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 mice had lost their immunity to infection with S. pneumoniae

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

C  The infectious strain cannot be killed by heating

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  order in which amino acids are joined in a polypeptide chain

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

D  unique three-dimensional shape of the fully folded polypeptide

E  bonding together of several polypeptide chains by weak bonds

A  replication, translation, transcription

B  translation, transcription, replication

C  replication, transcription, translation

D  translation, replication, transcription

A  The sugar and the base

B  All nucleotide are the same

C  The phosphate group

D  The sugar

E  The base

A  A pH gradient

B  A salt gradient

C  A temperature gradient

D  A density gradient

A  recognition of the substrate by the enzyme

B  the rate of product release by the enzyme

C  the rate of the reaction at ½ the maximum rate

D  the maximum velocity of the catalytic reaction

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

B  modifying the N-terminal tails of core histones

C  using the energy of ATP hydrolysis to move nucleosomes

D  recruiting other enzymes

A  barrier destruction

B  Euchromatin depletion

C  epigenetic inheritance

D  heterochromatization

A  protein secretion

B  membrane association

C  nuclear translocation

D  protein degradation

A  feedback inhibition

B  oxidative phosphorylation

C  allosteric activation

D  substrate-level phosphorylation

A  ΔH and ΔS are both positive and TΔH >H

B  ΔH – T ΔS <0

C  ΔH – T ΔS =0

D  ΔH – T ΔS >0

E  things are moving from higher to lower concentration

A  maybe coupled to the hydrolysis of ATP

B  are aided by various metal ions that act as catalysts

C  take place very slowly

D  take place when the cells are at unusually high temperatures

E  are catalyzed by enzyme

A  Enzymes reduce activation energy for the reactions they catalyze

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

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

D  Enzymes are proteins that function as catalysts

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

A  high Vmax

B  low affinity for their substrate

C  . high affinity for their substrate

D  low velocity of reaction

A  non-competitive inhibition and positive feedback.

B  negative feedback and allosteric inhibition/activation

C  irreversible inhibition and destruction of the enzyme molecule

D  negative feed-forward inhibition and homosteric activation

E  competitive and non-competitive inhibition

A  entropy increases in a closed system

B  every chemical transformed represents a loss of energy

C  the synthesis of large molecules from small molecules is exergonic

D  The Earth is an open system

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

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

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

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

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

A  The polypeptide remains denatured.

B  The polypeptide adopts a new, stable conformation.

C  The polypeptide returns to its original conformation.

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

A  increase in gene expression

B  displacement of histone H1

C  gene silencing

D  recruitment of remodeling complexes

A  C18H36018

B  C6H1005

C  C18H30015

D  C18H32016

E  C3H603

A  chromosome

B  euchromatin

C  nuclear pores

D  heterochromatin

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 always have a large percentage of purines

C  using the formula : G-A=C+T

D  Single-stranded genomes have a higher rate of mutation

A  5’UAACGU3’

B  3’UAACGU5’

C  5’UGCAAU3’

D  5’TAACGT3’

E  5’TGCAAT3’

A  scanning electron

B  bring-field

C  confocal

D  fluorescence

E  phase-contrast

F  transmission electron

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  starch

B  glucose

C  Protein

D  cellulose

E  DNA

A  proteomics

B  systems biology

C  structural biology

D  genomics

A  a disulfide bond

B  a β-Pleated Sheet

C  a peptide bond

D  an amino group

A  1,2,4,5

B  2,3,5

C  2,4,5

D  1,4,5

E  2,3,5

A  wavelength

B  intensity

C  filtering

D  absorption

A  water

B  methane

C  molecular oxygen

D  propane

A  cell motility

B  cell division

C  membrane support

D  vesicle transport

A  Fossil evidence of such a molecule was recently discovered.

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

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

D  RNA can carry information and catalyze chemical reactions

A  800g

B  160g

C  400g

D  125g

E  200g

A  constructing an extensive cell wall or extracellular matrix

B  digesting large food particles

C  enlarging its vacuole

D  primarily producing proteins for secretion

E  primarily producing proteins in the cytosol

A  sugar

B  fat

C  protein

D  fiber

A  Both contain DNA molecules

B  Both contain endoplasmic reticulum and Golgi bodies.

C  Both can reproduce on their own outside of the cell

D  Both have bacteria-like polysaccharide cell walls

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

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  plasma membrane

B  nuclear envelope

C  Golgi network

D  Mitochondrial membrane

A  ATP

B  complex cells

C  DNA

D  Ribozyme

E  RNA

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

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

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

A  hydrogen bonds.

B  van der Waals interactions

C  ionic bonds

D  polar covalent bonds

E  nonpolar covalent bonds

A  amenability to genetic manipulation

B  ability to grow under controlled conditions.

C  genome partially or completely sequenced

D  rapid rate of reproduction

E  All of the above is correct.

A  10

B  It is impossible to tell from the information given.

C  20

D  80

E  40

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

B  hydrogen bond 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  ionic bonds 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  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.

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

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

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  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.

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