Exam 1

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

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

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 harmless strain somehow revived the heat-killed pathogenic bacteria.

D  The infectious strain cannot be killed by heating

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  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  replication, transcription, translation

C  translation, transcription, replication

D  translation, replication, transcription

A  The sugar and the base

B  The sugar

C  The base

D  All nucleotide are the same

E  The phosphate group

A  A pH gradient

B  A density gradient

C  A salt gradient

D  A temperature gradient

A  the maximum velocity of the catalytic reaction

B  the rate of the reaction at ½ the maximum rate

C  recognition of the substrate by the enzyme

D  the rate of product release by the enzyme

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

B  modifying the N-terminal tails of core histones

C  recruiting other enzymes

D  using the energy of ATP hydrolysis to move nucleosomes

A  barrier destruction

B  epigenetic inheritance

C  Euchromatin depletion

D  heterochromatization

A  nuclear translocation

B  protein secretion

C  membrane association

D  protein degradation

A  oxidative phosphorylation

B  substrate-level phosphorylation

C  feedback inhibition

D  allosteric activation

A  ΔH – T ΔS <0

B  ΔH and ΔS are both positive and TΔH >H

C  things are moving from higher to lower concentration

D  ΔH – T ΔS >0

E  ΔH – T ΔS =0

A  are aided by various metal ions that act as catalysts

B  are catalyzed by enzyme

C  take place when the cells are at unusually high temperatures

D  take place very slowly

E  maybe coupled to the hydrolysis of ATP

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

B  Enzymes reduce activation energy for the reactions they catalyze

C  Enzymes are proteins that function as catalysts

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

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

A  . high affinity for their substrate

B  high Vmax

C  low velocity of reaction

D  low affinity for their substrate

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 Earth is an open system

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

C  the synthesis of large molecules from small molecules is exergonic

D  every chemical transformed represents a loss of energy

E  entropy increases in a closed system

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

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

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

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

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  gene silencing

C  recruitment of remodeling complexes

D  increase in gene expression

A  C18H30015

B  C6H1005

C  C18H36018

D  C18H32016

E  C3H603

A  euchromatin

B  heterochromatin

C  chromosome

D  nucleosomes

E  nuclear pores

A  gene

B  coding sequence

C  genetic code

D  genome.

A  Single-stranded genomes have a higher rate of mutation

B  using the formula : G-A=C+T

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

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

A  5’UGCAAU3’

B  5’UAACGU3’

C  3’UAACGU5’

D  5’TAACGT3’

E  5’TGCAAT3’

A  phase-contrast

B  transmission electron

C  bring-field

D  fluorescence

E  confocal

F  scanning electron

A  inside the catalytic domain

B  in the exact center of the protein

C  At either the N or C terminus

D  in allosteric activator domain

E  somewhere outside of the catalytic domain

A  DNA

B  starch

C  Protein

D  cellulose

E  glucose

A  genomics

B  proteomics

C  systems biology

D  structural biology

A  a disulfide bond

B  a peptide bond

C  a β-Pleated Sheet

D  an amino group

A  1,4,5

B  2,3,5

C  2,3,5

D  1,2,4,5

E  2,4,5

A  intensity

B  wavelength

C  absorption

D  filtering

A  methane

B  water

C  molecular oxygen

D  propane

A  membrane support

B  cell division

C  cell motility

D  vesicle transport

A  RNA can carry information and catalyze chemical reactions

B  Fossil evidence of such a molecule was recently discovered.

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

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

A  125g

B  800g

C  200g

D  400g

E  160g

A  constructing an extensive cell wall or extracellular matrix

B  primarily producing proteins for secretion

C  primarily producing proteins in the cytosol

D  enlarging its vacuole

E  digesting large food particles

A  fat

B  fiber

C  protein

D  sugar

A  Both contain endoplasmic reticulum and Golgi bodies.

B  Both contain DNA molecules

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

D  Both can reproduce on their own outside of the cell

E  Both have bacteria-like polysaccharide cell walls

A  at an allosteric site

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

C  in or near the active site

D  at a cofactor binding site

E  Such mutations could occur anywhere with equal probability

A  Golgi network

B  plasma membrane

C  nuclear envelope

D  Mitochondrial membrane

A  Ribozyme

B  RNA

C  ATP

D  complex cells

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  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  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  polar covalent bonds

D  nonpolar covalent bonds

E  ionic bonds

A  genome partially or completely sequenced

B  rapid rate of reproduction

C  amenability to genetic manipulation

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  20

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  covalent bonds

B  van der Waals interactions

C  hydrogen bonds

D  ionic bonds

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

F  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