Exam 1 Flashcards
What is translation
the production of an amino acid sequence of a polypeptide
What is transcription?
genetic information in DNA is copied into a nucleotide sequence of RNA
What are the four levels of biological organization
molecular level, cellular level, organism level, and population level
Genetic variation results in changes from
gene mutations(heritable changes), changes in chromosome structure (segments of chromosome may be lost/rearranged) or changes in chromosome number (lost or gained)
Which structure in the central dogma contains chromatin?
the DNA structure
Which molecules are critical to RNA Processing?
snRNAs
The building blocks of DNA are
Nucleotides
Backbone of the DNA molecule is formed by
phosphodiester bonds
How many hydrogen bonds form between Cytosine and Guanine? How many bonds in Adenine and Thymine?
C/G- 3 Hydrogen Bonds
A/T- 2 Hydrogen Bonds
Based on Chargaff’s Rules, if Adenine makes up 30% of the bases in a certain DNA sample, what % of the bases must be Thymine? Cytosine and Guanine?
30% thymine
20% Cytosine
20% Guanine
A piece of DNA wound around 8 histone proteins make a structural unit known as
nucleosome
Ways in which an RNA strand differs from a DNA strand
contains ribose instead of deoxyribose
contains uracil instead of thymine
purine fo one strand of the DNA always pairs with what on the other strand
a pyrimidine
Genes that are found in regions of genome DNA associated with histones with high ACETYLATED tails are likely to be
Active
C-value paradox ?
No correlation between genome size and organism complexity
How many origins of replication are there in a bacterial chromosome
1
Where is the bacterial chromosome located?
nucleoid
Prokaryotic topoisomerase 1 functions to
relax negative supercoils
Quinolones kill bacteria by what mechanism
it inhibits DNA gyrase
what is found at the end of a eukaryotic chromosome
telomeres
areas of chromosomes that are highly condensed and transcriptionally inactive are called
heterochromatin
Where do kinetochores attach to chromosomes
centromere
Which enzyme synthesizes the majority of the DNA of an Okazaki fragment?
DNA polymerase 3
Which enzyme is responsible for removing supercoiling in the DNA strand ahead of the replication fork during replication?
DNA topoisomerase (gyrase)
What way is DNA synthesized
5’ to 3’
After receiving a sample of human cells, you determine that the enzyme telomerase is expressed in these cells. What conclusion can you make about the cells?
the cells are cancerous and the cells could be gamete producing cells
What of the following classes of RNA are produced by the action of the enzyme DICER?
siRNA-
Which of the following classes of RNA are involved in mRNA splicing
snRNA
Bacterial RNA polymerase 2 complexes have variable sigma subunits. What effect does this have?
the different complexes synthesize recognize different promoter sequences
In eukaryotic organisms, what RNA modification is important for mRNA stability?
3’ polyA tailing
What is the function of the Shine-Delgarno sequence in Prokaryotes?
it pairs with a region of rRNA to position the ribosome correctly to start translation
Which factors are involved in eukaryotic but not prokaryotic transcription?
chromatin remodeling
Following transcription, the RNA has a complementary sequence to
the template strand of DNA
which type of bond is created by ribosomes?
peptide
If you are looking at hemoglobin at the level that includes multiple amino acid chains and associated metal ions, what level of structure are you looking at?
quaternary
What function do tRNA (in prokaryotes) or tRNA (in eukaryotes) have?
they are always used to decode the first amino acid codon in all protein synthesized
In eukaryotic organisms, alternative splicing allows an organism to
carry fewer gens
Which of the following amino acids DO NOT exhibit “degeneracy”?
Tryptophan (Trp)
ribosomes are composed of
rRNA subunits and proteins
What class of enzyme is responsible for “charging” tRNAs?
aminoacyl-tRNA synthetase
In bacteria, the sequences that facilitates the binding of the mRNA to the ribosome is called the
Shine-Dalgarno sequence
The C-terminus of a polypeptide always contains
a carboxyl group
which of the following are TRUE of bacterial “promoters”?
they are cis-acting DNA sequences
which process uses a bacteriophage as an intermediary for the genetic information?
transduction
Bacterial cheeks that can participate in ________ are known as competent cells
transformation
After a conjugation bridge forms between bacterial cells, the protein complex that initiates DNA transfer is the….
relaxosome
small circular pieces of DNA, separate from the bacterial chromosome, are called _____
Plasmids
Which of the following acts to protect COVID viral RNA?
nucleocapsid protein
