Chapter 1- Lec 9

Question 1

The achievement of classical biochemistry was to show that_____,but within the cells these functions must be ____and ___.

Answer 1

Isolated cell components could retain their individual functions even after purification,

Integrated and regulated.

Question 2

Briefly explain the two main cellular networks.

There is a clear____distinction between two,but not so clear a ___ distinction.

Answer 2

1. Metabolic pathways that govern possible interconversions of metabolites .
2. Regulatory interactions that control traffic through the pathways

Logical, physical

Question 3

What does the central dogma of molecular biology ( DNA - RNA - PROTEIN) have to offer?

True/false mechanisms that apply at the levels of expressed proteins have faster effects than those that control gene expression.

Answer 3

1. Several possible leverage points for regulation of protein activity.
2. True

Question 4

Why must transcription and translation be dynamic?

What might be the driving force for changes in profiles of protein expression?

Distinguish between prokaryotes and eukaryotes in terms of their transcriptional regulation.

Identify the two mechanisms of transcription regulation in eukaryotes.

Answer 4

To produce the right amount of the right protein at the right time at the right place.

Changes in the environment, or internal signals.

Prokaryotes transcription regulation vs eukaryotes
1. Is at or near binding site for RNA polymerase vs. It is more complex and regulation at proximal and distal sites.

1. Complexity being robustness, which is facilitated by redundancy.
2. Involves changes in patterns of methylation of DNA associated with changes in structure of chromatin.

Question 5

Know fig 1.27 page.43

Box 1.16 control of Beta - globin gene expression, briefly explain the well known enhancer of globin expression, the erythropoietin.

Answer 5

Is a glycoprotein hormone,

Encoded on chromosome 7

Enhances globin expression by activating intracellular signaling pathways.

It’s expression is sensitive to oxygen tension, so if hypoxia ⬆️’ses erythropoietin production at sea level or high altitudes.

Question 6

Acetycholinesterase

Answer 6

Known for its neural synapses and neuromuscular junctions.

Also regulates globin synthesis( in muscles)