BIO CHEM I Flashcards
A reaction with a delta G of zero:
Requires energy
Is at equilibrium
Is spontaneous
None of the above
Is at equilibrium
A solution with a pH of 5 is:
Acidic
Basic
Neutral
None of the above
Acidic
Alcohols contain a _________ group.
Hydroxyl
Sulfur
Phenol
None of the above
Hydroxyl
Biologically important noncovalent bonds include:
Van der Waals interactions
Hydrogen bonds
Electrostatic interactions
All of the above
All of the above
Entropy is ______________.
The degree of disorder of a system
The degree of energy of a system
A type of noncovalent bond
A type of covalent bond
The degree of disorder of a system
The DNA of a eukaryotic cell is stored within the _____________.
Lysosome
Nucleus
Ribosome
Endoplasmic Reticulum
Nucleus
The term “kinetics” refers to:
The energy required for a reaction
The disorder of a system
The speed at which a reaction will occur
The pH of a solution
The speed at which a reaction will occur
______ is the process by which the information in DNA is transferred to RNA.
Translation
Replication
Transcription
Ubiquitination
Transcription
The strongest bonds that are present in biochemical compounds are ______________.
Ionic bonds
Covalent bonds
Hydrogen bonds
Van der Waals interactions
Covalent bonds
A chiral compound _________________.
Is non-superimposable on its mirror image
Is the same as its mirror image
Is inorganic
Contains a sulfur atom
Is non-superimposable on its mirror image
A zwitterion ________________.
Has a positive charge
Has a negative charge
Overall, has no charge
All of the above
All of the above
All amino acids contain both a(n) ______ and a(n) ________ group.
Hydrogen, carbohydrate
Amine, carboxylic acid
Sulfur, amine
None of the above
Amine, carboxylic acid
Essential amino acids:
Are made by organisms
Must be obtained from dietary sources
Are made from DNA
Include proline
Must be obtained from dietary sources
The first reaction of amino acid degradation is?
Deamination
Decarboxylation
Cyclization
None of the above
Deamination
The only amino acid without a chiral center is _____________.
Proline
Methionine
Alanine
Glycine
Glycine
There are ______ common amino acids.
15
25
20
10
20
______ is the initiating amino acid of most newly synthesized proteins.
Proline
Alanine
Glycine
Methionine
Methionine
_____________ is an example of a hydrophilic amino acid.
Lysine
Leucine
Methionine
Tryptophan
Lysine
_____________ is an example of a hydrophobic amino acid.
Glutamic acid
Lysine
Arginine
Leucine
Leucine
Nonessential amino acids are:
Provided in the diet
Synthesized by mammals
Both A and B
None of the above
Both A and B
Provided in the diet
Synthesized by mammals
A(n) _________ is a short protein tag that attaches to and targets proteins for degradation.
Peptide
Ubiquitin
Alanine
Urea
Ubiquitin
Protein secondary structures include:
Loops
alpha helices
beta sheets
All of the above
All of the above
Protein synthesis is carried out by __________.
Mitochondria
Chromosomes
Ribosomes
Lysosomes
Ribosomes
The amino acid _______ places certain constraints on the protein backbone.
Leucine
Alanine
Proline
Glycine
Proline
The difference between a peptide and a protein is ____________.
Length
Bond formation
Subunits
All of the above
Length
The formation of a dimer refers to a protein’s ___________.
Primary structure
Tertiary structure
Secondary structure
None of the above
None of the above
The tertiary structure of a protein refers to its __________.
Overall 3D shape
Multisubunit composition
Amino acid sequence
None of the above
Overall 3D shape
The ______ carries out protein degradation.
Proteosome
Lysosome
Ribosome
Chromosome
Proteosome
________ aid in protein folding.
Chromosomes
Chaperones
Proteosome
None of the above
Chaperones
Amino acids are linked by a(n) _______ bond to form a protein.
Hydrophobic
Peptide
Ionic
All of the above
Peptide
Each of the following is one of the six classes of enzyme catalysts, except:
Ligases
Kinases
Transferases
Isomerases
Kinases
Enzymes within metabolic pathways can be regulated by ____________.
Allosteric enzymes
Post translational modifications
Localization
All of the above
All of the above
n competitive inhibition, the competitor binds to ________________.
The substrate
The substrate binding site
Distant to the substrate binding site
None of the above
The substrate binding site
The maximum rate at which an enzyme can convert substrate to product
The maximum amount of product produced in a reaction
The free energy of a reaction
None of the above
The maximum rate at which an enzyme can convert substrate to product
Kinases are enzymes that add a(n) _____ group to proteins.
Hydrogen
Nitrogen
Phosphoryl
Alcohol
Phosphoryl
The rate of an enzymatic reaction can be regulated by __________.
pH
Temperature
Concentration
All of the above
All of the above
_______ are derived from vitamins and are necessary for the function of some enzymes.
Helicases
Cofactors
Carbohydrates
None of the above
None of the above
________ is an example of a post translational modification of a protein.
Acetylation
Phosphorylation
Ubiquitination
All of the above
All of the above
Enzymes act as catalysts to ___________________.
