Exam 1

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

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

C  Covalent bonds require carbon whereas ionic bonds do not.

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

A  The harmless strain somehow revived the heat-killed pathogenic bacteria.

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 mice had lost their immunity to infection with S. pneumoniae

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

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  bonding together of several polypeptide chains by weak bonds

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

A  translation, transcription, replication

B  translation, replication, transcription

C  replication, transcription, translation

D  replication, translation, transcription

A  The sugar

B  All nucleotide are the same

C  The phosphate group

D  The base

E  The sugar and the base

A  A pH gradient

B  A density gradient

C  A temperature gradient

D  A salt gradient

A  the maximum velocity of the catalytic reaction

B  the rate of product release by the enzyme

C  recognition of the substrate by the enzyme

D  the rate of the reaction at ½ the maximum rate

A  using the energy of ATP hydrolysis to move nucleosomes

B  modifying the N-terminal tails of core histones

C  recruiting other enzymes

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

A  barrier destruction

B  heterochromatization

C  Euchromatin depletion

D  epigenetic inheritance

A  protein degradation

B  membrane association

C  protein secretion

D  nuclear translocation

A  substrate-level phosphorylation

B  oxidative 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  take place when the cells are at unusually high temperatures

C  maybe coupled to the hydrolysis of ATP

D  are catalyzed by enzyme

E  take place very slowly

A  Enzymes are proteins that function as catalysts

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

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

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

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  negative feed-forward inhibition and homosteric activation

D  competitive and non-competitive inhibition

E  irreversible inhibition and destruction of the enzyme molecule

A  The Earth is an open system

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

C  entropy increases in a closed system

D  the synthesis of large molecules from small molecules is exergonic

E  every chemical transformed represents a loss of energy

A  They use energy derived from ATP hydrolysis to change the relative position of the DNA and 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 remove histone H1 from the linker DNA adjacent to the core histone octamer.

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

B  The polypeptide remains denatured.

C  The polypeptide returns to its original conformation.

D  The polypeptide adopts a new, stable conformation.

A  increase in gene expression

B  recruitment of remodeling complexes

C  gene silencing

D  displacement of histone H1

A  C18H36018

B  C6H1005

C  C3H603

D  C18H30015

E  C18H32016

A  euchromatin

B  nuclear pores

C  nucleosomes

D  chromosome

E  heterochromatin

A  gene

B  genetic code

C  genome.

D  coding sequence

A  using the formula : G-A=C+T

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

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

D  Single-stranded genomes have a higher rate of mutation

A  5’TAACGT3’

B  5’TGCAAT3’

C  5’UGCAAU3’

D  3’UAACGU5’

E  5’UAACGU3’

A  phase-contrast

B  scanning electron

C  transmission electron

D  fluorescence

E  bring-field

F  confocal

A  in allosteric activator domain

B  in the exact center of the protein

C  At either the N or C terminus

D  somewhere outside of the catalytic domain

E  inside the catalytic domain

A  glucose

B  cellulose

C  DNA

D  starch

E  Protein

A  genomics

B  proteomics

C  structural biology

D  systems biology

A  an amino group

B  a peptide bond

C  a disulfide bond

D  a β-Pleated Sheet

A  1,4,5

B  2,3,5

C  2,4,5

D  2,3,5

E  1,2,4,5

A  absorption

B  wavelength

C  filtering

D  intensity

A  water

B  molecular oxygen

C  methane

D  propane

A  vesicle transport

B  membrane support

C  cell division

D  cell motility

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

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  RNA can carry information and catalyze chemical reactions

A  125g

B  160g

C  200g

D  400g

E  800g

A  digesting large food particles

B  primarily producing proteins in the cytosol

C  primarily producing proteins for secretion

D  enlarging its vacuole

E  constructing an extensive cell wall or extracellular matrix

A  fiber

B  protein

C  fat

D  sugar

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

B  Both contain DNA molecules

C  Both have bacteria-like polysaccharide cell walls

D  Both can reproduce on their own outside of the cell

E  Both contain endoplasmic reticulum and Golgi bodies.

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

B  in or near the active site

C  Such mutations could occur anywhere with equal probability

D  at an allosteric site

E  at a cofactor binding site

A  Mitochondrial membrane

B  nuclear envelope

C  Golgi network

D  plasma membrane

A  ATP

B  Ribozyme

C  complex cells

D  RNA

E  DNA

A  The cells on Mars gain energy by using minerals found only on Mars., not 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  Life on Mars uses a different genetic code (DNA & RNA) than life on Earth

A  nonpolar covalent bonds

B  van der Waals interactions

C  polar covalent bonds

D  ionic bonds

E  hydrogen 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  20

B  40

C  10

D  80

E  It is impossible to tell from the information given.

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

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

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

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

A  van der Waals interactions

B  hydrogen bonds

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

C  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.

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

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