Exam 1

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

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

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

D  Covalent bonds require carbon whereas ionic bonds do not.

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

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

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

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

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  order in which amino acids are joined in a polypeptide chain

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

A  replication, transcription, translation

B  translation, replication, transcription

C  translation, transcription, replication

D  replication, translation, transcription

A  The base

B  The sugar

C  All nucleotide are the same

D  The phosphate group

E  The sugar and the base

A  A pH gradient

B  A salt gradient

C  A density gradient

D  A temperature gradient

A  the maximum velocity of the catalytic reaction

B  the rate of the reaction at ½ the maximum rate

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  modifying the N-terminal tails of core histones

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

D  recruiting other enzymes

A  epigenetic inheritance

B  Euchromatin depletion

C  heterochromatization

D  barrier destruction

A  protein degradation

B  nuclear translocation

C  protein secretion

D  membrane association

A  feedback inhibition

B  oxidative phosphorylation

C  substrate-level phosphorylation

D  allosteric activation

A  ΔH – T ΔS =0

B  ΔH – T ΔS >0

C  things are moving from higher to lower concentration

D  ΔH – T ΔS <0

E  ΔH and ΔS are both positive and TΔH >H

A  are catalyzed by enzyme

B  maybe coupled to the hydrolysis of ATP

C  take place when the cells are at unusually high temperatures

D  take place very slowly

E  are aided by various metal ions that act as catalysts

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

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

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

D  Enzymes reduce activation energy for the reactions they catalyze

E  Enzymes are proteins that function as catalysts

A  . high affinity for their substrate

B  high Vmax

C  low velocity of reaction

D  low affinity for their substrate

A  negative feedback and allosteric inhibition/activation

B  irreversible inhibition and destruction of the enzyme molecule

C  negative feed-forward inhibition and homosteric activation

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  life exists at the expense of greater energy than it contains

D  every chemical transformed represents a loss of energy

E  the synthesis of large molecules from small molecules is exergonic

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

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

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

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

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

B  The polypeptide remains denatured.

C  The polypeptide adopts a new, stable conformation.

D  The polypeptide returns to its original conformation.

A  displacement of histone H1

B  recruitment of remodeling complexes

C  gene silencing

D  increase in gene expression

A  C18H32016

B  C6H1005

C  C18H36018

D  C18H30015

E  C3H603

A  chromosome

B  nuclear pores

C  heterochromatin

D  euchromatin

E  nucleosomes

A  genome.

B  coding sequence

C  gene

D  genetic code

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

B  Single-stranded genomes have a higher rate of mutation

C  using the formula : G-A=C+T

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

A  5’TAACGT3’

B  5’UGCAAU3’

C  5’TGCAAT3’

D  5’UAACGU3’

E  3’UAACGU5’

A  confocal

B  bring-field

C  scanning electron

D  transmission electron

E  phase-contrast

F  fluorescence

A  At either the N or C terminus

B  somewhere outside of the catalytic domain

C  inside the catalytic domain

D  in allosteric activator domain

E  in the exact center of the protein

A  glucose

B  starch

C  Protein

D  DNA

E  cellulose

A  proteomics

B  structural biology

C  genomics

D  systems biology

A  an amino group

B  a β-Pleated Sheet

C  a disulfide bond

D  a peptide bond

A  1,4,5

B  1,2,4,5

C  2,3,5

D  2,4,5

E  2,3,5

A  wavelength

B  intensity

C  filtering

D  absorption

A  methane

B  water

C  molecular oxygen

D  propane

A  cell division

B  vesicle transport

C  cell motility

D  membrane support

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  160g

B  125g

C  400g

D  200g

E  800g

A  primarily producing proteins for secretion

B  digesting large food particles

C  enlarging its vacuole

D  constructing an extensive cell wall or extracellular matrix

E  primarily producing proteins in the cytosol

A  fiber

B  protein

C  sugar

D  fat

A  Both can reproduce on their own outside of the cell

B  Both contain DNA molecules

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

D  Both contain endoplasmic reticulum and Golgi bodies.

E  Both have bacteria-like polysaccharide cell walls

A  Such mutations could occur anywhere with equal probability

B  at an allosteric site

C  in or near the active site

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

E  at a cofactor binding site

A  nuclear envelope

B  Mitochondrial membrane

C  Golgi network

D  plasma membrane

A  DNA

B  complex cells

C  Ribozyme

D  RNA

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  van der Waals interactions

B  polar covalent bonds

C  hydrogen bonds.

D  ionic bonds

E  nonpolar covalent bonds

A  genome partially or completely sequenced

B  ability to grow under controlled conditions.

C  amenability to genetic manipulation

D  rapid rate of reproduction

E  All of the above is correct.

A  10

B  40

C  It is impossible to tell from the information given.

D  20

E  80

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

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

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

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

A  covalent bonds

B  van der Waals interactions

C  hydrogen bonds

D  ionic bonds

A  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

B  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.

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

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

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

F  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.