Exam 1

A  Covalent bonds involve the transfer of electrons between charged atoms; ionic bonds involve the sharing of electrons between atoms.

B  Covalent bonds involve the sharing of electrons between atoms; ionic bonds involve the sharing of protons between charged atoms.

C  Covalent bonds require carbon whereas ionic bonds do not.

D  Covalent bonds involve the sharing of pairs of electrons between atoms; ionic bonds involve the sharing of single electrons between atoms

E  Covalent bonds involve the sharing of electrons between atoms; ionic bonds involve the between charged atoms.

A  the mice had lost their immunity to infection with S. pneumoniae

B  The heat-killed pathogenic bacteria “transformed” the harmless strain into a lethal one.

C  The harmless strain somehow revived the heat-killed pathogenic bacteria.

D  The infectious strain cannot be killed by heating

A  bonding together of several polypeptide chains by weak bonds

B  unique three-dimensional shape of the fully folded polypeptide

C  organization of a polypeptide chain into an a-helix or β-Pleated sheet

D  overall protein structure resulting from the aggregation of two or more polypeptide subunits

E  order in which amino acids are joined in a polypeptide chain

A  replication, translation, transcription

B  translation, replication, transcription

C  replication, transcription, translation

D  translation, transcription, replication

A  The phosphate group

B  All nucleotide are the same

C  The sugar and the base

D  The sugar

E  The base

A  A pH gradient

B  A temperature gradient

C  A salt gradient

D  A density gradient

A  the rate of the reaction at ½ the maximum rate

B  the maximum velocity of the catalytic reaction

C  recognition of the substrate by the enzyme

D  the rate of product release by the enzyme

A  using the energy of ATP hydrolysis to move nucleosomes

B  recruiting other enzymes

C  denaturing the DNA by interfering with hydrogen-bonding between base pairs.

D  modifying the N-terminal tails of core histones

A  epigenetic inheritance

B  heterochromatization

C  barrier destruction

D  Euchromatin depletion

A  protein secretion

B  protein degradation

C  membrane association

D  nuclear translocation

A  substrate-level phosphorylation

B  feedback inhibition

C  allosteric activation

D  oxidative phosphorylation

A  ΔH – T ΔS >0

B  ΔH and ΔS are both positive and TΔH >H

C  things are moving from higher to lower concentration

D  ΔH – T ΔS =0

E  ΔH – T ΔS <0

A  are aided by various metal ions that act as catalysts

B  take place very slowly

C  take place when the cells are at unusually high temperatures

D  are catalyzed by enzyme

E  maybe coupled to the hydrolysis of ATP

A  Enzymes reduce activation energy for the reactions they catalyze

B  The activity of enzymes cannot be regulated by factors in their immediate

C  Enzymes are proteins that function as catalysts

D  An enzyme maybe used many times over for a specific reaction.

E  Enzymes display specificity for a certain molecules to which they attach or which attach to them

A  low affinity for their substrate

B  . high affinity for their substrate

C  low velocity of reaction

D  high Vmax

A  negative feed-forward inhibition and homosteric activation

B  negative feedback and allosteric inhibition/activation

C  irreversible inhibition and destruction of the enzyme molecule

D  competitive and non-competitive inhibition

E  non-competitive inhibition and positive feedback.

A  The Earth is an open system

B  entropy increases in a closed system

C  the synthesis of large molecules from small molecules is exergonic

D  every chemical transformed represents a loss of energy

E  life exists at the expense of greater energy than it contains

A  They use energy derived from ATP hydrolysis to change the relative position of the DNA and the core histone octamer

B  They remove histone H1 from the linker DNA adjacent to the core histone octamer.

C  They chemically modify core histones to alter the affinity between the histone octamer and the DNA.

D  They chemically modify the DNA, changing the affinity between the histone octamer and the DNA

A  The polypeptide remains denatured.

B  The polypeptide adopts a new, stable conformation.

C  The polypeptide returns to its original conformation.

D  The polypeptide forms solid aggregates and precipitates out of solution.

A  gene silencing

B  displacement of histone H1

C  recruitment of remodeling complexes

D  increase in gene expression

A  C18H36018

B  C18H30015

C  C6H1005

D  C3H603

E  C18H32016

A  nucleosomes

B  nuclear pores

C  euchromatin

D  chromosome

E  heterochromatin

A  genetic code

B  gene

C  coding sequence

D  genome.

