Exam 1 Flashcards
which of the following is not true regarding living organisms ?
all organisms are capable of resurrection
Recall Pasteur’s experiment on spontaneous generation. If he had just warmed the nutrient-rich broth,rather than boiled it , what would have been the likely outcome of his experiment ? Cells would ____ ?
Have appeared in both flasks
A covalent chemical bond is one in which ?
Outer shell electrons of two atoms so as to satisfactorily fill their respective orbitals
How may electrons are involved in a single covalent bond ?
two
In a single molecule of water , two hydrogen atoms are bonded to a single oxygen atom by
polar covalent bonds
when the atoms involved in a covalent bond have the same electronegativity , what type of bond results?
a nonpolar covalent bond
the partial negative charge at one end of water molecule is attracted to the partial positive charge pf another water molecule. What is this attraction called ?
hydrogen bond
what component of amino acid structure varies among different amino acids ?
the components of the R-group
Which one of the following is NOT a component of each monomer used to make proteins ?
a phosphorus atom, P
you disrupt all hydrogen bonds in a protein . What level structure will be preserved ?
primary structure
Which type of interaction stabilizes the a-helix and the b-pleated sheet structures of proteins ?
hydrogen bonds
what type of interaction is directly responsible for the formation of secondary structure ?
hydrogen bonds between sections of the polypeptide backbone
the tertiary structure of a protein is the ?
unique shape of the fully folded polypeptide
Nucleic acids are polymers made up of which of the following monomers ?
nucleotides
An enzye has total of four active sites. When you denature the molecule and study its composition ,you find that each active site occurs on a different polypeptide. Which of the following hypotheses does this observation support ?
the protein has quaternary structure
what is the difference between a ribonucleotide and a deoxyribonucleotide ?
riobnucleotides have a hydroxyl group on the 2 carbon of their subunit
Which of the following uncludes all of the pyrimidines found in RNA and DNA ?
Cytosine , uracil & thymine
When nucleotides polymerize to form a nucleic acid ?
a covalent bond forms between the sugar of one nucleotide and the phosphate of a second
Which of the following descriptions best fits the class of molecules known as nucleotides ?
a base , a phosphate group and a sugar
The difference between the sugar in DNA and the sugar in RNA is that the sugar in DNA ?
contains one less oxygen atom
compare proteins to nucleic acids. Which of the following is TRUE ?
Both have primary and secondary structure
Adouble-stranded DNA molecule contains a total of 120 purines and 120 pyrimidines. DNA molecule could be composed of ?
120 thymine and 120 adenine molecules
Which of the following statements best summarizes the difference between DNA and RNA
DNA nucleotides contain a different sugar than RNA
Which of the following can vary among monosaccharides ?
the number of carbon atoms
what is the difference between an aldose sugar and a ketose sugar ?
the position of the carbonyl group
All of the following are polysaccharides EXCEPT
ribose
Lactose, a sugar in milk, is composed of one glucose molecule joined by a glycosdic linkage to one galactose molecule. How is lactose classified ?
a disaccharide
A glycosidic linkage is analogous to which of the following in proteins ?
a peptide bond
Cellulose is
a major structural component of plant cell walls
Which of the following is NOT a polymer ?
ribose
List the two components of theory
Pattern & Process
The scientific name for baker yeast , Saccharomyces cerevisiae. Which part of this name consisting of the genus.
saccharomyces
The element Calcium has 20 proton. How many electrons are found in the outer orbital ?
Two
This covalent bond forms the primary structure of proteins .
peptide bond
This type of bond must be broken for water to vaporize
Hydrogen bond
Name the sugar found in DNA ?
Ribose
This covalent bond between two carbohydrate
Glycosidic bond
Name the secondary structures of DNA
Double helix
Animal store sugar in this molecule
glycogen
This chemical bonds involve the sharing of electrons between atoms
Non polar covalent bond
List the pyrimidine found in nucleic acid
Cytosine , Uracil & Thymine
