Bio L8

Components of a DNA nucleotide

Adenine, Thymine, Guanine, Cytosine

Use Chargaff’s rule to calculate the percentage of each base in DNA

A= 20% G=30% T=20% C=30%

Identify type of bond that hold the base pairs together in a double helix

hydrogen bond

What is the complementary DNA to

A-T-C-G-T-T-C-A

T-A-G-C-A-A-G-T

What is semiconservative replication?

each daughter DNAs are half parent and half new

describe the function of DNA polymerase

adds new nucleotides to the 3’ end of an existing strand

describe the function of helicase

enzyme that unzips DNA strand @ the fork

describe primase

builds a short RNA primer attached to the DNA

describe what happens during replication

a copy of the DNA is made

Where does replication happen in eukaryotes?

nucleus

Where does replication happen in prokaryotes?

cytoplasm

describe a lagging strand:

* direction: away from or towards the fork
* protein number: multiple or single

* away from
* multiple

describe a leading strand:

* direction: away from or towards the fork
* protein number: multiple or single

* towards the fork
* single

What are Okazaki fragments?

short lagging strand segments

In what direction are new strands of DNA built?

5’ to 3’ direction

New nucleotides can only be added to which prime end?

3’

Describe the origin of replication

where the DNA replication begins

Describe a replication bubble

the space between the separating strands

describe a replication fork

the part where the two strands separate

Components of an RNA nucleotide

Adenine, Uracil, Guanine, Cytosine

3 differences between the structures of DNA and RNA

* sugar in RNA is ribose not deoxyribose
* RNA is singe stranded not double
* RNA contains bade Uracil in place of Thymine

describe the function of mRNA

(messenger) carries info from DNA in the nucleus to ribosomes in cytoplasm

describe the function of tRNA

(transfer) carries amino acids to ribosomes as specified by the coded messages in mRNA

describe rRNA

(ribosomal) makes up part of a ribosome