Exam 1

A  Covalent bonds require carbon whereas ionic bonds do not.

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

E  Covalent bonds involve the transfer of electrons between charged atoms; ionic bonds involve the sharing of 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  organization of a polypeptide chain into an a-helix or β-Pleated sheet

B  bonding together of several polypeptide chains by weak bonds

C  unique three-dimensional shape of the fully folded polypeptide

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

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

A  translation, transcription, replication

B  translation, replication, transcription

C  replication, translation, transcription

D  replication, transcription, translation

A  The phosphate group

B  The sugar and the base

C  All nucleotide are the same

D  The sugar

E  The base

A  A density gradient

B  A temperature gradient

C  A salt gradient

D  A pH gradient

A  the rate of product release by the enzyme

B  recognition of the substrate by the enzyme

C  the rate of the reaction at ½ the maximum rate

D  the maximum velocity of the catalytic reaction

A  recruiting other enzymes

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

C  using the energy of ATP hydrolysis to move nucleosomes

D  modifying the N-terminal tails of core histones

A  barrier destruction

B  epigenetic inheritance

C  heterochromatization

D  Euchromatin depletion

A  membrane association

B  nuclear translocation

C  protein degradation

D  protein secretion

A  substrate-level phosphorylation

B  allosteric activation

C  feedback inhibition

D  oxidative phosphorylation

A  ΔH – T ΔS =0

B  things are moving from higher to lower concentration

C  ΔH and ΔS are both positive and TΔH >H

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

B  Enzymes are proteins that function as catalysts

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

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

E  Enzymes reduce activation energy for the reactions they catalyze

A  . high affinity for their substrate

B  low affinity for their substrate

C  high Vmax

D  low velocity of reaction

A  negative feedback and allosteric inhibition/activation

B  non-competitive inhibition and positive feedback.

C  competitive and non-competitive inhibition

D  irreversible inhibition and destruction of the enzyme molecule

E  negative feed-forward inhibition and homosteric activation

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  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 adopts a new, stable conformation.

B  The polypeptide remains denatured.

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

D  The polypeptide returns to its original conformation.

A  gene silencing

B  recruitment of remodeling complexes

C  displacement of histone H1

D  increase in gene expression

A  C18H30015

B  C18H36018

C  C3H603

D  C18H32016

E  C6H1005

A  nucleosomes

B  heterochromatin

C  chromosome

D  nuclear pores

E  euchromatin

A  genome.

B  coding sequence

C  genetic code

D  gene

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’TAACGT3’

B  5’UAACGU3’

C  5’UGCAAU3’

D  5’TGCAAT3’

E  3’UAACGU5’

A  transmission electron

B  confocal

C  scanning electron

D  phase-contrast

E  bring-field

F  fluorescence

A  in the exact center of the protein

B  At either the N or C terminus

C  somewhere outside of the catalytic domain

D  inside the catalytic domain

E  in allosteric activator domain

A  cellulose

B  DNA

C  Protein

D  glucose

E  starch

A  proteomics

B  systems biology

C  genomics

D  structural biology

A  a disulfide bond

B  a peptide bond

C  an amino group

D  a β-Pleated Sheet

A  2,3,5

B  2,3,5

C  1,2,4,5

D  2,4,5

E  1,4,5

A  absorption

B  filtering

C  wavelength

D  intensity

A  water

B  methane

C  molecular oxygen

D  propane

A  cell motility

B  cell division

C  membrane support

D  vesicle transport

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

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

C  RNA can carry information and catalyze chemical reactions

D  Fossil evidence of such a molecule was recently discovered.

A  800g

B  125g

C  200g

D  400g

E  160g

A  digesting large food particles

B  constructing an extensive cell wall or extracellular matrix

C  primarily producing proteins in the cytosol

D  enlarging its vacuole

E  primarily producing proteins for secretion

A  fat

B  sugar

C  protein

D  fiber

A  Both contain endoplasmic reticulum and Golgi bodies.

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

C  Both have bacteria-like polysaccharide cell walls

D  Both contain DNA molecules

E  Both can reproduce on their own outside of the cell

A  Such mutations could occur anywhere with equal probability

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

C  at a cofactor binding site

D  at an allosteric site

E  in or near the active site

A  Golgi network

B  plasma membrane

C  nuclear envelope

D  Mitochondrial membrane

A  ATP

B  complex cells

C  RNA

D  Ribozyme

E  DNA

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

A  van der Waals interactions

B  polar covalent bonds

C  hydrogen bonds.

D  nonpolar covalent bonds

E  ionic bonds

A  amenability to genetic manipulation

B  genome partially or completely sequenced

C  ability to grow under controlled conditions.

D  rapid rate of reproduction

E  All of the above is correct.

A  It is impossible to tell from the information given.

B  20

C  80

D  40

E  10

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

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

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

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

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

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.