Molecular Genetics Lectures Flashcards
Irreversbility
you can’t recreate progenitor generation
you can’t recreate progenitor generation
Irreversbility
Eukaryotes
animals – plants – fungi
animals – plants – fungi
Eukaryotes
DNA
Deoxyribo – Nucleic – Acid
RNA
Ribo – Nucleic – Acid
The backbone
triphosphate and a base (a sugar)
is made out of a triphosphate and a base
The backbone
Base pairs are bound by
by phosphoiester bonds
bound by phosphoiester bonds
Base pairs
polynucleotide
a long chain of nucleotides
= DNA
DNA chemically
polynucleotide
a long chain of nucleotides
Connections between the base pairs
are very weak
Connections between them are very weak
base pairs
First function of DNA
DNA replication = copying
Second function of DNA
Gene expression
5-3 strand
coding strand
sense strand
coding strand
5-3 strand
sense strand
sense strand
coding strand
5-3 strand
3-5 strand
template strand
anti-sense strand
starts transcription
RNA polymerase
End of transcription is signaled by
upstream signal AAUAAA
upstream signal AAUAAA
End of transcription is signaled by
Exon
Codes
Coding part
exon
Intron
Does not code
Non-coding part
Intron
Non-coding RNA
rRNA = ribosomal RNA tRNA = transfer RNA
rRNA = ribosomal RNA tRNA = transfer RNA
Non-coding RNA
tRNA
= transfer RNA
Transfers amino acids to the protein chain
Transfers amino acids to the protein chain
tRNA
possible codons n
64
amino acids n
20
stop codons n
three
initiation codon n
one
tRNA
= tRNA
Transcribes the mRNA into the polypeptide
tRNA has a cloverleaf structure
Transcribes the mRNA into the polypeptide
tRNA
has a cloverleaf structure
Four arms of tRNA
Acceptor arm, connects to the codon
D arm and TpsyC arm
Anticodon arm
Base wobble
Reduces the number of ribosomal RNAs needed
by enabling on transfer RNA to read different codons
Reduces the number of rRNAs needed
by enabling on tRNA to read different codons
Base wobble
Eukaryotic cells
almost always belong to a multicellular
almost always belong to a multicellular
Eukaryotic cells
Prokaryotes
don’t have a membrane that surrounds the nucleus
don’t have a membrane that surrounds the nucleus
Prokaryotes
yeasts, protophyta, protozoa
unicellular versions of fungi, plants and animals
unicellular versions of fungi, plants and animals
yeasts, protophyta, protozoa
Prokaryotes
made up of bacteria of archaea
made up of bacteria of archaea
Prokaryotes
Endosymbiosis
one cell within another
one cell within another
Endosymbiosis
Most somatic cells are diploid, except:
Some cells are nulliploid, have lost their DNA nucleus
Some cells are polyploid
Example: many blood cells
nulliploid
Examples are liver cells and cardiomyocytes
polyploid
Cell life phases
G1, S, G2 and M
M phase
seperation
seperation
M phase
Early S phase
Late S phase
One chromosome arm
Two chromosome arms
One chromosome arm
Two chromosome arms
Early S phase
Late S phase
Phases of mitosis
Interphase Prophase Prometaphase Anaphase Telophase Cytokinesis
methods to create variation
Recombination
independent assortment
Two methods of amplifying DNA
Cell-based DNA cloning
Polymerase chain reaction