Nucleic Acids Large polymers Made of linked nucleotides 2 types Components of a nucleotide? A nucleotide consists of a 5-carbon sugar, phosphate group, nitrogenous base 2 types

DNA / RNA structure DNA RNA Sugar Nitrogenous bases Shape

DNA is anti-parallel One strand is “flipped” in relation to the other

CELL CYCLE IN EUKARYOTIC CELLS Fig. 8-5 CELL CYCLE IN EUKARYOTIC CELLS INTERPHASE G1 S (DNA synthesis) First gap phase -growth -normal cell activities -DNA copies (replicates) itself G2 Second gap phase -growth -cell prepares for mitosis Cytokinesis Mitosis MITOTIC PHASE (M) Mitosis = division of the nucleus Cytokinesis = division of the cytoplasm

Semi-conservative replication The new strand consists of one old DNA and one new DNA strand Two strands separate Nucleotides come and pair with their complementary base DNA replication Semi-conservative replication

DNA replication starts at an origin of replication (many in eukaryotes) forming replication bubbles

Enzymes involved in replication Helicase  unwinds the double helix DNA polymerase  builds the new DNA strand DNA ligase “glues” DNA fragments together

DNA Polymerase Adds nucleotides to a growing nucleic acid chain Can ONLY add to the 3’ end of the chain Result: The two sides of the DNA molecule are copied differently

Function of DNA????? But where is eukaryotic DNA found? Where are proteins built?

Central idea of genetics Flow of genetic information in organisms Trait

template Where would this occur? Where would this occur?

Structure of a chromosome made up of DNA and Protein many genes on single chromosome Structure of a gene

3 types of RNA all coded for by the DNA in the nucleus tRNA Transfer RNA mRNA Messenger RNA rRNA Ribosomal RNA

Process of Transcription Step 1 Initiation The promoter is sequence of DNA recognized by RNA polymerase Determines which of the two strands will act as the template

Step 2: Elongation RNA polymerase moves down the DNA elongating the mRNA strand based on the sequence in DNA RNA will use Uracil to base pair with Adenine

Step 3: Termination When RNA polymerase reaches the terminator region on the DNA it will stop and release the mRNA

template Codon: 3 nucleotide sequence that specifies one amino acid or signals translation to stop

Who are the players in translation?? mRNA tRNA Ribosomes (made of protein and rRNA)

mRNA

tRNA

Made of rRNA and Protein Ribosome Made of rRNA and Protein Large subunit

Initiation of Translation

Elongation of the polypeptide chain

Termination

TACGTTGCGACGATC AUGCAACGCUGCUAG Met - Gln - Arg - Cys

RNA processing in Eukaryotic cells

Prokaryotic cell No RNA processing Transcription and translation may occur simultaneously

AIDS research Malaria Recently, scientists engineered several rhesus macaques to express GFP, along with a protein that pre-disposes the animals to Huntington's disease, a neurodegenerative disorder. The researchers used GFP to confirm that the monkeys had received the disease-causing gene

Prokaryote transcription and translation can occur simultaneously no nucleus

Prokaryotic cell Transcription and translation may occur simultaneously No RNA processing

Semi-conservative replication The new strand consists of one old DNA and one new DNA strand Two strands separate Nucleotides come and pair with their complementary base DNA replication Semi-conservative replication

Enzymes involved in replication Helicase  unwinds the double helix DNA polymerase  builds the new DNA strand DNA ligase “glues” DNA fragments together

DNA Polymerase Adds nucleotides to a growing nucleic acid chain Can ONLY add to the 3’ end of the chain Result: The two sides of the DNA molecule are copied differently