BSC 2011 – Biology II

Don Levitan

Biology II

• Development

• Genetics

• Evolution

• EcologyMy research interests:The evolution of reproductivestrategies

Biology II

The pattern and process of the life-cycle

Science - the investigation of rational concepts that can be evaluatedby observations and experimentation.

Hypothesis - a proposed explanation for an observed phenomenon

Theory - a hypothesis that is consistent with all available evidence

Some Important Definitions

Outline of Lecture 1

I. THE CENTRAL DOGMAA. DNA structureB. DNA ReplicationC. Chromosomes

1. Prokaryotic2. Eukaryotic

D. RNA Structure

E. Transcription1. Summary2. Prokaryotes3. Eukaryotes

F. Translation1. The genetic code2. Summary of translation

Fig 16.3

Fig 16.3

Fig 16.5

1

23

4

5

5 ´ end

3´end

Fig 16.12

Fig 16.5

Prokaryotic cells

Fig. 19.1Levels of DNA packing

Eukaryotic cells

Number of chromosomes per cell

Humans 46Onions 8Drosophila ?

Number of chromosomes per cell

Humans 46Onions 8Drosophila 4Potato ?

Number of chromosomes per cell

Humans 46Onions 8Drosophila 4Potato 48

DNA RNA Proteintranscription translationreplication

Fig. 19.1Levels of DNA packing

Fig. 16.7

DNA Replication

Fig. 16.16 (modified)

3’

5’

3’

5’

DNA polymerase RNA primer

DNA Replication

Transcription

Template strand - the single strand of DNA that is transcribed

RNA polymerase - the enzyme that catalyzes the synthesis of RNA using DNA as the template

Promoter - the segment of the DNA template strand where RNApolymerase binds and initiates transcription

DNA - RNA

Adenine (A) – (U) UracilThymine (T) – (A) AdenineCytosine (C) – (G) GuanineGuanine (G) – (C) Cytosine

3’5’

promoter stop codon

transcription unit

Fig 17.9

Transfer RNA (tRNA)Fig. 17.13

Translation of mRNAinto protein

Fig. 17.12

Fig. 17.25

Fig 17.3

Fig 17.4

U U C C C G U G A

phy proline stop

U U C C C G U G A

ser arg ?

DNA RNA Proteintranscription translation

DNA bases (AGCT)

to RNA bases(AGCU)

RNA base codons

to amino acids

replication

DNA bases (AGCT)

to DNA bases