DNA Structure, Replication & Mitosis

DNA Structure, Replication, Mitosis and Protein Synthesis Outline 4

Name______Date______Per______

PART I. THE STRUCTURE OF DNA 1. What do the letters DNA stand for?

2. What is the purpose of the DNA?

3. Where is the DNA located? (be specific)

4. DNA is composed of repeating subunits (monomers). What are these subunits called?

5. What are the 3 main parts of each nucleotide?

6. What is the name of the sugar used in DNA?

7. How many strands does a DNA molecule possess?

8. What are the 4 nitrogen bases in a DNA molecule?

9. What is the main difference between a purine and a pyrimidine? Which of the two nitrogen bases are purines and which two are pyrimidines?

10. The strands of DNA form a ---- structure. What 2 scientists were responsible for this model?

11. What is shown in the figure to the right? Who discovered this? How did this help the scientists in question 10 with their discovery?

12. What compounds make up the sides of the DNA molecule?

13. Where are the nitrogen bases located in the DNA molecule?

14. The nitrogen bases always follow a “pairing rule.” List the pairing rule for DNA.

15. What is meant by the idea that DNA is made of complementary strands?

15. Label the DNA molecule using the terms: deoxyribose, phosphate, adenine, cytosine, guanine, thymine, hydrogen bonds.

PART II. STRUCTURE AND FUNCTION OF PROTEIN 1. List a few PROTEINS discussed in the Power Point. 2. ______are biological catalysts that speed up the rate of a chemical reaction. It does this by lowering the ______energy required to start the reaction.

3. The Many Functions of Proteins  Proteins function as a structural component: ______

 Proteins function as chemical messengers/receivers: ______

 Proteins defend our body from disease:______

 Many proteins are enzymes:______

4. Proteins are long chains of ______.

5. The long chains of amino acids (known as______) coil up to create a ______(working) protein. The protein will not work unless it is folded up.

6. Most amino acids look exactly the same except for the _____ group or ______group.

7. There are ______different functional groups that give each amino acid different properties.

Forming a polypeptide 8. aa=______

aa + aa + aa + aa aa – aa – aa – aa + 3H2O

9. DNA, the blueprint that tells us which proteins to make, is located in the ______. ______(where proteins are made) are located in the ______.

10. DNA is too ______to leave the nucleus. There must be a better way to get the message out.

Part III. RNA Structure and Function 1. DNA vs. RNA DNA RNA

2. There are 3 types of RNA  ______RNA (mRNA)  ______RNA (rRNA)  ______RNA (tRNA)

3. What is a gene?

Part IV. Protein Synthesis: How your cell makes proteins! 1. Transcription: Rewriting DNA into RNA language

Step1:

 Occurs in the ______

 ______polymerase (an enzyme) binds to the DNA & unzips the DNA

Step2:

 RNA polymerase adds free RNA ______using the DNA

______

 Follows the complementary base paring rules:

A = ____

C= ____

 Transcription uses only a specific region of the DNA known as a ______

 As RNA polymerase moves past DNA ______

Step3:

 RNA polymerase reaches a specific sequence of ______that marks the ______of

the gene (“stop” signal)

 ______releases the DNA & newly formed mRNA.

 mRNA ______the nucleus.

messenger RNA (mRNA):  ______stranded

 Carries the instructions on how to make a specific ______.

 Moves from the nucleus to the ______.

 Each group of three bases is known as a ______.

mRNA strand: U A U G G C A U A U U A

2. Translation: Making a Protein

ribosomal RNA (rRNA):

 is part of the ______of ribosomes.

 Ribosomes are made from ______& other ______.

 Ribosomes ______the mRNA and help ______the amino acids to make a protein.

transfer RNA (tRNA):

 ______the amino acids to the ribosome to make a protein.

 Assembles the amino acids in the correct order based on the ______matching.

Step1:

 The mRNA attaches to a ______.

 Translation will not start until the ribosome reads a “______”______(usually AUG)

Step2:

 A ______RNA molecule arrives at the ribosome.

 It brings an ______to the first three bases (codon) on the mRNA.

 The three unpaired bases (anticodon) on the ______link up with the ______on the mRNA.

Step3:  Another ______molecule comes into place, bringing a second ______.

 Its ______links up with the second codon on the mRNA.

 A ______bond forms between the two amino acids.

 The first tRNA molecule ______its amino acid and moves off into the cytoplasm.

Step4:

 The ribosome moves along the mRNA to the next ______.

 Another ______molecule brings the next amino acid into place.

 A peptide bond joins the second and third amino acids to form a ______chain.

 The process continues. The polypeptide chain gets longer. This continues until a ______(stop) codon is reached.

 The ______is then complete. It is released from the ribosome.

3. Which amino acids do the following mRNA sequences code for?

 AUG ______

 CCC ______

 GGC ______

 UAA ______

4. What types of mutations could occur?