Chapter 3: Cellular Level (Test Review)

Transcription

The process of synthesizing messenger RNA (mRNA) from a specific segment of DNA, serving as a template.

Translation

The process of interpreting the mRNA sequence into a specific amino acid chain (polypeptide), forming a protein.

Initiation (Transcription)

A region called a promoter triggers the start of transcription.

Elongation (Transcription)

RNA polymerase unwinds the DNA and synthesizes mRNA by aligning complementary nucleotides with the DNA template.

Termination (Transcription)

A terminator sequence signals the end of transcription, causing mRNA to detach from the gene.

Post-Transcriptional Modifications

The pre-mRNA undergoes splicing, removing introns and joining exons before exiting the nucleus.

Initiation (Translation)

The ribosome subunits bind to the mRNA at the start codon, preparing for translation.

Elongation (Translation)

Transfer RNA (tRNA) brings appropriate amino acids based on mRNA codons, with ribosomes catalyzing peptide bonds.

Termination (Translation)

A stop codon signals the end of translation, resulting in the release of the newly synthesized polypeptide chain.

Endocytosis

Process of a cell ingesting material by enveloping it in a portion of its membrane and forming an intracellular vesicle.

Exocytosis

Process of exporting material out of the cell using vesicular transport and fusion of membrane-bound vesicles.

Types of Endocytosis

Includes phagocytosis, pinocytosis, and receptor-mediated endocytosis.

Cell Cycle

Sequence of events from cell creation to division, generating two new cells, composed of interphase and mitosis.

Interphase Phases

Includes G1, S, G2 phases and G0 phase which is a resting stage.

Mitosis

The process of dividing genetic material, typically lasting 1-2 hours and consisting of Prophase, Metaphase, Anaphase, and Telophase.

Cell Cycle Control

Regulation mechanisms that ensure proper progression through the cell cycle and prevent uncontrolled cell division.

Cyclins and CDKs

Proteins that determine progression through checkpoints during the cell cycle.

Tumors

Abnormal masses of tissue classified as benign (non-threatening) or malignant (capable of damaging tissues).