IA - Cell and Genomes Flashcards
the study of the structure, function, and behavior of cells
Cell biology
distinguishes life from other processes, in which orderly structures are generated but without the same type of link between the peculiarities of parents and the peculiarities of offspring
Heredity
The linear chemical code that store hereditary information
DNA
where do all cells store hereditary information
DNA
Description of DNA
- Long, unbranched paired polymer chains, formed of same four types of monomers
All Cells Replicate Their Hereditary Information by …?
Templated polymerization
nucleotide, consists of two parts: a sugar (deoxyribose) with a phosphate group
attached to it, and a base
Monomers
two parts of monomers
- Sugar with phosphate group
- Base
DNA to RNA
Transcription
RNA to Protein
Translation
The intermediary form of all cells
RNA
molecules that guide the synthesis of proteins according to the genetics instructions stored in the DNA
mRNA
monomer of proteins
amino acids
How many types of amino acids?
20 types
carry information in the form of a linear sequence of symbols
proteins
Protein molecules are created by
joining its amino acid in a particular sequence
a segment of DNA sequence corresponding to a single protein or set of alternative protein variants or to a single catalytic regulatory, or structural RNA molecule
gene
regulates the expression of genes, which are interpersed among the segments that code for proteins
Regulatory DNA
each cell is enclosed by….
- acts as selective barrier
plasma membrane
consisting of a hydrophobic and a hydrophilic parts,
creating a bilayer
Amphiphilic
largely determine which molecules enter the cell
membrane transport proteins
the number of genes for a viable cell
not less than 300
530 genes, about 400 of which are essential
Mycoplasma genitalium (italicize)
DNA sequence of any given organism can be readily obtained by
standard biochemical techniques
feeding on other living things or the organic chemicals they produce
organotrophic
feeding on sunlight
phototrophic
feeding on rock
lithotrophic
Elements composed by DNA, RNA, and proteins
-H, C, N, S, P
live mostly as independent individuals or in loosely organized communities, rather than as multicellular organisms
Prokaryotes
Prokaryotic cells live in an enormous variety of
Ecological niches
Primary branches of Tree of life
- Bacteria, Archea, Eukaryotes
Two groups that belongs to prokaryotes
- Bacteria and archea
have recently revealed that the first eukaryotic cell formed after a particular type of ancient archaeal cell engulfed an ancient bacterium
Detailed genome analyses
may represent a change for the better or cause serious damage
Alterations of nucleotide sequence
example of alterations of nucleotide sequence
Mutations (changes in DNA sequence)
evolution of organisms
mutations and natural selection
How many genes does most bacteria and Archaea have?
1000-6000 genes
cells that can reproduce the fastest
prokaryotic cells
what does most prokaryotic cells carry?
Very little superfluous baggage
Four modes of genetic innovation
- Intragenic mutation
- Gene Duplication
- DNA segment shuffling
- Horizontal gene transfer
an existing cell can be randomly modified by changes in its dna sequence
Intragenic mutation
an existing cell can be randomly modified by changes in its dna sequence
Intragenic mutation
existing gene can be accidentally duplicated as to create a pair of initially identical gene within a single cell
Gene Duplication
two or more existing gene and break and rejoin to make a hybrid gene consisting of dna segment that originally belong to separate gene
DNA segment shuffling
- usually done by prokaryotes
- a piece of dna can be transferred from one genome of one cell to that of another
Horizontal gene transfer
give rise to families of related genes within a single cell
Gene Duplications
genes that are related by descent
orthologs
related genes that resulted from a gene duplication event
paralogs
infects bacterial cells and can transfer genome to bacteria
bacteriophage
the transfer of genetic material from parent to offspring
Vertical gene transfer
two complementary approaches in the analysis of gene functions
- Genetics
- Biochemistry
study of mutant
Genetics
function of molecules
biochemistry
molecular biology begin with a spotlight on what organism
- small, rod shaped bacteria
E. coli (Escherichia coli)
Adaptation and evolution of E. coli
- Adapts to variable chemical conditions and reproducers rapidly
- Evolve by mutation and selection at remarkable speed
Genetic Information of Eukaryotes
Eukaryotic cells
- may have originated as predators
- originated as predators
- modern eukaryotic cells evolve from symbiosis
- Eukaryotic genomes are bug
- Live as solitary cell
are bigger and more elaborate than prokaryotic cells, and their genomes are bigger and more elaborate, too.
Eukaryotic Cells
where do eukaryotic cells keep their DNA?
In the nucleus
by definition, act as a barrier that separates the contents of the nucleus from the cytoplasm.
Nuclear envelope
Importance of cytoskeleton
important for cell division
life of a primordial cell that was a predator
living by capturing other cells and eating them
What is the term used to describe the way of life of a primordial cell that survived by capturing and consuming other cells?
Predatory lifestyle.
How did primordial predatory cells obtain nutrients?
By capturing and eating other cells.
Organelle that was considered as different identity as they have their own genome
Mitochondria and Chloroplast
What organism did Mitochondria originated
Free-living oxygen-metabolizing (aerobic) bacteria
originated as symbiotic photosynthetic bacteria
Chloroplast
provides energy to eukaryotic cells
chloroplast
percentage of human genome that do not code for proteins
~98.5%
percentage that E. coli genome do not for proteins
11%
can also be a regulatory DNA
Introns
act
by binding, directly or indirectly, to the regulatory
DNA adjacent to the genes
that are to be controlled, or by interfering with the
abilities of other proteins to do so
Transcription regulators
Serves as a minimal model for eukaryotes
Yeast (Saccharomyces cerevisiae)
- reproduce vegetatively
has been chosen out of 300,000 plant species as a model plant
Arabidopsis
Arabidopsis thaliana (italicized)
- can be grown indoors
Thale creds
genome size of Arabidopsis thaliana
approx. 220 million nucleotide pairs
why was arabidopsis a model plant?
- possesses a relatively small, genetically tractable genome
- manipulated through genetic engineering more easily and rapidly than any other plant genome
organisms that represent the world of animal cells
-Worm
-Fly
-Fish
-Mouse
-Human
Which nematode worm species is a model organism in molecular genetic studies?
Caenorhabditis elegans (italicized)
Which nematode worm species is a model organism in genetic research?
Caenorhabditis elegans (italicized)
Which fly species is a model organism in molecular genetic studies?
Drosophila melanogaster (italicized)
Which zebrafish species is a model organism in molecular genetic studies?
Danio rerio (italicized)
Which zebrafish species is a model organism in molecular genetic studies?
Danio rerio (italicized)
Which mouse species is a model organism in molecular genetic studies?
Mus musculus (italicized)
Which human species is a model organism in molecular genetic studies? (Halata na to)
Homo sapiens (italicized)
What does Drosophila provide?
key to vertebrate development
- definitive proof that genes are carried on chromosomes
is a product of repeated duplications
Vertebrate genome
Commonly used in studying embryonic development
frogs
why is the frog used to for embryonic development?
Eggs are large, easy to manipulate, and fertilized outside of the animal
Provide accessible models for vertebrate development
- Frogs
- Zebrafish
the predominant mammalian model organism
Mouse
% amino acid identical between human and elephant
85%
% amino acid similarity between human and bird
70%
why mouse as model organism?
-many naturally occurring mutations are known
-have same biological features as human
