Exam 1

A  Covalent bonds require carbon whereas ionic bonds do not.

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

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

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

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

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

B  The infectious strain cannot be killed by heating

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  bonding together of several polypeptide chains by weak bonds

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  order in which amino acids are joined in a polypeptide chain

E  unique three-dimensional shape of the fully folded polypeptide

A  replication, transcription, translation

B  replication, translation, transcription

C  translation, replication, transcription

D  translation, transcription, replication

A  The phosphate group

B  All nucleotide are the same

C  The sugar

D  The sugar and the base

E  The base

A  A pH gradient

B  A temperature gradient

C  A salt gradient

D  A density gradient

A  the maximum velocity of the catalytic reaction

B  recognition of the substrate by the enzyme

C  the rate of product release 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  recruiting other enzymes

C  modifying the N-terminal tails of core histones

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

A  epigenetic inheritance

B  barrier destruction

C  heterochromatization

D  Euchromatin depletion

A  protein secretion

B  membrane association

C  nuclear translocation

D  protein degradation

A  feedback inhibition

B  oxidative phosphorylation

C  substrate-level phosphorylation

D  allosteric activation

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  take place very slowly

B  are catalyzed by enzyme

C  are aided by various metal ions that act as catalysts

D  maybe coupled to the hydrolysis of ATP

E  take place when the cells are at unusually high temperatures

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

B  Enzymes are proteins that function as catalysts

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

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

E  Enzymes reduce activation energy for the reactions they catalyze

A  high Vmax

B  low affinity for their substrate

C  . high affinity for their substrate

D  low velocity of reaction

A  irreversible inhibition and destruction of the enzyme molecule

B  negative feedback and allosteric inhibition/activation

C  non-competitive inhibition and positive feedback.

D  negative feed-forward inhibition and homosteric activation

E  competitive and non-competitive inhibition

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

B  every chemical transformed represents a loss of energy

C  entropy increases in a closed system

D  the synthesis of large molecules from small molecules is exergonic

E  The Earth is an open system

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

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

C  They chemically modify the DNA, changing 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 returns to its original conformation.

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

C  The polypeptide remains denatured.

D  The polypeptide adopts a new, stable conformation.

A  displacement of histone H1

B  recruitment of remodeling complexes

C  gene silencing

D  increase in gene expression

A  C3H603

B  C18H30015

C  C18H32016

D  C6H1005

E  C18H36018

A  chromosome

B  euchromatin

C  nucleosomes

D  heterochromatin

E  nuclear pores

A  genetic code

B  gene

C  coding sequence

D  genome.

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

B  Single-stranded genomes have a higher rate of mutation

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

D  using the formula : G-A=C+T

A  5’TGCAAT3’

B  5’TAACGT3’

C  5’UAACGU3’

D  3’UAACGU5’

E  5’UGCAAU3’

A  confocal

B  scanning electron

C  transmission electron

D  fluorescence

E  bring-field

F  phase-contrast

A  somewhere outside of the catalytic domain

B  in allosteric activator domain

C  At either the N or C terminus

D  in the exact center of the protein

E  inside the catalytic domain

A  Protein

B  starch

C  cellulose

D  DNA

E  glucose

A  genomics

B  systems biology

C  structural biology

D  proteomics

A  a β-Pleated Sheet

B  a disulfide bond

C  an amino group

D  a peptide bond

A  2,3,5

B  2,4,5

C  1,4,5

D  2,3,5

E  1,2,4,5

A  filtering

B  absorption

C  wavelength

D  intensity

A  methane

B  water

C  propane

D  molecular oxygen

A  vesicle transport

B  cell motility

C  membrane support

D  cell division

A  RNA can carry information and catalyze chemical reactions

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

C  Fossil evidence of such a molecule was recently discovered.

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

A  400g

B  125g

C  160g

D  200g

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  protein

B  fiber

C  fat

D  sugar

A  Both contain DNA molecules

B  Both can reproduce on their own outside of the cell

C  Both have bacteria-like polysaccharide cell walls

D  Both contain endoplasmic reticulum and Golgi bodies.

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 a cofactor binding site

C  at an allosteric site

D  Such mutations could occur anywhere with equal probability

E  in or near the active site

A  nuclear envelope

B  Mitochondrial membrane

C  Golgi network

D  plasma membrane

A  ATP

B  Ribozyme

C  RNA

D  complex cells

E  DNA

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  ionic bonds

B  nonpolar covalent bonds

C  van der Waals interactions

D  hydrogen bonds.

E  polar covalent bonds

A  amenability to genetic manipulation

B  ability to grow under controlled conditions.

C  rapid rate of reproduction

D  genome partially or completely sequenced

E  All of the above is correct.

A  It is impossible to tell from the information given.

B  10

C  40

D  20

E  80

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

A  covalent bonds

B  ionic bonds

C  hydrogen bonds

D  van der Waals interactions

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

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

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  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.

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

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