Unit 8: Gene Expression Flashcards
What are genes?
segments of DNA that can be expressed as either PROTEINS or RNA
what is protein synthesis?
the process when gene expression is for a protein
genes: instructions that tell proteins what to do
without genes, there won’t be proteins
there must be genes to make proteins to make a feature
gene expression of eukaryotes (characteristics)?
- eukaryotic genes are found on linear chromosomes within the cell nucleus
- eukaryotic cells have large and randomly sized segments of non coding DNA between them
gene of chromosomes begins with ___ and ends with __
gene of chromosomes begins with START CODON and ends with STOP CODON
purpose of promoter region?
important role in the initiation of transcription
Where does RNA processing take place in the eukaryotic cell?
nucleus
Before RNA polymerase can begin transcribing a gene (transcription), what must happen first?
transcription factors (proteins) must bind to the promoter gene
What is ‘X’ ?
Template and Antisense strand
what is the direction of the transcription?
left
first 4 bases of mRNA?
GUAC
Proteins assembled at free ribosomes are most likely?
stay in the cell
combination of ribosomal parts found in eukaryotes?
40S + 60S = 80S (no units just S!)
combination of ribosomal parts found in prokaryotes?
30S + 50S = 70S
Where do new tRNA molecules arrive to translation with an amino acid attach to the ribosome?
A site
How does translation end (3)?
- ribosome reaches stop codon (1)
- 3 possible stop codons (1)
- stop codon codes for release factor (1)
What causes mutations?
dna replication errors & mutagens
What causes sickle cell disease?
- substitution mutation for 6th amino acid of beta hemoglobins
- supposed to be glumatic acid (good), but mutation changed to valine (bad) -> weird cell shape!
- genetically mutated
who and how were cyclins discovered?
tim hunt researching sea urchins
transcription
a copy of the gene
5’ to 3’
adding to 3’, 5’ already added
- transcription in nucleus
mRNA copy of gene
translation happens in cytoplasm
pre mrna, mrna, amino acids, protein
the order!!
function of capsid?
helps bacteria stick to substrate
what do genes code for?
most genes code for PROTEIN but some for RNA
combination of ribosomal parts in eukaryotes and prokaryotes?
eu (even): 40+60=80
pro (not even): 30+70=50
why is it bad to have sickle cell disease?
reduce ability to carry oxygen
- increased risk for stroke, chronic pain
