Exam 1

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

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

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

E  Covalent bonds require carbon whereas ionic bonds do not.

A  The infectious strain cannot be killed by heating

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 mice had lost their immunity to infection with S. pneumoniae

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

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

C  unique three-dimensional shape of the fully folded polypeptide

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  translation, replication, transcription

C  replication, transcription, translation

D  translation, transcription, replication

A  The phosphate group

B  The base

C  The sugar and the base

D  The sugar

E  All nucleotide are the same

A  A temperature gradient

B  A density gradient

C  A salt gradient

D  A pH gradient

A  the rate of the reaction at ½ the maximum rate

B  recognition of the substrate by the enzyme

C  the maximum velocity of the catalytic reaction

D  the rate of product release by the enzyme

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

B  using the energy of ATP hydrolysis to move nucleosomes

C  modifying the N-terminal tails of core histones

D  recruiting other enzymes

A  heterochromatization

B  barrier destruction

C  Euchromatin depletion

D  epigenetic inheritance

A  protein degradation

B  protein secretion

C  membrane association

D  nuclear translocation

A  substrate-level phosphorylation

B  allosteric activation

C  oxidative phosphorylation

D  feedback inhibition

A  ΔH – T ΔS >0

B  ΔH – T ΔS <0

C  ΔH – T ΔS =0

D  ΔH and ΔS are both positive and TΔH >H

E  things are moving from higher to lower concentration

A  are catalyzed by enzyme

B  take place very slowly

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  Enzymes are proteins that function as catalysts

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

C  Enzymes reduce activation energy for the reactions they catalyze

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

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  non-competitive inhibition and positive feedback.

B  irreversible inhibition and destruction of the enzyme molecule

C  competitive and non-competitive inhibition

D  negative feedback and allosteric inhibition/activation

E  negative feed-forward inhibition and homosteric activation

A  every chemical transformed represents a loss of energy

B  the synthesis of large molecules from small molecules is exergonic

C  The Earth is an open system

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

E  entropy increases in a closed system

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 adopts a new, stable conformation.

B  The polypeptide returns to its original conformation.

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

D  The polypeptide remains denatured.

A  displacement of histone H1

B  recruitment of remodeling complexes

C  gene silencing

D  increase in gene expression

A  C3H603

B  C18H36018

C  C6H1005

D  C18H32016

E  C18H30015

A  heterochromatin

B  chromosome

C  euchromatin

D  nucleosomes

E  nuclear pores

A  gene

B  coding sequence

C  genome.

D  genetic code

A  using the formula : G-A=C+T

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

C  Single-stranded genomes have a higher rate of mutation

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

A  5’UGCAAU3’

B  3’UAACGU5’

C  5’TAACGT3’

D  5’UAACGU3’

E  5’TGCAAT3’

A  bring-field

B  transmission electron

C  phase-contrast

D  scanning electron

E  fluorescence

F  confocal

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  glucose

B  Protein

C  starch

D  DNA

E  cellulose

A  genomics

B  systems biology

C  proteomics

D  structural biology

A  a β-Pleated Sheet

B  an amino group

C  a disulfide bond

D  a peptide bond

A  2,4,5

B  2,3,5

C  1,2,4,5

D  2,3,5

E  1,4,5

A  intensity

B  filtering

C  wavelength

D  absorption

A  molecular oxygen

B  water

C  propane

D  methane

A  vesicle transport

B  cell motility

C  cell division

D  membrane support

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  800g

C  200g

D  160g

E  125g

A  primarily producing proteins for secretion

B  constructing an extensive cell wall or extracellular matrix

C  digesting large food particles

D  primarily producing proteins in the cytosol

E  enlarging its vacuole

A  sugar

B  protein

C  fiber

D  fat

A  Both can reproduce on their own outside of the cell

B  Both contain DNA molecules

C  Both have bacteria-like polysaccharide cell walls

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

E  Both contain endoplasmic reticulum and Golgi bodies.

A  Such mutations could occur anywhere with equal probability

B  in or near the active site

C  at a cofactor binding site

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

E  at an allosteric site

A  Mitochondrial membrane

B  plasma membrane

C  Golgi network

D  nuclear envelope

A  DNA

B  complex cells

C  ATP

D  Ribozyme

E  RNA

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  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  10

B  80

C  It is impossible to tell from the information given.

D  40

E  20

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  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  ionic bonds

B  van der Waals interactions

C  covalent bonds

D  hydrogen 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  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.

C  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

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

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