Pre-AP DNA and Protein Synthesis Review - KEY

  1. Describe the experimental procedure and conclusion for each of the following scientists:
  2. Griffith

Conclusion: Transformation (The transfer of genetic material from one cell to another cell or from one organism to another organism) can occur

  1. Chargaff (tell only his conclusion, not the procedure)

In all living organisms, % of A=% of T and % of C=% of G

  1. Hershey and Chase

DNA, and not proteins, is the hereditary material.

  1. Watson and Crick (tell only their conclusion, not their procedure)

Double Helix

  1. What is the monomer of a nucleic acid? Nucleotide
  2. What 3 parts make up a nucleotide? nitrogenous base, sugar, phosphate
  3. Draw a nucleotide, label each part, and tell what parts would be different if it were a DNA nucleotide vs. an RNA nucleotide.
  1. List by order of size the following: gene, cell, chromosome, atom, nucleus of a cell, base, nucleotides, DNA molecule.  (Important note: The only difference between a DNA molecule and a chromosome is that a DNA molecule refers only to a strand of DNA while a chromosome is a strand of DNA AND the histone proteins it is associated with).

atom, base, nucleotide, gene, chromosome, nucleus, cell

  1. What are pyrimidines and what are the examples?

C, T, and U

  1. What are purines and what are the examples?

A and G (Purines Are Good)

  1. What is the bond between two bases?

Hydrogen (very weak, can be broken – MUST UNZIP DNA TO USE IT)

  1. Write all of the complementary base pairs.

A to T (or A to U if it’s RNA)

C to G

  1. Answer all of the following questions concerning DNA replication.
  2. What is it?copying DNA (during S phase of interphase)
  3. Where does it happen?nucleus (everything that involves DNA must occur in the nucleus)
  4. Why does it happen? So that we have 2 sets of DNA and we can perform mitosis (with each new cell getting a complete set of DNA)
  5. What is the difference in the leading and lagging strand of DNA replication?

Both are involved in DNA replication. Leading strand adds continuously to the 3’ end toward the replication fork. The lagging strand must add to the 3’ end away from the replication fork; therefore, it is built in segments that are then joined together by DNA ligase.

  1. What is the function of each of the following enzymes?
  2. DNA Polymerase

build new DNA

  1. RNA Polymerase

build new RNA

  1. Helicase

separates strands of DNA by breaking hydrogen bonds between bases

  1. Primase

adds primer so that polymerase can build a new DNA strand

  1. Ligase

closing gap between Okazaki fragments on lagging strand

Questions 13-16 should be answered together

  1. What is the complimentary strand of DNA for the following template of DNA?
  2. CGC TAT CCG

GCG ATA GGC

  1. What would be the mRNA for the template above?

GCG AUA GGC

  1. What would be the tRNA for thetemplate above?BONDS WITH MRNA

CGC UAU CCG

  1. What amino acids are produced from the process described in questions 13-15?

ALA, ILE, GLY

USE MRNA

  1. Answer all of the following questions concerning transcription.
  2. What is it?DNA to mRNA (just a cheap copy of DNA)
  3. Where does it happen?nucleus (because DNA is involved)
  4. Why does it happen? DNA is too important to take out of the nucleus and risk it getting messed up. Also, DNA is too big to get out of the nucleus.
  1. Answer all of the following questions concerning translation.
  2. What is it?mRNA to proteins
  3. Where does it happen?ribosomes (in the cytoplasm or rough ER)
  4. Why does it happen? to make proteins that do all of the work in the cell
  1. Answer the following questions concerning codons
  2. Where are they located? mRNA
  3. How many bases are they made of? 3
  4. What do they “code” for?amino acid (monomer of protein)
  5. Using the answer given in part c, how many of they does each codon “code” for?1
  6. What is an anticodon?

3 bases on tRNA that are complementary to codon on mRNA

  1. Draw the generic shape of a tRNA and label the amino acid, the tRNA, and the anticodon.(What does the t in tRNA stand for? What are they transferring?)

  1. What kind of bond forms between amino acids?peptide (covalent bond)
  2. If the DNA analysis of a gene shows 20% adenine bases, what would be the percentage of Thymine, Cytosine, Guanine, and Uracil?

T = 20% percent, C = 30%, G = 30%, U = 0%

  1. Draw a double helix and indicate the location of each of the following:
  2. Phosphate group
  3. Sugar (deoxyribose)
  4. Hydrogen bond
  5. Covalent bond
  6. Adenine
  7. Thymine
  8. Cytosine
  9. guanine

Biotechnology = using our knowledge of life for our own benefit (cloning, recombinant DNA, GM food, etc)

  1. Prokaryotic genes are expressed in groups using an operon. Draw an operon(ONLY IN BACTERIA) below and label the following: promoter, operator, structural genes. We modeled this using straw, noodle, paper clip, etc.

  1. All of the following terms apply to the usage of operons drawn above. Define each of the following terms:
  1. Operon – A group of prokaryotic genes with a related function that are often grouped and transcribed together.
  2. Promoter-The nucleotide sequence that can bind with RNA polymerase to start transcription. This sequence also contains the operator region.
  3. Operator-The nucleotide sequence that can bind with repressor protein to inhibit transcription.ON/OFF SWITCH

d. Structural genes- genes that are related and code for related enzymes in a biochemical

pathway.

e. RNA Polymerase – enzymes that reads DNA and makes mRNA

f. Regulatory Gene – Gene that lies outside the operon region and produces a protein called a

repressor that can inhibit the transcription of an operon by attaching to the operator.

  1. What is the difference in an inducible operon and a repressible operon? (Hint: The lac operon is an example of an inducible operon and the trp operon is an example of a repressible operon).

Inducible = usually off but can be turned on(induce labor)

repressible = normally on but can be turned off

  1. Define the following terms.
  2. Plasmid –
  3. These are small, circular, exchangeable pieces of DNA.
  4. These are in addition the main large circular DNA strand.
  5. These help to increase variation and survival.
  6. Restriction Site – site where a restriction enzyme MUST cut
  7. Restriction Enzyme – enzyme found in bacteria used to cut specific DNA sequences
  8. Recombinant DNA – DNA from 2 different sources (Remember spider-goats?). Use restriction enzyme to cut DNA from one source and insert it into another. TRANSFORMATION - GRIFFITH
  1. What are the 4 steps to bacterial cloning? (Hint: Be sure to understand the purpose of the ampR gene on the plasmid as well as placing the bacteria in an antibiotic.)
  2. The first step in this process uses restriction enzymes to create “Sticky Ends” on a plasmid and DNA from another source. This plasmid will also have a gene for antibiotic resistance on it.
  3. The second step is to introduce the fragments to the “open” plasmids for recombination to occur.
  4. Recombination – This is the DNA of the plasmid recombining to contain both the original plasmid DNA and the new DNA.
  5. The “sticky ends” base pairs will match allowing for recombination to occur.
  6. The third step uses the enzyme Ligase to seal the DNA fragments together.
  7. The third step is to introduce the recombined plasmids back into the bacteria. The bacteria are also called a Cloning Vector. A vector is a carrier organism.
  8. The fourth step is to identify the bacteria that took the plasmid up by putting them on ampicillin. The bacteria that took up the plasmid will have antibiotic resistance and will live. The bacteria that did not will not have antibiotic resistance and will die.

Then let the bacteria reproduce, by binary fission, to achieve a large working population.

  1. What is Gel Electrophoresis used for?

separate DNA fragments based on size