Biological Principles of Human Medicine (Stoyanov)
Wichtiges zum merken aus den Kurs Biological Principles of Human Medicine
Wichtiges zum merken aus den Kurs Biological Principles of Human Medicine
Set of flashcards Details
| Flashcards | 84 |
|---|---|
| Language | English |
| Category | Biology |
| Level | University |
| Created / Updated | 08.10.2021 / 09.01.2022 |
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What does an enzyme do?
It lowers the actication energy and makes reactions go faster.
What does GATC stand for?
G: guanine
A: adenine
T: thymine
C: cytosine
What is the role of hydrogen and covalen bonds in forming DNA?
Hydrogend bonds bring the DNA together, covalent bonds hold them together.
Like scotch (hydorgen bonds) to stick something to the wall and then screw (covalent bonds) it down
In which direction does the DNA replication flow?
Always from 5' to 3'.
The two strings develop in antiparalell direction
How is eucaryotic DNA packed?
Into 22 chromosomes (plus X and Y chromosome)
They consist of a centremere (where the genes get separated) and the telomere
What is the most common protein in DNA?
Histons
How many levels of DNA packaging are there in chromosomes?
Explain them
6 levels.
1. DNA double helix , 2. beads-on-a-string --> chromatin, 3. cromatin fiber of packed nucleosomes
4. section of chromosome, 5. condensed section of chromosome 6. entire mitotic chromosome
What is nucleodynamics?
If the DNA gets packed and unpacked in different configurations to allow acess to different parts at different times
Where does the DNA synthesis begin? Which way do they move?
At Replication origins and move in both directions
Where does the energy come from to drive the DNA synthetisation?
From deoxyribonucleoside triphosphates
What bases do connect together?
Adenine and Thymine
Cytosine and Guanine
What is a nucleotide?
A base (GAT or C) covalently attachet to a pentose and with a posphate group
How are the two stings of DNA connected?
Hydrogen bonds bring them together, covalent bonds fix them
Why are wome more reistent to genetic disesas?
They have two X chromosomes, which are long thus an error can be compensated.
Males with an X and a Y chromosome (which is shortter) can not fix mistakes that easyli
What does it mean that the DNA replication is Semiconservativ?
1 Strand is the template and one new strand gets syntetisized
In which direction is the DNA synthetisation going? and why?
From 5' to 3' direction.
It can only go this way because the molecule is Polar
What is an osaki fragment?
Fragments in the lagging strand of the DNA synthetization
Other strand is the leading strand
What does it mean if a chain gets nucleised?
The chain deforms back in to nucleotides
What do mutations do to the DNA sequence?
They change it
What is the DNA Polymeraze? What is different to the DNA Ligase?
Enzyme that catalyzes the DNA syntesition, and brings its own nucleotides
DNA Ligase is used for repair and therefore brings NO new nucleotide
What are the three DNA repair steps?
Excision (take away damaged part)
Resynthesis (DNA Polymerase makes new strand)
Ligation (DNA Ligase seals the nick)
What are the trhee different types of mutations?
Mutation in coding sequence
Gene amplification (protein gets overproduced)
Chromosome rearrangement (protein overproduced)
What is the process from DNA to RNA called?
RNA synthesis (transcription)
What is the step from RNA to Protein called?
Protein synthesis (translation)
how can a reverse transcription happen?
Only viruses can do that
What is main component used in DNA and in RNA?
RNA: ribose
DNA: deoxyribose
Which base gets replaced by what if DNA changes to RNA?
RNA --> only one strand
the Thymine is changed to uracil in RNA
Dow does the RNA fold?
The RNA can fold in many different structures
always G-C and A-U connections
What is an atypical bond in RNA structure?
If A-G bond
By what is DNA transcribed to RNA?
By RNA Polymerase (a protein)
What is the direction of transription in RNA?
5' to 3' (pay attention to not confuse it with the direction of the DNA that gets transcribed)
Why doesn't RNA need a Mutation-protection?
It gets used up
Where does the energy for the RNA transcription come from?
ribonucleoside triphosphates (building blocks of the RNA)
How Stabel are DNA and RNA?
DNA: very stabel (ages)
RNA: unstable (days, min)
How are the two strands while RNA transcription called?
Template strand (RNA forms the complementary of this strand)
Coding strand (here the enzyme reads where to start)
What is a promoter and a terminator?
Promotor = Start signal, terminator = stop signal in transcription (is found in the coding string)
How can RNA transcription be regulated?
By the sequence that the promotor (in the coding string) has (RNA Polymerase "likes" more or less to bind)
By activators (align DNA optimally for RNA Polymerase to bind) or repressors (does opposite until signal comes to stop)
What is the sigma factor and what does it?
Part of the RNA Polymerase. It recognizes the start --> falls off --> and binds again after termination of transcription
What is different from Eucaryotic to procaryotic genes?
Eucaryotic genes are interrupted
Coding regions (exon), noncoding regions (introns)
What is diferent in procaryotiy mRNA to eucaryotic mRNA?
Procaryotic: one mRNA = several proteins
Eucaryotic: one mRNA = one protein, has a 5' cap and a Poly-A 3' end (needed because eucaryotic mRNA is more complex)
