BIOCHEM - PRELIM Flashcards
B-N-glycosidic bond is formed between
CYTOSINE AND RIBOSE
Which of the following groups of chemical elements are considered as trace elements?
Se, Fe, Cu, Zn
What is the buffer systems in the blood is regulated by the lungs and kidneys?
BICARBONATE BUFFER SYSTEM
Which is the true of a replicating segment of eukaryotic DNA that has three origins of replication?
THERE WILL BE 6 REPLICATION FORKS
What happens to the Carboxyl group when it donates a proton?
NEGATIVELY CHARGED
The chirality of an amino acid results from the fact that it’s a carbon
IS BONDED TO FOUR DIFFERENT CHEMICAL GROUPS
Which of the following is TRUE for Fully Protonated form of an Amino Acid?
ALL HYDROGEN IONS ARE
ATTACHED (because, hydrogen are protons)
Specific type of covalent bond that links several amino acids together to form peptides or proteins
PEPTIDE BOND
Of the 20 standard amino acids, only () is not optically active. The reason is that its side chain ().
GLYCINE; is a hydrogen atom
The PO4 end of the DNA is also known as
5- PRIME END
The resonance structure that can be drawn for the peptide bond indicate that the peptide bond
HAS PARTIAL DOUBLE BOND CHARACTER
Packaging site of cellular secretions:
GOLGI
Why is pKa an important property of a compound?
IT IS THE ABILITY OF A COMPOUND TO TAKE UP OR DONATE PROTONS INTO SOLUTION
It protects the separated DNA from destruction by nucleases?
SSB
When two cysteine molecules dimerize, what happens to the R groups present?
THEY REACT WITH EACH OTHER TO PRODUCE A COVALENT DISULFIDE
Which statement is false regarding polypeptides?
CAN FORM UNLIMITED NUMBER OF CONFIGURATIONS
Two amino acids of the standard 20 contain sulfur atoms. They are:
CYSTEINE and METHIONINE
The chromosome of a bacterium has 22 percent guanine. What is the percent composition of cytosine in this chromosome?
22
What class of lipids is usually present in biological membranes?
PHOSPHOLIPIDS
What cation serves as a co-factor and is required by the DNA polymerase for its activity?
Mg
What forms phosphodiester bonds between fragment of DNA during replication?
DNA LIGASE
Unfolding of a protein can be termed as
DENATURATION
In condensation process, how many hydrogen atoms are removed?
2
Which is TRUE about a single-stranded DNA?
THE TOTAL NUMBER OF PURINES IS NOT EQUAL TOTAL NUMBER OF PYRIMIDINES
Amino acids that cannot participate in hydrogen bonding?
VALINE
Which of the following is TRUE regarding peptide nomenclature?
C-TERMINAL AMINO ACID RESIDUE KEEPS ITS FULL AMINO ACID NAME
Amino acid containing nonpolar, aliphatic R groups
Ala, Leu and Gly
The following is made up of nucleotides?
COENZYME, CYCLIC-AMP, ATP
It is the amount of heat, per unit mass of liquid, required to raise the temperature by one degree Celsius.
SPECIFIC HEAT
What is the amino acids is the most hydrophobic in nature?
LEUCINE
Which is true about DNA denaturation?
IT OCCURS BY HEATING
If the NH2 group is oriented to the right it is a
-D ISOMER
Which is an RNA sequence?
GCAUAC
What type of amino acid R group is involved in Electrostatic interaction interactions that contribute to tertiary protein structure?
ACIDIC AND BASIC R GROUP
What is the correct classification of polysaccharides?
STORAGE AND STRUCTURAL
are conjugated proteins that contain carbohydrates or carbohydrate derivatives in addition to amino acids
GLYCOPROTEINS
What is the name of the organic molecule that contains a carboxyl group and amino group?
PROTEIN, AMINO ACID
What are places where protein play an important role?
ENZYME PRODUCTION
If pK1= 2.34 and pK2 = 9.60, then the isoelectric point pI is?
5.97
Proteins that are generally insoluble in water and they are involved in structural functions
SELENOCYSTEINE
What liquids has the highest specific heat?
WATER
Which statement is mismatched?
THE QUARTENARY STRUCTURE IS RELATED TO THE BASIC LINEAR STRUCTURE OF A PROTEIN
The two strands of the DNA helix are held together by
HYDROGEN BONDS BETWEEN THE BASES
What groups of chemicals can be used to denature proteins?
ALKALOIDAL REAGENTS, INORGANIC ACIDS, HEAVY METALS
Adenine forms a covalent bond with a nucleic sugar at
N9
A type of protein structure which involves the associations among the peptide chains present in a multimeric protein
QUARTERNARY
In eukaryotes, histones can bind with DNA because histones have amino acids that are
POSITIVELY CHARGED
Amino acid with hydroxyl OH group include
TYROSINE
Which of the following is not the classified form of conjugated proteins?
