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 infectious strain cannot be killed by heating

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

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

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

A  bonding together of several polypeptide chains by weak bonds

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

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

D  unique three-dimensional shape of the fully folded polypeptide

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

A  replication, transcription, translation

B  replication, translation, transcription

C  translation, replication, transcription

D  translation, transcription, replication

A  The base

B  All nucleotide are the same

C  The sugar

D  The phosphate group

E  The sugar and the base

A  A salt gradient

B  A pH gradient

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

C  recruiting other enzymes

D  modifying the N-terminal tails of core histones

A  epigenetic inheritance

B  Euchromatin depletion

C  barrier destruction

D  heterochromatization

A  membrane association

B  protein degradation

C  protein secretion

D  nuclear translocation

A  substrate-level phosphorylation

B  allosteric activation

C  oxidative phosphorylation

D  feedback inhibition

A  things are moving from higher to lower concentration

B  ΔH – T ΔS =0

C  ΔH – T ΔS >0

D  ΔH – T ΔS <0

E  ΔH and ΔS are both positive and TΔH >H

A  maybe coupled to the hydrolysis of ATP

B  take place very slowly

C  are aided by various metal ions that act as catalysts

D  take place when the cells are at unusually high temperatures

E  are catalyzed by enzyme

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

B  Enzymes are proteins that function as catalysts

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

D  Enzymes reduce activation energy for the reactions they catalyze

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

A  high Vmax

B  low velocity of reaction

C  low affinity for their substrate

D  . high affinity for their substrate

A  competitive and non-competitive inhibition

B  negative feed-forward inhibition and homosteric activation

C  negative feedback and allosteric inhibition/activation

D  non-competitive inhibition and positive feedback.

E  irreversible inhibition and destruction of the enzyme molecule

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  life exists at the expense of greater energy than it contains

E  every chemical transformed represents a loss of energy

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 forms solid aggregates and precipitates out of solution.

B  The polypeptide returns to its original conformation.

C  The polypeptide adopts a new, stable conformation.

D  The polypeptide remains denatured.

A  gene silencing

B  recruitment of remodeling complexes

C  increase in gene expression

D  displacement of histone H1

A  C18H32016

B  C18H36018

C  C3H603

D  C18H30015

E  C6H1005

A  nucleosomes

B  nuclear pores

C  chromosome

D  heterochromatin

E  euchromatin

A  coding sequence

B  genetic code

C  gene

D  genome.

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

B  using the formula : G-A=C+T

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

D  Single-stranded genomes have a higher rate of mutation

A  5’TGCAAT3’

B  5’UAACGU3’

C  5’UGCAAU3’

D  5’TAACGT3’

E  3’UAACGU5’

A  transmission electron

B  bring-field

C  scanning electron

D  phase-contrast

E  fluorescence

F  confocal

A  in allosteric activator domain

B  At either the N or C terminus

C  somewhere outside of the catalytic domain

D  inside the catalytic domain

E  in the exact center of the protein

A  DNA

B  Protein

C  cellulose

D  glucose

E  starch

A  systems biology

B  proteomics

C  genomics

D  structural biology

A  a peptide bond

B  a disulfide bond

C  an amino group

D  a β-Pleated Sheet

A  2,3,5

B  2,3,5

C  1,4,5

D  2,4,5

E  1,2,4,5

A  wavelength

B  intensity

C  filtering

D  absorption

A  methane

B  water

C  propane

D  molecular oxygen

A  cell motility

B  vesicle transport

C  membrane support

D  cell division

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

B  Fossil evidence of such a molecule was recently discovered.

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

D  RNA can carry information and catalyze chemical reactions

A  125g

B  160g

C  800g

D  400g

E  200g

A  enlarging its vacuole

B  primarily producing proteins for secretion

C  digesting large food particles

D  constructing an extensive cell wall or extracellular matrix

E  primarily producing proteins in the cytosol

A  fiber

B  fat

C  sugar

D  protein

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 have bacteria-like polysaccharide cell walls

E  Both contain endoplasmic reticulum and Golgi bodies.

A  at a cofactor binding site

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

C  Such mutations could occur anywhere with equal probability

D  in or near the active site

E  at an allosteric site

A  nuclear envelope

B  Mitochondrial membrane

C  Golgi network

D  plasma membrane

A  ATP

B  DNA

C  Ribozyme

D  RNA

E  complex cells

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  The cells on Mars gain energy by using minerals found only on Mars., not 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 uses a different genetic code (DNA & RNA) than life on Earth

A  hydrogen bonds.

B  polar covalent bonds

C  nonpolar covalent bonds

D  ionic bonds

E  van der Waals interactions

A  genome partially or completely sequenced

B  amenability to genetic manipulation

C  rapid rate of reproduction

D  ability to grow under controlled conditions.

E  All of the above is correct.

A  40

B  It is impossible to tell from the information given.

C  80

D  10

E  20

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  hydrogen bonds

B  ionic bonds

C  van der Waals interactions

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

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