DNA Lesson 1 Structure and function of DNA

• Biologie
• Middelbare school
• vwo
• Leerjaar 4

DNA Lesson 1

Structure and function

DNA

Chapter 21 & 22

0

Levels of organisation

On which level do we find DNA?

Learning Goals BS1

• You can describe the structure of DNA
• You can describe the function of DNA

• Key words 1 - Structure and function of DNA p. 45-49

• DNA
• genome
• nuclearDNA
• mtDNA
• plasmids
• nucleic acid
• nucleotide
• desoxyribose
• Adenine (A)
• Thymine (T)
• Cytosine (C)

• Guanine (G)
• one strand of DNA
• base pairing
• basepair
• double strand of DNA
• helix structure
• sequence
• gene
• (non coding DNA)
• (repetitive DNA)

Genome - all of the DNA in a cell

prokaryote = unicellular organism without a nucleus, e.g. a bacterium (p. 65)

In a prokaryotic organism the DNA lies in a  

circle and is surrounded by cytoplasm 

instead of a nuclear membrane.

A bacterium often contains another 

short circle of DNA called a plasmid.

Genome - all of the DNA in a cell

eukaryote - cell with a nucleus e.g. plant, animal or fungus (p. 66)

genome of an animal cell:

nuclearDNA

mitochondrial DNA(mtDNA)

genome of a plant cell:

nuclearDNA 

mitochondrialDNA (mtDNA) AND

DNA in chrloroplasts

DNA - DesoxyriboNucleicAcid - desoxyribonucleïnezuur

DNA is constructed from 4 different building blocks (nucleotides); A,C,T,G (p. 64)

Every nucleotide is made of 

3 elements:

1. a phosphate group

2. desoxyribose (a pentose sugar)

3. a base that contains nitrogen (-N) 

engels                                  nederlands

Structure of  DNA

Draw one complete nucleotide in your notebook and number the five corners of the C-atom positions 1-5.

single strand DNA

ssDNA

double strand  DNA

dsDNA

Can you think of a way that makes it possible for DNA to be copied identical to  their parent strand?

Double helix

- A, C, T, G are complementary

- Like a ladder: rungs = bases and uprights = phosphates and sugar

- The DNA of all organisms is constructed of ACTG

- Antiparallel

- The sequence (= ACTG order) is unique for each organism

Next video

0:00 - 04:80 Structure and function of DNA

04:80 - 12:59 DNA Replication (Next lesson)

Homework

- Learn the first three bullet points of the summary p. 57

- Make sure you have drawn a complete nucleotide with numbered C atoms as instructed on slide # 10 in. LessonUp

- Copy and complete question 1 (p. 57)

- In classroom (Subject DNA) is a worksheet posted named Lesson 1 DNA: Structure and function. Make exercise 1 - 5 of the worksheet.

05:18

What is the opposite strand of:
5' AGGTCCG '3 ?

1. 5' TCCAGGC '3
2. 3' TCCAGGC '5
3. '3 AGGTCCG '5

06:09

Name the three differences between DNA and RNA