Decrease the activation energy of a reaction
Increase the rate of a reaction
Mediate the conversion of substrate to product
All of the above
All of the above
An important product of glycolysis is ____________.
Glucose
ATP
Lectins
Both A and B
ATP
Carbohydrates are also known as ____________.
Sugars
Starches
Fats
A and B
A and B
Sugars
Starches
Carbohydrates are commonly used as ___________.
A source of energy
An amino acid source
A source of nitrogen
None of the above
A source of energy
Disaccharides are formed by ______________.
The condensation of two monosaccharides
Hydrolysis of a polysaccharide
Both A and B
Neither A or B
Both A and B
The condensation of two monosaccharides
Hydrolysis of a polysaccharide
animals, the process of gluconeogenesis occurs in the __________.
Fat
Liver
Spleen
Gall bladder
Liver
Lectins are ____________.
DNA binding proteins
Lipid binding proteins
Carbohydrate binding proteins
None of the above
Carbohydrate binding proteins
Protein glycosylation takes place in the ____________.
Nucleus
Cell membrane
Golgi apparatus
Lysosome
Golgi apparatus
Starch is an example of a ___________.
Monosaccharide
Disaccharide
Polysaccharide
Trisaccharide
Polysaccharide
Sucrose, aka table sugar, is composed of ____________.
Glucose
Fructose
Both A and B
Neither A or B
Both A and B
Glucose
Fructose
Fischer projections convey useful information about _____________.
Electron positions
3D structural positioning
Resonance
Bond lengths
3D structural positioning
ATP facilitates the occurrence of energetically unfavorable reactions via ___________.
Phosphoryl transfer
Energy coupling
ATP to ADP conversion
All of the above
All of the above
Both DNA and RNA are composed of three important parts, which are:
Glucose, side chains, phosphate group
Nitrogenouse base, phosphate group, sugar
Nitrogenous base, peptide bond, lipid
Phosphate group, sugar, side chain
Nitrogenouse base, phosphate group, sugar
Cytosine makes _______ with guanine when base paired in DNA.
Three hydrogen bonds
Two hydrogen bonds
Three peptide bonds
Three covalent bonds
Three hydrogen bonds
DNA is synthesized in a _____ direction.
3’ to 5’
5’ to 3’
Top to bottom
Left to right
5’ to 3’
Double stranded DNA takes on a __________ structure.
Beta sheet
Looped
Double helix
A-form helix
Double helix
In the cell, _____ is used as energy currency.
UTP
Fat
ATP
AMP
ATP
The correct pairing of bases in DNA is __________.
A-G; C-T
A-C; G-T
A-T; C-G
A-U; C-G
A-T; C-G
The DNA chromosome of bacteria consists of ___________.
A circular double stranded DNA
A circular single stranded DNA
A linear double stranded DNA
A linear single stranded DNA
A circular double stranded DNA
What is the base that is used by RNA but not DNA?
Guanine
Uracil
Thymine
Cytosine
Uracil
What type of base is adenine?
a. Purine
b. Pyrimidine
c. Both A and B
d. Neither A and B
Purine
The sugar used in RNA is ____________.
Deoxyribose
Dideoxyribose
Ribose
Glucose
Ribose
Fatty acids contain ________________.
A carboxyl group and hydrocarbon chain
A phosphate group and hydrocarbon chain
A sugar group and hydrocarbon chain
Only a hydrocarbon chain
A carboxyl group and hydrocarbon chain
Glycerolphospholipids create a double layer lipid membrane, such as the cell membrane, because of _____________.
Their high energy phospho group
Their hydrophilic heads and hydrophobic tails
Their unsaturated tails
Their ability to covalently bond to each other
Their hydrophilic heads and hydrophobic tails
Lipids are the starting material of important biological molecules, including ___________.
Steroids
DNA
Carbohydrates
All of the above
Steroids
Lipids play a role in which of the following?
Energy storage
Membrane structure
Cell signaling
All of the above
All of the above
Phospholipids can be composed of _______________.
Fatty acids
Glycerol
Sphingomyelin
All of the above
All of the above
The difference between saturated and unsaturated fatty acids is ______________.
The number of hydrocarbon chains
The length of the hydrocarbon chain
The presence of single or double bonds in the hydrocarbon chain
All of the above
The presence of single or double bonds in the hydrocarbon chain
The fluidity of the cell membrane is determined by ___________.
The lipid content
The amount of cholesterol present
The number of saturated and unsaturated fatty acids present
All of the above
All of the above
Triacylglycerol is composed of ___________.
Glycerol and fatty acids
Glycerol and long chain alcohols
Glycerol and cholesterol
None of the above
Glycerol and fatty acids
Which of the following are composed of lipids?
Waxes
Cholesterol
Triacylglecerols
All of the above
All of the above
Glycolysis gives a net yield of __________.
8 moles ATP per glucose
1 mole ATP per glucose
2 moles ATP per glucose
3 moles ATP per glucose
2 moles ATP per glucose
Glycolysis takes place in the _________.
