bgenetics-1 - BACTERIAL GENETICS DEOXYRIBONUCLEIC ACID...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
BACTERIAL GENETICS DEOXYRIBONUCLEIC ACID Nucleiod A. No nuclear membrane B. No paired chromosomes C. No nucleolus D. Single molecule DNA (circular) STRUCTURE of DNA ( see figs. in text) Components of DNA A. 2- deoxyribose 1. 5 carbon (C) sugar 2. Lacks O on #2 carbon B. Phosphate group (PO 4 ) C. Nitrogen (N) bases 1. Pyrimidines a. Thymine b. Cytosine 2. Purines a. Adenine b. Guanine D. Nucleotides 1. Subunits (structural units) of DNA 2. Structure of a nucleotide ( see fig. in text) a. 2-deoxyribose b. Phosphate group on #5 C c. Nitrogen base on #1 C E. Arrangement of nucleotides 1. Nucleotides form two chains 2. Bonds (covalent) between nucleotides a. P on #5C of one nucleotide b. #3C on next nucleotide 3. Two chains combined in ladder-like arrangement a. “Sides” of ladder - sugar and phosphate b. “Rungs” of ladder - two nitrogen bases 4. Pairing of N bases is specific a. Adenine to thymine - 2 “weak” hydrogen (H) bonds b. Guanine to cytosine - 3 “weak” H bonds D. Antiparallel structure of DNA 1. Chains of nucleotides - opposite directions
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
2. One side - 5’ to 3’ side 3. Opposite side - 3’ to 5’ side 4. Two sides twist double helix ( see fig. in text) GENETIC CODE IN DNA A. Sequence of nitrogen base pairs = genetic code B. Language of DNA - DNAese 1. Symbols (alphabet) in DNA a. A = T b. T = A c. C G d. G C 2. Form three letter words - triplets 3. Each triplet codes for one amino acid 4. 64 triplets 5. 20 amino acids form proteins C. Gene - genetic code for one protein DNA REPLICATION ( fig. pg. in text ) A. Enzymes (DNA polymerases, DNA ligases) B. Begins at replication fork C. Each strand acts as template D. New nucleotides combine with complementary nucleotides on each parent strand E. Semiconservative replication - each new DNA strand = I/2 original DNA & 1/2 “new” DNA F. DNA polymerase adds new nucleotides in 5’ 3’ direction G. Formation of one strand - continuous or leading strand 1. Nucleotides added on one at a time as replication fork opens (from 5’ to 3’ )
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 8

bgenetics-1 - BACTERIAL GENETICS DEOXYRIBONUCLEIC ACID...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online