of lambda (λ) phage?
the phage genome replicated along with the host genome
A researcher lyses a cell that contains nucleic acid molecules and capsomeres of tobacco mosaic virus (TMV). The cell contents are left in a covered test tube overnight. The next day this mixture is sprayed on tobacco plants that have been exposed to extremely windy conditions. Which of the following would be expected to occur?
the plants would develop the typical symptoms of TVM infection
which of the following is true of integral membrane proteins
they are usually transmembrane proteins
which of the following is a true statement for anabolic pathways
they consume energy to build up polymers d=from monomers
the order of chemical bonds from EASIEST to HARDEST to break is
van der Waals interactions, hydrogen bonds, ionic bonds in the formation of salt crystals, covalent bonds
Mammalian blood contains the equivalent of 0.15 M NaCl. Seawater contains the equivalent of 0.45 M NaCl. What will happen if red blood cells are transferred to seawater?
water will leave the cells , causing them to shrivel and collapse
