nucleic acids - onlinebiosurgery

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Transcript nucleic acids - onlinebiosurgery

NUCLEIC ACIDS
Objective:
describe the structure of RNA and DNA and explain the
importance of base pairing and hydrogen bonding
- DNA is a polynucleotide, usually double stranded,
made up of nucleotides with bases A,T,C and G.
- RNA is a polynucleotide, usually single stranded
made up of nucleotides containing the bases A,U,C
and G.
CENTRAL DOGMA OF BIOLOGY
•DNA
•RNA
•Protein
HOMEWORK:


Devise and complete a table of key roles for each
specified ion – information coming from
bibliographic and web-based research
in living organisms: calcium, sodium, potassium,
magnesium, chloride, nitrate, phosphate
NUCLEIC ACIDS

1)
2)
They come in two forms:
DNA (deoxyribonucleic acid)
RNA (Ribonucleic acid)
DNA in eukaryotic cells are found in the nucleus,
acting as a information store.
CONTINUED…
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
Nucleic acids are composed of monomers called
a nucleotide.
A nucleotide is composed of 3 subunits:
One phosphate group;
One sugar molecule ;
One organic nitrogenous base.
These subunits are joined by covalent bonds to
form a nucleotide molecule.
BASE TYPES
FEATURES OF NUCLEOTIDES
DNA(double helix)
RNA(single)
Same phosphate group
Same phosphate group
5-carbon sugar normally
deoxyribose
5-carbon sugar normally ribose
Base pairs Guanine, Cytosine,
Adenine and Thymine
Base pairs, Guanine, Adenine,
Cytosine and Uracil.
JOINING NUCLEOTIDES


A condensation reaction between the phosphate
group of one nucleotide and the sugar of another
join the two together.
This forms chains called the “Backbone.” Organic
bases will project from this, and it is this
sequence of bases that forms coded information of
nucleic acid.
HOW NUCLEOTIDES JOIN TOGETHER
DNA STRUCTURE
BASE PAIR- ACRONYM
Gangsters – Can
Ask - Time
A-T 2 H bonds
G-C 3 H-bonds
DRAW AND LABEL THE DIAGRAM EVERY
COMPONENT AND BOND
DRAW AND LABEL
ribosomal RNA (rRNA)
Makes up the bulk of the ribosome.
Large folded molecule.
messenger RNA (mRNA)
Carries the genetic message from DNA in the nucleus to the ribosomes
where proteins are synthesised (made) accordingly.
Long molecule, not folded.
Variable in length and base sequence.
Readily broken down and remade.
transfer RNA (tRNA)
Collects amino acids and takes them to the ribosomes for assembly
into proteins.
AMINO ACID
Small molecule.
Winds back on itself to
form a “clover-leaf” shape.
One end carries an amino acid.
One loop has a special triplet
of bases (ANTICODON) which
determines the amino acid carried.
ANTICODON
RIBONUCLEIC ACID (RNA)
Single stranded polynucleotide.
Sugar is always ribose.
Organic bases are always A, G, C, and U, NEVER T.
3 types :-
ribosomal RNA (rRNA)
messenger RNA (mRNA)
transfer RNA (tRNA)
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