A  Double-stranded genomes have equal amounts of A and T

B  using the formula : G-A=C+T

C  single-stranded genomes always have a large percentage of purines

D  Single-stranded genomes have a higher rate of mutation

A  5’UGCAAU3’

B  3’UAACGU5’

C  5’TGCAAT3’

D  5’TAACGT3’

E  5’UAACGU3’

A  transmission electron

B  fluorescence

C  scanning electron

D  confocal

E  bring-field

F  phase-contrast

A  At either the N or C terminus

B  somewhere outside of the catalytic domain

C  inside the catalytic domain

D  in the exact center of the protein

E  in allosteric activator domain

A  starch

B  cellulose

C  DNA

D  Protein

E  glucose

A  structural biology

B  genomics

C  systems biology

D  proteomics

A  a peptide bond

B  a β-Pleated Sheet

C  an amino group

D  a disulfide bond

A  1,2,4,5

B  2,3,5

C  2,4,5

D  2,3,5

E  1,4,5

A  absorption

B  filtering

C  wavelength

D  intensity

A  propane

B  methane

C  molecular oxygen

D  water

A  cell division

B  membrane support

C  vesicle transport

D  cell motility

A  RNA is the only type of molecule that can catalyze a chemical reaction.

B  Self-replicating molecules of RNA exist today, in human cells

C  RNA can carry information and catalyze chemical reactions

D  Fossil evidence of such a molecule was recently discovered.

A  800g

B  125g

C  200g

D  160g

E  400g

A  primarily producing proteins in the cytosol

B  enlarging its vacuole

C  primarily producing proteins for secretion

D  digesting large food particles

E  constructing an extensive cell wall or extracellular matrix

A  protein

B  fat

C  fiber

D  sugar

A  Both contain ribosomes that are identical to ribosomes of the eukaryotic

B  Both have bacteria-like polysaccharide cell walls

C  Both contain DNA molecules

D  Both can reproduce on their own outside of the cell

E  Both contain endoplasmic reticulum and Golgi bodies.

A  in regions of the protein that determine packaging into the virus capsid

B  in or near the active site

C  at a cofactor binding site

D  Such mutations could occur anywhere with equal probability

E  at an allosteric site

A  Golgi network

B  plasma membrane

C  Mitochondrial membrane

D  nuclear envelope

A  RNA

B  DNA

C  Ribozyme

D  complex cells

E  ATP

A  Life on Mars tolerates the much higher levels of radiation found on Mars than life on Earth, which could be poisoned by the radiation

B  Studies of the earliest Mars and Earth cells show that they can both survive for many years in the harsh vacuum of space

C  The cells on Mars gain energy by using minerals found only on Mars., not on Earth.

D  Life on Mars uses a different genetic code (DNA & RNA) than life on Earth

A  polar covalent bonds

B  hydrogen bonds.

C  ionic bonds

D  nonpolar covalent bonds

E  van der Waals interactions

A  ability to grow under controlled conditions.

B  rapid rate of reproduction

C  amenability to genetic manipulation

D  genome partially or completely sequenced

E  All of the above is correct.

A  80

B  10

C  20

D  40

E  It is impossible to tell from the information given.

A  ionic bonds formed between the hydrogen of one water molecule and the oxygen of another water molecule

B  hydrogen bond formed between the hydrogen of one water molecule and the oxygen of another water molecule

C  polar covalent bond formed between the oxygen and a hydrogen of single water molecule

D  covalent bond formed between the hydrogen of one water molecule and the oxygen of another water molecule

A  van der Waals interactions

B  hydrogen bonds

C  ionic bonds

D  covalent bonds

A  has the ability to resolve cellular components as small as 2 nm.

B  requires the use of two sets of filters. The first filter narrows the wavelength range that reaches the specimen and the second blocks out all wavelengths that pass back up to the eyepiece except for those emitted by the dye in the sample.

C  employs a light microscope and requires that samples be fixed and stained in order to reveal cellular details

D  scans the specimen with a focused laser beam to obtain a series of two-dimensional optical sections, which can be used to reconstruct an image of the specimen in three dimensions. The laser excites a fluorescent dye molecule, and the emitted light from each illuminated point is captured through a pinhole and recorded by a detector.

E  uses a light microscope with an optical component to take advantage of the different refractive indices of light passing through different regions of the cell

F  requires coating the sample with a thin layer of a heavy metal to produce three dimensional images of the surface of a sample