lecture 12- DNA, transcription, translation

Question 1

dna

Answer 1

deoxyribonucleic acid

Question 2

griffith experiment

Answer 2

s strain- kills mouse
r strain- mouse lives
s strain with heat- mouse lives
s strain with heat, and r strain- kills mouse

Question 3

avery and colleagues transformation experiment

Answer 3

found that DNA, not RNA was responsible for the transformation

Question 4

Hershey and Chase

Answer 4

labeled bacteriophage with radioactivity

Question 5

building block of DNA

Answer 5

deoxyribose (pentose sugar) with 3’ -OH
phosphate (on 5’ carbon)
nitrogenous base ( adenine, guanine, cytosine, thymine)

Question 6

purine

Answer 6

adenine, guanine

Question 7

pyriminide

Answer 7

cytosine, thymine

Question 8

nucleotide

Answer 8

the smallest heritable unit

Question 9

DNA structure

Answer 9

Double helix (spiral), nucleotide held together by phosphodiester bonds- phosphate groups form bridge between OH- and 2 adjacent sugar residues, helices connected by hydrogen bonds, hydrogen bonds between bases

Question 10

DNA replication

Answer 10

the 2 strands of the parental double helix unwind and each strand serves as template for synthesis of complement, using rules of base pairing also known
1.) helicase opens the helix while topoisomerase prevents overwinding
- this type of replication is also known as semiconservative replication

Question 11

synthesizing the lagging strand

Answer 11

1.) primase synthesizes the short RNA oligonucleotides (primers) copied from DNA
2.) DNA polymerase III elongates the RNA primers with new DNA
3.) DNA polymerase I removes RNA at 5’ end of neighboring fragment and fills gap
4.) DNA ligase connects adjacent fragments

Question 12

DNA unit of measurement

Answer 12

base pair (bp)
kilobase (kb)
megabase (Mb)

Question 13

mutation

Answer 13

replacement, insertion, deletion of nucleotide results in altered sequence

Question 14

introns

Answer 14

found in eukaryotes not prokaryotes

Question 15

RNA

Answer 15

ribonucleic acid- single stranded, has ribose and phosphate group
adenine, uracil, guanine, cytosine

Question 16

informational RNA

Answer 16

intermediate in the synthesis of a functional product of a gene. in the majority of genes, this is the messenger RNA (mRNA)

Question 17

functional RNA

Answer 17

transfer RNA (tRNA) brings amino acids to mRNA during translation

Question 18

intron

Answer 18

noncoding region of gene, excised by processing from primary transcript

Question 19

exon

Answer 19

coding region of gene (sequences that are included in mature transcription)

Question 20

promoter

Answer 20

regulatory region where typically RNA polymerase binds

Question 21

UTR

Answer 21

untranslated regions at both 5’ and 3’ ends that are part of a transcript

Question 22

RNA polymerase

Answer 22

catalyzes transcription ( RNA synthesizes from DNA)

Question 23

RNA polymerase I

Answer 23

located in the nucleolus, transcribes the 3 major rRNAs

Question 24

RNA polymerase II

Answer 24

located in the nucleoplasm, transcribes mRNAs and some snRNAs

Question 25

RNA polymerase III

Answer 25

located in the nucleoplasm, transcribes tRNAs, 5S rRNA, and the remaining snRNAs

Question 26

initiation

Answer 26

• at 5’ end of gene
• binding of RNA polymerase to promoter
• unwinding of DNA

Question 27

elongation

Answer 27

addition of nucleotides to 3’ end

Question 28

termination

Answer 28

• at 3’ end of gene

Question 29

transcription step by step

Answer 29

• RNA is transcribed 5’ to 3’
• the template DNA strand is read to 3’ to 5’
• the non-template DNA strand has the same polarity as the RNA 5’-3’

Question 30

5’ end: capping

Answer 30

addition of 7-methylguanosine

Question 31

3’ end: poly(A) tail

Answer 31

• addition of up to 200 adenine nucleotides
• downstream of AAUAAA polyadenylation signal

Question 32

eukaryotic RNA processing

Answer 32

intron removal by spliceosome which are small nuclear ribonucleoprotein particles (snRNPs) associated with pre-mRNAs

Question 33

amino acids (aa)

Answer 33

• twenty naturally occurring amino acids belong to 4 major protein groups:
• basic
• acidic
• neutral polar
• neutral non-polar

Question 34

the genetic code

Answer 34

• it is almost universal
• it is a triplet code
• each 3- nucleotide codon in mRNA specifies an a.a. in the polypeptide
• it is comma free
• it is nonoverlapping

Question 35

protein synthesis

Answer 35

• protein synthesis is mostly similar in prokaryotes and eukaryotes.
  3 stages:
  initiation
  elongation
  termination

Question 36

initiation of translation requires

Answer 36

• a mRNA
• ribosome complex
• specific initiator tRNA
• initiation factors

Question 37

the polypeptide

Answer 37

• a linear arrangement of amino acids linked with peptide binds (primary structure)
• a peptide chain has polarity

Question 38

primary structure

Answer 38

• amino acid chain

Question 39

secondary structure

Answer 39

hydrogen bonds between amino acids at different locations in polypeptide chain (alpha helix and beta pleated sheet)

Question 40

tertiary structure

Answer 40

heme, beta polypeptide

Question 41

quaternary structure

Answer 41

actual ball looking thing at this point (you know)

Question 42

protein function

Answer 42

• function determined by the amino acid sequence
• two broad types of protein (structural proteins, active proteins including enzymes)