dna functions as the inherited directions for a cell or organism
DESCRIPTION
Flow of Genetic Information. DNA functions as the inherited directions for a cell or organism. How are these directions carried out?. Gene. DNA. Nucleic acids. RNA. Amino acid. Protein. Flow of Genetic Information. - PowerPoint PPT PresentationTRANSCRIPT
– DNA functions as the inherited directions for a cell or organism.
– How are these directions carried out?
Flow of Genetic Information
Gene
DNA
RNA
Protein
Amino acid
Nucleic acids
Gene
DNA
RNA
Protein
Amino acid
Nucleic acids
– An organism’s genotype is its genetic makeup, the sequence of nucleotide bases in DNA.
– The phenotype is the organism’s physical traits, which arise from the actions of a wide variety of proteins.
Flow of Genetic Information
Phosphategroup
Nitrogenous baseA, G, C, or U
Uracil U
Sugar ribose
Nitrogenous base(A,G,C, or T)
Phosphategroup
Thymine (T)
Sugar(deoxyribose)
Phosphate
Base
Sugar
●Nucleic acids are polymers of nucleotides– DNA, deoxyribonucleic acid– RNA, ribonucleic acid
Nucleic Acids
Review nucleotide structure:
Nucleic Acids
Nucleic Acids●Each DNA nucleotide has one of the following bases:
Adenine (A)Guanine (G)Cytosine (C)Thymine (T) Adenine A Guanine G
Thymine T Cytosine C
● Each RNA nucleotide has one of the following bases:
Adenine (A) Guanine (G) Cytosine (C) Uracil (U)
DNA Structure*Early 1950’s Rosalind Franklin*1953 Watson and Crick
Sugar-phosphatebackbone
NucleotideBasepair
Hydrogenbond
Bases
a DNA strandpolynucleotide
b Double helixtwo polynucleotide strands
●Nucleic Acid Structure
DNA Structure
Sugar-phosphatebackbone
Phosphate group
Nitrogenous base
DNA nucleotide
Nucleotide Thymine (T)Sugar
Polynucleotide
DNAdouble helix
Sugar(deoxyribose)
Phosphategroup
Nitrogenous base(can be A, G, C, or T)
DNA Structure
DNA Structure
•Complementarity
”It has not escaped our notice that the specific pairing we have postulated immediately suggests a possible copying mechanism … “
•Mode of DNA ReplicationSemiconservative
DNA Replication
*Overview: DNA replication
*Complementarity determines which nucleotide will be added
*Chain elongation in a 5’-to-3’ direction
DNA Replication
Initiation
*Primase
*Strands must separate•Helicases•SSBPs•DNA gyrase
*Two are antiparallel•Continuous DNA synthesis = leading•Discontinuous DNA synthesis = lagging
DNA Replication
A large team of enzymes carry out DNA replication:•Helicases
•SSBPs
•DNA gyrase
Elongation:
•Association of polymerase
•Sliding clamp
•Primase
•DNA synthesis (DNA pol)
•Primer removal and replacement (DNA pol)
•Ligase closes the gaps
DNA Replication