Chapter 9 & 10 notes part 2

1. CHAPTER 9 & 10 CHAPTER 9 & 10
NOTES PART 2NOTES PART 2
DNA DNA
PROCESSESPROCESSES

2. I. REPLICATIONI. REPLICATION
The DNA molecule can build an exact The DNA molecule can build an exact copycopy of of
itself.itself.
DNA separates into DNA separates into twotwo strandsstrands exposing the exposing the
bases. The exposed bases combine with free bases. The exposed bases combine with free
nucleotides. This process is repeated until nucleotides. This process is repeated until twotwo
wholewhole DNA molecules are formed. DNA molecules are formed.

4. WebsiteWebsite
This is a website showing the process of This is a website showing the process of
replication.replication.
http://http://www.dnai.org/a/index.htmlwww.dnai.org/a/index.html

5. II. TRANSCRIPTIONII. TRANSCRIPTION
The information contained in the DNA must be The information contained in the DNA must be
delivered to the delivered to the ribosomesribosomes where proteins are where proteins are
synthesized (made).synthesized (made).
The information on one strand of DNA is The information on one strand of DNA is
copied almost exactly in a process called copied almost exactly in a process called
transcriptiontranscription..
This near copy of DNA is called This near copy of DNA is called ribonucleic acidribonucleic acid
– RNA.– RNA.
When When nitrogen bases nitrogen bases do not copy correctly, a do not copy correctly, a
mutationmutation happens. happens.

6. What is RNA?What is RNA?
RNA differs from DNA in 3 ways:RNA differs from DNA in 3 ways:
1. The sugar in RNA is called 1. The sugar in RNA is called riboseribose..
2. In RNA, the base 2. In RNA, the base uraciluracil replaces thymine. replaces thymine.
3. RNA is a 3. RNA is a singlesingle strand. strand.

7. What are the types of RNA?What are the types of RNA?
There are 3 types of RNA:There are 3 types of RNA:
1. mRNA (messenger RNA) – acts as a pattern for 1. mRNA (messenger RNA) – acts as a pattern for
the order of amino acids in the protein.the order of amino acids in the protein.
2. tRNA (transfer RNA) – carries amino acids in the 2. tRNA (transfer RNA) – carries amino acids in the
cytoplasm to the ribosomes.cytoplasm to the ribosomes.
3. rRNA (ribosomal RNA) – found in the 3. rRNA (ribosomal RNA) – found in the
ribosomes. ribosomes.

8. WebsiteWebsite
ThisThis is a website showing the process of is a website showing the process of
transcription.transcription.

9. III. TRANSLATIONIII. TRANSLATION
The bases on the mRNA act as a code for each The bases on the mRNA act as a code for each
aminoamino acidacid. Groups of 3 bases, called . Groups of 3 bases, called codonscodons, ,
act as a specific code for each amino acid.act as a specific code for each amino acid.
The The ribosomesribosomes move along the mRNA reading move along the mRNA reading
the codons. The the codons. The tRNAtRNA picks up the correct picks up the correct
amino acid and brings it to the amino acid and brings it to the mRNAmRNA..
A chain of amino acids builds up a A chain of amino acids builds up a proteinprotein..

10. WebsiteWebsite
ThisThis is a website showing the process of is a website showing the process of
translation.translation.