transcription and translation

Question 1

What is the purpose of transcription?

Answer 1

Converts message in a gene into a single stranded RNA molecule

Question 2

where within a eukaryotic cell does transcription take place

Answer 2

nucleus

Question 3

Describe the structure of RNA

Answer 3

single stranded, single nucleobases on the strand (no base pair), backbone held by covalent bonds

Question 4

RNA monomer

Answer 4

nucleotides

Question 5

what makes up RNA nucleotides

Answer 5

ribose sugar, phosphate group, nitrogenous base (Adenine, uracil, cytosine, guanine)

Question 6

DNA sugar vs RNA sugar

Answer 6

DNA- deoxyribose, RNA- ribose

Question 7

DNA # of strand vs RNA

Answer 7

DNA- double stranded, RNA- single stranded

Question 8

Base pairing rules for RNA compared to DNA

Answer 8

DNA- adenine pairs with thymine and cytosine with guanine, RNA-adenine pairs with uracil and cytosine still with guanine

Question 9

3 types of RNA

Answer 9

mRNA, tRNA, rRNA

Question 10

what is mRNA function

Answer 10

messenger RNA, carries the instructions from DNA out of nucleus and into cyto, hold the code for building proteins

Question 11

tRNA function

Answer 11

transfer RNA, brings and ensures correct amino acids from the cytoplasm to a ribosome to build proteins

Question 12

rRNA function

Answer 12

ribosomal RNA, forms part of ribosomes where proteins are made,bond amino acids together resulting in the release of polypeptide

Question 13

what is the first step of transcription

Answer 13

Initiation: RNA polymerase is attached and aligned to DNA w/ the help of other proteins, forming a transcription complex, the start of a gene is located on the DNA molecule and transcription complex rna polymerase unwinds and unzips segment of DNA (about 10-20 nucleotides)

Question 14

what is 2nd step of transcription

Answer 14

Elongation: RNA polymerase binds complementary free floating RNA nucleotides to one strand of the DNA template, forming a strand of RNA. Newly formed RNA peels away (5’-3’) from DNA template strand as it is made, RNA polymerase only synthesizes RNA in the 5’ to 3’ direction

Question 15

what is the 3rd step of transcription

Answer 15

Termination: A sequence in DNA signals the end of a gene, the RNA strand detaches completely. DNA winds back up, RNA polymerase is released and transcription complex disassembles.

Question 16

direction transcription occurs

Answer 16

5’-3’

Question 17

end result of transcription

Answer 17

A single stranded of RNA molecule

Question 18

What happens to end product of transcription?

Answer 18

mRNA carries the genetic info from DNA to ribosomes for protein synthesis

Question 19

What enzyme(s) are involved, and what do they do?

Answer 19

RNA polymerase- unwinds and unzips DNA double helix, signals start of the gene, binds free floating RNA nucleotides to DNA template, releases newly formed RNA molecule and detaches from DNA,

Question 20

purpose of translation

Answer 20

synthesizing proteins, Converting an mRNA message into a polypeptide (protein)

Question 21

where within a eukaryotic cell does translation take place

Answer 21

cytoplasm

Question 22

Describe how the correct amino acids are brought to the ribosome in the correct order in translation

Answer 22

The codons give a specific order to which the matching anti-codons will match up, the tRNA with the matching codon will have the corresponding amino acid, so the sequence of codons ensure the correct order

Question 23

describe the role of tRNA in translation

Answer 23

tRNA- transfer RNA, carries AA from cytoplasm to ribosome for protein synthesis, responsible for the anti codons and carrying the corresponding amino acids

Question 24

describe the role of mRNA in translation

Answer 24

mRNA- acts as a template for the tRNA to build amino acids on, has the sequence of codons that the tRNA needs

Question 25

describe the role of rRNA in translation and describe its large subunit and small subunit

Answer 25

rRNA - site of protein synthesis, large subunit has 3 binding sites for tRNA , small subunit binds to mRNA

Question 26

first step of translation

Answer 26

initiation- small ribosomal subunit moves along mRNa to find start codon, the matching anticodon forms a hydrogen bond, large subunit ensures that it is in the middle of binding site (P)

Question 27

3rd step of translation

Answer 27

once the stop codon is reached, ribosome releases the polypeptide and the complex dissasembles

Question 28

2nd step of translation

Answer 28

Elongation- the next tRNA with anticodons matches with the next set of codons (codon set= 3 letters) in the A site, ribosome catalyzes peptide bond formed between amino acids, tRNA in P site is shifted to E (exit) and detaches, tRNA in A site is shifted to P site opening up the spot in A site and repeats this process, tRNa is reused and leaves ribosome to go to cytoplasm to pick up another AA

Question 29

what structure acts as an enzyme in translation

Answer 29

The rRNa acts as an enzyme as it catalyzes the formation of peptide bonds between the amino acids to form a polypeptide chain

Question 30

what enzymes are in translation

Answer 30

there are no actual enzymes in translation

Question 31

direction of AA being added in translation

Answer 31

5’-3’

Question 32

end result of translation

Answer 32

a polypeptide chain (protein)

Question 33

why are hydrogen bonds between the anti codons and codons important

Answer 33

it ensures the correct amino acid

Question 34

what is confirmation

Answer 34

bending and binding of itself forming a unique 3D shape