Unit 1 Flashcards
DNA, RNA, and Protein Synthesis
How many rings do purines have? Pyrimidines?
Purines: two rings
Pyrimidines: one ring
The Nitrogen bases are connected to… (PO4 or Sugar)
Sugar!
What does mRNA do?
messenger RNA: found in nucleus, then moves to the cytoplasm through nuclear pores. Single, uncoiled chains, carries genetic info of DNA from nucleus to cytoplasm
What does tRNA do?
transfer RNA: bonds to amino acid and carries it to the ribosome
what does rRNA do?
functions in the ribosomes as a metabolic molecule that aids in protein synthesis (most common, least understood)
What are a couple of differences between DNA and RNA
DNA: 2 strands, deoxyribose, Thymine, must stay in nucleus
RNA: 1 strand, ribose, Uracil, can leave nucleus
What are promoters?
Signals in DNA that indicate the enzyme- DNA polymerase- to bind to make RNA
BRIEFLY describe steps of transcription
1) RNA polymerase binds to the promoter site
2) complementary strand of DNA separates
3) RNA polymerase uses on strand of DNA to copy its complements onto RNA
4) RNA polymerase reaches the termination site and is released
5) RNA leaves the nucleus through nuclear pores, will travel in cytoplasm to ribosomes
What is the start codon, and what does it code for?
AUG, Methionene
What are the three stop codons?
UGA, UAA, UAG
What are the 4 types of chromosomal mutations
Deletions, Duplication, Inversion, translocation
What does mutate mean
to change
What are mutagens? Give examples.
Chemical or physical agents in the environment which may cause mutations
- tobacco smoke, pesticides, environmental pollutants, etc.
What are polyploidy
Condition which organism has an extra set of chromosomes
What are the source of genetic variablity in species?
Mutations
