CH 461 Lecture Notes - Lecture 46: Proliferating Cell Nuclear Antigen, Eukaryotic Dna Replication, Chromatin

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silvercicada472

19 Jul 2018

School

University of Alabama

Department

Course

CH 461

Professor

Dunkel

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Document Summary

Eukaryotic genetic replication involves both dna synthesis and chromatin assembly. Chromosomal dna synthesis is similar to prokaryotic dna replication in that each of the two strands serves as template for new synthesis. In contrast to the situation in prokaryotes, eukaryotic dna replication is limited to a single portion, the s phase, of the cell cycle. The cell cycle of eukaryotic cells is divided into distinct phases. M phase, which is the phase where mitosis takes place, is the (cid:1688)start(cid:1689) of the cycle. After cell division, a (cid:1688)gap(cid:1689) phase, g1, commences, in which enzyme synthesis and metabolism take place. G1 can last for a very long period of time, and many cells in animals are (cid:1688)arrested(cid:1689) in g1 for years without dividing. Controlling g1 arrest is clearly important for understanding cancer, which is essentially a disease of replication control. The movement from g1 to s phase (the dna replication phase) commits the cell to dividing.

Related Questions

1) When studying living cells in a laboratory, researchers sometimes use drugs as a way to cause cells to remain in a particular phase of the cell cycle. For example, aphidicolin inhibits DNA synthesis in eukaryotic cells and causes them to remain in the G1 phase because they cannot replicate their DNA. In what phase of the cell cycleâG1, S, G2, prophase, metaphase, anaphase, or telophaseâwould you expect somatic cells to stay if the following types of drug were added?

a) A drug that inhibits microtubule formation

b) A drug that allows microtubules to form but prevents them from shortening

c) A drug that inhibits cytokinesis

d) A drug that prevents chromosomal condensation

rosewallaby553

Part A:

In prokaryotes and eukaryotes cell reproduction is similar in that it requires some kind of signal to proceed, DNA replication, careful separation of the DNA into two equal portions, and division of the cytoplasm. How is cell reproduction different in prokaryotes and eukaryotes?

Select one:

a. In a eukaryotic organism, the signals for cell division are usually not related to the environment but to the function of the entire organism.

b. Eukaryotic cells constantly divide whenever environmental conditions are adequate and the cells are large enough.

c. The linear chromosomes in prokaryotes are constantly being updated.

d. Prokaryotic cell division requires cytokinesis before mitosis because of their small size.

e. The sexual phase of most prokaryotes (bacteria) is essential to the rapid cell division required for infection.

Part B:

What does the name Cyclin Dependent Kinase stand for?

Select one:

a. A protein important to the cell cycle that is dependent on DNA synthesis.

b. An enzyme that cuts DNA so that chromosomes can segregate.

c. An enzyme that phosphorylates other proteins using ATP only when the protein Cyclin is bound to the enzyme.

d. An enzyme that rolls along microtubules dragging a vesicle.

e. An enzyme that connects chromosomes to the spindle fiber.

Part C:

The Cell Cycle is divided into Mitosis, Cytokinesis, and Interphase. Mitosis can be ordered into the following phases:

Select one:

a. Prophase/Prometaphase/Metaphase/Anaphase/Telophase

b. Anaphase/Prometaphase/Metaphase/Prophase/Telophase

c. Metaphase/Anaphase/Telophase/Prophase/Prometaphase

d. Telophase/Prophase/Prometaphase/Metaphase/Anaphase

e. Anaphase/Telophase/Prophase/Prometaphase/Metaphase

Part D:

The Cell Cycle is divided into Mitosis, Cytokinesis, and Interphase. Interphase can be ordered into the following phases:

Select one:

a. S/G1/G2

b. G2/G1/S

c. G1/S/G2

d. G2/S/G1

e. G1/G2/S

amethystyak657

Match the term with its correct definition or explanation.

Chromatin

Homologous Chromosomes

Sister chromatids

Diploid

Interphase

S Phase

Synapsis

Crossing Over

Cell Plate

Cleavage Furrow

A. The exchange of genetic material between homologous chromosomes during meiosis I.

B. The pairing or tight association of homologous chromosomes in meiosis I. Results in the formation of a tetrad.

C. Non-identical copies of the same chromosome. Present in all diploid cells, even before replication. These chromosomes are the same length and contain genes for the same characteristics, but may have different alleles for each gene. D.

The period of the cell cycle that includes G1, S phase, and G2. E. A structure that develops during cytokinesis in plants.

F. Condensed chromosomes.

G. An invagination that develops during cytokinesis in animal cells.

H. When an organism has two copies of every chromosome (2n).

I. Two identical copies of a chromosome. These are only present after DNA replication.

J. The phase of the cell cycle when DNA is replicated.

CH 461 Lecture Notes - Lecture 46: Proliferating Cell Nuclear Antigen, Eukaryotic Dna Replication, Chromatin

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