Cytosol
Mitochondria
Nucleus
Golgi
Cytosol
In the citrate cycle, energy from the oxidation of acetyl-CoA is converted to _____________.
4 moles ATP, 6 moles FADH2
3 moles, NADH, 1 mole FADH2, 1 mole GTP, 2 CO2
2 moles NADH, 2 moles FADH2, 2 ATP
1 mole NADH, 1 mole GTP, 4 CO2
3 moles, NADH, 1 mole FADH2, 1 mole GTP, 2 CO2
Oxidative phosphorylation occurs in the _______.
Nucleus
Cytosol
Mitochondria
Cell membrane
Mitochondria
The complete oxidation of glucose to CO2 and H2O results in a yield of __________.
38 ATP/glucose
42 ATP/glucose
60 ATP/glucose
32 ATP/glucose
32 ATP/glucose
The electron transport system links oxidation of NADH and FADH2 to _____________.
Glucose synthesis
Ethanol fermentation
ATP synthesis
GTP synthesis
ATP synthesis
The input and output of glycolysis is ____________.
Two molecules glucose, 6 molecules CO2
One molecule glucose, 2 molecules pyruvate
One molecule glucose, 4 molecules pyruvate
One molecule glycogen, 2 molecules pyruvate
One molecule glucose, 2 molecules pyruvate
The sugar on ATP is _______________.
Deoxyribose
Glucose
Cholesterol
Ribose
Ribose
The __________ is a hub of cellular metabolism because it links the oxidation of carbohydrates, fatty acids, and proteins to ATP synthesis.
TCA/citrate cycle
Urea cycle
Glycolysis cycle
Pentose pathway
TCA/citrate cycle
True or False: Glycolysis requires oxygen.
True
False
True
Under aerobic conditions, the pyruvate produced during glycolysis can go on to ________.
The pentose pathway
Oxidative phosphorylation
The urea cycle
All of the above
Oxidative phosphorylation
Rank the following, from highest to lowest, in terms of energy: AMP, ATP, ADP?
ATP, ADP, AMP
AMP, ADP, ATP
ADP, ATP, AMP
ATP, AMP, ADP
ATP, ADP, AMP
A Holliday Junction structure occurs during which process?
Recombination
Replication
Transcription
Translation
Recombination
DNA is synthesized in a _______ direction.
Left to right
Top to bottom
5’ to 3’
3’ to 5’
5’ to 3’
DNA replication is carried out by a ________ enzyme.
Helicase
Polymerase
Kinase
Topoisomerase
Polymerase
DNA replication is semi-conservative. What does this mean?
Half the total DNA is copied
Each DNA strand serves as a template during replication
Only some base pairs are altered during replication
None of the above
Each DNA strand serves as a template during replication
DNA serves as a template for which type of RNA?
mRNA
rRNA
tRNA
All of the above
All of the above
There are three types of RNA polymerases in eukaryotic cells. RNA polymerase I transcribes ______, RNA polymerase II transcribes _______, and RNA polymerase III mainly transcribes _________.
Introns, mRNA, rRNA
rRNA, mRNA, tRNA
tRNA, introns, rRNA
mRNA, tRNA, rRNA
rRNA, mRNA, tRNA
Which of the following are post-transcriptional modifications of RNA?
Cap addition
Poly A tail addition
Intron removal
All of the above
All of the above
_________ enzymes maintain the torsional stress of DNA.
Helicase
Topoisomerase
Kinase
Restriction
Topoisomerase
Activation of receptor tyrosine kinases results in ____________.
The opening of ion channels
The phosphorylation of the receptor
Membrane potential alterations
The exchange of GTP for GDP
The phosphorylation of the receptor
Intracellular pathways are altered through extracellular molecules binding to __________.
Polymerases
Ligases
Receptors
All of the above
Receptors
Molecules that play an important role in cell adhesion and structure include _________.
Integrins
Cadherins
Selectins
All of the above
All of the above
Steroids act as signaling molecules by __________________.
Binding to extracellular domains of receptor molecules
Binding to the plasma membrane
Binding to receptors internal to the cell
None of the above
Binding to receptors internal to the cell
True or false: Ligand binding to receptors can result in wide-spread gene expression changes via signal amplification.
True
False
True
Stimulation of a G protein coupled receptor results in __________.
The flow of ions through the receptor
Phosphorylation of the receptor
The exchange of GDP for GTP
None of the above
The exchange of GDP for GTP
ELISAs use __________, enabling the measurement of specific proteins in a solution.
PCR
Purification
Antibodies
None of the above
Antibodies
In a Southern blot, probes are used to _________________.
Hybridize to a specific sequence of DNA
Hybridize to a specific sequence of RNA
Amplify a specific piece of DNA
Degrade a specific piece of RNA
Hybridize to a specific sequence of DNA
PCR is a valuable tool for analyzing DNA because ___________________.
It allows for the exponential amplification of a small amount of starting material
It takes a short amount of time
The DNA sequence amplified need not be known
All of the above
All of the above
During SDS-PAGE, proteins are primarily separated according to their _______________.
Mass
Shape
Charge
All of the above
Mass
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