Exam 1

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

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

E  Covalent bonds require carbon whereas ionic bonds do not.

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 infectious strain cannot be killed by heating

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  unique three-dimensional shape of the fully folded polypeptide

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

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

A  translation, replication, transcription

B  replication, transcription, translation

C  replication, translation, transcription

D  translation, transcription, replication

A  The phosphate group

B  The sugar and the base

C  The base

D  The sugar

E  All nucleotide are the same

A  A density gradient

B  A temperature gradient

C  A salt gradient

D  A pH 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  recruiting other enzymes

B  modifying the N-terminal tails of core histones

C  using the energy of ATP hydrolysis to move nucleosomes

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

A  Euchromatin depletion

B  barrier destruction

C  heterochromatization

D  epigenetic inheritance

A  protein secretion

B  protein degradation

C  nuclear translocation

D  membrane association

A  oxidative phosphorylation

B  substrate-level phosphorylation

C  feedback inhibition

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  take place when the cells are at unusually high temperatures

B  are aided by various metal ions that act as catalysts

C  maybe coupled to the hydrolysis of ATP

D  are catalyzed by enzyme

E  take place very slowly

A  Enzymes reduce activation energy for the reactions they catalyze

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

C  Enzymes are proteins that function as catalysts

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

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

A  low velocity of reaction

B  low affinity for their substrate

C  . high affinity for their substrate

D  high Vmax

A  negative feed-forward inhibition and homosteric activation

B  irreversible inhibition and destruction of the enzyme molecule

C  negative feedback and allosteric inhibition/activation

D  non-competitive inhibition and positive feedback.

E  competitive and non-competitive inhibition

A  the synthesis of large molecules from small molecules is exergonic

B  The Earth is an open system

C  entropy increases in a closed system

D  every chemical transformed represents a loss of energy

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

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

A  The polypeptide remains denatured.

B  The polypeptide returns to its original conformation.

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

D  The polypeptide adopts a new, stable conformation.

A  displacement of histone H1

B  increase in gene expression

C  gene silencing

D  recruitment of remodeling complexes

A  C18H30015

B  C6H1005

C  C3H603

D  C18H32016

E  C18H36018

A  euchromatin

B  nucleosomes

C  heterochromatin

D  nuclear pores

E  chromosome

A  genome.

B  genetic code

C  coding sequence

D  gene

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

B  using the formula : G-A=C+T

C  Single-stranded genomes have a higher rate of mutation

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

A  3’UAACGU5’

B  5’TAACGT3’

C  5’TGCAAT3’

D  5’UAACGU3’

E  5’UGCAAU3’

A  fluorescence

B  confocal

C  phase-contrast

D  bring-field

E  scanning electron

F  transmission electron

A  in allosteric activator domain

B  in the exact center of the protein

C  somewhere outside of the catalytic domain

D  inside the catalytic domain

E  At either the N or C terminus

A  Protein

B  glucose

C  DNA

D  starch

E  cellulose

A  proteomics

B  genomics

C  systems biology

D  structural biology

A  an amino group

B  a peptide bond

C  a disulfide bond

D  a β-Pleated Sheet

A  2,3,5

B  1,4,5

C  1,2,4,5

D  2,3,5

E  2,4,5

A  filtering

B  absorption

C  intensity

D  wavelength

A  propane

B  water

C  molecular oxygen

D  methane

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  RNA can carry information and catalyze chemical reactions

C  Fossil evidence of such a molecule was recently discovered.

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

A  160g

B  200g

C  125g

D  800g

E  400g

A  primarily producing proteins for secretion

B  digesting large food particles

C  constructing an extensive cell wall or extracellular matrix

D  enlarging its vacuole

E  primarily producing proteins in the cytosol

A  fat

B  fiber

C  sugar

D  protein

A  Both contain DNA molecules

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

C  Both can reproduce on their own outside of the cell

D  Both have bacteria-like polysaccharide cell walls

E  Both contain endoplasmic reticulum and Golgi bodies.

A  Such mutations could occur anywhere with equal probability

B  at a cofactor binding site

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

D  at an allosteric site

E  in or near the active site

A  plasma membrane

B  Golgi network

C  nuclear envelope

D  Mitochondrial membrane

A  complex cells

B  ATP

C  Ribozyme

D  RNA

E  DNA

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  ionic bonds

C  nonpolar covalent bonds

D  polar covalent bonds

E  hydrogen bonds.

A  ability to grow under controlled conditions.

B  genome partially or completely sequenced

C  rapid rate of reproduction

D  amenability to genetic manipulation

E  All of the above is correct.

A  20

B  It is impossible to tell from the information given.

C  40

D  80

E  10

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

B  covalent 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  hydrogen 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  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  has the ability to resolve cellular components as small as 2 nm.

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

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  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.