Molbio Lec Unit 2 Flashcards
True or False: Organisms contain genetic material that governs an individual is characteristics and is transferred from progeny to parent
False: parent to progeny
It is the genetic material of all living organisms and some viruses
Deoxyribonucleic acid (DNA)
It is the genetic material of certain viruses
Ribonucleic acid (RNA)
TRUE OR FALSE: In prokaryotes and eukaryotes, the DNA is may be double-or-single stranded DNA or RNA, where as viruses the genetic material is always double stranded
FALSE: In prokaryotes and eukaryotes, the DNA is always double stranded, where as viruses the genetic material may be double-or-single stranded DNA or RNA
Four nitrogen bases of DNA
Adenine, cytosine, guanine, and thymine
Four nitrogen bases of RNA
Adenine, cytosine, guanine, uracil
These are the units of measure for nucleic acids
Nt/bp
It is the unit of length for single-stranded nucleic acids
nt
It is the unit of length for double-stranded nucleic acids
Base pairs (bp)
Three major types of DNA
Right handed A- DNA
Right handed B- DNA
Left handed Z- DNA
It is a macromolecule made of nucleotides bound together by the phosphate and hydroxyl groups on their sugars
NUCLEIC ACIDS
Are the products of transcription and translation of the nucleic acids
PROTEINS
Is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms and some viruses
DNA
3 components of DNA
Deoxyribose (a pentose sugar)
Base (adenine, guanine, cytosine, and thymine)
Phosphate
4 different levels of DNA
Primary
Secondary
Tertiary
Quaternary
Nucleoside + phosphate =?
Nucleotide
What are the purine nucleosides?
Adenosine
Guanosine
Pyrimidine nucleosides
Cytidine
Uridine
This type of DNA is biologically the most common
B-DNA
The ideal B-DNA has ___ base pairs per turn ( _____ rotation of helix)
10 base pairs; 360 degrees
Base pairs of B-DNA are _____ nm apart
0.34 nm
Minor groove is narrow, shallow
Major groove is wide, deep
B- DNA
This type of DNA is the most stable
B-DNA
This structure exists when plenty of water surrounds molecule
B-DNA
Wider and flatter than B-DNA
A-DNA
11 base pairs per turn
A-DNA
Minor groove: broad shallow
Major groove: Narrow and deep
A- DNA
Observed when less water is present
A-DNA
A-DNA has been observed in two context:
- Active site of DNA polymerase (~3bp)
- Gram (+) bacteria undergoing sporulation
Seen in high salt concentrations
Z-DNA
12 base pairs per turn
Z-DNA
Minor groove: deep
Major groove: none
Z-DNA
Distance between adjacent base of A-DNA
0.23 nm
Distance between adjacent bases of Z-DNA
0.38 nm
Is a polymer of ribonucleotides linked together by phosphodiester linkage
RNA
3 main component of RNA
Phosphate group
Sugar ( ribose)
Nitrogenous base
It is made of a 6 member ring, fused to a 5 member ring
Purines
What are the purines
Adenine
Guanine
Made of a 6 member ring
Pyrimidine
What are the pyrimidine in RNA
Cytosine
Uracil
True or False:
Adenine forms 3 hydrogen bonds with Uracil. Similarly, Guanine is bonded with Cytosine with 2 hydrogen bonds
False:
Adenine forms 2 hydrogen bonds with Uracil. Similarly, Guanine is bonded with Cytosine with 3 hydrogen bonds
Key activator of innate immune response
Double stranded RNA (dsRNA)
These are regions held together by hydrogen bonds
Complementary regions
This region have bases projecting away from double stranded regions
Non complementary regions
Types of RNA
Messenger RNA
Transfer RNA
Ribosomal RNA
The 5’ terminal end is capped by 7-methyl guanosine triphosphate cap
Messenger RNA
It stabilizes mRNA by protecting it from 5’ exonuclease
MRNA
Messenger RNA:
The ____ is involved in the recognition of mRNA
Cap
Messenger RNA:
The ____ prevents the attack by 3’ exonucleases
The tail
It is the smallest RNA
Transfer RNA (t-RNA)
They have 74-95 nucleotide residues
Transfer RNA
Transfer RNA: they transfer the amino acids from ___ cytoplasm to the protein synthesizing machinery
Cytoplasm
TransferRNA are also called _____ is the only RNA species that contains the ______
Adapter molecules tRNA; nucleoside thymidine
What kind of structure is that The nucleotide sequence of all the tRNA molecules allows extensive intrasand complementarity that generates a secondary structure
Primary structure
This type of structure: each single tRNA shows extensive internal base pairing and acquires a clover leaf like structure
Secondary structure
What are under the secondary structure
Acceptor arm
Anticodon arm
The L shaped tertiary structure is formed by further folding of the clover leaf due to hydrogen bonds between _____ and _____ arms
T and D ARMS
Is the RNA component of the ribosome
Ribosomal ribonucleic acid
Tertiary structure of trna constitutes the predominant material within the ribosome, which is approximately ____ and _____ by weight
60% rRNA
40% PROTEIN
The ribosomal RNAs form two subunits, the ____ and ______
Large subunit
Small subunit
This type of subunit acts as a ribozyme, catalyzing _____
LSU; peptide bond formation
Major types of small RNA molecules
Small nuclear RNA
Small nucleolar RNA
Micro RNA and short interfering RNA
THIS TYPE OF SMALL RNA IS INVOLVED IN MRNA SPLICING
Small nuclear RNA
This type of small RNA molecule directs the modification of ribosomal RNAs
Small nucleolar RNA (SNORNA)
This type of small RNA molecule regulates gene expression
Micro RNA and short interfering RNA
Anticancer drugs
5-bromouridine (5BrdU)
Cytosine arabinoside (ara-C)
Antiviral therapy
HIV-AIDS (retrovir, AZT)
HERPES AND VARICELLA ACYCLOVIR, ZOVIRAX
It is an organic chemical compound related to another by substitution of atoms with other groups
Analogue
Are prepared by altering the base ring or sugar moeity
Nucleotide analogues
Anti-tumor agents used in chemotherapy
- interfere with the synthesis of DNA and thereby preferentially kill rapidly dividing cells such as tumor cell
6-mercaptopurine
5-fluorouracil
Anti-viral drugs
AZT (azidothymidine or zidovudine) - HIVE
Lamivudine ____ hepatitis b
Is a structural analogue of hypoxanthine is used to treat gout
Allopurinol
The drug is an inhibitor of the enzyme xanthine oxidase which converts hypoxanthine to uric acid
Allopurinol
Biomedical importance of nucleotides
Metabolic regulators such as cAMP
CTP and UTP are used in the production of biomolecules
Synthetic analogues used in medicine
The genetic material of prokaryotes is ___
Double stranded DNA
The complete set of metaphase chromosomes in a eukaryotic cell is
Karyotype
True or false: the histones are constant from cell to cell within an organism, whereas non histones vary significantly between cell types
True
True or false: the more condensed a region of a chromosome is, the less likely it is that the genes in that regions will be active
True
True or false: Prokaryotic genomes consist mostly of unique DNA sequences, they only have a few repeated sequences and genes. Eukaryotes gave both unique and repetitive sequences in the genome
True
Is the process of copying genetic information in DNA into RNA
Transcription
Recognition factors
Initiation
Elongation
Termination
In___, DNA replication occurs in the S phase of the cell cylce and is biochemically and molecularly similar to replication in projaryotes
Eukaryotes
In____, DNA replication begins at a single replication origin and proceeds bidirectionally
Prokaryotes
