Biology Molecular Genetics
Molecular Genetics -DNA -DNA Replication -RNA -Protein Synthesis -Transcription; Translation
Molecular Genetics -DNA -DNA Replication -RNA -Protein Synthesis -Transcription; Translation
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Kartei Details
| Karten | 13 |
|---|---|
| Sprache | English |
| Kategorie | Biologie |
| Stufe | Mittelschule |
| Erstellt / Aktualisiert | 13.12.2014 / 05.12.2019 |
| Lizenzierung | Keine Angabe |
| Weblink |
https://card2brain.ch/box/biology_molecular_genetics
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DNA (what does it look like? of what does it exist?)
- nucleic acid made of two long chains of repeating subunits --> nucleotides
- the two chains (or strands) wrap around each other in the form of a double helix
DNA nucleotides
- consist of three parts:
- deoxyribose (five-carbon sugar)
- phosphate group
- nitrogenous base
- connected by covalent bonds between sugar of one nucleotide and phosphate group of the next nucleotide
- hydrogen bonds
- connect nitrogenous bases of one strand with those of the other strand
- help hold the two strands together
Nitrogenous bases
- purines (double ring): adenine & guanine
- pyrimidines (single ring): cytosine & thymine
- base-pairing-rules:
- the bases are complementary --> purine pairs always with pyrimidine
- cytosine + guanine
- adenine + thymine
- order of nitrogenous bases : base sequence
DNA replication
- process, by which DNA is copied in a cell before it divides
- two nucleotide strands separate along the strands
- each strand serves as a template to make a new complementary strand
- after replication the two identical new DNA molecules separate and move to the new cells formed during cell division
Prokaryotic & Eukaryotic Replication
- Prokaryotic
- one circluar chromosome
- replication begins at one place along chromosome
- two replication forks proceed in opposite directions
- Eukaryotic
- long chromosome, but not circular
- replication begins at many points ("origins") along DNA
- two replication forks moving in opposite directions
Errors in replication
- DNA polymerases have repair functions that "proofread" DNA
- change in the nucleotide sequence of a DNA molecule --> mutation:
- can have serious effects on the function of an important gene and disrupt an important cell function
- can lead to diseases (e.g. cancer)
Flow of genetic information (in an eukaryotic cell)
- Transcription
- DNA acts as a template for the synthesis of RNA
- Translation
- RNA directs assembly of proteins
- Protein Synthesis (/gene expression)
- Forming of proteins based on information of DNA --> carried out by RNA
Differences DNA & RNA
- RNA
- nucleic acid made up of nucleotides
- sugar: ribose
- nitrogenous bases: uracil, guanine, cytosine, adenine
- single stranded
- much shorter than DNA (length of one gene)
- DNA
- also made up of nucleotides
- sugar: deoxyribose
- nitrogenous bases: thymine, guanine, cytosine, adenine
- double stranded
- contains thousands of genes
