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 between charged atoms.

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

D  Covalent bonds involve the sharing of electrons between atoms; ionic bonds involve the sharing of protons between charged 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  unique three-dimensional shape of the fully folded polypeptide

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

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

D  bonding together of several polypeptide chains by weak bonds

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

A  replication, translation, transcription

B  translation, transcription, replication

C  translation, replication, transcription

D  replication, transcription, translation

A  The phosphate group

B  The base

C  The sugar

D  The sugar and the base

E  All nucleotide are the same

A  A pH gradient

B  A temperature gradient

C  A density gradient

D  A salt gradient

A  the rate of the reaction at ½ the maximum rate

B  the maximum velocity of the catalytic reaction

C  the rate of product release by the enzyme

D  recognition of the substrate by the enzyme

A  modifying the N-terminal tails of core histones

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

C  using the energy of ATP hydrolysis to move nucleosomes

D  recruiting other enzymes

A  epigenetic inheritance

B  heterochromatization

C  barrier destruction

D  Euchromatin depletion

A  protein degradation

B  protein secretion

C  membrane association

D  nuclear translocation

A  substrate-level phosphorylation

B  allosteric activation

C  feedback inhibition

D  oxidative phosphorylation

A  ΔH – T ΔS =0

B  ΔH and ΔS are both positive and TΔH >H

C  ΔH – T ΔS <0

D  things are moving from higher to lower concentration

E  ΔH – T ΔS >0

A  take place when the cells are at unusually high temperatures

B  are catalyzed by enzyme

C  take place very slowly

D  are aided by various metal ions that act as catalysts

E  maybe coupled to the hydrolysis of ATP

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 are proteins that function as catalysts

D  Enzymes reduce activation energy for the reactions they catalyze

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

A  . high affinity for their substrate

B  low affinity for their substrate

C  high Vmax

D  low velocity of reaction

A  non-competitive inhibition and positive feedback.

B  irreversible inhibition and destruction of the enzyme molecule

C  competitive and non-competitive inhibition

D  negative feed-forward inhibition and homosteric activation

E  negative feedback and allosteric inhibition/activation

A  the synthesis of large molecules from small molecules is exergonic

B  The Earth is an open system

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

D  every chemical transformed represents a loss of energy

E  entropy increases in a closed system

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

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

A  The polypeptide adopts a new, stable conformation.

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

C  The polypeptide returns to its original conformation.

D  The polypeptide remains denatured.

A  increase in gene expression

B  recruitment of remodeling complexes

C  displacement of histone H1

D  gene silencing

A  C18H30015

B  C6H1005

C  C18H36018

D  C3H603

E  C18H32016

A  nucleosomes

B  euchromatin

C  chromosome

D  heterochromatin

E  nuclear pores

A  coding sequence

B  genetic code

C  gene

D  genome.

A  using the formula : G-A=C+T

B  Single-stranded genomes have a higher rate of mutation

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

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

A  5’TAACGT3’

B  5’TGCAAT3’

C  3’UAACGU5’

D  5’UGCAAU3’

E  5’UAACGU3’

A  phase-contrast

B  transmission electron

C  confocal

D  fluorescence

E  scanning electron

F  bring-field

A  inside the catalytic domain

B  At either the N or C terminus

C  in allosteric activator domain

D  somewhere outside of the catalytic domain

E  in the exact center of the protein

A  DNA

B  starch

C  Protein

D  cellulose

E  glucose

A  genomics

B  systems biology

C  proteomics

D  structural biology

A  a β-Pleated Sheet

B  a disulfide bond

C  an amino group

D  a peptide bond

A  2,3,5

B  1,4,5

C  2,4,5

D  1,2,4,5

E  2,3,5

A  wavelength

B  filtering

C  intensity

D  absorption

A  molecular oxygen

B  methane

C  water

D  propane

A  cell division

B  membrane support

C  vesicle transport

D  cell motility

A  Fossil evidence of such a molecule was recently discovered.

B  RNA can carry information and catalyze chemical reactions

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

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

A  800g

B  200g

C  160g

D  125g

E  400g

A  primarily producing proteins for secretion

B  enlarging its vacuole

C  primarily producing proteins in the cytosol

D  constructing an extensive cell wall or extracellular matrix

E  digesting large food particles

A  sugar

B  protein

C  fiber

D  fat

A  Both contain endoplasmic reticulum and Golgi bodies.

B  Both can reproduce on their own outside of the cell

C  Both have bacteria-like polysaccharide cell walls

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

E  Both contain DNA molecules

A  Such mutations could occur anywhere with equal probability

B  in or near the active site

C  at a cofactor binding site

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

E  at an allosteric site

A  Mitochondrial membrane

B  plasma membrane

C  nuclear envelope

D  Golgi network

A  DNA

B  Ribozyme

C  RNA

D  ATP

E  complex cells

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

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

A  nonpolar covalent bonds

B  van der Waals interactions

C  ionic bonds

D  hydrogen bonds.

E  polar covalent bonds

A  ability to grow under controlled conditions.

B  rapid rate of reproduction

C  genome partially or completely sequenced

D  amenability to genetic manipulation

E  All of the above is correct.

A  It is impossible to tell from the information given.

B  80

C  10

D  40

E  20

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

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

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

C  hydrogen bonds

D  covalent 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  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

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

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

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.