Molecular Biology

Fig. 10-1a

Head

Tail fiber

DNA

Tail

Fig. 10-1b

Batch 1Radioactiveprotein

Bacterium

Radioactiveprotein

DNA

Phage

Pellet

RadioactiveDNA

Batch 2RadioactiveDNA

Emptyprotein shell

PhageDNA

Centrifuge

Radioactivityin liquid

Measure theradioactivity inthe pellet andthe liquid.

4Centrifuge the mixtureso bacteria form apellet at the bottom ofthe test tube.

3Agitate in a blender toseparate phagesoutside the bacteriafrom the cells andtheir contents.

2Mix radioactivelylabeled phages withbacteria. The phagesinfect the bacterial cells.

1

Pellet

CentrifugeRadioactivityin pellet

DNA Structure

Fig. 10-3b

Fig. 10-3a

Fig. 10-2aa

Sugar(deoxyribose)

Thymine (T)

Nitrogenous base(A, G, C, or T)

Phosphategroup

Fig. 10-2b

Pyrimidines

Guanine (G)Adenine (A)Cytosine (C)Thymine (T)

Purines

Fig. 10-2c

Sugar(ribose)

Uracil (U)

Nitrogenous base(A, G, C, or U)

Phosphategroup

Fig. 10-3da

Basepair

Ribbon model

Fig. 10-4a-3

Parentalmoleculeof DNA

Nucleotides

Both parentalstrands serveas templates

Two identicaldaughter

molecules of DNA

DNA replication occurs during S phase of the Cell Cycle

Fig. 10-4b

Fig. 10-5b

3 end 5 end

3 end5 end

3

5

2

4

13

5

2

41

P

P

P

P

P

P

P

P

Fig. 10-5a

Origin of replication Parental strand

Daughter strand

Bubble

Two daughter DNA molecules

Fig. 10-5c

Parental DNA

35

DNA polymerasemolecule

DNA ligase

35

Overall direction of replication

Daughter strandsynthesizedcontinuously

35

35

Daughter strandsynthesizedin pieces

Protein Synthesis occurs during G0, G1 and G2 of the cell cycle

Fig. 10-6a-3

Cytoplasm

Nucleus

DNA

Transcription

RNA

Translation

Protein

Fig. 10-7a

Polypeptide

Translation

Transcription

DNA strand

Codon

Amino acid

RNA

Fig. 10-9b

TerminatorDNA

DNA of gene

RNA polymerase

Initiation

PromoterDNA

1

Elongation2

Area shownin Figure 10.9A

Termination3 Growing

RNA

RNApolymerase

CompletedRNA

Fig. 10-8a

Fir

st

ba

se

Th

ird

ba

se

Second base

Fig. 10-12a

tRNAmolecules

Growingpolypeptide

Largesubunit

Smallsubunit

mRNA

Fig. 10-12c

mRNA

Next amino acidto be added topolypeptide

Growingpolypeptide

Codons

tRNA

Fig. 10-14-4

Polypeptide

A site

1 Codon recognitionCodons

Aminoacid

Anticodon

P site

mRNA

2 Peptide bondformation

3 Translocation

Newpeptidebond

Stopcodon

mRNAmovement

Mutations

Fig. 10-16a

Normal hemoglobin DNA Mutant hemoglobin DNA

Sickle-cell hemoglobinNormal hemoglobin

mRNAmRNA

ValGlu

Plasmodium falciparum

Fig. 10-16bNormal gene

Protein

Base substitution

Base deletion Missing

mRNA

Met Lys Phe Ser Ala

Met Lys Phe Gly Ala

Met Lys Leu Ala His