40S Unit 2 - Molecular Genetics II Protein Synthesis

Question 1

what is the central dogma/belief of molecular biology

Answer 1

genetic information flows from DNA → RNA → Protein

Question 2

what are amino acids

Answer 2

the building blocks of protein that are linked together

Question 3

what is the same and different about amino acids

Answer 3

they have the same general structure but each type has it’s unique ‘R’ group

Question 4

how many animo acids are there

Answer 4

20

Question 5

what makes up an amino acid

Answer 5

an R group
a carbon atom
a carboxyl group
a hydrogen atom
an amine group

Question 6

what is a polypeptide chain

Answer 6

amino acids linked together in long chains that are held together by peptide bonds

Question 7

how are proteins produced?

Answer 7

a polypeptide chain must assume a precise structure comprising of several folds

Question 8

DNA codes for the assembly of __________

Answer 8

amino acids

Question 9

the code of DNA is always read in groups of ________ called a __________

Answer 9

three
codon

Question 10

start and stop codons will begin or end the formation of the ______________________

Answer 10

polypeptide chain

Question 11

what are 3 bases of DNA called

Answer 11

triplet

Question 12

what are 3 bases of mRNA called

Answer 12

codon

Question 13

what are 3 bases of tRNA called

Answer 13

anticodon

Question 14

what is the start codon or triplet

Answer 14

codon - AUG
triplet - TAC

Question 15

what are the 4 major differences between RNA and DNA

Answer 15

1. RNA contains ribose sugar (OH) at 2’ while DNA contains deoxyribose sugar (H)
2. RNA contains the nitrogenous base Uracil while DNA contains Thymine
3. RNA molecules are short as they contain only the information for the gene being synthesized and they are single stranded while DNA molecules are longer as they contain information for all genes and are double stranded
4. there are 3 different types of RNA and they all have different tasks, mRNA, tRNA, rRNA

Question 16

what is the function of mRNA

Answer 16

messenger RNA is the complementary copy of the DNA in the form of mRNA

Question 17

what is the function of tRNA

Answer 17

transfer RNA brings the amino acid to the ribosome based on the 3 letter codon on the mRNA

Question 18

what is the function if rRNA

Answer 18

ribosome RNA reads the mRNA one codon at a time and signals to the tRNA to bring an amino acid

Question 19

what are the 2 major stages of protein synthesis

Answer 19

transcription and translation
(remember c comes before l)

Question 20

what is protein synthesis

Answer 20

the making of proteins in the cell using the flow of genetic information from DNA → RNA → protein

Question 21

what occurs during transcription

Answer 21

information in a portion of the DNA molecule is copied into a mRNA molecule

Question 22

what is an intron

Answer 22

stretches of DNA that don’t appear in the final mRNA

Question 23

what is an exon

Answer 23

the stretches of DNA that appear in the mRNA and are expressed in the form of protein

Question 24

explain the 3 steps that occur in transcription

Answer 24

1. enzymes unwind and separate the DNA strands
2. RNA nucleotides pair with complementary nucleotides on one DNA strand
3. RNA polymerase joins the RNA nucleotides together, forming a mRNA molecule

Question 25

where dies transcription occur in the cell

Answer 25

in the nucleus of the cell

Question 26

how does an mRNA molecule take genetic information to the ribosome in the cytoplasm

Answer 26

it travels through the pores of the nuclear membrane into the cytoplasm

Question 27

what happens in translation

Answer 27

the mRNA acts as a template and guides the synthesis of a chain of amino acids that form a protein

Question 28

where does translation occur

Answer 28

in the cytoplasm where the ribosomes are

Question 29

what are the 3 steps of translation

Answer 29

1. initiation 2. elongation 3. termination

Question 30

what happens in the initiation process of translation

Answer 30

mRNA moves into a rRNA and a tRNA molecule carrying Methionine binds to the start codon on the mRNA

Question 31

what happens in the elongation process of translation

Answer 31

the polypeptide chain grows as more tRNA brings more amino acids together as dictated by the codons on the mRNA

Question 32

what happens in the termination process of translation

Answer 32

a stop codon is reached on the mRNA and translation stops

Question 33

what was the function of the beta lactamase gene in the pGLO lab

Answer 33

made E.coli resistant to ampicillin

Question 34

what was the function of the Green Fluorescent Protein (GFP) in the pGLO lab

Answer 34

allowed E.coli to produce the green fluorescent protein that glowed in UV light

Question 35

what was the function of the araC regulator protein in the pGLO lab

Answer 35

turned on the GFP gene when the E.coli was the the presence of arabinose sugar also called an operon

Question 36

what is an operon and what is its function

Answer 36

a group of closely related genes that act together and code for the enzymes or proteins and they control when transcription will happen

Question 37

what 2 processes control operon activity

Answer 37

induction - transcription is switched on when an inducer is present repression - transcription is switched off when requirements are met

Question 38

what was the function of CaCl2 (transformation solution) in the pGLO lab

Answer 38

neutralizes the cell membrane

Question 39

what was the function of the crushed ice in the pGLO lab

Answer 39

slowed down cell membrane movement

Question 40

what was the function of the heat shock in the pGLO lab

Answer 40

opened pores of the cell membrane

Question 41

what was the function of the LB broth

Answer 41

food source for the E.coli