Lecture Exam 1: Protein Synthesis and Cell Lifecycle

Define Protein Synthesis

the process by which cells make proteins, based on the information in DNA

What are the main stages of Protein Synthesis

Transcription (DNA to mRNA) and Translation (mRNA to protein).

the nucleus

Where does Transcription occur

What is transcription

DNA is used to make messenger RNA (mRNA)

DNA nucleotide base pairs

ATGC

RNA nucleotide base pairs

AUGC

DNA’s A pairs with RNA’s…

U

DNA’s T pairs with RNA’s…

A

DNA’s C pairs with RNA’s…

G

DNA’s G pairs with RNA’s

C

What is translation

the process where mRNA is used as a template to assemble proteins

ribosome

Where does translation occur

what are codons

sets of 3 nucleotide bases on mRNA

what are anticodons

brought by tRNA, matches with the mRNA codon

how a protein is built during translation

each codon is read, the correct amino acid is added to the growing chain until a stop codon (which signals the end of translation) is reached

Role of tRNA

bring the correct amino acid to the ribosome

Steps of Interphase

G1, G0, S, G2

G1 Phase (Gap 1)

Cell grows and performs normal functions, and protein synthesis

G0 Phase

A resting or non-dividing state, permanent functional stage

S Phase (Synthesis)

DNA replication occurs, begins formation of chromosomes

G2 Phase (Gap 2)

The cell continues to grow and prepares for mitosis, additional proteins are synthesized

Mitosis

cell division

Stages of mitosis

prophase, metaphase, anaphase, telophase, cytokinesis

Prophase

Chromatin condenses into visible chromosomes; the nuclear membrane starts to break down; spindle fibers begin to form

Metaphase

Chromosomes line up at the cell's equatorial plane

Anaphase

Sister chromatids are pulled apart to opposite poles of the cell

Telophase

Chromosomes de-condense back into chromatin; the nuclear envelope re-forms around each set of chromosomes

Cytokinesis

The cytoplasm divides, resulting in two separate cells

Necrosis

Uncontrolled cell death, leads to inflammation and can affect neighboring cells

Apoptosis

Programmed cell death, a controlled process that removes damaged or unneeded cells, Cells shrink, minimal inflammation

Autophagy

A self-degradative process where cells recycle their own components to survive stress or starvation, Cells form double-membrane vesicles