Lecture 1

Question 1

What is the difference between nucleus in prokaryotes and eukaryotes?

Answer 1

Presence of a nucleus and dense-staining chromatin in eukaryotes
Prokaryotic DNA is located in the nucleoid which lacks a limiting membrane and isn’t bound to chromatin

Question 2

Describe 2 structural differences between eukaryotes and prokaryotes:

Answer 2

Internal compartmentalisation afforded by complex endo-membrane system of eukaryotes
Complex cytoskeleton of filamentous proteins found in eukaryotes

Question 3

What does chromatin pattern reflect?

Answer 3

Chromatin pattern reflects transcriptional activity

Question 4

What is the endomembrane system?

Answer 4

Composed of different membranes suspended in the cytoplasm which divide the cell into organelles

Question 5

What does concentration of polyribosomes in cytoplasm align with?

Answer 5

Translational activity

Question 6

What does the disposition of polyribosomes indicate?

Answer 6

Indicates whether proteins under translation are destined for internal use or export

Question 7

What do proteins for internal use require?

Answer 7

They require membrane packaging

Question 8

What does cell ultrastructure correlate with and give 2 examples?

Answer 8

Correlates with transcriptional and synthetic activity

1 - finely dispersed euchromatin of the myofibroblast contrasts with the densely-stained heterochromatin of adjacent melanocytes

2 - bulk production of matrix proteins for export in the myofibroblasts is reflected by the R.E.R and GA adjacent to the nucleus

Question 9

What does the distribution of organelles correlate with?

Answer 9

Correlates with discrete local activities