7.1 DNA structure and replication

• Biologie
• Middelbare school
• vwo
• Leerjaar 5

7.1 DNA structure and replication

Essential idea: The structure of DNA is ideally suited to its function

lesson outline (60min)

- review/note taking activities (replication, regions in DNA) 10-15min

- intro into DNA profiling 15min

- CY practise questions 5min

- HW: start next lesson (7.2 (1))

note: slides identified as 'extra practise' or 'extra challenge' are optional)

Aims:

- describe the DNA structure and how it suggests a method for replication

- describe the replication process using 'replication fork' & enzymes

- outline functions of coding and non-coding DNA

- outline base sequencing and DNA profiling

- describe findings: Hershy and Chase & Rosalind Franklin experiments

- describe nucleosomes within DNA

00:39

Where would sulfur atoms be found in the proteins?

1. in the hydroxyl group of the amino acid
2. in the rest (R) group of the amino acid
3. in the amino group of the amino acid
4. in the di-sulfide bonds

00:43

S-35 is an isotope of sulfur. What is an isotope?

1. A sulfur(16) atom with different number of electrons
2. A sulfur (16) atom with a different number of protons
3. A sulfur (16) atom with same atomic mass but different chemical properties (ex. radio activity)
4. none of the above

01:24

Where would P-32 be found in the DNA molecule?

1. in the sugar phosphate backbone
2. in the bases
3. in the hydrogen bonds
4. in the covalent bonds

01:36

What can be concluded from these two experiments?

1. Proteins do not contain genetic material
2. DNA does not contain genetic material

In your notes:

Describe the proteins and enzymes involved in DNA replication: helicase, DNA gyrase, single strand binding proteins, DNA primase and DNA polymerases I and III.

(revision video here)

In your notes:

Outline the regions of DNA that do not code for proteins. This should be limited to regulators of gene expression, introns, telomeres and genes for tRNAs.

Some regions of DNA do not code for the production of proteins. What are these regions of DNA used as?

1. A. They have no known function and are recycled to provide nucleotides
2. B. Gene regulation and coding for production of enzymes used in translation
3. C. Telomeres and coding for production of tRNA
4. D. Introns and coding for production of structural proteins

1. A
2. B
3. C
4. D

Intro into DNA profiling (you will learn more about this in T3.5)

DNA profiling (also called DNA fingerprinting) is the process of determining an individual's DNA characteristics.

AIMS:

You should show awareness that the Sanger method of base sequencing uses nucleotides containing dideoxyribonucleic acid (DNA with deoxyribose missing 2 oxygen molecules) to stop DNA replication at a specific base which allows sequencing using fluorescent markers and computers. (Sanger chain termination. Video here)
You should show awareness that in DNA profiling Tandem repeats are used. (video here)

Tasks: (see next slides)

RSQ Pearson pg 328 in Pearson textbook & complete CY5

RSQ pg 332,333 in Pearson textbook & complete CY6 pg333

What are polymorphisms in DNA?

1. regions that are analysed by DNA profiling
2. sections of DNA made up of STR's
3. specific regions of DNA with significant variation between individuals
4. all are correct

Review the aims of this lesson and write down any questions you have on the next slide:

Aims:

- describe the DNA structure and how it suggests a method for replication
- describe the replication process using 'replication fork' & enzymes
- outline functions of coding and non-coding DNA
- outline base sequencing and DNA profiling
- describe findings: Hershy and Chase, Rosalind Franklin experiments
- describe nucleosomes within DNA

What I do not understand / questions I have about the content are:

The end of the lesson