DNA Flashcards
What makes up a nucleotides?
Phosphate group, nitrogenous, deoxyribose/ribose
What are the complementary base pairs in DNA?
C&G
T&A
What are the complementary base pairs for RNA?
C&G
A&U
What are purines and pyrimidines?
Purines = A&G
Pyrimidines = C&T
What is a stable polynucleotides?
- 2 polynucleotide chains that come together to form a ladder (sugar-phosphate backbone)
- 3 H bonds at C&G
- 2 H bonds at A&T
What is RNA?
- single stranded
- an unstable polynucleotides
What’s the Hydrolosis reaction for ATP?
ATP + (H2O) -> ADP + Pi + energy
What’s the Condensation reaction for ATP?
ADP + Pi + energy -> ATP + (H2O)
What is phosphorylation?
The process of adding phosphate to anything
Define histone?
Protein that DNA wraps around
Define Nulecosome
Stack of histones & DNA
Define chromosomes
Organised chromotin strands
Define chromatin
Threads of nucleuosomes
What is semi-conservative replication?
- existing strands are used as a template (allows for error correction)
- requires the bases to be unwound and unzipped, leaving bases exposed
- free nucleotides in the cell must attach to the exposed bases
What is step 1 of DNA transcription?
Helicase unzips DNA
What is step 2 of DNA transcription?
Free RNA nucleotides bind to the exposed bases of the DNA
What is step 3 of DNA transcription?
RNA polymerase moves along one of the DNA strands to form template strand
What is step 4 of DNA transcription?
RNA polymerase joins the backbones of the complementary RNA nulceotides
What is step 5 of DNA transcription?
As the RNA nucleotides join together the pre-mRNA is formed
What is step 6 of DNA transcription?
The DNA behind the RNA polymerase rejoins into a double helix
What is the last step of DNA transcription?
When the RNA polymerase reaches a “stop” sequence, the chain is terminated and the pre-mRNA detaches
Define double helix
DNA sequence, individual base pairs
Define nucleosome
Histone proteins attach to DNA
Define DNA-histone complex
DNA strand is coiled around histone proteins
Define chromotain
Histone proteins stacked on top of each other
Define Chromosomes
Chromatin loops coiled & packaged together
What chromosome numbers do human have?
22 pairs of autosomes chromosomes & 1 pair of sex chromosomes
Define Allele
Different forms of the same gene
What is a homologous pair?
Pairs of chromosomes that have the same order of genes