Untitled Flashcard Set

What is a fundamental component shared by both prokaryotes and eukaryotes?

Plasma membrane, cytosol, ribosomes, and chromosomes.

What is one key difference between prokaryotes and eukaryotes?

Prokaryotes lack membrane-bound organelles, while eukaryotes possess organelles such as the nucleus.

Define the function of ribosomes in a cell.

Ribosomes are the sites of protein synthesis, translating mRNA into polypeptides.

What is the structure that carries genetic information within eukaryotic cells?

Chromosomes.

What is the composition of DNA?

DNA is composed of nucleotides, which include purines (adenine, guanine) and pyrimidines (cytosine, thymine).

Explain the antiparallel nature of DNA strands.

One strand runs 5' to 3' while the other runs 3' to 5', facilitating complementary base pairing.

What are the three phases of transcription?

Initiation, elongation, and termination.

What role does the spliceosome play in eukaryotic transcription?

It removes introns and connects exons, producing mature mRNA.

What is the significance of the lac operon in gene regulation?

It demonstrates how the presence of lactose induces gene expression in prokaryotes.

How can mutations affect proteins?

Mutations can lead to silent, missense, or nonsense mutations that affect protein function.

What is a key role of the proteasome in a cell?

The proteasome degrades unneeded proteins, regulating protein levels and function.

Describe the semiconservative nature of DNA replication.

Each new DNA molecule consists of one old and one new strand.

What are the phases of the cell cycle?

G1, S (synthesis), G2, and M (mitosis).

What is the function of cyclins and cyclin-dependent kinases (CDKs)?

They regulate the cell cycle, ensuring cells proceed to the next phase only when conditions are favorable.

What stages are encompassed in the acronym PMAT?

Prophase, Metaphase, Anaphase, Telophase.