Organic compounds: nucleic acids

Composition

C, H, O, N, P

Nucleotide:

complex molecule

Base:

N containing organic molecule,

Nucleic acids

are macromolecules that transmit hereditary information and

determine what proteins a cell manufactures.

deoxyribonucleic acid

makes up the genes, the hereditary material of the

cell, and contains instructions for making all the proteins as well as all

ribonucleic acid.

participates in the process in

which amino acids are linked to form polypeptides.

Ester bond

is a type of covalent bond formed between a hydroxyl group and a carboxyl group, linking fatty acids to glycerol in lipid molecules.

Formation of polynucleotide chain

 The ribose and the phosphate

group bind by condensation and

form a pentose-phosphate

backbone

 The basis are attached to this

backbone

ATP Function :

Main energy transporting and

storing molecule

NAD+, NADP+ Function:

NAD+ : in cell respiration,

able to carry 2 H atoms

dissociated into e- and p+.

• NADP+: it transports 1 p+

and 2 e- in photosynthesis.

CoA Function:

Function: carries acetyl

group in cell

respiration in the

glucose or lipid

breakdown.

CoA Contains

• Contains: adenine,

ribose, 3 phospahet

and a vit B5 with an SH

group.

ATP Contains

ATP → ADP+P +30KJ (hydrolysis)

ATP ADP +P+30KJ (condensation)

NAD+, NADP+ Contains

NAD+ +2H ++ 2e− NADH+ H+

ATP Is converted…

to cyclic adenosine monophosphate (cyclic AMP, or cAMP) by the enzyme adenylyl cyclase

cyclic guanosine monophosphate (cGMP),

also plays a role in certain cell signaling

processes.

Composition:

DNA is a double stranded molecule

Orientation:

Nitrogenous bases are closely packed together on the inside and phosphates form an outer

backbone

Shape:

The DNA molecule twists at regular intervals (every 34 Angstrom) to form a helix (two strands =

double helix)

m-RNA:

messenger RNA

r- RNA:

ribosomal RNA

t-RNA:

transfer RNA

phosphodiester bond

Phosphate and sugar(covalent)

Bubbles→

replication origin (helicase)

Replication forks→

ends of the bubbles

Replication process is bidirectional→

bubbles enlarge in both directions

Leading strand:

CONTINUOUS SYNTHESIS

Lagging strand:

has to be built backwards→ DISCONTINUOUS SYNTHESIS

Primase:

lays down a little chain of RNA→ primer

DNA Polymerase III.

(Okazaki fragments)

DNA polymerase I.

place the RNA sengments with proper DNA

DNA Ligase:

glues the DNA segments (covalent bonds)

PCR purpose

used to amplify large quantities of a specific sequence of DNA from an initial minute sample

PCR

an artificial method of replicating DNA under laboratory conditions

Taq polymerase

is an enzyme isolated from the thermophilic bacterium Thermus aquaticus

Taq polymerase purpose

extends the nucleotide chain from the primers – therefore primers are used to

select the sequence to be copied

Denaturation

DNA sample is heated (~90oC) to separate the two strands

Annealing

Sample is cooled (~55oC) to allow primers to anneal (primers designate sequence to

be copied)

Elongation

Sample is heated to the optimal temperature for a heat-tolerant polymerase (Taq) to

function (~75oC)

Frederick Griffith-1928

VACCINE AGAINST

Pneumococcus.

Watson and Crick→

DNA structure

Meselson and Stahl→

semi-consercative model of DNA replication