Exam 1

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

B  Covalent bonds require carbon whereas ionic bonds do not.

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

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 infectious strain cannot be killed by heating

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

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

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

B  unique three-dimensional shape of the fully folded polypeptide

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

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

E  bonding together of several polypeptide chains by weak bonds

A  translation, transcription, replication

B  replication, translation, transcription

C  translation, replication, transcription

D  replication, transcription, translation

A  All nucleotide are the same

B  The sugar and the base

C  The sugar

D  The phosphate group

E  The base

A  A temperature gradient

B  A pH gradient

C  A salt gradient

D  A density gradient

A  recognition of the substrate by the enzyme

B  the maximum velocity of the catalytic reaction

C  the rate of product release by the enzyme

D  the rate of the reaction at ½ the maximum rate

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  heterochromatization

B  epigenetic inheritance

C  Euchromatin depletion

D  barrier destruction

A  nuclear translocation

B  protein secretion

C  protein degradation

D  membrane association

A  oxidative phosphorylation

B  feedback inhibition

C  allosteric activation

D  substrate-level phosphorylation

A  ΔH – T ΔS =0

B  ΔH – T ΔS >0

C  ΔH and ΔS are both positive and TΔH >H

D  things are moving from higher to lower concentration

E  ΔH – T ΔS <0

A  are aided by various metal ions that act as catalysts

B  maybe coupled to the hydrolysis of ATP

C  take place very slowly

D  take place when the cells are at unusually high temperatures

E  are catalyzed by enzyme

A  Enzymes are proteins that function as catalysts

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

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

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

E  Enzymes reduce activation energy for the reactions they catalyze

A  low affinity for their substrate

B  . high affinity for their substrate

C  low velocity of reaction

D  high Vmax

A  negative feedback and allosteric inhibition/activation

B  negative feed-forward inhibition and homosteric activation

C  competitive and non-competitive inhibition

D  irreversible inhibition and destruction of the enzyme molecule

E  non-competitive inhibition and positive feedback.

A  every chemical transformed represents a loss of energy

B  the synthesis of large molecules from small molecules is exergonic

C  entropy increases in a closed system

D  The Earth is an open system

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

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

B  They chemically modify core histones to alter 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 remove histone H1 from the linker DNA adjacent to the core histone octamer.

A  The polypeptide remains denatured.

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

C  The polypeptide returns to its original conformation.

D  The polypeptide adopts a new, stable conformation.

A  gene silencing

B  increase in gene expression

C  recruitment of remodeling complexes

D  displacement of histone H1

A  C3H603

B  C18H30015

C  C18H36018

D  C18H32016

E  C6H1005

A  nuclear pores

B  chromosome

C  nucleosomes

D  heterochromatin

E  euchromatin

A  gene

B  genome.

C  coding sequence

D  genetic code

A  Single-stranded genomes have a higher rate of mutation

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

C  using the formula : G-A=C+T

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

A  5’UGCAAU3’

B  5’TGCAAT3’

C  5’UAACGU3’

D  3’UAACGU5’

E  5’TAACGT3’

A  phase-contrast

B  transmission electron

C  confocal

D  fluorescence

E  bring-field

F  scanning electron

A  in allosteric activator domain

B  inside the catalytic domain

C  At either the N or C terminus

D  somewhere outside of the catalytic domain

E  in the exact center of the protein

A  Protein

B  cellulose

C  DNA

D  starch

E  glucose

A  proteomics

B  structural biology

C  systems biology

D  genomics

A  a peptide bond

B  a disulfide bond

C  a β-Pleated Sheet

D  an amino group

A  1,4,5

B  2,3,5

C  1,2,4,5

D  2,4,5

E  2,3,5

A  filtering

B  wavelength

C  intensity

D  absorption

A  water

B  methane

C  molecular oxygen

D  propane

A  cell division

B  vesicle transport

C  membrane support

D  cell motility

A  RNA can carry information and catalyze chemical reactions

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

C  Fossil evidence of such a molecule was recently discovered.

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

A  125g

B  200g

C  800g

D  400g

E  160g

A  enlarging its vacuole

B  digesting large food particles

C  primarily producing proteins in the cytosol

D  constructing an extensive cell wall or extracellular matrix

E  primarily producing proteins for secretion

A  fat

B  fiber

C  protein

D  sugar

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

B  Both have bacteria-like polysaccharide cell walls

C  Both can reproduce on their own outside of the cell

D  Both contain endoplasmic reticulum and Golgi bodies.

E  Both contain DNA molecules

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

B  at an allosteric site

C  Such mutations could occur anywhere with equal probability

D  at a cofactor binding site

E  in or near the active site

A  Golgi network

B  plasma membrane

C  Mitochondrial membrane

D  nuclear envelope

A  complex cells

B  Ribozyme

C  RNA

D  DNA

E  ATP

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

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

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

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

A  ionic bonds

B  hydrogen bonds.

C  van der Waals interactions

D  nonpolar covalent bonds

E  polar covalent bonds

A  genome partially or completely sequenced

B  amenability to genetic manipulation

C  ability to grow under controlled conditions.

D  rapid rate of reproduction

E  All of the above is correct.

A  20

B  It is impossible to tell from the information given.

C  80

D  10

E  40

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

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

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

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

A  hydrogen bonds

B  covalent bonds

C  van der Waals interactions

D  ionic bonds

A  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.

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

D  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

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

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