COMPLETE PROTEINS
It is a process of modifying the molecular structure of a protein. It involves the breaking of many of the weak linkages, or bonds (e.g., hydrogen bonds), within a protein molecule that are responsible for the highly ordered structure of the protein in its natural (native) state.
DENATURATION
It provides the OH group to which the DNA polymerase adds the new nucleotide to the growing DNA strand?
RNA PRIMER
In DNA replication, which enzyme is responsible for the elongation of the new DNA strand?
DNA POL III
Which was NOT observed in the experiment that showed that DNA replication is semiconservative?
The daughter DNAs in the first replication consisted of parent double-stranded DNA (15N strand-15N strand) and a DNA having two new strands (14N strand-14N strand).
Defined as the amount of heat needed to turn 1g of a liquid into a vapor.
HEAT OF VAPORIZATION
Which is a pyrimidine in the DNA?
THYMINE
What is an example of Fibrous protein?
COLLAGEN
Zwitterions are?
EXIST IN A NEUTRAL pH
The monomers of nucleic acids are
NUCLEOTIDES
What introduces a swivel point in advance of the replication fork to relieve the torsional strain caused by unwinding of the DNA double helix?
TOPOISOMERASE
A buffer solution is composed of 0.25M acetic acid and 1.20M sodium acetate. What would be the pH of the solution? Select the closest value. (pka of acetic acid is 4.74)
5.00
This hormone is also called as Anti-Diuretic Hormone and contains 9 amino acid residues
VASOPRESSIN
Which of the following statements concerning secondary protein is TRUE?
IN AN A-HELIX, ALL THE AMINO ACID R GROUPS LIE OUTSIDE THE HELIX
Arrange the following in order of molecular complexity (start from the the most complex level):
ORGANELLE > SUPRAMOLECULAR COMPLEX > BIOMOLECULES > METABOLITES > INORGANIC PRECURSORS
The three-letter abbreviation for the amino acid asparagine is
ASN
It refers to particularly stable arrangements of amino acid residues in a protein that give rise to recurring patterns?
SECONDARY STRUCTURE
Which part of the amino acid gives it uniqueness?
SIDE CHAIN
Polarity compounds are also “water-loving”
TRUE
Which is NOT true about the synthesis of the lagging strand?
THE DIRECTION OF SYNTHESIS IS TOWARD THE REPLICATION FORK
Amino acid are ampholytes because they can function as either a(n)
ACID OR BASE
Which is NOT true about prokaryote and eukaryote DNA replication?
EUKARYOTES REQUIRE RNA PRIMERS BUT PROKARYOTES DO NOT
What amino acid has indole ring in its side chain?
TRYPTOPHAN
The acid component of the buffer:
ADDS MORE H+ TO THE SOLUTION, RELEASE H+
The smallest amino acid is
GLYCINE
Which pair of amino acid absorbs the UV light at 280nm?
TRP AND TYR
Which of the following statements concerning secondary protein is TRUE?
Both a-helix and b-pleated sheet structures can be present in the same protein.
Which base pair is not found in DNA?
ADENINE- GUANINE
Which statement is not true about the side chains of amino acids?
ARE ALWAYS CHARGED AND PRESENT IN ALL AMINO ACID
Peptide bond is a?
COVALENT BOND
Protein folding is?
RESULTS IN HYDROPHILIC EXTERIOR
Which of the following is correct with respect to the amino acid composition of proteins?
Proteins with different functions usually differ significantly in their amino acid composition
A branch of science that describes the molecular nature of life processes.
BIOCHEMISTRY
Amino acids are building blocks of
PROTEIN AND POLYPEPTIDES
The peptide bond in proteins is
PLANAR, USUALLY FOUND IN TRANS CONFORMATION
The site of formation of new DNA is called
REPLICATION FORK
Derivatives of purines and pyrimidines that have a sugar linked to a ring nitrogen
NUCLEOSIDES
What amino acids is the uncharged derivative of an acidic amino acid?
GLUTAMINE
Specific type of covalent bond that links several monosaccharides together to form carbohydrates.
GLYCOSIDIC BOND
This is an important small organic biochemical compound that supplies energy to numerous chemical reactions.
ATP
Which is NOT required in DNA synthesis
dUTP
Ten base pairs per complete turn of the helix is a characteristic of
B-DNA
The alpha helix is an example of which of the following structural properties of proteins?
SECONDARY
Command center of the cell:
NUCLEUS
Which is a wrong nomenclature?
DEOXYTHYMINE
Which is NOT true regarding the sugar in DNA?
LACKS O AT C1-PRIME
What happens if the pH of the solution is greater than the pKa of the amino acid?
AMINO ACID WILL BE DEPROTONATED
Arrange the following in order of molecular complexity (start from the simplest level):
METABOLITES > MONOSACCHARIDES > RIBOSOMAL COMPLEX > CELL
Which statement is FALSE?
THE TWO COILED STRANDS OF DNA RUN IN PARALLEL DIRECTIONS
