Unit 8: Gene Expression

Question 1

What are genes?

Answer 1

segments of DNA that can be expressed as either PROTEINS or RNA

Question 2

what is protein synthesis?

Answer 2

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

Question 3

gene expression of eukaryotes (characteristics)?

Answer 3

• 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

Question 4

gene of chromosomes begins with ___ and ends with __

Answer 4

gene of chromosomes begins with START CODON and ends with STOP CODON

Question 5

purpose of promoter region?

Answer 5

important role in the initiation of transcription

Question 6

Where does RNA processing take place in the eukaryotic cell?

Answer 6

nucleus

Question 7

Before RNA polymerase can begin transcribing a gene (transcription), what must happen first?

Answer 7

transcription factors (proteins) must bind to the promoter gene

Question 8

What is ‘X’ ?

Answer 8

Template and Antisense strand

Question 9

what is the direction of the transcription?

Answer 9

left

Question 10

first 4 bases of mRNA?

Answer 10

GUAC

Question 11

Proteins assembled at free ribosomes are most likely?

Answer 11

stay in the cell

Question 12

combination of ribosomal parts found in eukaryotes?

Answer 12

40S + 60S = 80S (no units just S!)

Question 13

combination of ribosomal parts found in prokaryotes?

Answer 13

30S + 50S = 70S

Question 14

Where do new tRNA molecules arrive to translation with an amino acid attach to the ribosome?

Answer 14

A site

Question 15

How does translation end (3)?

Answer 15

• ribosome reaches stop codon (1)
• 3 possible stop codons (1)
• stop codon codes for release factor (1)

Question 16

What causes mutations?

Answer 16

dna replication errors & mutagens

Question 17

What causes sickle cell disease?

Answer 17

• 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

Question 18

who and how were cyclins discovered?

Answer 18

tim hunt researching sea urchins

Question 19

transcription

Answer 19

a copy of the gene

Question 20

5’ to 3’

Answer 20

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!!

Question 21

function of capsid?

Answer 21

helps bacteria stick to substrate

Question 22

what do genes code for?

Answer 22

most genes code for PROTEIN but some for RNA

Question 23

combination of ribosomal parts in eukaryotes and prokaryotes?

Answer 23

eu (even): 40+60=80

pro (not even): 30+70=50

Question 24

why is it bad to have sickle cell disease?

Answer 24

reduce ability to carry oxygen

• increased risk for stroke, chronic pain

Question 25

what are mutagens? 3 categories?

Answer 25

any agents in the environment that change DNA

1. electromagnetic radiation (X rays, UV light)
2. chemicals in tabocco, processed meat
3. some viruses

Question 26

what happened in the Hiroshima Atomic Bomb?

Answer 26

• bomb that killed 100,000 instantly and 50,00 in the next 10 years of leukemia
• nuclear radiation caused changes to oncogenes/tumor suppresor genes

Question 27

proteins assembled at free ribosome most likely?

Answer 27

stay in the cell

Question 28

which ribosomes are used for proteins made for secretion?

Answer 28

1. RER
2. Nuclear Membrane

Question 29

purpose of transcription?

Answer 29

transcribe a copy of a gene from dna to rna

Question 30

how does translation end?

Answer 30

• ribosome reach stop codon, realase factor bind to stop codon
• finished polypeptides leave through exit tunnel
• some energy spend (GDP) and ribosomes come apart, realeasing from mRNA

Question 31

on tRNA, 3 base opposite from from amino acid called?

Answer 31

anticodon