Gene structure DNA replication

Figure 7.4A

Figure 7.5 16

DNA Structure The DNA double helix has grooves: a wide major groove and a narrow minor groove. - These provide DNA-binding proteins access to base sequences. Figure 7.6 17

RNA Structure RNA differs from DNA: - Usually single-stranded - Contains ribose sugar - Uracil replaces thymine Figure 7.4B 18

The Bacterial Nucleoid Bacteria pack their DNA into a series of loops or domains, collectively called the nucleoid. - Loops are anchored by histone-like proteins Figure 7.8 19

DNA Replication Replication of cellular DNA in most cases is semiconservative. - Each daughter cell receives one parental and one newly synthesized strand. Figure 7.13 20

Figure 7.14 21

Figure 7.15 22

Figure 7.18b Figure 7.18a 23

Click box to launch animation DNA Replication Animation: DNA Replication Click box to launch animation

Figure 7.19 25

Figure 7.21 26

Analysis of DNA Figure 7.27A Restriction endonucleases cleave DNA at specific recognition sites, which are usually 4 to 6 bp and palindromes. - May generate blunt or staggered ends 27

Analysis of DNA Agarose gel electrophoresis can be used to analyze the DNA fragments obtained by treatment with restriction enzymes. Figure 7.27B 28

Analysis of DNA The polymerase chain reaction (PCR) can produce over a million-fold amplification of target DNA within a few hours. Figure 7.29 29