BACTERIAL GENETICS Flashcards
the science of heredity
GENETICS
Study of genes include
- How they carry information
- How they are replicated and passed to subsequent generation of cells
- How the expression of their information within an organism determines the particular characteristics of that organism
unit of heredity
Gene
the genetic information in a cell, it includes chromosomes and plasmids.
Genome
contains the genes
Chromosomes
small circles of double stranded DNA that can replicate in bacterial cells independently of the bacterial chromosome hence are commonly used as cloning vectors
PLASMIDS
carry hereditary materials
DNA
Every plasmid has its own _____ - a stretch of DNA that ensures it gets replicated (copied) by the host bacterium.
origin of replication
why can plasmids can copy themselves independently of the bacterial chromosome, so there can be many copies of a plasmid – even hundreds – within one bacterial cell.
because of the origin of replication
Shape of bacterial DNA?
Bacterial DNA is circular
the chromosome of E. coli contains about _____ base pairs and is approximately _____ times longer than the cell.
4.6M / 1000
is the molecular characterization of genomes.
Genomics
Type of chromosome that is looped or folded and attached at one several points to the plasma membrane
Bacterial Chromosome
Bacterial Chromosomes take up only about _____ of the cell’s volume because DNA is twisted/supercoiled
10%
Shape of eukaryotic chromosome
Linear/ Line
The building block of DNA
Nucleotide
Components of Nucleotides
- Sugar(deoxy-ribose)
- phosphate
- base / nitrogenous bases
2 types of nitrogenous bases:
- Pyrimidines – have one ring
- Purines – have 2 rings
Pyrimidines – have one ring, which consists of what
-Cytosine and Thymine
Purines – have 2 rings, which consists of what
-Adenine and Guanine
Complementary base pairing by ______: G-C; A-T
Chargaff’s rule
Chargaff’s rule
The rule that in DNA there is always equality in quantity between the bases A and T and between the bases G and C.
the set of rules that determines how a nucleotide sequence is converted into the amino acid sequence of a protein.
Genetic codes
TWO PRIMARY FEATURES OF BIOLOGICAL INFORMATION STORAGE:
- The linear sequence of bases provides the actual information.
- Complementary structure allows for the precise duplication of DNA during cell division.
RNA structure differs from DNA in 3 major ways:
- Sugar - ribose
- one strand instead of 2
- has uracil (U) instead of thymine
Base pair of RNA
G-C; A-U
Base pair of RNA
G-C; A-T
STRUCTURE OF RNA AND DNA is made up of
made up of a polynucleotide
1. sugar group
2. phosphate group
3. nitrogen base
3 types of RNA
- m RNA (messenger RNA)
- r RNA ( ribosomal RNA )
- t RNA ( transfer RNA )
- template for protein synthesis
- messenger and carrier of genetic information for protein synthesis from DNA to ribosomes
- m RNA (messenger RNA)
- forms an integral part of ribosomes
- bind the mRNA and specific enzyme for protein synthesis
- r RNA ( ribosomal RNA )
-recognize the specific codons and transport the
required amino acid
- t RNA ( transfer RNA )
deals with the flow of genetic information within a biological system. It is often stated as “DNA makes RNA, and RNA makes protein”
Central dogma of molecular biology
Semiconservative character of replication consists of a fact that…
during replication double helix is being unwound and its code serves as templates. That means that new, free nucleotides are being paired with the old ones, practically making a new chain.
Each side of the double helix runs in
opposite (anti-parallel) directions
DNA does not unzip entirely. It
unzips in a small area called a
_____, which then moves
down the entire length of the
replication fork
Leading strand –oriented from ______
Lagging strand – oriented from ________
Leading strand – oriented from 3’ to 5’
Lagging strand – oriented from 5’ to 3’
